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Studies on uronic acid materials
320
EIsener Pubhhmg
STUDIES
ON
PART XXIX* D
M
W
URONIC
ANDERSON,~
Department
ACID
SOME STRUCTURAL C
of Chemrstn,
M
Research
Company, Amsterdam Prmted m Belgmm
MATERIALS
FExTuREs
DEA,AND
Carbohydraie
R N
OF
Acacra [aera GUM
SMITH
The Umrersrt~, Edmbwgh
9 (Great Bntam)
(Recewed January Ist, 1968)
ABSTRACT
The gum polysaccharlde exuded by Acma beta trees contams D-galactose, r_-arabmose, L-rharnnose, D-gh.ICUrOnlC acid, and 40-methyl-D-glucuromc acid L&cage analysis has ylelded 3-0-P-L-arabmopyranosyl-L-arabmose, ~-O-/&Larabmofuranosyl-L-arabmose, 3-O-a-D-galactopyranosyl-L-arabmose, 3-0-/3-Dgalactopyranosyl-D-galactose, and 6-0-fi-D-galactopyranosyl-D-galactose The O-methyl derivatives of A Iaeta gum and autohydrolysed A Iaeta gum were analysed, after methanolysls, by g 1 c The autohydrolysed gum was subjected to a Smith degradation, and the product exammed by linkage and methylatlon analysts A laeta gum was subjected to eight successive Smith-degradations, the O-methyl denvatlves of each of the polysaccharldes obtamed from the first SIXdegradations and from the eighth degradation were analysed, after methanolysls, by g 1 c The structural evidence obtained does not @ve unequivocal proof that the gum contains a “mam cham” of p-( l-+3)-lmked D-galactose residues INTRODUCTION A laeta R Br ex Benth IS a natural hybrid of A Senegal (L ) Wllld and A melLfera (Vahl ) Benth , and it occurs m two varletles A Iaera var hasha& (which
resembles A Senegal) and A laeta var melhfera (which resembles A melhfera) The results of a detaded exammatlon of A beta var. hashab gum are reported m this Paper, and the structural features of this gum are compared with those of A Senegal gum (gum arable) The charactensatlon of two aldoblouromc acids, 6-O-(/3-~glucopyranosyluromc acid)-D-galactose and 6-O-(4-0-methyl-/3-D-giucopyranosyluromc acid)-D-galactose, from A laetn var hashab gum has been reported2, together with the results of an analytical study of the extensive inter-nodule vanatlon shown by this species, from wluch average values for the analytlcal parameters expressmg the composltlon of the gum were calculated RESULTS AND DISCUSSION
The gum nodules from A Zaeta var hashab were collected, by the Gum Research Officer to the Repubhc of Sudan, from botamcally authenticated trees at the El *For Part XXVIII,
Curbohtd
see Ref
1
Pes , 7 (1968) 320-333
D M W. ANDERSON, I C M DEA, R N SMITH
332
borohydnde, hydrolysed, and the correspondmg degraded-polysaccharrdes were recovered as for the first Snuth-degradatron Polysacchande 1 (16 5 g) gave polysacchande2(875g),2(835g)-,3(5Og),3(46g)-,4(3Og),4(26g)-,5(19g); 5 (1 55 g) --, 6 (1.2 g); 6 (0 86 g) --, 7 (0 68 g), 7 (0 63 g) --, 8 (0 49 g) The relevant data are given m Table I TABLE @hfETHYL
V SUGARS
PRESENT
IN
hfEl%YLATED,
ShIITH-DEGRADED
1
2
3
POLYSACCHARIDES
4
5
6
8
l-6
AND
Approxmate rerarrLe maIar PTOpOrtlOJJS
2,3,5-Tn-0-methyl+arabmose 2.5DI-0-methyl-L-arabmose 2,3,4,6-Tetra-0-methyl-D-galactose 2,4,6-Tn-0-methyl-D-galactose 2,3,4-Tn-0-methyl-D-galactose 2,6-DI-0-methyl-D-galactose 2,4-DI-O-methyl-D-galactose 2 3,4-Tn-0-methyl-D-glucuromc acid
+ + + + + + +++++++
+
+ + ++++++
+
+
++-I-++++ +++++++
+
+
+ +
8
111
5
6
8
1 14
1 16
1 18
Trace Trace Trace 3 1 Trace I 1 I
+
Partral, acrd hydrolysis of polysaccharrde 2 (20 mg), followed by paper-chromatographic exammatron of the hydroIysate, Indicated the presence of equal amounts of 3-O-B-D-gahrctopyranosyl-D-galactose and 6-O-B-D-gaIactopyranosyI-D-gaiactose, and equal amounts of the /I-(1-,3)-hnked [Rcnl 0 22 m solvent (a) and 0 23 m solvent (c)] and the #%(1+6)-lmked D-gaiactose tnsacchande [RCnl 0 15 m solvent (a> and 0 18 m solvent (c)] Partial, acrd hydrolyses of polysaccharrdes 3 and 4 gave the same ohgosaccharrdes as obtamed from poIysacchande 2 However, the proportrons of the /&(I +6)-hnked dr- and tn-saccharrdes decreased steaddy from polysacchandes 2 to 4 Partial, acrd hydrolyses of polysacchandes 5 to 8 mdrcated the presence of the /&(I +3)-hnked dr- and tn-saccharides, and the B-(1 +6)-lmked drsacchande The proportion of the latter dlsaccharrde contmued to fall from polysaccharrdes 5 to 8, only a trace was obtained from polysacchande 8 Polysacchandes l-6 and 8 were methylated (Table VI) Methanolysrs of a sample of the products, followed by g 1 c exammatron of the mrxture of methyl gIycosrdes, gage the results shown m Table V Preparation, and partial acid hydrolysis of polysaccharrde 5’ - A Iaera gum (30 g) was subjected to five successrve Smrth-degradatrons, wrthout rsolatron of the mtermedrare polysacchandes, to obtam polysaccharrde 5’ (2 2 g) The polysaccharrde was hydrolyzed wrth 0 5N sulphunc acrd (500ml) for 1 h on a borhng-water bath The hyarolysate was chromatographed on Whatman 3MM papers m solvent (a), and a pure trrsaccharrde was Isolated The trrsacchande (44 mg), [x]D -t-51” (c 0 88), yielded gaIactose and 3-0-p-Dgalactopyranosyl-D-galactose, as the only drsacchande, on par-Da1hydrolyses wrth Carboh_vd
Res , 7 (1968) 320-333
URONIC TABLE
333
ACID hfAlJ.?RIAL.S VI
hfEI'%IYLA'l-IONOFShfITH-DEGRADED POLYSACCHARIDES Po[vsaccharrde
Amount of polysacchande Amount of product (mg) [a]D of product (degrees) OMe (%)
used (mg)
1
2
3
4
5
6
8
200 125 -43 39.5
193 120 -33 413
165 80 -11 39 1
158 85 -1 372
184 76 -1 371
180 65 fl 368
250 81 +1 365
aced The tnsacchande (crystalhsed from aqueous ethanol) had m p and mlxed m p 237-242” (decomp ), and R Gnlvalues of 0 22 m solvent (a) and 0 23 m solvent (c) ACKNOWLEDGmS
It 1s a pIeasure to have this opportumty of thankmg Professor Sir Edmund Hurst C B E , F R S , for his advice and interest m this Senes smce its mceptlon We thank the Science Research Councli for a mamtamance allowance (to I C M D.), and acknowledge financial support from Laing-NatIonal Ltd. (Manchester) and Rowntree Ltd. TYork). REFERENCES
1 Part XXVIII D M W ANDERSON AND I C M DEA, Carbohvd Res, 7 (1968) 109 2 D M W ANDERSON AND R N SM*~~TH, Carbobyd Res ,4 (1967) 55 3 M A JER~~YN,AustraZ J BraZ Chem , I5 (1962) 789 4 D M W ANDERSON,SIREDMUND HIRST,AND J F STODDAFCT, J Cbem Sot (C),(1966)1959 5 D M W ANDERSON AND J F STODDART, Carbobvd Res 2 (1966) 104 6 F SMITH, J C’bem Sot, (1939) 744, 1724. (1940) 1035, 3 JACRSOX AND F SMITH, tbrd, (1940) 74,79 7 D M W ANDERSON,SIRED~~IJND HIRSTAND J F STODDART, J Cbem Sot (C),(1967) 1476 8 D M W ANDERSON AND G M CREE, CarbohJd Res , 6 (1968) 385 9 D M W ANDERSONAND I C M DEA unpubhshed results 10 D M W ANDERSON,~ C M DEA,S RAHMAN,AND J F STODDART,C~~I Commrm,(1965) 145 11 D M W ANDERSON AND J F STODDART, Anal Cbml Acta, 34 (1966) 401, Lab Pratt , 16 (1967) 841 12 I J GOLDSTEIN, G W HAY, B A LEWIS. AND F SMITH, Methods Carbohyd Chem, 5 (1965) 361 13 P ANDREWS AND J K N JONES,J Cbem Sot, (1955) 583 14 J K N JONES, .I Chem Sot, (1953) 1672 15 H KLOSTERMAN AND F SMITH, J Amer Chem Sot, 74 (1952) 5336 16 H B OAKLEY, Tram Faraday Sot, 31 (1935) 136, 32 (1936) 1360, 33 (1937) 372 17 A B S CONACHER AND D I REES,Analysf, 91 (1966) 55 18 W N HAWORTH, .J Chem Sot. 107 (1915) 8 19 R KUHN, H TRISCWMANN, AND I Low, Angers C/rel?r, 67 (1955) 32 20 T P~DIE AND J C IRVINE,J Chem Sot, 83 (1903) 1021 Carbohyd
Res , 7 (1968) 320-333
EIsener Pubhhmg
STUDIES
ON
PART XXIX* D
M
W
URONIC
ANDERSON,~
Department
ACID
SOME STRUCTURAL C
of Chemrstn,
M
Research
Company, Amsterdam Prmted m Belgmm
MATERIALS
FExTuREs
DEA,AND
Carbohydraie
R N
OF
Acacra [aera GUM
SMITH
The Umrersrt~, Edmbwgh
9 (Great Bntam)
(Recewed January Ist, 1968)
ABSTRACT
The gum polysaccharlde exuded by Acma beta trees contams D-galactose, r_-arabmose, L-rharnnose, D-gh.ICUrOnlC acid, and 40-methyl-D-glucuromc acid L&cage analysis has ylelded 3-0-P-L-arabmopyranosyl-L-arabmose, ~-O-/&Larabmofuranosyl-L-arabmose, 3-O-a-D-galactopyranosyl-L-arabmose, 3-0-/3-Dgalactopyranosyl-D-galactose, and 6-0-fi-D-galactopyranosyl-D-galactose The O-methyl derivatives of A Iaeta gum and autohydrolysed A Iaeta gum were analysed, after methanolysls, by g 1 c The autohydrolysed gum was subjected to a Smith degradation, and the product exammed by linkage and methylatlon analysts A laeta gum was subjected to eight successive Smith-degradations, the O-methyl denvatlves of each of the polysaccharldes obtamed from the first SIXdegradations and from the eighth degradation were analysed, after methanolysls, by g 1 c The structural evidence obtained does not @ve unequivocal proof that the gum contains a “mam cham” of p-( l-+3)-lmked D-galactose residues INTRODUCTION A laeta R Br ex Benth IS a natural hybrid of A Senegal (L ) Wllld and A melLfera (Vahl ) Benth , and it occurs m two varletles A Iaera var hasha& (which
resembles A Senegal) and A laeta var melhfera (which resembles A melhfera) The results of a detaded exammatlon of A beta var. hashab gum are reported m this Paper, and the structural features of this gum are compared with those of A Senegal gum (gum arable) The charactensatlon of two aldoblouromc acids, 6-O-(/3-~glucopyranosyluromc acid)-D-galactose and 6-O-(4-0-methyl-/3-D-giucopyranosyluromc acid)-D-galactose, from A laetn var hashab gum has been reported2, together with the results of an analytical study of the extensive inter-nodule vanatlon shown by this species, from wluch average values for the analytlcal parameters expressmg the composltlon of the gum were calculated RESULTS AND DISCUSSION
The gum nodules from A Zaeta var hashab were collected, by the Gum Research Officer to the Repubhc of Sudan, from botamcally authenticated trees at the El *For Part XXVIII,
Curbohtd
see Ref
1
Pes , 7 (1968) 320-333
D M W. ANDERSON, I C M DEA, R N SMITH
332
borohydnde, hydrolysed, and the correspondmg degraded-polysaccharrdes were recovered as for the first Snuth-degradatron Polysacchande 1 (16 5 g) gave polysacchande2(875g),2(835g)-,3(5Og),3(46g)-,4(3Og),4(26g)-,5(19g); 5 (1 55 g) --, 6 (1.2 g); 6 (0 86 g) --, 7 (0 68 g), 7 (0 63 g) --, 8 (0 49 g) The relevant data are given m Table I TABLE @hfETHYL
V SUGARS
PRESENT
IN
hfEl%YLATED,
ShIITH-DEGRADED
1
2
3
POLYSACCHARIDES
4
5
6
8
l-6
AND
Approxmate rerarrLe maIar PTOpOrtlOJJS
2,3,5-Tn-0-methyl+arabmose 2.5DI-0-methyl-L-arabmose 2,3,4,6-Tetra-0-methyl-D-galactose 2,4,6-Tn-0-methyl-D-galactose 2,3,4-Tn-0-methyl-D-galactose 2,6-DI-0-methyl-D-galactose 2,4-DI-O-methyl-D-galactose 2 3,4-Tn-0-methyl-D-glucuromc acid
+ + + + + + +++++++
+
+ + ++++++
+
+
++-I-++++ +++++++
+
+
+ +
8
111
5
6
8
1 14
1 16
1 18
Trace Trace Trace 3 1 Trace I 1 I
+
Partral, acrd hydrolysis of polysaccharrde 2 (20 mg), followed by paper-chromatographic exammatron of the hydroIysate, Indicated the presence of equal amounts of 3-O-B-D-gahrctopyranosyl-D-galactose and 6-O-B-D-gaIactopyranosyI-D-gaiactose, and equal amounts of the /I-(1-,3)-hnked [Rcnl 0 22 m solvent (a) and 0 23 m solvent (c)] and the #%(1+6)-lmked D-gaiactose tnsacchande [RCnl 0 15 m solvent (a> and 0 18 m solvent (c)] Partial, acrd hydrolyses of polysaccharrdes 3 and 4 gave the same ohgosaccharrdes as obtamed from poIysacchande 2 However, the proportrons of the /&(I +6)-hnked dr- and tn-saccharrdes decreased steaddy from polysacchandes 2 to 4 Partial, acrd hydrolyses of polysacchandes 5 to 8 mdrcated the presence of the /&(I +3)-hnked dr- and tn-saccharides, and the B-(1 +6)-lmked drsacchande The proportion of the latter dlsaccharrde contmued to fall from polysaccharrdes 5 to 8, only a trace was obtained from polysacchande 8 Polysacchandes l-6 and 8 were methylated (Table VI) Methanolysrs of a sample of the products, followed by g 1 c exammatron of the mrxture of methyl gIycosrdes, gage the results shown m Table V Preparation, and partial acid hydrolysis of polysaccharrde 5’ - A Iaera gum (30 g) was subjected to five successrve Smrth-degradatrons, wrthout rsolatron of the mtermedrare polysacchandes, to obtam polysaccharrde 5’ (2 2 g) The polysaccharrde was hydrolyzed wrth 0 5N sulphunc acrd (500ml) for 1 h on a borhng-water bath The hyarolysate was chromatographed on Whatman 3MM papers m solvent (a), and a pure trrsaccharrde was Isolated The trrsacchande (44 mg), [x]D -t-51” (c 0 88), yielded gaIactose and 3-0-p-Dgalactopyranosyl-D-galactose, as the only drsacchande, on par-Da1hydrolyses wrth Carboh_vd
Res , 7 (1968) 320-333
URONIC TABLE
333
ACID hfAlJ.?RIAL.S VI
hfEI'%IYLA'l-IONOFShfITH-DEGRADED POLYSACCHARIDES Po[vsaccharrde
Amount of polysacchande Amount of product (mg) [a]D of product (degrees) OMe (%)
used (mg)
1
2
3
4
5
6
8
200 125 -43 39.5
193 120 -33 413
165 80 -11 39 1
158 85 -1 372
184 76 -1 371
180 65 fl 368
250 81 +1 365
aced The tnsacchande (crystalhsed from aqueous ethanol) had m p and mlxed m p 237-242” (decomp ), and R Gnlvalues of 0 22 m solvent (a) and 0 23 m solvent (c) ACKNOWLEDGmS
It 1s a pIeasure to have this opportumty of thankmg Professor Sir Edmund Hurst C B E , F R S , for his advice and interest m this Senes smce its mceptlon We thank the Science Research Councli for a mamtamance allowance (to I C M D.), and acknowledge financial support from Laing-NatIonal Ltd. (Manchester) and Rowntree Ltd. TYork). REFERENCES
1 Part XXVIII D M W ANDERSON AND I C M DEA, Carbohvd Res, 7 (1968) 109 2 D M W ANDERSON AND R N SM*~~TH, Carbobyd Res ,4 (1967) 55 3 M A JER~~YN,AustraZ J BraZ Chem , I5 (1962) 789 4 D M W ANDERSON,SIREDMUND HIRST,AND J F STODDAFCT, J Cbem Sot (C),(1966)1959 5 D M W ANDERSON AND J F STODDART, Carbobvd Res 2 (1966) 104 6 F SMITH, J C’bem Sot, (1939) 744, 1724. (1940) 1035, 3 JACRSOX AND F SMITH, tbrd, (1940) 74,79 7 D M W ANDERSON,SIRED~~IJND HIRSTAND J F STODDART, J Cbem Sot (C),(1967) 1476 8 D M W ANDERSON AND G M CREE, CarbohJd Res , 6 (1968) 385 9 D M W ANDERSONAND I C M DEA unpubhshed results 10 D M W ANDERSON,~ C M DEA,S RAHMAN,AND J F STODDART,C~~I Commrm,(1965) 145 11 D M W ANDERSON AND J F STODDART, Anal Cbml Acta, 34 (1966) 401, Lab Pratt , 16 (1967) 841 12 I J GOLDSTEIN, G W HAY, B A LEWIS. AND F SMITH, Methods Carbohyd Chem, 5 (1965) 361 13 P ANDREWS AND J K N JONES,J Cbem Sot, (1955) 583 14 J K N JONES, .I Chem Sot, (1953) 1672 15 H KLOSTERMAN AND F SMITH, J Amer Chem Sot, 74 (1952) 5336 16 H B OAKLEY, Tram Faraday Sot, 31 (1935) 136, 32 (1936) 1360, 33 (1937) 372 17 A B S CONACHER AND D I REES,Analysf, 91 (1966) 55 18 W N HAWORTH, .J Chem Sot. 107 (1915) 8 19 R KUHN, H TRISCWMANN, AND I Low, Angers C/rel?r, 67 (1955) 32 20 T P~DIE AND J C IRVINE,J Chem Sot, 83 (1903) 1021 Carbohyd
Res , 7 (1968) 320-333