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Bactericidal Effect of Acrylic Acid Esters
Zbl. Bakt. Abt. II, Bd. 131, S. 661- 664 (1976)
[Fac. of Agric., Mansura University; Inst. of Soil Sciens, Ministry of Agric.; National Res. Centre and Drug Res. and Control Centre]
Bactericidal Effect of Acrylic Acid Esters I. Ibrahim, Y. Hamdi, M. N. Tolba, and M. A. Madkour Summary The antibacterial effect of p-Cl, p-Br, p-CH 3 , o-N0 2, m-N0 2 , and p-N02 substitutions of dimethylaminoethyl-lX·phenyl-cinnamate on Bacillu8 8ubtilis, Sarcina lutea, and Escherichia coli was studied. The compounds were found to be more active against B. subtilis and S.lutea than against E. coli. The N0 2 group in the para position was found to have the highest activity compared with the meta and or-tho positions.
Zusammenfassung Der bakterizide Effekt von p-Cl-, p-Br-, p-CH3 -, o-N0 2-, m-N0 2 - und p-N0 2-substituierten Dimethylaminoathyl-IX-phenylsalzen der Zimtsii.ure wurde an Bacillus 8ubtilis, Sarcina lutea und Escherichia coli untersucht. Die Wirkung der untersuchten Verbindungen war gegeniiber B. subtilis und S. lutea hoher als gegeniiber E. coli. Die N0 2 -Gruppe zeigte in para-Position im Vergleich zu metaund or-tho-SteHung die hochste Aktivitat.
Acrylic acid, which is widely used in plastics industries, is known to gain no cumulative toxic reactions (1). Further investigations showed thatcinnamaldehyde, which is a derivative from acrylic acid, has germicidal effect (2). The sodium salt of cinnamic acid was noticed to posses fungicidal activity (3). The aim of this work is to study the antibiotical effect of substitutions, such as p-CI, p-Br, p-CHa, o-N0 2 , m-N0 2 , and p-N0 2 , to diaminoethyl-iX-phenylcinnamate on different Gram-negative and Gram-positive bacteria.
Synthesis of the tested compounds The tested substituted dimethylaminoethyl-iX-phenylcinnamate hydrochlorides (3a-f) were prepared by the following general procedure:
SOC 12
3 a, R =p- CI
b, R -HOCH2· CH2 ·N( CHJ }2
c,
~
=
P - 8r
R = Pd, R = 0 e, R =mf, R = p-
CH3 NOZ NOZ
N02
- 6
p-CI p-B r p -CH s o-N0 2 m -N 0 2 p-N0 2
3a
92 90 98 96 94 95
Y ie ld
%
145 127 70 120 143 205
M.p.oC
ell]
'
-HCt
90 60 90 30 15 5
R ea.ct ion time/min.
1) All compounds wer e cr ystallized from ethanol. 2) All the IR spectra were det ermined in CHCIs solution .
c d e f
b
R
1.&
~
Compound1)
IT
O -oCH = C- CDDCH2 0CH2 oN /
eN3
1,724 1,724 1,718 1,727 1,730 1,730
IR2) cm-1
C
Calcd.
Analysis
62.47 Cl, H21CI~02 C1,H n BrCl N02 55.61 69.57 C25H24CINOs C1,H 21 CIN20 4 60.64 60.64 Cl'H21 CIN2 0 4 C1,H21 ClN2 0 4 60.64
Formula
T a ble 1. Ana lytical data of the tested substituted dimethylaminoethyl-lX-phen y lcinnamate h y drochloride
5. 75 5.1 2 6.95 5.58 5.58 5.58
H
%
3.83 3.41 4.05 7.44 7.44 7.44
N
62.44 55.53 69.56 60.62 60.63 60.62
C
Found
5 .74 5 .10 6.93 5.55 5.56 5.55
H
3.82 3.42 4 .08 7.43 70 23 7.41
N
>-<
~ F ?'
~
~
Il:l
!""'
t-:)
~
~
Bactericidal Effect of Acrylic Acid Esters
663
A solution of iX- phenyl-p-chlorocinnamic acid (4.9 g; 0.02 mole) in dry benzene (50 ml) was treated with 4 ml of thionyl chloride together with two drops of dry pyridine. The mixture was heated under reflux for one hour. The solvent, together with the excess of thionyl chloride, was evaporated under reduced pressure. The remaining residue was dissolved in dry benzene (80 ml) and a solution of 2-dimethylamino ethanol (7 g; 0.02 mole) in 10 ml of dry benzene was added dropwise. The reaction mixture was heated under reflux for 2 hours, allowed to cool, and the precipitated dimethylaminoethyl-iX-phenyl-p-chlorocinnamate hydrochloride (3a) was collected by filtration, washed with dry benzene, and crystallized from ethanol to give colourless crystals (5.3 g; 80 % yield; m.p. 70°). The same procedure was adopted for the synthesis of the substituted dimethylaminoethyl-iX-phenylcinnamate hydrochloride (3 b -f). The structure of these compounds (3a-f) was established by their correct microanalytical data, as well as in consideration of their LR. spectral data (cf. Table 1). Table 1 comprises the tested dimethylaminoethyl-iX-phenylcinnamate hydrochloride (3a-f), together with its physical and chemical data.
Biological assay The dimethylaminoethyl-iX-phenylcinnamate hydrochlorides (3a-e) were tested for their germicidal effect, using two different bacteria, one was E8cherichia coli that is Gram-negative and the other was Bacillu8 8ubtili8 that is Gram-positive. These two organisms were suspended in agar culture media, containing 1 g yeast extract, 10 g mannitol, 0.1 g sodium chloride, 0.5 g magnesium sulphate (MgS0 4 • 5H2 0), K 2HP0 4 , and 12 g agar. The organism-agar suspensions were distributed in Petri dishes, small glass rings of 0.8 mm diameter were placed on the surface of the agar, and the media were allowed to solidify before the solutions of the compounds tested were added into the glass rings. The solution of each compound added contained 2 mg in 0.2 ml of water. The dishes were incubated at 37 °0 and the inhibition zones were estimated. Results Table 2 shows the tested compounds and their effect on E. coli, B.8ubtili8, and S. lutea. Table 2. Relation of germicidal activity and substituent Organism
E. coli B. BubtiliB S.lutea
Inhibition zone in cm2 due to the substitution of p-Br
p-CI
p-CHa
p-N0 2
o-N0 2
m-N0 2
5.0 8.2 3.5
3.5 6.5 5.5
2.0 5.5 3.5
1.6 8.1 5.0
0.8 0.85 3.9
0.6 4.5 3.0
The germicidal activity was generally higher in the case of the Gram-positive B. 8ubtili8 than in that of Gram-negative E. coli. This effect was specially noticed in the case of the p-N0 2 substitution. It was as highly effective as p-Br substitution.
Discussion It was clear that the p-N0 2 substituent had the highest effect, whereas the o-N0 2 had the lowest one and the m-N0 2 derivative was between. This may be considered as a result of the degree of difficulty for building a hydrogen bond between the N0 2
664
I.
I B RAHHI ll.
a .• Baet
group in the para position and t he hydrogen atom, attached t o the carbon atom that is closely attached to the benzene ring. This may be easily formed with the meta substituent and even more easily with the ortho one. This fact will permit a smaller amount of respiration H + to react with the N0 2 group, and that may explain the drop of activity in the meta and ortho positions. The activity drop of the p -N0 2 substituted compound in E. coli may be due to its micro-aerophilic nature, that means, the organism has a higher ability for utilizing highly oxidized groups in the molecule, such as p-N0 2 , as an oxygen acceptor, and it seems that is not the case with B. subtilis which is obligatory aerobic and has no such anaerobic systems (5). Sarcina lutea may occupy a position between B . subtilis and E. coli . The effect of p-Br and nitro- substitutions on Sarcina lutea in the investigated compounds needs more detailed study. References 1. 2. 3. 4. 5.
PATTY, F. A.: Industrial Hygiene and Toxicology. 1962, Vol. II, 1994. KELLNER, W., and KOBER, W.: Arzneimittelforschung 5 (1955), 224. COHEN, R.: Arizona Med. 12 (1955),106. ROBERT, E. B. , and COOPER, J. A.: J. Org. Chern. 30 (1965),1588. Cox, C. S., and BALDWIN, J .: J. gen. Microbiol. 49 (1967), 11 5.
Authors' address : Prof. Dr. Y. HAMDI, D ept. of Microbiology, Inst. of Soil Science, Ministry of Agriculture, Cairo (A.R.E.).
[Fac. of Agric., Mansura University; Inst. of Soil Sciens, Ministry of Agric.; National Res. Centre and Drug Res. and Control Centre]
Bactericidal Effect of Acrylic Acid Esters I. Ibrahim, Y. Hamdi, M. N. Tolba, and M. A. Madkour Summary The antibacterial effect of p-Cl, p-Br, p-CH 3 , o-N0 2, m-N0 2 , and p-N02 substitutions of dimethylaminoethyl-lX·phenyl-cinnamate on Bacillu8 8ubtilis, Sarcina lutea, and Escherichia coli was studied. The compounds were found to be more active against B. subtilis and S.lutea than against E. coli. The N0 2 group in the para position was found to have the highest activity compared with the meta and or-tho positions.
Zusammenfassung Der bakterizide Effekt von p-Cl-, p-Br-, p-CH3 -, o-N0 2-, m-N0 2 - und p-N0 2-substituierten Dimethylaminoathyl-IX-phenylsalzen der Zimtsii.ure wurde an Bacillus 8ubtilis, Sarcina lutea und Escherichia coli untersucht. Die Wirkung der untersuchten Verbindungen war gegeniiber B. subtilis und S. lutea hoher als gegeniiber E. coli. Die N0 2 -Gruppe zeigte in para-Position im Vergleich zu metaund or-tho-SteHung die hochste Aktivitat.
Acrylic acid, which is widely used in plastics industries, is known to gain no cumulative toxic reactions (1). Further investigations showed thatcinnamaldehyde, which is a derivative from acrylic acid, has germicidal effect (2). The sodium salt of cinnamic acid was noticed to posses fungicidal activity (3). The aim of this work is to study the antibiotical effect of substitutions, such as p-CI, p-Br, p-CHa, o-N0 2 , m-N0 2 , and p-N0 2 , to diaminoethyl-iX-phenylcinnamate on different Gram-negative and Gram-positive bacteria.
Synthesis of the tested compounds The tested substituted dimethylaminoethyl-iX-phenylcinnamate hydrochlorides (3a-f) were prepared by the following general procedure:
SOC 12
3 a, R =p- CI
b, R -HOCH2· CH2 ·N( CHJ }2
c,
~
=
P - 8r
R = Pd, R = 0 e, R =mf, R = p-
CH3 NOZ NOZ
N02
- 6
p-CI p-B r p -CH s o-N0 2 m -N 0 2 p-N0 2
3a
92 90 98 96 94 95
Y ie ld
%
145 127 70 120 143 205
M.p.oC
ell]
'
-HCt
90 60 90 30 15 5
R ea.ct ion time/min.
1) All compounds wer e cr ystallized from ethanol. 2) All the IR spectra were det ermined in CHCIs solution .
c d e f
b
R
1.&
~
Compound1)
IT
O -oCH = C- CDDCH2 0CH2 oN /
eN3
1,724 1,724 1,718 1,727 1,730 1,730
IR2) cm-1
C
Calcd.
Analysis
62.47 Cl, H21CI~02 C1,H n BrCl N02 55.61 69.57 C25H24CINOs C1,H 21 CIN20 4 60.64 60.64 Cl'H21 CIN2 0 4 C1,H21 ClN2 0 4 60.64
Formula
T a ble 1. Ana lytical data of the tested substituted dimethylaminoethyl-lX-phen y lcinnamate h y drochloride
5. 75 5.1 2 6.95 5.58 5.58 5.58
H
%
3.83 3.41 4.05 7.44 7.44 7.44
N
62.44 55.53 69.56 60.62 60.63 60.62
C
Found
5 .74 5 .10 6.93 5.55 5.56 5.55
H
3.82 3.42 4 .08 7.43 70 23 7.41
N
>-<
~ F ?'
~
~
Il:l
!""'
t-:)
~
~
Bactericidal Effect of Acrylic Acid Esters
663
A solution of iX- phenyl-p-chlorocinnamic acid (4.9 g; 0.02 mole) in dry benzene (50 ml) was treated with 4 ml of thionyl chloride together with two drops of dry pyridine. The mixture was heated under reflux for one hour. The solvent, together with the excess of thionyl chloride, was evaporated under reduced pressure. The remaining residue was dissolved in dry benzene (80 ml) and a solution of 2-dimethylamino ethanol (7 g; 0.02 mole) in 10 ml of dry benzene was added dropwise. The reaction mixture was heated under reflux for 2 hours, allowed to cool, and the precipitated dimethylaminoethyl-iX-phenyl-p-chlorocinnamate hydrochloride (3a) was collected by filtration, washed with dry benzene, and crystallized from ethanol to give colourless crystals (5.3 g; 80 % yield; m.p. 70°). The same procedure was adopted for the synthesis of the substituted dimethylaminoethyl-iX-phenylcinnamate hydrochloride (3 b -f). The structure of these compounds (3a-f) was established by their correct microanalytical data, as well as in consideration of their LR. spectral data (cf. Table 1). Table 1 comprises the tested dimethylaminoethyl-iX-phenylcinnamate hydrochloride (3a-f), together with its physical and chemical data.
Biological assay The dimethylaminoethyl-iX-phenylcinnamate hydrochlorides (3a-e) were tested for their germicidal effect, using two different bacteria, one was E8cherichia coli that is Gram-negative and the other was Bacillu8 8ubtili8 that is Gram-positive. These two organisms were suspended in agar culture media, containing 1 g yeast extract, 10 g mannitol, 0.1 g sodium chloride, 0.5 g magnesium sulphate (MgS0 4 • 5H2 0), K 2HP0 4 , and 12 g agar. The organism-agar suspensions were distributed in Petri dishes, small glass rings of 0.8 mm diameter were placed on the surface of the agar, and the media were allowed to solidify before the solutions of the compounds tested were added into the glass rings. The solution of each compound added contained 2 mg in 0.2 ml of water. The dishes were incubated at 37 °0 and the inhibition zones were estimated. Results Table 2 shows the tested compounds and their effect on E. coli, B.8ubtili8, and S. lutea. Table 2. Relation of germicidal activity and substituent Organism
E. coli B. BubtiliB S.lutea
Inhibition zone in cm2 due to the substitution of p-Br
p-CI
p-CHa
p-N0 2
o-N0 2
m-N0 2
5.0 8.2 3.5
3.5 6.5 5.5
2.0 5.5 3.5
1.6 8.1 5.0
0.8 0.85 3.9
0.6 4.5 3.0
The germicidal activity was generally higher in the case of the Gram-positive B. 8ubtili8 than in that of Gram-negative E. coli. This effect was specially noticed in the case of the p-N0 2 substitution. It was as highly effective as p-Br substitution.
Discussion It was clear that the p-N0 2 substituent had the highest effect, whereas the o-N0 2 had the lowest one and the m-N0 2 derivative was between. This may be considered as a result of the degree of difficulty for building a hydrogen bond between the N0 2
664
I.
I B RAHHI ll.
a .• Baet
group in the para position and t he hydrogen atom, attached t o the carbon atom that is closely attached to the benzene ring. This may be easily formed with the meta substituent and even more easily with the ortho one. This fact will permit a smaller amount of respiration H + to react with the N0 2 group, and that may explain the drop of activity in the meta and ortho positions. The activity drop of the p -N0 2 substituted compound in E. coli may be due to its micro-aerophilic nature, that means, the organism has a higher ability for utilizing highly oxidized groups in the molecule, such as p-N0 2 , as an oxygen acceptor, and it seems that is not the case with B. subtilis which is obligatory aerobic and has no such anaerobic systems (5). Sarcina lutea may occupy a position between B . subtilis and E. coli . The effect of p-Br and nitro- substitutions on Sarcina lutea in the investigated compounds needs more detailed study. References 1. 2. 3. 4. 5.
PATTY, F. A.: Industrial Hygiene and Toxicology. 1962, Vol. II, 1994. KELLNER, W., and KOBER, W.: Arzneimittelforschung 5 (1955), 224. COHEN, R.: Arizona Med. 12 (1955),106. ROBERT, E. B. , and COOPER, J. A.: J. Org. Chern. 30 (1965),1588. Cox, C. S., and BALDWIN, J .: J. gen. Microbiol. 49 (1967), 11 5.
Authors' address : Prof. Dr. Y. HAMDI, D ept. of Microbiology, Inst. of Soil Science, Ministry of Agriculture, Cairo (A.R.E.).