Physicochemical study of (solute + solute) and (solute + solvent) interactions of l -asparagine and l -glutamine in aqueous-d -mannose solutions at temperatures from (293.15 to 318.15) K

Accepted Manuscript Physicochemical study of solute-solute and solute-solvent interactions of l-asparagine and l-glutamine in aqueous− d-mannose solutions at temperatures from 293.15 K to 318.15 K Anil Kumar Nain, Preeti Droliya, Jyoti Yadav, Anjali Agarwal PII: DOI: Reference:

S0021-9614(15)00424-3 http://dx.doi.org/10.1016/j.jct.2015.11.014 YJCHT 4462

To appear in:

J. Chem. Thermodynamics

Received Date: Revised Date: Accepted Date:

1 August 2015 13 November 2015 14 November 2015

Please cite this article as: A.K. Nain, P. Droliya, J. Yadav, A. Agarwal, Physicochemical study of solute-solute and solute-solvent interactions of l-asparagine and l-glutamine in aqueous− d-mannose solutions at temperatures from 293.15 K to 318.15 K, J. Chem. Thermodynamics (2015), doi: http://dx.doi.org/10.1016/j.jct.2015.11.014

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Physicochemical study of solute-solute and solute-solvent interactions of l-asparagine and l-glutamine in aqueous− −d-mannose solutions at temperatures from 293.15 K to 318.15 K Anil Kumar Nain*, Preeti Droliya, Jyoti Yadav and Anjali Agarwal Department of Chemistry, Dyal Singh College, University of Delhi, New Delhi – 110 003, India *

Corresponding author: Tel.: 91-9810081160; Fax: 91-11-24365606 E-mail address: [email protected]

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Abstract The density, ρ, ultrasonic speed, u and viscosity, η of solutions of l-asparagine and lglutamine in water and in aqueous−d-mannose (2.5% and 5% d-mannose in water, w/w) solvents were measured at temperatures (293.15, 298.15, 303.15, 308.15, 313.15 and 318.15) K and at pressure, p = 101 kPa. The ρ and u values have been used to calculate apparent molar volume, Vφ , limiting apparent molar volume, Vφ° , apparent molar compressibility, K s ,φ , limiting apparent molar compressibility, K s°,φ , transfer limiting apparent molar volume, Vφ°,tr , transfer limiting apparent molar compressibility, K s°,φ ,tr , limiting apparent molar expansivity, Eφ° , the Hepler constant, (∂ 2Vφ° / dT 2 ) and hydration number, nH . The η values have been used to calculate the Falkenhagen Coefficient, A, Jones-Dole coefficient, B, Gibbs energy of activation of viscous flow per mole of the solvent, ∆µ1° # and the solute, ∆µ2° # . The calculated parameters have been discussed in terms of various solute-solute and solute-solvent interactions prevailing in these solutions. The structure making/breaking ability of the amino acids in the aqueous-mannose solution is also discussed. Keywords: Density; ultrasonic speed; viscosity; l-asparagine/l-glutamine; d-mannose, molecular interactions.

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1. Introduction Physicochemical properties are useful in understanding the solute-solvent and solutesolute interactions in solutions [1−5]. Most biochemical processes occurs in aqueous medium; therefore studies on physicochemical properties of bio-molecules, such as proteins and sugars in aqueous solution provide useful information which help in understanding the complex mechanism of molecular interactions. The stabilization of native conformations of biological macromolecules (proteins) is related to several non-covalent interactions including hydrogen-bonding, electrostatic and hydrophobic interactions [6,7]. The additives, like sugars, alcohols, polyhydroxy alcohols, etc. decrease the denaturation of proteins [8], in particular, sugars help in stabilizing the native conformation of globular proteins [9]. This stabilizing ability of different sugars depends on the number of hydroxyl groups present in them. Back et al. [10] and Fujita et al. [11] studied the effect of a variety of sugars on the thermal transition of lysozyme and other proteins and enzymes and tried to correlate the stabilizing effect of sugars and polyols to the number and configuration of the OH groups present in them. But due to complicated structure of proteins the study of their interactions are somewhat difficult [12−16], therefore, for better understanding of the hydration behavior of proteins, one useful approach is to study the peptides and amino acids, as model constituents of proteins. Several physicochemical properties of constituent amino acids in aqueous and mixed aqueous solutions have been used by various researchers to investigate solute-solvent interactions [1−5,12−16]. In continuation to our ongoing research [17−23] on the interactions of amino acids in aqueous-carbohydrate solutions, here we report the results of our study on physicochemical properties of l-asparagine/l-glutamine in aqueous−d-mannose solutions. In the present article, we report the densities, ρ, ultrasonic speeds, u and viscosities, η of solutions of lasparagine and l-glutamine in water and in aqueous-mannose [2.5% and 5% mannose in 3

water, w/w] solvents at temperatures (293.15, 298.15, 303.15, 308.15, 313.15 and 318.15) K and at pressure, p = 101 kPa. These experimental results have been used to calculate the values of Vφ , Vφ° , K s ,φ , K s°,φ , Vφ°,tr , K s°,φ ,tr , Eφ° , (∂ 2Vφ° / dT 2 ) , nH , coefficient, A, coefficient, B, ∆µ1° # and ∆µ2° # . The results have been interpreted in terms of solute-solvent and solute-solute interactions in these systems. The structure making/breaking ability of the amino acids in these solutions is also discussed. 2. Experimental 2.1. Chemicals l-Asparagine (SRL India, mass fraction purity > 0.99) and l-glutamine (SRL India, mass

fraction purity > 0.99) were recrystallized from ethanol-water solutions, and dried in vacuum at room temperature for 24 h. Thereafter, these chemicals were stored over P2O5 in desiccator before use. The carbohydrate, d-mannose (SRL India, mass fraction purity > 0.99) was used as such without further purification, except drying in oven for 24 h. The purity of the purified chemicals was checked by performing gas chromatography analysis using Shimadzu Gas Chromatograph (Model: GC-2010 Plus). The final purities and other specifications of the chemicals used are given in table 1. The aqueous-mannose solutions 2.5% (0.139 mol·kg−1) and 5% (0.278 mol·kg−1) mannose in water were prepared using triple distilled water (conductivity less than 1×10−6 S·cm−1). These stock solutions (dmannose + water solvents) were used as solvents to prepare solutions of six different molal concentrations of l-asparagine and l-glutamine ranging from (0 to 0.15) mol·kg−1. The weighing was done on an electronic balance (Model: GR-202R, AND, Japan) with a precision of ± 0.01 mg. All the solutions were prepared with care and stored in special airtight bottles to avoid contamination and evaporation. The uncertainty in the molality of the solutions was estimated within ± 1×10−4 mol·kg−1.

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2.2. Equipment and procedures The density of the solutions was measured by using a single-capillary pycnometer (made of Borosil glass) having a bulb capacity of ~ 10 mL. The capillary, with graduated marks, had a uniform bore and could be closed by a well-fitting glass cap. The marks on the capillary were calibrated by using triple distilled water. The densities of pure water used in the calibration at required temperatures were taken from the literature [24]. The uncertainty in density measurements was within ± 0.83 kg⋅m−3. The ultrasonic speeds in the solutions were measured using a single-crystal variable-path multifrequency ultrasonic interferometer (Model: M-81DS, Mittal Enterprises, India) having stainless steel sample cell (with digital micrometer) operating at 3 MHz. The uncertainty in ultrasonic speed measurements was within ± 1.7 m·s−1. The viscosities of the solutions were measured by using Ubbelohde type suspended level viscometer. The viscometer was calibrated by using triple distilled water. The viscosities of pure water for calculations of viscosity at required temperatures were taken from the literature [25]. The viscometer containing the test liquid was allowed to stand for about 30 minutes in a thermostatic water bath so that the thermal fluctuations in viscometer were minimized. The times of flow were recorded in triplicate with a digital stopwatch with an accuracy of ± 0.01 second and the results were averaged. The uncertainty in viscosity measurements was within ± 1.1%. The temperature of the test solutions during the measurements was maintained to an accuracy of ± 0.02 K in an electronically controlled thermostatic water bath (JULABO, Model: ME-31A, Germany). 3. Results The values of density, ρ, ultrasonic speed, u and viscosity, η of the solutions of amino acids (l-asparagine and l-glutamine) in water and in aqueous-mannose solvents as functions of concentration and temperature are listed in tables 2−4, respectively. The experimental values of ρ and u were compared with the data available in the literature at 298.15 K. The

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comparison is given graphically as figures S1 and S2 in the supplementary material along with the citations. The comparison is found good in general, except a few data points in case of ultrasonic speed, however, these deviations were found within the stated uncertainty limits. 3.1. Apparent molar volume and compressibility The ultrasonic speed may be considered as a thermodynamic property, provided that a negligible amount of ultrasonic absorption of the acoustic waves of low frequency and of low amplitude is observed; in which case, the ultrasonic absorption of the acoustic waves is negligible [26]. The apparent molar volume, Vφ and apparent molar compressibility, K s ,φ of the solutions were calculated by using the relations Vφ =

1000( ρo − ρ ) M + m ρρo ρ

K s ,φ =

(1)

1000(κ s ρ o − κ s° ρ ) κ s M + m ρρ o ρ

(2)

where m is the molality of the solute (l-asparagine and l-glutamine), ρ and ρo are the densities of the solution and the solvent (water and aqueous-mannose) respectively; and M is the molar mass of the solute (l-asparagine and l-glutamine), κs and κ s° represent the isentropic compressibility of the solution and the solvent (water and aqueous-mannose), respectively, calculated using the relation

κ s = 1/ u 2 ρ

(3)

The values of Vφ and K s ,φ as functions of molality of l-asparagine/l-glutamine and temperature are shown graphically in figures 1−4. It is observed that for l-asparagine/lglutamine in water and in aqueous-mannose solvents, Vφ vs. m curves and K s ,φ vs. m curves (figures 1−4) are almost linear at each investigated temperature.

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3.2. Limiting apparent molar volume and compressibility

The values of limiting apparent molar volume, Vφ° , and limiting apparent molar compressibility, K s°,φ were estimated by the least squares fitting of the apparent molar volume and apparent molar compressibility in the following equations [27] Vφ = Vφ° + Sv m

(4)

K s,φ = K s°,φ + S k m

(5)

where the intercepts, Vφ° and K s°,φ are partial molar volume and partial molar compressibility, respectively, at infinite dilution and Sv or Sk is the experimental slope. The values of Vφ° , Sv, K s°,φ and Sk along with the standard deviations, σ for l-asparagine/lglutamine in aqueous-mannose solutions at different temperatures are listed in tables 5 and 6, respectively. 3.3. Transfer volume and transfer compressibility

The transfer volumes, Vφ°,tr and transfer compressibility, K s°,φ ,tr of l-asparagine/lglutamine from water to aqueous-mannose solutions were calculated by using the relation [28,29] Vφ°,tr = Vφ°,aq.−mannose − Vφ°, water

(6)

K s°,φ ,tr = K s°,φ ,aq − mannose − K s°,φ ,water

(7)

where Vφ°,water is the limiting apparent molar volume of l-asparagine/l-glutamine in water (table 5) and K s°,φ ,water is the limiting apparent molar compressibility of l-asparagine/lglutamine in water (table 6). The Vφ°,tr and K s°,φ ,tr values for l-asparagine/l-glutamine from water to aqueous-mannose solutions are included in tables 5 and 6, respectively. 7

3.4. The Hepler Constant

The temperature dependence of partial molar volumes, Vφ° can be expressed in terms of the absolute temperature, T by the following relation

Vφ° = a + bT + cT 2

(8)

where a, b and c are the coefficients. The partial molar expansibilities, Eφ° [30] are obtained by the following equation

Eφ° = (∂Vφ° / ∂T ) p = b + 2cT

(9)

The values of Eφ° are given in table 7. The Hepler [31] constant, which provides information about the structure-making or structure-breaking ability of a solute in solution, has been calculated by the following relation

( ∂ 2Vφ° / ∂T 2 ) p = 2c

(10)

The values of the Hepler constant are given in table 8. 3.5. Hydration number

The hydration number, nH to an amino acid can be estimated from the electrostriction partial molar volume Vφ° (elect.) using the following relation [32] nH = Vφ° (elect.)/(Vφ°,e − Vφ°,b )

(11)

where Vφ°,e is the molar volume of electrostricted water and Vφ°,b is the molar volume of bulk water. This model assumes that for every water molecule taken from the bulk to the region near the amino acids, the volume is decreased by (Vφ°,e − Vφ°,b ) . According to Millero et al. [32] the value of (Vφ°,e − Vφ°,b ) = −3.3 × 10−6 m3 mol−1 at 298.15 K. using the value of

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(Vφ°,e − Vφ°,b ) and the values of Vφo (elect.) , the nH values estimated from equation (11) are included in table 8. The value of Vφ° (elect.) can be calculated from experimental values of Vφ° using the relation

Vφ° (elect.) = Vφ° − Vφ° (int .)

(12)

where Vφ° (int .) is the intrinsic partial molar volume of the amino acid calculated using Vφ° ( int.) = (0.7 / 0.634)Vφ° ( cryst.)

(13)

where Vφ° (cryst.) = M s /ρ (cryst.) is the crystal molar volume, 0.7 is the packing density for molecules in organic crystals and 0.634 is the packing density for random packing spheres. The value of Vφ° (int .) for the amino acid can be estimated from above equation (13) using

ρcryst values for l-asparagine/l-glutamine taken from the literature [33,34]. Further, the number of water molecules hydrated to the amino acid, nH was calculated by using the method given by Millero et al. [32], nH = − Kφ° (elect.) /(Vφ°,b .K s°,φ ,b )

(14)

where, K s°,φ ,b is the isothermal compressibility of bulk water. Value of (Vφ°,b .K s°,φ ,b ) is 0.81 × 10−12 m5·N−1·mol−1. The electrostriction partial molar compressibility K s°,φ (elect.) can be calculated from the experimentally measured values of K s°,φ using the following equation K s°,φ (elect.) = K s°,φ − K s°,φ (int .)

(15)

where K s°,φ (int .) is K s°,φ (isomer) for l-asparagine/l-glutamine (= 3 × 10-6 m3 mol−1 GPa−1). Since K s°,φ (int .) is less than 5 × 10−6 m3·mol−1·Pa−1 for ionic crystals and many organic solutes in water. So, we can assume K s°,φ (int .) = 0 and equation (15) becomes

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K s°,φ (elect.) = K s°,φ

(16)

The nH values estimated from equation (14) are included in table 8. 3.6. Analysis of viscosity data

The viscosity was analysed by using the Jones-Dole [35] equation of the form

ηr =

η = 1 + Am1/ 2 + Bm ηo

(17)

where ηr is the relative viscosity of the solution, η and ηo are the viscosities of solution and the solvent (water and aqueous-mannose), respectively, A and B are the Falkenhagen [36,37] and Jones-Dole [35] coefficients, respectively. The values of A and B have been obtained as the intercept and slope from linear regression of [(ηr − 1) / m1/ 2 ] vs. m1/2 curves (figures 5 and 6), which were found almost linear for these systems. The values of A and B along with the standard deviations σ are listed in table 9. The variation of B-coefficients with temperature for these systems is shown graphically in figure 7 and the temperature derivative of B-coefficients, dB/dT have also been calculated. 3.7. Thermodynamics of viscous flow

The viscosity has also been used for calculating Gibbs energies of activation per mole of solute and of activation per mole of solvent according to transition state theory of the relative viscosity proposed by Feakins et al. [38]. According to this theory, the B-coefficient is given by the relation °

B=

°

°

[(V 1 − V 2 ) + V 1 (∆µ2° # − ∆µ 1° # ) / RT ] 1000

(18)

°

where V 1 is the apparent (partial) molar volume of the solvent (water and aqueous°

mannose) and V 2 (= Vφ° ) is the limiting apparent (partial) molar volume of the amino acid,

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respectively. The Gibbs of activation per mole of solvent, ∆µ 1° # has been calculated by using the Eyring viscosity [39] relation °

∆µ 1° # = RT ln(ηo V 1 / hN )

(19)

where h and N are Planck’s constant and Avogadro number, respectively. Equation (18) rearranges to give Gibbs of activation per mole of the solute, ∆µ2° #

 RT  ° ° ∆µ2° # = ∆µ 1° # +  °  1000 B − (V 1 − V 2 )       V1 

(20)

The values of ∆µ 1° # and ∆µ2° # are included in table 9. 4. Discussion

The solute-solute interaction is considered negligible at infinite dilution; therefore limiting apparent molar volume Vφ° and its temperature dependence provide valuable information of the solute-solvent interactions, whereas the experimental slope, Sv provides information regarding solute-solute interaction. Table 5 shows that both the amino acids (lasparagine and l-glutamine) exhibit positive Vφ° values in aqueous-mannose solutions at each investigated temperature, thereby suggesting the presence of strong solute-solvent interactions and negative values of Sv indicate weak solute-solute interactions in these systems. The trends observed in Vφ° values can be considered due to their hydration behaviour [40−42], which comprise of two types of interactions in these systems: (a) The terminal groups of zwitterions of amino acids, NH3+ and COO− are hydrated in an electrostatic manner whereas, hydration of R group depends on its nature, which may be hydrophilic, hydrophobic or amphiphilic; and (b) the overlap of hydration co-spheres of terminal NH3+ and COO− groups and of adjacent groups results in volume change. The Vφ° 11

values increase due to reduction in the electrostriction at terminals, whereas it decreases due to disruption of side group hydration by that of the charged end. The increase in Vφ° values with increase in temperature for l-asparagine and l-glutamine in aqueous-mannose solutions and this can be explained by considering the size of primary and secondary solvation layers around the zwitterions. At higher temperatures the solvent from the secondary solvation layer of amino acid (l-asparagine/l-glutamine) zwitterions is released into the bulk of the solvent, resulting in the expansion of the solution, as inferred from larger Vφ° values at higher temperatures [29,43]. Similar trends in Vφ° values were obtained in our earlier studies on interactions of l-histidine in aqueous-glucose/sucrose [17,18] solutions and l-arginine in aqueous-xylose/arabinose [21] solutions. The limiting apparent molar volumes of transfer, Vφ°,tr are by definition free from solutesolute interactions, and therefore provide information regarding solute-solvent interactions. The Vφ°,tr values for l-asparagine/l-glutamine from water to aqueous-mannose solutions are included in table 5, which indicates that Vφ° of l-asparagine and l-glutamine in aqueousmannose solvents are more than those in pure water, i.e., Vφ°,tr values are positive and these values decrease with increase in temperature. In general, the following types of interactions are expected to occur between l-asparagine/l-glutamine and mannose, which affect the hydration behaviour of these amino acids [16,40−42]: (i) The hydrophilic-ionic interaction between OH of mannose and zwitterions of lasparagine and l-glutamine. (ii) Hydrophilic-hydrophilic interaction the OH groups of mannose and NH2 and C=O groups in the side chain of l-asparagine and l-glutamine mediated through hydrogen bonding. 12

(iii) Hydrophilic-hydrophobic interaction between the OH groups of mannose molecule and non-polar (CH2) in side chain of l-asparagine and l-glutamine molecules. (iv) Hydrophobic-hydrophobic group interactions between the non-polar groups of mannose and non-polar (CH2) in side chain of l-asparagine and l-glutamine molecule. The values of Vφ°,tr for these systems can also be explained on the basis of co-sphere overlap model developed by Friedman and Krishnan [44] in terms of solute-solvent interactions. According to this model hydrophilic-ionic and hydrophilic-hydrophilic interactions (i) and (ii) contribute positively, whereas hydrophilic-hydrophobic and hydrophobic-hydrophobic group interactions (iii) and (iv) contribute negatively to the Vφ°,tr values [44,45]. The observed positive Vφ°,tr values suggest that the ion-hydrophilic and hydrophilic-hydrophilic group interactions dominate in these systems. The Vφ°,tr values increase with increase in mannose concentration in the solutions (table 5). This may be due to greater hydrophilic-ionic groups and hydrophilic-hydrophilic group interactions with increased concentrations of mannose. Similar trends in Vφ° and Vφ°,tr values of l-arginine in aqueous-d-xylose/l-arabinose solutions were also observed in our earlier study [21]. The Vφ°,tr values of are lesser in case of l-glutamine than l-asparagine solutions due to more

hydrophobic groups (CH2) present in side chain l-glutamine, which leads to lesser hydrophilic-hydrophilic interactions in case of l-glutamine as compared to l-asparagine. Figure 3 reveals that the K s ,φ values of the l-asparagine and l-glutamine in water and aqueous-mannose are negative indicating that the water molecules around ionic charged groups of amino acids are less compressible than the water molecules in bulk solution. This further supports the conclusion that interaction of mannose with amino acid zwitterions localized at the head groups decreases the electrostriction of water caused by the charged

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centers of amino acids resulting in an increase in volume, therefore increasing the compressibility of the solution. The K s°,φ values can be expressed as the extent to which hydration around the solute molecule can be compressed. The K s°,φ values (table 7) are found to be negative within concentration region studied and become less negative with increasing temperature. The K s°,φ values of l-asparagine and l-glutamine in aqueous-mannose solutions are more than those in pure water (table 7), i.e., K s°,φ ,tr values are positive and increase with increase in concentration of mannose. This phenomenon can be explained by the co-sphere overlap model [44]. According to this model, the overlap of hydration co-spheres of two ionic species results in an enhanced volume as some electrostricted water molecules return to the bulk water with a higher volume contribution then elelctrosticted water molecules; whereas overlap of hydration co-spheres of hydrophobic-hydrophobic groups and ionhydrophobic/hydrophilic-hydrophobic groups results in a net volume decrease. The K s°,φ ,tr values of l-glutamine are smaller than those of l-asparagine, this is due to lesser hydrophilichydrophilic group interaction in case of l-glutamine as compared to l-asparagine. The values of Eφ° [30] of any solute ought to be a sensitive measure of solute-solvent interaction. Table 7 indicates that the Eφ° values are positive for l-asparagine and lglutamine in water and in aqueous-mannose solvents indicating the presence of solutesolvent interactions in these systems, as reflected by the apparent molar volume data. A careful examination of table 7 reveals that the Eφ° values decrease with increase concentration of mannose in solution indicating that the solute-solvent interactions become stronger at higher mannose concentrations. The Eφ° values increase with increasing temperature due to fact that molecular motions get fast through enhancement in temperature 14

and the difference in water structure between hydration shell and bulk water becomes smaller and consequently the corresponding effect from the overlap of hydration shells becomes weaker and the Eφ° values increase with increase in temperature. The increase in Vφ° values with increase in temperature is also indicated by the positive value of the Hepler constant, (∂ 2Vφ° / ∂T 2 ) p (table 8). According to Hepler [31], if the sign of (∂ 2Vφ° / ∂T 2 ) p is positive, the solute is structure-maker; and if it is negative, the solute is structure-breaker. It is clear from positive values (∂ 2Vφ° / ∂T 2 ) p given in table 8 that lasparagine and l-glutamine act as structure-makers in water and aqueous-mannose solvents. A perusal of Table 8 reveals that nH values for l-asparagine and l-glutamine in and aqueous-mannose solvents solutions are less than those in water and decrease with increase in concentration of mannose. This indicates the increase in solute-cosolute interactions. The hydration numbers mainly come from the electrostriction effect of the charged end/polar groups of amino acids on water. If it is less than water, the co-solute has dehydrating effect on amino acids, i.e., water molecules in the hydration sphere are replaced by mannose molecules with increasing concentration of mannose in solution. These trends in nH values further support our earlier conclusions regarding interactions drawn from values of Vφ° , Vφ°,tr , K s°,φ , K s°,φ ,tr and Eφo .

It is observed from table 9 that values of A-coefficient are very small at all concentrations indicate the presence of weak solute-solute interactions. Further the values of B-coefficients are observed to be higher in magnitude for amino acids (l-asparagine and l-

glutamine) in aqueous-mannose solutions (table 9). A-coefficient accounts for the solutesolute interactions so independent of concentration and B-coefficient is a measure of effect

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of amino acids on the structure of solvents [36,37]. Large B-coefficient values indicate the dominance of solute-solvent interactions over solute-solute interactions in these systems. The values of B-coefficients increase with increasing concentration of mannose, the reason may be that the friction increases to prevent water flow at increased mannose concentration. Similar trends in B-coefficient values were obtained in our earlier studies on interactions of l-histidine in aqueous-glucose/sucrose solutions [17,18] and l-arginine in aqueous-d-

xylose/l-arabinose solutions [21] in our earlier studies. Thus, the values of coefficients A and B support the behaviours of Vφ° , K s°,φ and Vφ°,tr , K s°,φ ,tr which suggest stronger solutesolvent interactions as compared to solute-solute interactions in these solutions. It is observed from figure 7 that B-coefficients decrease with increase in temperature for l-asparagine and l-glutamine in water and aqueous-mannose solvents. The temperature

derivative of B-coefficient, dB/dT provides important information regarding structuremaking or structure-breaking ability of the solute in solvent media [46]. Strongly hydrated solutes are known as kosmotropes (structure makers) and weakly hydrated solutes are chaotropes (structure breakers). In general, the positive values of dB/dT indicate structurebreaking whereas negative values of dB/dT indicate structure-making ability of the solute. The negative dB/dT values for l-asparagine and l-glutamine in water and aqueous-mannose solutions (table 9 and figure 7) indicate that l-asparagine and l-glutamine act as structure makers in these solutions. Thus, the values of dB/dT further support the conclusion drawn from positive values of the Hepler constant. It is evident from table 9 that for l-asparagine and l-glutamine in water and in aqueousmannose solutions, the ∆µ2° # values are positive and much larger than those of ∆µ 1° # in water and aqueous-mannose solvents. This suggests that the interactions between lasparagine/l-glutamine and solvent (water and aqueous-mannose) molecules in the ground

16

state are stronger than in the transition state. Hence in the transition state, the solvation of the solute molecules is less favoured in Gibbs terms. It is observed that the values of ∆µ 1° # and ∆µ2° # for these amino acids in aqueous-mannose solvents are larger than those in water and these values increase with increase in concentration of mannose in solution (table 9). This further supports the existence of strong solute-solvent (hydrophilic-ionic group and hydrophilic-hydrophilic group) interactions in these systems, which increase with increase in mannose concentration leading to an increase in the friction preventing water flow at increased mannose concentrations. The ∆µ °2# values decrease with rise in temperature for both the amino acids, indicating that solute–solvent interaction decrease with rise in temperature due to release of the solvent molecules from the secondary solvation layer of amino acid zwitterions into the bulk of the solvent, resulting in decreased solute–solvent interactions in these solutions. According to Feakins et al. [38,47], ∆µ2° # > ∆µ 1° # for solutes with positive viscosity B-coefficients indicates stronger solute-solvent interactions in the ground state than in the transition state, i.e., the formation of a transition state is accompanied by the rupture and distortion of the intermolecular forces in the solvent structure. Thus, the conclusions drawn from ∆µ2° # are in agreement with those drawn from the trends of Vφ° , Vφ°,tr , K s°,φ , K s°,φ ,tr and B values. 5. Conclusions

This study reports the densities, ρ, ultrasonic speeds, u and viscosities, η of solutions of l-asparagine/l-glutamine in aqueous-mannose solutions (1 and 5 % of mannose, w/w in

water) at different temperatures. Various derived parameters, viz., Vφ , Vφ° , Vφ°,tr , K s ,φ , K s°,φ ,tr , Falkenhagen Coefficient, A, Jones-Dole coefficient, B, ∆µ1° # and ∆µ2° # indicate

that there exist strong solute-solvent (hydrophilic-ionic group and hydrophilic-hydrophilic 17

group) interactions in these systems, which increase with increase in mannose concentration. The positive values of Hepler’s constant and negative values of temperature derivative of B-coefficients indicated that l-asparagine and l-glutamine acts as structure makers in these solutions. Acknowledgement

The author AKN is thankful to Council of Scientific & Industrial Research (CSIR), Govt. of India for the financial support in form of major research project [No. 01(2263)/08/EMR-II].

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[10] J.F. Back, D. Oakenfull, M. B. Smith, Biochemistry 18 (1979) 5191−5196. [11] Y. Fujita, Y. Iwasa, Y. Noda, Bull. Chem. Soc. Jpn. 55 (1982) 1896−1900. [12] I. Banik, M.N. Roy, J. Mol. Liq. 169 (2012) 8−14. [13] A.M. Ronero, E. Moreno, J.L. Rojas, Thermochim. Acta 328 (1999) 33−38. [14] K. Gekko, J. Biochem. 90 (1981) 1633–1641. [15] R. Sadeghi, A. Gholamireza, J. Chem. Thermodyn. 43 (2011) 200−215. [16] A. Pal, N. Chauhan, J. Solution Chem. 39 (2010) 1636−1652. [17] A.K. Nain, R. Pal, R.K. Sharma, J. Chem. Thermodyn. 43 (2011) 603−612. [18] A.K. Nain, R. Pal, R.K. Sharma, J. Mol. Liq. 165 (2012) 154−160. [19] A.K. Nain, R. Pal, J. Chem. Thermodyn. 60 (2013) 98−104.

19

[20] A.K. Nain, M. Lather, R.K. Sharma, J. Mol. Liq. 159 (2011) 180−188. [21] A.K. Nain, M. Lather, Neetu, J. Chem. Thermodyn. 63 (2013) 67−73. [22] A.K. Nain, R. Pal, Neetu, J. Chem. Thermodyn. 68 (2014) 169−182. [23] A.K. Nain, M. Lather, Phys. Chem. Liq. 53 (2015) 599−618. [24] J.A. Riddick, W.B. Bunger, T. Sakano, Organic Solvents: Physical Properties and Methods of Purification, 4th ed., Wiley-Interscience, New York, 1986. [25] R.H. Stokes, R. Mills, Viscosity of Electrolytes and Related Properties, Pergamon Press, New York, 1965. [26] J.S. Rowlinson, Liquids and Liquid Mixtures, Butterworths, London, 1959, pp. 17. [27] D.O. Masson, Phil. Mag. 8 (1929) 218−223. [28] R. Bhat, N. Kishore, J.C. Ahluwalia, J. Chem. Soc., Faraday Trans. I 88 (1988) 2651−2665. [29] R.K. Wadi and P. Ramasami, J. Chem. Soc., Faraday Trans. 93 (1997) 243−247. [30] B. Sinha, A. Sarkar, P. Roy, D. Brahman, Int. J. Thermophys., 32 (2011) 2092−2078. [31] G. Hepler, Can. J. Chem., 47 (1969) 4613−4617. [32] F.J. Millero, A. Lo Surdo, C. Shin, J. Phys. Chem. 82 (1978) 784−792. [33] Y. Weisinger-Lewin, F. Frolow, R.K. McMullan, T.F. Koetzle, M. Lahav, L. Leiserowitz, Reduction in crystal symmetry of a solid solution: A neutron diffraction study at 15 K of the host/guest system asparagines/aspartic acid, J. Am. Chem. Soc. 111 (1989) 1035−1040. [34] W. Cochran, B.R. Penfold, The crystal structure of L-glutamine, Acta. Cryst. 5 (1952) 644−653. [35] G. Jones, M. Dole, J. Am. Chem. Soc. 51 (1929) 29502964. 2950−2964. [36] H. Falkenhagen, M. Dole, Z. Phys. 30 (1929) 611−616.

20

[37] H. Falkenhagen, E.L. Vernon, Z. Phys. 33 (1932) 140−145. [38] D. Feakins, D.J. Freemantle, K.G. Lawrence, J. Chem. Soc., Faraday Trans. 70 (1974) 795−806. [39] S. Glasstone, K.J. Laidler, H. Eyring, The Theory of Rate Processes, McGraw-Hill, New York, 1941, pp. 477. [40] D. P. Kharakoz, Biophys. Chem. 34 (1989) 115−125. [41] D.P. Kharakoz, J. Phys. Chem. 95 (1991) 5634−5642. [42] G.R. Hedwig, H. Hoiland, J. Chem. Thermodyn. 25 (1993) 349−354. [43] A.K. Mishra, J.C. Ahluwalia, J. Phys. Chem. 88 (1984) 86−92. [44] H.L. Friedman, C.V. Krishnan, in: F. Franks (ed.), Water: A Comprehensive Treatise, Vol. 3, Plenum Press, New York, 1973, Chapter 1. [45] A.K. Mishra, K.P. Prasad, J.C. Ahluwalia, Biopolymers 22 (1983) 2397-2409. [46] M. Kaminsky, Discuss. Faraday Soc. 24 (1957) 171−179. [47] D. Feakins, F.M. Canning, W.E. Waghorne, K.G. Lawrence, J. Chem. Soc., Faraday Trans. 89 (1993) 3381−3388.

21

Figure Captions Figure 1. Variations of apparent molar volume, Vφ vs. molality, m of l-asparagine in

mannose + water (w/w) solutions, (a) l-asparagine in water, (b) l-asparagine in 2.5% aqueous-mannose, (c) l-asparagine in 5% aqueous-mannose at temperatures, T/K = 293.15, ♦; T/K = 298.15, ■; T/K = 303.15, ▲; T/K = 308.15, □; T/K = 313.15, ∆; T/K = 318.15, ○. The points represent experimental values and lines represent values calculated from equation (4) Figure 2. Variations of apparent molar volume, Vφ vs. molality, m of l-glutamine in

mannose + water (w/w) solutions, (a) l-glutamine in water, (b) l-glutamine in 2.5% aqueous mannose, (c) l-glutamine in 5% aqueous mannose at temperatures, T/K = 293.15, ♦; T/K = 298.15, ■; T/K = 303.15, ▲; T/K = 308.15, □; T/K = 313.15, ∆; T/K = 318.15, ○. The points represent experimental values and lines represent values calculated from equation (4) Figure 3. Variations of apparent molar compressibility, K s ,φ vs. molality, m of l-asparagine

in mannose + water (w/w) solutions, (a) l-asparagine in water, (b) l-asparagine in 2.5% aqueous-mannose, (c) l-asparagine in 5% aqueous-mannose at temperatures, T/K = 293.15, ♦; T/K = 298.15, ■; T/K = 303.15, ▲; T/K = 308.15, □; T/K = 313.15, ∆; T/K = 318.15, ○. The points represent experimental values and lines represent values calculated from equation (5) Figure 4. Variations of apparent molar compressibility, K s ,φ vs. molality, m of l-glutamine

in mannose + water (w/w) solutions, (a) l-glutamine in water, (b) l-glutamine in 2.5% aqueous-mannose, (c) l-glutamine in 5% aqueous-mannose at temperatures, T/K = 293.15, ♦; T/K = 298.15, ■; T/K = 303.15, ▲; T/K = 308.15, □; T/K = 313.15, ∆; T/K = 318.15, ○. The points represent experimental values and lines represent values calculated from equation (5) Figure 5. Variations of [(ηr − 1) / m1/ 2 ] vs. m1/2 of of l-asparagine in mannose + water (w/w)

solutions, (a) l-asparagine in water, (b) l-asparagine in 2.5% aqueous-mannose, (c) lasparagine in 5% aqueous-mannose at temperatures, T/K = 293.15, ♦; T/K = 298.15, ■; T/K = 303.15, ▲; T/K = 308.15, □; T/K = 313.15, ∆; T/K = 318.15, ○. The points represent

experimental values and lines represent values calculated from equation (17)

22

Figure 6. Variations of [(ηr − 1) / m1/ 2 ] vs. m1/2 of of l-glutamine in mannose + water (w/w)

solutions, (a) l-glutamine in water, (b) l-glutamine

in 2.5% aqueous-mannose, (c) l-

glutamine in 5% aqueous-mannose at temperatures, T/K = 293.15, ♦; T/K = 298.15, ■; T/K = 303.15, ▲; T/K = 308.15, □; T/K = 313.15, ∆; T/K = 318.15, ○. The points represent

experimental values and lines represent values calculated from equation (17) Figure 7. Variations of Jones-Dole coefficient, B vs. temperature, T of (a) l-asparagine and

(b) l-glutamine in mannose + water (w/w) solutions, water, ♦; 2.5% aqueous-mannose, ■; 5% aqueous-mannose, ▲.

23

Table 1 Specification of chemicals Chemical Name (CAS number)

Provenance

Purification Method

Final Mass Fraction Purity

Analysis Method

l-Asparagine (70-47-3)

SRL, India

Re-crystallization

> 0.994

GCa

l-Glutamine (56-85-9)

SRL, India

Re-crystallization

> 0.994

GC

Used as received

> 0.99

-

d-Mannose (3458-28-4) SRL, India a

GC = Gas chromatography

24

Table 2 Densities, ρ/kg·m−3 of solutions of l-asparagine and l-glutamine in water and mannose + water (2.5 and 5% mannose, w/w in water) solvents as function of molality, m of lasparagine/l-glutamine at temperatures (293.15−318.15) K and at pressure p = 101 kPaa m/mol·kg−1 T/K

293.15

298.15

303.15

308.15

313.15

318.15

994.07 995.43 996.79 998.15 999.51 1000.87 1002.23

992.25 993.61 994.97 996.33 997.69 999.04 1000.40

990.24 991.60 992.96 994.32 995.68 997.04 998.40

1004.85 1006.14 1007.43 1008.73 1010.02 1011.32 1012.61

1003.27 1004.56 1005.86 1007.15 1008.44 1009.74 1011.03

1001.49 1002.78 1004.08 1005.38 1006.67 1007.97 1009.27

999.51 1000.81 1002.10 1003.40 1004.71 1006.01 1007.32

1014.78 1016.01 1017.24 1018.47 1019.70 1020.92 1022.15

1013.47 1014.70 1015.93 1017.16 1018.39 1019.62 1020.85

1011.95 1013.18 1014.41 1015.64 1016.87 1018.10 1019.33

1010.24 1011.47 1012.70 1013.94 1015.17 1016.40 1017.64

1008.32 1009.55 1010.78 1012.02 1013.25 1014.49 1015.72

997.07 998.40 999.73 1001.06 1002.39 1003.72

995.68 997.01 998.34 999.67 1001.00 1002.33

994.07 995.40 996.73 998.06 999.39 1000.72

992.25 993.58 994.91 996.25 997.58 998.91

990.24 991.58 992.91 994.25 995.58 996.91

ρ/kg·m−3

l-Asparagine in water

0.0000 0.0250 0.0500 0.0750 0.1000 0.1250 0.1500

998.24 999.60 1000.96 1002.32 1003.68 1005.03 1006.39

997.07 998.43 999.79 1001.15 1002.51 1003.87 1005.23

995.68 997.04 998.40 999.76 1001.12 1002.48 1003.85

l-Asparagine in 2.5% aqueous-mannose

0.0000 0.0250 0.0500 0.0750 0.1000 0.1250 0.1500

1007.37 1008.66 1009.95 1011.25 1012.54 1013.83 1015.12

1006.22 1007.51 1008.80 1010.09 1011.39 1012.68 1013.97

l-Asparagine in 5% aqueous-mannose

0.0000 0.0250 0.0500 0.0750 0.1000 0.1250 0.1500

1015.89 1017.12 1018.35 1019.58 1020.80 1022.02 1023.25

l-Glutamine in water

0.0000 0.0250 0.0500 0.0750 0.1000 0.1250

998.24 999.57 1000.90 1002.23 1003.56 1004.89

25

0.1500

1006.22

1005.05

1003.66

1002.05

1000.24

998.24

298.15

303.15

308.15

313.15

318.15

1004.85 1006.11 1007.37 1008.63 1009.89 1011.14 1012.39

1003.27 1004.53 1005.80 1007.06 1008.32 1009.57 1010.83

1001.49 1002.76 1004.02 1005.29 1006.55 1007.81 1009.07

999.51 1000.78 1002.05 1003.32 1004.59 1005.85 1007.11

1013.47 1014.67 1015.87 1017.06 1018.25 1019.44 1020.62

1011.95 1013.15 1014.35 1015.55 1016.74 1017.92 1019.11

1010.24 1011.44 1012.65 1013.84 1015.03 1016.22 1017.41

1008.32 1009.53 1010.73 1011.93 1013.13 1014.32 1015.51

Table 2 contd. m/mol·kg−1 T/K

293.15

l-Glutamine in 2.5% aqueous-mannose

0.0000 0.0250 0.0500 0.0750 0.1000 0.1250 0.1500

1007.37 1008.63 1009.89 1011.15 1012.40 1013.65 1014.90

1006.22 1007.48 1008.74 1010.00 1011.25 1012.50 1013.75

l-Glutamine in 5% aqueous-mannose

0.0000 0.0250 0.0500 0.0750 0.1000 0.1250 0.1500 a

1015.89 1017.09 1018.29 1019.48 1020.67 1021.86 1023.04

1014.78 1015.98 1017.18 1018.37 1019.56 1020.74 1021.93

m is the molality of amino acid in aqueous−d-mannose solvents. Uncertainty in

composition of d-mannose + water solvent s(%) = ± 0.01%. Standard uncertainties s are s(T) = ±0.01 K, s(m) = ±1.0 × 10−4 mol·kg−1, and s(ρ) = ±0.83 kg·m−3, s(p) = ±1.0 kPa.

26

Table 3 Ultrasonic speeds, u/m·s−1 of solutions of l-asparagine and l-glutamine in water and mannose + water (2.5 and 5% mannose, w/w in water) solvents as function of molality, m of l-asparagine/l-glutamine at temperatures (293.15−318.15) K and at pressure, p = 101 kPa a m/mol·kg−1 T/K

293.15

298.15

303.15

308.15

313.15

318.15

1519.8 1521.9 1523.6 1524.9 1525.8 1526.3 1526.4

1526.8 1528.8 1530.4 1531.5 1532.3 1532.7 1532.7

1533.0 1534.8 1536.3 1537.4 1538.0 1538.3 1538.2

1517.8 1519.6 1521.1 1522.3 1523.1 1523.5 1523.6

1527.4 1529.2 1530.6 1531.7 1532.5 1532.9 1532.9

1537.0 1538.7 1540.1 1541.1 1541.8 1542.2 1542.1

1546.6 1548.2 1549.5 1550.5 1551.1 1551.3 1551.2

1516.6 1518.2 1519.5 1520.5 1521.1 1521.4 1521.3

1525.2 1526.8 1528.0 1528.9 1529.5 1529.7 1529.6

1534.1 1535.6 1536.8 1537.7 1538.2 1538.3 1538.2

1542.2 1543.7 1544.8 1545.6 1546.0 1546.1 1545.8

1551.3 1552.7 1553.7 1554.4 1554.8 1554.9 1554.5

1496.9 1498.9 1500.6 1501.9 1502.9 1503.6

1508.4 1510.4 1512.0 1513.3 1514.3 1514.9

1519.8 1521.7 1523.3 1524.6 1525.5 1526.0

1526.8 1528.6 1530.1 1531.3 1532.0 1532.5

1533.0 1534.7 1536.1 1537.2 1537.9 1538.2

u/m·s−1 l-Asparagine in water

0.0000 0.0250 0.0500 0.0750 0.1000 0.1250 0.1500

1483.6 1485.8 1487.7 1489.1 1490.3 1491.1 1491.5

1496.9 1499.1 1500.9 1502.4 1503.5 1504.2 1504.5

1508.4 1510.5 1512.3 1513.7 1514.7 1515.3 1515.5

l-Asparagine in 2.5% aqueous-mannose

0.0000 0.0250 0.0500 0.0750 0.1000 0.1250 0.1500

1500.2 1502.1 1503.7 1504.9 1505.8 1506.4 1506.6

1508.3 1510.2 1511.7 1512.9 1513.8 1514.3 1514.5

l-Asparagine in 5% aqueous-mannose

0.0000 0.0250 0.0500 0.0750 0.1000 0.1250 0.1500

1508.3 1509.9 1511.3 1512.3 1512.9 1513.3 1513.3

l-Glutamine in water

0.0000 0.0250 0.0500 0.0750 0.1000 0.1250

1483.6 1485.6 1487.3 1488.7 1489.7 1490.4

27

0.1500

1490.8

1503.9

1515.1

1526.1

1532.5

1538.2

298.15

303.15

308.15

313.15

318.15

1517.8 1519.5 1521.0 1522.2 1523.1 1523.7 1524.1

1527.4 1529.1 1530.5 1531.7 1532.5 1533.1 1533.4

1537.0 1538.6 1540.0 1541.1 1541.9 1542.4 1542.6

1546.6 1548.2 1549.5 1550.5 1551.2 1551.7 1551.8

1525.2 1526.8 1528.2 1529.4 1530.4 1531.2 1531.8

1534.1 1535.7 1537.1 1538.2 1539.2 1540.0 1540.6

1542.2 1543.7 1545.1 1546.3 1547.2 1548.0 1548.6

1551.3 1552.8 1554.1 1555.3 1556.2 1557.0 1557.6

Table 3 contd. m/mol·kg−1 T/K

293.15

l-Glutamine in 2.5% aqueous-mannose

0.0000 0.0250 0.0500 0.0750 0.1000 0.1250 0.1500

1500.2 1502.0 1503.6 1504.9 1505.9 1506.7 1507.2

1508.3 1510.1 1511.6 1512.9 1513.9 1514.6 1515.0

l-Glutamine in 5% aqueous-mannose

0.0000 0.0250 0.0500 0.0750 0.1000 0.1250 0.1500

1508.3 1509.9 1511.4 1512.6 1513.6 1514.4 1515.0

1516.6 1518.2 1519.6 1520.9 1521.9 1522.7 1523.3

a

m is the molality of amino acid in aqueous−d-mannose solvents. Uncertainty in composition of d-mannose + water solvent s(%) = ± 0.01%. Standard uncertainties s are s(T) = ±0.01 K, s(m) = ±1.0·10−4 mol·kg−1 and s(u) = ±1.7 m·s−1, s(p) = ±1.0 kPa.

28

Table 4 Viscosities, 103·η/N·s·m−2 of l-asparagine and l-glutamine in water and mannose + water (2.5 and 5% mannose, w/w in water) solvents as function of molality, m of l-asparagine/lglutamine at temperatures (293.15−318.15) K and at pressure, p = 101 kPa a m/mol·kg−1 T/K

293.15

298.15

303.15

308.15

313.15

318.15

0.7190 0.7243 0.7292 0.7340 0.7388 0.7436 0.7484

0.6526 0.6573 0.6615 0.6657 0.6699 0.6740 0.6782

0.5972 0.6013 0.6050 0.6087 0.6123 0.6159 0.6195

0.8259 0.8332 0.8406 0.8479 0.8553 0.8630 0.8710

0.7416 0.7479 0.7542 0.7605 0.7668 0.7734 0.7800

0.6702 0.6757 0.6811 0.6865 0.6919 0.6975 0.7032

0.6127 0.6176 0.6223 0.6270 0.6317 0.6365 0.6414

0.9767 0.9886 1.0002 1.0121 1.0240 1.0364 1.0488

0.8625 0.8727 0.8826 0.8924 0.9025 0.9128 0.9232

0.7717 0.7805 0.7890 0.7975 0.8060 0.8146 0.8233

0.6965 0.7042 0.7114 0.7185 0.7258 0.7334 0.7408

0.6354 0.6422 0.6484 0.6546 0.6610 0.6675 0.6740

0.8903 0.8970 0.9031 0.9090 0.9150 0.9209

0.7973 0.8032 0.8084 0.8135 0.8186 0.8237

0.7190 0.7243 0.7288 0.7332 0.7376 0.7420

0.6526 0.6573 0.6613 0.6651 0.6689 0.6727

0.5972 0.6013 0.6048 0.6082 0.6115 0.6148

103·η/N·s·m−2 l-Asparagine in water

0.0000 0.0250 0.0500 0.0750 0.1000 0.1250 0.1500

1.0019 1.0099 1.0176 1.0254 1.0332 1.0409 1.0487

0.8903 0.8972 0.9037 0.9104 0.9170 0.9236 0.9301

0.7973 0.8033 0.8089 0.8146 0.8202 0.8258 0.8314

l-Asparagine in 2.5% aqueous-mannose

0.0000 0.0250 0.0500 0.0750 0.1000 0.1250 0.1500

1.0517 1.0617 1.0725 1.0829 1.0935 1.1043 1.1150

0.9294 0.9379 0.9468 0.9556 0.9646 0.9736 0.9827

l-Asparagine in 5% aqueous-mannose

0.0000 0.0250 0.0500 0.0750 0.1000 0.1250 0.1500

1.1157 1.1297 1.1438 1.1580 1.1723 1.1871 1.2021

l-Glutamine in water

0.0000 0.0250 0.0500 0.0750 0.1000 0.1250

1.0019 1.0097 1.0168 1.0239 1.0309 1.0379

29

0.1500

1.0451

0.9269

0.8288

0.7464

0.6765

0.6181

298.15

303.15

308.15

313.15

318.15

0.8259 0.8333 0.8404 0.8477 0.8550 0.8621 0.8693

0.7416 0.7480 0.7542 0.7604 0.7666 0.7728 0.7789

0.6702 0.6758 0.6811 0.6865 0.6918 0.6972 0.7025

0.6127 0.6176 0.6223 0.6270 0.6317 0.6363 0.6410

0.8625 0.8727 0.8825 0.8922 0.9018 0.9116 0.9211

0.7717 0.7806 0.7891 0.7974 0.8057 0.8140 0.8223

0.6965 0.7044 0.7117 0.7190 0.7262 0.7334 0.7406

0.6354 0.6424 0.6488 0.6552 0.6616 0.6678 0.6741

Table 4 contd. m/mol·kg−1 T/K

293.15

l-Glutamine in 2.5% aqueous-mannose

0.0000 0.0250 0.0500 0.0750 0.1000 0.1250 0.1500

1.0517 1.0618 1.0717 1.0817 1.0918 1.1020 1.1123

0.9294 0.9380 0.9464 0.9550 0.9636 0.9720 0.9804

l-Glutamine in 5% aqueous-mannose

0.0000 0.0250 0.0500 0.0750 0.1000 0.1250 0.1500 a

1.1157 1.1296 1.1431 1.1567 1.1703 1.1840 1.1977

0.9767 0.9885 1.0000 1.0114 1.0227 1.0341 1.0458

m is the molality of amino acid in aqueous−d-mannose solvents. Uncertainty in

composition of d-mannose + water solvent s(%) = ± 0.01%. Standard uncertainties s are s(T) = ±0.01 K, s(m) = ±1.0×10−4 mol·kg−1 and s(η) = ±1.1%, s(p) = ±1.0 kPa

30

Table 5 Limiting apparent molar volume, Vφ° , slope, Sv, transfer limiting apparent molar volume, Vφ°,tr , and standard deviations of linear regression, σ for l-asparagine/l-glutamine in water

and mannose + water (2.5 and 5% mannose, w/w in water) solutions at temperatures (293.15−318.15) K Property

T/K 293.15 298.15

303.15

308.15

313.15

318.15

7.805

7.842

7.880

7.916

7.956

8.000

0.013

0.001

0.010

0.007

0.014

0.014

-0.894

-1.011

-1.065

-1.043

-0.956

-0.957

l-Asparagine in water

105 · Vφ° /m3·mol−1 10 · σ for equation (4) 5

−1

3

−1

10 · Sv/m ·mol ·kg

l-Asparagine in 2.5 % aqueous-mannose

105 · Vφ° / m3·mol−1 10 · σ for equation (4) 5

3

6

Vφ°,tr /

−1

−1

10 · Sv/m ·mol ·kg 10 ·

−1

3

m ·mol

7.869

7.902

7.935

7.968

8.005

8.046

0.027

0.012

0.007

0.016

0.022

0.017

-0.924

-0.963

-1.016

-0.996

-1.045

-1.138

0.640

0.591

0.553

0.516

0.489

0.464

l-Asparagine in 5 % aqueous-mannose

105 · Vφ° / m3·mol−1 10 · σ for equation (4) 5

3

6

Vφ°,tr /

−1

−1

10 · Sv/m ·mol ·kg 10 ·

−1

3

m ·mol

7.924

7.947

7.977

8.012

8.050

8.095

0.002

0.009

0.008

0.011

0.006

0.009

-0.755

-0.773

-0.820

-0.859

-0.925

-0.974

1.184

1.120

1.062

1.013

0.982

0.949

9.338

9.371

9.408

9.445

9.483

9.520

0.013

0.019

0.011

0.001

0.012

0.013

-1.036

-1.068

-1.088

-1.061

-1.060

-1.016

l-Glutamine in water

105 · Vφ° /m3·mol−1 10 · σ for equation (4) 5

−1

3

−1

10 · Sv/m ·mol ·kg

l-Glutamine in 2.5 % aqueous-mannose

105 · Vφ° / m3·mol−1

9.389

9.415

9.445

9.476

9.509

9.542

0.011

0.018

0.021

0.011

0.019

0.021

10 · Sv/m ·mol ·kg

-0.808

-0.800

-0.835

-0.858

-0.886

-0.889

10 · Vφ°,tr / m ·mol

0.504

0.439

0.377

0.315

0.262

0.222

9.425

9.451

9.483

9.515

9.548

9.579

0.004

0.004

0.006

0.010

0.007

0.004

10 · Sv/m ·mol ·kg

-0.619

-0.621

-0.629

-0.648

-0.649

-0.635

106 · Vφ°,tr / m3·mol−1

0.861

0.794

0.728

0.670

0.611

0.590

10 · σ for equation (4) 5

−1

3

6

−1

−1

3

l-Glutamine in 5 % aqueous-mannose

105 · Vφ° / m3·mol−1 10 · σ for equation (4) 5

3

−1

−1

31

Table 6 Limiting apparent molar compressibility, K s°,φ , slope, Sk, transfer limiting apparent molar compressibility, K s°,φ ,tr and standard deviations of linear regression, σ for l-asparagine/lglutamine in water and mannose + water (2.5 and 5 % mannose, w/w in water) solutions at temperatures (293.15−318.15) K Property

T/K 293.15 298.15

303.15

308.15

313.15

318.15

-10.772 -10.542

-10.283

-10.002

-9.690

-9.346

0.007

0.010

0.006

0.013

0.012

18.235

18.492

18.555

18.614

18.193

-9.119

-8.924

-8.732

-8.502

-8.253

0.071

0.129

0.100

0.109

0.070

15.953

15.987

15.867

15.621

15.492

1.423

1.359

1.270

1.188

1.093

l-Asparagine in water

1011⋅ K s°,φ /(m5⋅N−1⋅mol−1)

σ for equation (8) 0.008 11 5 −1 −1 −1 10 ⋅Sk /(m ⋅N ⋅mol ⋅kg ) 18.075

l-Asparagine in 2.5 % aqueous-mannose

1011⋅ K s°,φ /(m5⋅N−1⋅mol−1)

-9.294

σ for equation (8) 0.067 11 5 −1 −1 −1 10 ⋅ Sk /(m ⋅N ⋅mol ⋅kg ) 16.144 1011⋅ K s°,φ ,tr /(m5⋅N−1⋅mol−1) 1.478

l-Asparagine in 5 % aqueous-mannose

1011⋅ K s°,φ /(m5⋅N−1⋅mol−1)

-8.157

-8.021

-7.864

-7.678

-7.474

-7.231

σ for equation (8) 1011⋅ Sk /(m5⋅N−1⋅mol−1⋅kg−1) 1011⋅ K s°,φ ,tr /(m5⋅N−1⋅mol−1) l-Glutamine in water 1011⋅ K s°,φ /(m5⋅N−1⋅mol−1) σ for equation (8)

0.075

0.096

0.083

0.078

0.079

0.092

15.022

15.116

15.143

14.976

14.873

14.426

2.614

2.525

2.426

2.328

2.219

2.115

-10.161 -9.972

-9.743

-9.504

-9.242

-8.958

0.008

0.007

0.004

0.009

0.002

0.009

16.688

16.657

16.566

16.682

16.177

-8.741

-8.554

-8.374

-8.175

-7.952

0.060

0.043

0.098

0.078

0.087

12.935

13.201

13.155

13.011

12.768

1.231

1.189

1.130

1.067

1.005

11

5

−1

−1

−1

10 ⋅ Sk /(m ⋅N ⋅mol ⋅kg ) 16.585

l-Glutamine in 2.5 % aqueous-mannose

1011⋅ K s°,φ /(m5⋅N−1⋅mol−1)

-8.865

σ for equation (8) 0.042 11 5 −1 −1 −1 10 ⋅ Sk /(m ⋅N ⋅mol ⋅kg ) 12.572 1011⋅ K s°,φ ,tr /(m5⋅N−1⋅mol−1) 1.297 l-Glutamine in 5 % aqueous-mannose

1011⋅ K s°,φ /(m5⋅N−1⋅mol−1)

-7.912

-7.797

-7.673

-7.544

-7.419

-7.259

σ for equation (8)

0.055

0.027

0.064

0.041

0.044

0.052

10 ⋅ Sk /(m ⋅N ⋅mol ⋅kg ) 9.930

9.649

9.446

9.169

8.906

8.430

2.175

2.070

1.960

1.823

1.699

11 11

10

5

⋅ K s°,φ ,tr

−1

5

−1

−1

−1

−1

/(m ⋅N ⋅mol ) 2.249

32

Table 7 Limiting apparent molar expansibility, 109· Eφ° /m3⋅mol−1⋅K−1 for glycine/l-alanine/l-valine/lisoleucine in streptomycin sulphate + water (1 and 2 % streptomycin sulphate, w/w in water) solutions at different temperatures

System

T/K

293.15

298.15

303.15

308.15

313.15

318.15

0.704

0.732

0.759

0.786

0.814

0.841

l-Asparagine + 2.5% mannose 0.605

0.644

0.684

0.723

0.762

0.802

l-Asparagine + 5% mannose

0.563

0.610

0.656

0.703

0.749

0.796

l-Glutamine + water

0.685

0.704

0.724

0.743

0.762

0.781

l-Glutamine + 2.5% mannose 0.542

0.572

0.602

0.633

0.663

0.693

0.529

0.566

0.604

0.641

0.679

0.716

109· Eφ° /m3⋅mol−1⋅K−1 l-Asparagine + water

l-Glutamine + 5% mannose

33

Table 8 Hepler’s constant, (∂ 2Vφ° / ∂T 2 ) p and hydration number, nH for l-asparagine and l-glutamine in water and mannose + water (2.5 and 5% mannose, w/w in water) solvents at 298.15 K System

109· (∂ 2Vφ° / ∂T 2 ) p

Volumetric method

Compressibility method

m3·mol−1·K−2 l-Asparagine + water

0.547

7.018

13.015

l-Asparagine + 2.5% mannose

0.787

6.839

11.258

l-Asparagine + 5% mannose

0.930

6.678

9.898

l-Glutamine + water

0.386

3.356

12.311

l-Glutamine + 2.5% mannose

0.603

3.223

10.791

l-Glutamine + 5% mannose

0.748

3.115

9.625

34

Table 9 Falkenhagen coefficient, A, Jones-Dole coefficient, B, standard deviations of linear regression, σ, free energies of activation of viscous flow per mole of solvent, ∆µ 1° # , and solute, ∆µ 2° # , for l-asparagine and l-glutamine in water and mannose + water (2.5 and 5% mannose, w/w in water) solvents at temperatures (293.15−318.15) K Property

T/K

293.15

298.15

303.15

308.15

313.15

318.15

10 · A /kg1/2·mol−1/2

0.0184

0.0314

0.0436

0.0559

0.0643

0.0737

B /kg·mol−1

0.3063

0.2904

0.2740

0.2576

0.2441

0.2303

10 · σ for equation (17)

0.0019

0.0031

0.0021

0.0010

0.0021

0.0011

∆µ 1° # /kJ·mol−1)

9.29

9.16

9.04

8.93

8.83

8.74

∆µ2° # /kJ·mol−1)

423.02

407.54

390.74

373.09

358.87

343.58

l-Asparagine in water

l-Asparagine in 2.5% aqueous-mannose

10 · A /kg1/2·mol−1/2

-0.0488

-0.0434

-0.0295

-0.0176

-0.0030

0.0175

B /kg·mol−1

0.4138

0.3929

0.3685

0.3479

0.3270

0.3061

10 · σ for equation (17)

0.005

0.004

0.009

0.006

0.006

0.005

∆µ 1° # /kJ·mol−1)

9.44

9.30

9.16

9.04

8.93

8.84

∆µ2° # /kJ·mol−1)

561.03

541.34

515.80

494.45

471.76

448.22

l-Asparagine in 5% aqueous-mannose

10 · A /kg1/2·mol−1/2

-0.0448

-0.0251

0.0025

0.0247

0.0384

0.0491

B /kg·mol−1

0.5247

0.4955

0.4656

0.4380

0.4116

0.3896

10 · σ for equation (17)

0.010

0.011

0.010

0.004

0.011

0.011

∆µ 1° # /kJ·mol−1)

9.62

9.46

9.31

9.18

9.06

8.97

∆µ2° # /kJ·mol−1)

699.89

671.74

641.20

612.44

584.31

561.03

10 · A /kg1/2·mol−1/2

0.0623

0.0767

0.0891

0.1023

0.1142

0.1172

B /kg·mol−1

0.2704

0.2540

0.2400

0.2265

0.2138

0.2033

10 · σ for equation (17)

0.0036

0.0023

0.0025

0.0029

0.0020

0.0008

∆µ 1° # /kJ·mol−1)

9.29

9.16

9.04

8.93

8.83

8.74

∆µ2° # /kJ·mol−1)

374.42

357.63

343.41

329.20

315.44

304.40

l-Glutamine in water

35

Table 9 contd. Property

T/K

293.15

298.15

303.15

308.15

313.15

318.15

l-Glutamine in 2.5% aqueous-mannose -0.0056 0.0073 10 · A /kg1/2·mol−1/2

0.0164

0.0247

0.0304

0.0317

B /kg·mol−1

0.3841

0.3645

0.3461

0.3292

0.3132

0.2996

10 · σ for equation (17)

0.005

0.003

0.003

0.001

0.003

0.001

∆µ 1° # /kJ·mol−1)

9.44

9.30

9.16

9.04

8.93

8.84

∆µ2° # /kJ·mol−1)

521.49

502.83

485.09

468.38

452.35

438.90

l-Glutamine in 5% aqueous-mannose

10 · A /kg1/2·mol−1/2

0.0177

0.0331

0.0536

0.0673

0.0824

0.0899

B /kg·mol−1

0.4845

0.4617

0.4394

0.4196

0.4006

0.3829

10 · σ for equation (17)

0.004

0.004

0.002

0.002

0.001

0.002

∆µ 1° # /kJ·mol−1)

9.62

9.46

9.31

9.18

9.06

8.97

∆µ2° # /kJ·mol−1)

647.03

626.55

605.69

587.16

568.83

551.49

36

8.00

105.Vφ /m3.mol−1

7.95

(a)

7.90 7.85 7.80 7.75 7.70 7.65 0.00

0.02

0.04

0.06

0.08

0.10

0.12

0.14

0.16

0.18

8.05

105.Vφ /m3.mol−1

8.00

(b)

7.95 7.90 7.85 7.80 7.75 7.70 7.65 0.00

0.02

0.04

0.06

0.08

0.10

0.12

0.14

0.16

0.18

8.10

105.Vφ /m3.mol−1

8.05

(c)

8.00 7.95 7.90 7.85 7.80 0.00

0.02

0.04

0.06

0.08

0.10

m (mol kg−1)

Figure 1

37

0.12

0.14

0.16

0.18

9.55

105.Vφ /m3.mol−1

9.50

(a)

9.45 9.40 9.35 9.30 9.25 9.20 9.15 0.00

0.02

0.04

0.06

0.08

0.10

0.12

0.14

0.16

0.18

9.55

105.Vφ /m3.mol−1

9.50

(b)

9.45 9.40 9.35 9.30 9.25 0.00

0.02

0.04

0.06

0.08

0.10

0.12

0.14

0.16

0.18

9.60

105.Vφ /m3.mol−1

9.55

(c)

9.50 9.45 9.40 9.35 9.30 0.00

0.02

0.04

0.06

0.08

0.10

m (mol kg−1)

Figure 2

38

0.12

0.14

0.16

0.18

(a)

-7.0

(a)

-8.0

11

5

10 .K s,φ /m .N−1.mol−1

-6.0

-9.0 -10.0 -11.0 0.00

0.02

0.04

0.06

0.08

0.10

0.12

0.14

0.16

0.18

0.08

0.10

0.12

0.14

0.16

0.18

0.08

0.10

0.12

0.14

0.16

0.18

1011.K s,φ /m5.N−1.mol−1

-5.5 -6.0 -6.5

(b)

-7.0 -7.5 -8.0 -8.5 -9.0 -9.5 0.00

0.02

0.04

0.06

0.04

0.06

1011.K s,φ /m5.N−1.mol−1

-4.5 -5.0

(c)

-5.5 -6.0 -6.5 -7.0 -7.5 -8.0 -8.5 0.00

0.02

m (mol kg−1)

Figure 3

39

11

5

10 .K s,φ /m .N−1.mol−1

-6.0 -6.5 -7.0

(a)

-7.5 -8.0 -8.5 -9.0 -9.5 -10.0 -10.5 0.00

0.02

0.04

0.06

0.08

0.10

0.12

0.14

0.16

0.18

0.08

0.10

0.12

0.14

0.16

0.18

0.08

0.10

0.12

0.14

0.16

0.18

1011.K s,φ /m5.N−1.mol−1

-5.5 -6.0

(b)

-6.5 -7.0 -7.5 -8.0 -8.5 -9.0 0.00

0.02

0.04

0.06

0.04

0.06

1011.K s,φ /m5.N−1.mol−1

-5.5

-6.0

(c)

-6.5

-7.0

-7.5

-8.0 0.00

0.02

−1

m (mol kg )

Figure 4

40

(ηr − 1)/m1/2 /(mol kg−1)−1/2

0.14

(a)

0.12 0.10 0.08 0.06 0.04 0.02 0.10

0.15

0.20

0.25

0.30

0.35

0.40

0.45

0.20

0.25

0.30

0.35

0.40

0.45

0.30

0.35

0.40

0.45

(ηr − 1)/m

1/2

/(mol kg−1)−1/2

0.18

(b)

0.15

0.12

0.09

0.06

0.03 0.10

0.15

0.23

(ηr − 1)/m

1/2

/(mol kg−1)−1/2

0.21

(c)

0.19 0.17 0.15 0.13 0.11 0.09 0.07 0.05 0.10

0.15

0.20

0.25

m

1/2

−1 1/2

(mol kg )

Figure 5

41

(ηr − 1)/m1/2 /(mol kg−1)−1/2

0.13

(a)

0.11 0.09

0.07 0.05

0.03 0.10

0.15

0.20

0.25

0.30

0.35

0.40

0.45

0.15

0.20

0.25

0.30

0.35

0.40

0.45

0.15

0.20

0.30

0.35

0.40

0.45

(ηr − 1)/m

1/2

/(mol kg−1)−1/2

0.17

(b)

0.15 0.13 0.11 0.09 0.07 0.05 0.03 0.10 0.22

(ηr − 1)/m

1/2

/(mol kg−1)−1/2

0.20

(c)

0.18 0.16 0.14 0.12 0.10 0.08 0.06 0.04 0.10

0.25

m

1/2

−1 1/2

(mol kg )

Figure 6

42

0.55

(a)

0.50

B /kg·mol−1

0.45 0.40 0.35 0.30 0.25 0.20 290

295

300

305

310

315

320

T/K 0.50

(b) 0.45

B /kg·mol−1

0.40

0.35

0.30

0.25

0.20

0.15 290

295

300

305

T/K

Figure 7

43

310

315

320

Research Highlights

•

Study reports density, ultrasonic speed and viscosity data of l-asparagine/l-glutamine in aqueous-d-mannose

•

The study elucidates interactions of l-asparagine/l-glutamine with d-mannose in aqueous media

•

The study correlates physical properties of l-asparagine/l-glutamine with their interactions in these solutions

44