Two flavonol glycosides from seeds of Camellia sinensis.

Two novel flavonol triglycosides, camelliaside A and B, have been isolated from seeds of Camellia sinensis. The structures were determined to be kaempferol 3-O-[2-O-beta-D- galactopyranosyl-6-O-alpha-L-rhamnopyranosyl]-beta-D-glucopyranoside and kaempferol 3-O-[2-O-beta- D-xylopyranosyl-6-O-alpha-L-rhamnopyranosyl]-beta-D-glucopyranoside on the basis of spectroscopic, chemical and enzymatic studies. These types of interglycosidic linkages, Gal(1----2)[Rha(1----6)]Glc and Xyl(1----2)[Rha(1----6)]Glc, have not been reported previously in flavone and flavonol glycosides.     

Total synthesis of globotriaosyl-E and Z-ceramides and isoglobotriaosyl-E-ceramide

Stereoselective, total synthesis of O-alpha-D-galactopyranosyl-(1----4) -O-beta-D-galactopyranosyl-(1----4)-O-beta-D-glucopyranosyl-(1----1)-N -tetracosanoyl-[2S,3R,4E (and 4Z)]-sphingenine and O-alpha-D -galactopyranosyl-(1----3)-O-beta-D-galactopyranosyl-(1----4)-O-beta-D -glucopyranosyl-(1----1)-N-tetracosanoyl-(2S,3R,4E)-sphin gen ine was achieved by using O-(2,3,4,6-tetra-O-acetyl-alpha-D-galactopyranosyl) -(1----4)-O-(2,3,6-tri-O-acetyl-beta-D-galactopyranosyl)-(1----4)-2,3,6- tri-O-acetyl-alpha-D-glucopyranosyl trichloroacetimidate, O-(2,3,4,6-tetra-O-acetyl-alpha-D-galactopyranosyl) -(1----4)-O-(2,3,6-tri-O-acetyl-beta-D-galactopyranosyl)-(1----4)-2,3,6- tri-O-acetyl-alpha (and beta)-D-glucopyranosyl fluoride, and O-(2,3,4,6-tetra-O-acetyl-alpha-D -galactopyranosyl)-(1----3)-O-(2,3,6-tri-O-acetyl-beta-D-galactopyran osyl)-(1----4)-2,3,6-tri-O-acetyl-alpha-D-glucopyranosyl trichloroacetimidate.     

A regio- and stereo-controlled synthesis of beta-D-Glcp NAc6SO3-(1----3)-beta-D-Galp6SO3-(1----4)-beta-D-GlcpNAc 6SO3- (1----3)-D-Galp, a linear acidic glycan fragment of keratan sulfate I

A stereocontrolled synthesis of beta-D-GlcpNAc6SO3-(1----3)-beta-D-Galp6SO3-(1----4)-beta-D- GlcpNAc6SO3- (1----3)-D-Galp, was achieved by use of benzyl O-(2-acetamido-3,4 di-O-benzyl-2-deoxy-6-O-p-methoxyphenyl-beta-D- glucopyranosyl)-(1----3)-O-(2,4-di-O-tert-butyldiphenylsilyl-beta- D- galactopyranosyl-(1----4)-O-(2-acetamido-3-O-benzyl-2-deoxy-6-O-p-methox yphenyl - beta-D-glucopyranosyl)-(1----3)-2,4,6-tri-O-benzyl-beta-D-galactopyranos ide as a key intermediate, which was in turn prepared by employing two glycosyl donors, 3,4-di-O-benzyl-2-deoxy-6-O-p-methoxyphenyl-2-phthalimido-beta-D- glucopyranosyl trichloroacetimidate and O-(3,6-di-O-acetyl-2,4-di-O-benzyl-beta-D-galactopyranosyl)-(1----4)-3-O - benzyl-2-deoxy-6-O-p-methoxyphenyl-2-phthalimido-beta-D-glucopyranosyl trichloroacetimidate, and a glycosyl acceptor, benzyl 2,4,6-tri-O-benzyl-beta-D-galactopyranoside.     

Synthesis of oligosaccharide determinants with amide spacers of T-type antigens

The hapten of the T-antigen was synthesized with a peptide-like amide-spacer as 2-(4-methoxycarbonylbutanecarboxamido)ethyl 2-acetamido-2-deoxy-3-O-beta-D-galactopyranosyl-alpha-D-galactopyranoside and coupled with serum albumin to give a synthetic antigen. Other O-beta-D-galactopyranosyl haptens, 2-(4-methoxycarbonylbutanecarboxamido)ethyl 2-acetamido-2-deoxy-4-O-beta-D-galactopyranosyl-alpha-D-galactopyranoside, O-beta-D-galactopyranosyl-(1 leads to 3)-O-[beta-D-galactopyranosyl-(1 leads to 4)]-2-acetamido-2-deoxy-alpha-D-galactopyranoside, and 2-acetamido-2-deoxy-3-O-beta-D-galactopyranosyl-alpha-D-glucopyranoside, the last compound being the determinant of the Lewis Lec antigen, were also synthesized.     

Isolation and structural characterization of alkali-labile oligosaccharides from bovine milk-fat-globule membrane.

Treatment of sialoglycopeptides derived from bovine milk-fat-globule membrane with alkaline borohydride released a reduced oligosaccharide fraction from which a tetrasaccharide and two trisaccharides were isolated. Periodate-oxidation studies coupled with methylation analysis and g.l.c.-mass spectrometry established their structures as: N-acetylneuraminyl-(2 leads to 3)-beta-D-galactopyranosyl-(1 leads to 3)-[N-acetylneuraminyl-(2 leads to 6)]-N-acetyl-D-galactosaminitol, N-acetylneuraminyl-(2 leads to 3)-D-glactopyranosyl-(1 leads to 3)-N-acetyl-D-galactosaminitol and beta-D-galactopyranosyl-(1 leads to 3)-[N-acteylneuraminyl-(2 leads to 6)]-N-acetyl-D-galactosaminitol respectively.     

Synthesis of a branched pentasaccharide sequence of "bisected" structure of N-glycoproteins

For the synthesis of the threefold-branched pentasaccharide, O-alpha-D-mannopyranosyl-(1----3)-O-[(2-acetamido-2-deoxy-beta-D- glucopyranosyl)-(1----4)]-O-[alpha-D-mannopyranosyl-(1----6)]-O-beta-D- mannopyranosyl-(1----4)-2-acetamido-2-deoxy-D-glucopyranose (20), which is a part of the structure of the N-glycoproteins, the disaccharide 4-O-(4-O-acetyl-3,6-di-O-allyl-2-O-benzyl-beta-D-mannopyranosyl) -1,6-anhydro-2-azido-3-O-benzyl-2-deoxy-beta-D-glucopyranose was synthesized as a key compound by use of the silver silicate-catalyst procedure. After elimination of the 4-O-acetyl group, a 2-acetamido-2-deoxy-beta-D-glucopyranosyl group was attached according to the phthalimido method. Further elimination of the allyl groups allowed the linkage of two alpha-D-mannopyranosyl groups in the presence of mercury salt. A deblocking sequence consisting of four steps gave 20.     

Conformation analysis of modified tetrasaccharide sequences of the N-glycoprotein type--problem of the alpha-(1 to 6)-glycosidic bond

The conformational analysis of the recently synthesized tetrasaccharides alpha-D-Manp (1----3)-[alpha-D-Manp-(1----6)]-4-deoxy-beta-D-lyx-hexp+ ++-(1----4)-D-GlcNAc (2) and alpha-D-Manp-(1----3)-[alpha-D-Manp-(1----6)]-beta-D-Talp -(1----4)-D-GlcNAc (3) will be described. The preferred solution conformation of 2 and 3 is a gt-conformation, which is nearly identical with the preferred conformation of the naturally occurring tetrasaccharide alpha-D-Manp-(1----3)-[alpha-D-Manp-(1----6)]-beta-D-Manp -(1----4)-D-GlcNAc (1). The main structural feature is the backfolding of the alpha-(1----6)-linked D-Man to the reducing D-GlcNAc unit. Conformational analysis of the tetrasaccharides alpha-D-Manp-(1----3)-[alpha-D-Manp-(1----6)]-beta-D-Manp -(1----4)-1,6- anhydro-beta-D-GlcNAc (4), alpha-D-Manp-(1----3)-alpha-D-Manp-(1----6)]-4-deoxy-beta-D- lyx-hexp-(1----4)- 1,6-anhydro-beta-D-GlcNAc (5), and alpha-D-Manp-(1----3)-[alpha-D-Manp-(1----6)]-beta-D-Talp -(1----4)- 1,6-anhydro-beta-D-GlcNAc (6) gave additional proof for this backfolding. The substitution of the reducing unit leads to a smaller amount of gt- and a greater amount of gg-conformers. The method used for conformational analysis of 2-6 is a combination of n.m.r.-experiments and HSEA-calculations with the program GESA. Concerning the application of new 2D-techniques, the COLOC-experiment turned out to be extremely useful in sequencing oligosaccharides.     

Stereoselectivity of glycosylation with derivatives of 2-azido-2-deoxy-d-galactopyranose. The synthesis of a determinant oligosaccharide related to blood-group a (type 1)

The stereoselective glycosylation of a model alcohol (cyclohexanol) by derivatives of 2-azido-2-deoxy-d-galactopyranose was studied under various conditions. 2-Azido-3,4,6-tri-O-benzyl-2-deoxy-β-d-galactopyranosyl chloride (9) was found to be the most efficient glycosylating agent for the synthesis of oligosaccharides containing 2-acetamido-2-deoxy-α-d-galactopyranose residues, and gave a tetrasaccharide, which is a determinant of the blood-group A (Type 1), i.e., O-α-l-fucopyranosyl-(1→2)-[O-2-acetamido-2-deoxy-α-d- galactopyranosyl-(1→3)]-O-β-d-galactopyranosyl-(1→3)-2-acetamido-2-deoxy-d-glucose, and its trisaccharide fragment, O-2-acetamido-2-deoxy-α-d-galactopyranosyl-(1→3)-O-β-d-galactopyranosyl-(1→3)-2-acetamido-2-deoxy-d-glucose. In the course of this synthesis, the determinant trisaccharide related to the H blood-group, i.e., O-α-l-fucopyranosyl-(1→2)-O-β-d-galactopyranosyl-(1→3)-2-acetamido-2- deoxy-d-glucose, was also obtained.     

Synthesis of aminoethylglycosides with oligosaccharide GM1 and asialo-GM1 ganglioside chains

4'-O-Glycosylation of 2-azidoethyl 2,3,6-tri-O-benzyl-4-O-(2,3-di-O- benzyl-6-O-benzoyl-beta-D-galactopyranosyl)-beta-D-glucopyranoside with a disaccharide donor, 4-trichloroacetamidophenyl 4,6-di-O-acetyl-2-deoxy-3-O-(2,3,4,6-tetra-O-acetyl-beta-D- galactopyranosyl)-1-thio-2-trichloroacetamido-beta-D-galactopyranoside, in dichloromethane in the presence of N-iodosuccinimide and trifluoromethanesulfonic acid resulted in a tetrasaccharide, 2-azidoethyl (2,3,4,6-tetra-O-acetyl-beta-D-galactopyranosyl)-(1-->3)- (4,6-di-O-acetyl-2-deoxy-2-trichloroacetamido-beta-D-galactopyranosyl)- (1-->4)-(2,3-di-O-benzyl-6-O-benzoyl-beta-D-galactopyranosyl)- (1-->4)-2,3,6-tri-O-benzyl-beta-D-glucopyranoside, in 69% yield. The complete removal of O-protecting groups in the tetrasaccharide, the replacement of N-trichloroacetyl by N-acetyl group, and the reduction of the aglycone azide group to amine led to the target aminoethyl glycoside of beta-D-Gal- (1-->3)-beta-D-GalNAc-(1-->4)-beta-D-Gal-(1-->4)-beta-D-Glc-OCH2CH2NH2 containing the oligosaccharide chain of asialo-GM1 ganglioside in 72% overall yield. Selective 3'-O-glycosylation of 2-azidoethyl 2,3,6-tri-O- benzyl-4-O-(2,6-di-O-benzyl-beta-D-galactopyranosyl)-beta-D-glucopyranoside with thioglycoside methyl (ethyl 5-acetamido-4,7,8,9-tetra-O- acetyl-3,5-dideoxy-2-thio-D-glycero-alpha-D-galacto-2-nonulopyranosyl)oate in acetonitrile in the presence of N-iodosuccinimide and trifluoroacetic acid afforded 2-azidoethyl [methyl (5-acetamido-4,7,8,9-tetra-O-acetyl- 3,5-dideoxy-D-glycero-alpha-D-galacto-2-nonulopyranosyl)oate in acetonitrile in the presence of N-iodosuccinimide and tri-fluoracetic acid afforded 2-azidoethyl[methyl (5-acetamido-4,7,8,9-tetra-O-acetyl- 3,5-dideoxy-D-glycero-alpha-D-galacto-2-nonulopyranosyl) (2,6-di-O-benzyl-beta-D-galactopyranosyl)-(1-->4)-2,3,6-tri-O-benzyl-beta-D- glucopyranoside, the selectively protected derivative of the oligosaccharide chain of GM3 ganglioside, in 79% yield. Its 4'-O-glycosylation with a disaccharide glycosyl donor, (4-trichloroacetophenyl-4,6-di-O-acetyl-2-deoxy-3-O-(2,3,4,6-tetra-O- acetyl-beta-D-galactopyranosyl) 1-thio-2-trichloroacetamido-beta-D-galactopyranoside in dichloromethane in the presence of N-iodosuccinimide and trifluoroacetic acid gave 2-azidoethyl (2,3,4,6-tetra-O-acetyl-beta-D-galactopyranosyl)- (1-->3)-(4,6-di-O-acetyl-2-deoxy-2-trichloroacetamido-beta-D- galactopyranosyl)-(1-->4)-[[methyl (5-acetamido-4,7,8,9-tetra-O-acetyl-3,5-dideoxy-D-glycero-alpha-D- galacto-2-nonulopyranosyl)onate]-(2-->3)]-(2,6-di-O-benzyl-beta-D- galactopyranosyl)-(1-->4)-2,3,6-tri-O-benzyl-beta-D-glucopyranoside in 85% yield. The resulting pentasaccharide was O-deprotected, its N-trichloroacetyl group was replaced by N-acetyl group, and the aglycone azide group was reduced to afford in 85% overall yield aminoethyl glycoside of beta-D-Gal-(1-->3)-beta-D-GalNAc-(1-->4)-[alpha-D-Neu5Ac-(2-->3)]- beta-D-Gal-(1-->4)-beta-D-Glc-OCH2CH2NH2 containing the oligosaccharide chain of GM1 ganglioside. The English version of the paper: Russian Journal of Bioorganic Chemistry, 2004, vol. 30, no. 1; see also http://www.maik.ru.     

Synthesis of modified tetrasaccharide sequences of N-glycoproteins

The tetrasaccharides O-alpha-D-mannopyranosyl-(1----3)-O-[alpha-D- mannopyranosyl-(1----6)]-O-(4-deoxy-beta-D-lyxo-hexopyranosyl)-(1- ---4)-2- acetamido-2-deoxy-alpha, beta-D-glycopyranose (22) and O-alpha-D-mannopyranosyl-(1----3)-O-[alpha-D-mannopyranosyl-(1----6)]-O- beta-D-talopyranosyl-(1----4)-2-acetamido-2-deoxy-alpha, beta-D- glucopyranose (37), closely related to the tetrasaccharide core structure of N-glycoproteins, were synthesized. Starting with 1,6-anhydro-2,3-di-O-isopropylidene-beta-D-mannopyranose, the glycosyl donors 3,6-di-O-acetyl-2-O-benzyl-2,4-dideoxy-alpha-D-lyxo- hexopyranosyl bromide (10) and 3,6-di-O-acetyl-2,4-di-O-benzyl-alpha-D-talopyranosyl bromide (30), were obtained in good yield. Coupling of 10 or 30 with 1,6-anhydro-2-azido-3-O-benzyl-beta-D-glucopyranose to give, respectively, the disaccharides 1,6-anhydro-2-azido-3-O-benzyl-2-deoxy-4-O-(3,6-di-O-acetyl-2-O-benzyl-4 -deoxy- beta-D-lyxo-hexopyranosyl)-beta-D-glucopyranose and 1,6-anhydro-2-azido-3-O-benzyl-2-deoxy-4-O-(3,6-di-O-acetyl-2,4-di-O-ben zyl- beta-D-talopyranosyl)-beta-D-glucopyranose was achieved with good selectivity by catalysis with silver silicate. Simultaneous glycosylation of OH-3' and OH-6' of the respective disaccharides with 2-O-acetyl-3,4,6-tri-O-benzyl-alpha-D-mannopyranosyl chloride yielded tetrasaccharide derivatives, which were deblocked into the desired tetrasaccharides 22 and 37.     

黄花远志的新齐墩果烷型三萜皂甙

从云南产远志科药用植物黄花远志(PolygalaarillataBuchHamexDDon)茎皮的乙醇提取物中分离得到4个新的齐墩果烷型三萜皂甙,命名为黄花远志皂甙(arillatanoside)A～D。同时还分离得到1个已知的三萜皂甙远志甙(polygalasaponin)XXXV。它们的结构通过波谱方法推定。     

Synthesis of alpha-D-Manp-(1----3)-[beta-D-GlcpNAc-(1----4)]-[alpha-D-Manp+ ++-(1----6)] - beta-D-Manp-(1----4)-beta-D-GlcpNAc-(1----4)-[alpha-L-Fucp- (1----6)]-D- GlcpNAc, a core glycoheptaose of a "bisected" complex-type glycan of glycoproteins

A synthesis of alpha-D-Manp-(1----3)-[beta-D-GlcpNAc-(1----4)]-[alpha-D-Manp++ +-(1----6)]- beta-D-Manp-(1----4)-beta-D-GlcpNAc-(1----4)-[alpha-L-Fucp-( 1----6)]-D- GlcpNAc was achieved by employing benzyl O-(3,4,6-tri-O-benzyl-2-deoxy-2-phthalimido-beta-D-glucopyranosyl)-(1--- -4)-O- (2-O-benzyl-beta-D-mannopyranosyl)-(1----4)-O-(3,6-di-O-benzyl-2-deoxy-2 - phthalimido-beta-D-glucopyranosyl)-(1----4)-3-O-benzyl-2-deoxy-6-O-p- methoxyphenyl-2-phthalimido-beta-D-glucopyranoside as a key glycosyl acceptor. Highly stereoselective mannosylation was performed by taking advantage of the 2-O-acetyl group in the mannosyl donors. The alpha-L-fucopyranosyl residue was also stereoselectively introduced by copper(II)-mediated activation of methyl 2,3,4-tri-O-benzyl-1-thio-beta-L-fucopyranoside.     

Synthese der pentasaccharid-kette des forssman-antigens

The pentasaccharide chain of the Forssman antigen, O-(2-acetamido-2-deoxy-α-d-galactopyranosyl)-(1→3)-O-(2-acetamido-2-deoxy-β-d-galactopyranosyl)-(1→3)-O-α-d- galactopyranosyl-(1→4)-O-β-d-galactopyranosyl-(1→4)-d-glucopyranose (46) was synthesized by a block synthesis in which an α-d-glycoside linkage between two d-galactose residues was formed. The trisaccharide O-(6-O-acetyl-2-azido-3,4-di-O-benzoyl-2-deoxy-α-d-galactopyranosyl)- (1→3)-O-(6-O-acetyl-4-O-benzyl-2-deoxy-2-phthalimido-β-d-galactopyranosyl)-(1→3)-6-O-acetyl-2,4-di-O-benzyl- α-d-galactopyranosyl bromide (40) (this was obtained through acetolysis of O-(6-O-acetyl-2-azido-3,4-di-O-benzoyl-2-deoxy-α-d-galactopyranosyl)- (1→3)-O-(6-O-acetyl-4-O-benzyl-2-deoxy-2-phthalimido-β-d-galactopyranosyl)-(1→3)-1,6-anhydro-2,4-di-O-benzyl-β-d- galactopyranose to the acetyl derivative, followed by reaction with titanium tetrabromide under anhydrous conditions) was condensed with benzyl-4-O-(6-O-benzoyl-2,3-di-O-benzyl-β-d-galactopyranosyl)-2,3,6- tri-O-benzyl-β-d-glucopyranoside were in the presence of silver carbonate and perchlorate. The resulting pentasaccharide was deprotected to give 46.     

The type-specific substance from Pneumococcus type 10A(34). Structure of the dephosphorylated repeating unit

1. A hexasaccharide unit was isolated from the specific substance S. 10A from Pneumococcus type 10A (34) by hydrolysis with alkali followed by enzymic dephosphorylation. 2. The hexasaccharide was shown to be O-d-galactofuranosyl-(1-->3)-O-d- galactopyranosyl-(1-->4)-O-[d-galactofuranosyl- (1-->6)]-O-2-acet-amido-2-deoxy-d-galactopyranosyl- (1-->3)-O-d-galactopyranosyl-(1-->2)-ribitol.     

Spacer-modified saccharides for the regioselective photoaffinity labelling of the binding site of an immunoglobulin.

The spacer-modified trisaccharides that mimic (1----6)-linked beta-D-galactotetraose (Gal4), namely, O-beta-D-galactopyranosyl-(1----6)-S-beta-D-galactopyranosyl-(1----11)-8 -azi- 6,7,8,9,10-pentadeoxy-11-thio-D-galacto-undecose (12) and O-beta-D-galactopyranosyl-(1----6)-O-beta-D-galactopyranosyl- (1----13)-8-azi-6,7,8,9,10,11,12-heptadeoxy-D-galacto-tri decose (20) were synthesised by coupling disaccharide derivatives with 8-azi-6,7,8,9,10-pentadeoxy-1,2:3,4-di-O-isopropylidene-11-O -tosyl-alpha-D-galacto-undecopyranose (10) and 8-azi-6,7,8,9,10,11,12-heptadeoxy-1,2:3,4-di-O-isopropyli den e-alpha-D-galacto- tridecopyranose (17), respectively. Compounds 12 and 20 had affinities for the combining sites of the antibodies IgA X24 and IgA J 539 similar to those of O-beta-D-galactopyranosyl-(1----6)-O-beta-D- galactopyranosyl-(1----11)-8-azi-6,7,8,9,10-pentadeoxy-D-gal acto-undecose (7) and the native ligand Gal4. Tritium-labelled 7 chemically modified the heavy and light chains of IgA J 539, whereas 8-azi-6,7,8,9,10-pentadeoxy-D-(11-3H)galacto-undecose (5a) reacted only with the heavy chain.     

Steroidal glycosides from Agave cantala.

Two new steroidal glycosides, agaveside A and B, isolated from the fruits of Agave cantala were characterized as 3 beta-O-[beta-D-xylopyranosyl-(1----2),beta-D-xylopyranosyl-(1----3), beta-D-glucopyranosyl-(1----3)-[beta-D-xylopyranosyl-(1----3)-beta-D- galactopyranosyl-(1----2)]-beta-D-glucopyranosyl]-(25R)-5 alpha-spirostane and 3 beta-O-[beta-D-xylopyranosyl-(1----2), beta-D-xylopyranosyl-(1----3)-beta-D-glucopyranosyl-(1----3)- [beta-D-galactopyranosyl-(1----2)]-beta-D-glucopyranosyl]-(25R)-5 alpha-spirostane. The structures were elucidated by a combination of 13CNMR spectroscopy, chemical degradation and fast atom bombardment mass spectrometry.     

Beshornin and beshornoside,steroidal saponins of Beshorneria yuccoides

Two new saponins beshornin and beshornoside have been isolated from the methanolic extract of Beshorneria yuccoides leaves and their structures elucidated. Beshornin is 3-O-[α-l-rhamnopyranosyl-(1 → 4)-β-d-glucopyranosyl- (1 → 2)-[α-l-rhamnopyranosyl-(1 -+ 4)-P-D-glucopyranosyl-(1 → 3)]-β-d-glucopyranosyl-(1 → 4)-β-d- galactopyranosyl-(25R)-5α-spirostan-3β-ol, whereas beshornoside is 3-O-[α-l-rhamnopyranosyl-(1 → 4)- β-d)-glycopyranosyl-(1 → 2)]-[α-l-rhamnopyranosyl-(1 → 4)-β-d-glucopyranosyl-(1 → 3)]-β-d-glucopyranosyl- (1 → 4)-β-d-galactopyranosyl 26-O-[β-d]-glucopyranosyl-(25R)-5α-furostan-3β,22α,26-triol.     

The type-specific substance from Pneumococcus type 33B (Short Communication)

1. The type-specific substance, S. 33B, from Pneumococcus type 33B contains P, 2.89; hexose, 51; total sugar, 69; galactosamine, 18; and d-glucose, 20%. 2. After degradation with alkali, followed by enzymic dephosphorylation, S. 33B yielded a hexasaccharide. 3. The hexasaccharide was assigned the structure O-beta-d-glucopyranosyl- (1-->5)-O-beta-d-galactofuranosyl- (1-->3)-O-2-acetamido-2-deoxy-beta-d- galactopyranosyl-(1-->4)-O-[alpha-d- galactopyranosyl-(1-->2)]-alpha-d-galactopyranosyl- (1-->2)-ribitol. 4. Phosphate residues in S. 33B are located on the hydroxyl groups at position 5 of ribitol units and on the hydroxyl groups at position 6 of hexopyranose residues.     

Endo-beta-galactosidase of Escherichia freundii. Purification and endoglycosidic action on keratan sulfates, oligosaccharides, and blood group active glycoprotein.

Endo-beta-galactosidase was purified 4400-fold from a culture filtrate of Escherichia freundii with 45% recovery. The enzyme preparation was practically free of exoglycosidases, sulfatase, and proteases. This enzyme hydrolyzed several keratan sulfates, endoglycosidically releasing oligosaccharides of various molecular sizes. Among the digestion products of the corneal keratan sulfate, the structure of a disaccharride and a tetrasaccharride were shown to be 2-acetamido-2-deoxy-6-O-sulfo-beta-D-glucosyl-(1 leads to 3)-D-galactose and 2-acetamido-2-deoxy-6-O-sulfo-beta-D-glucosyl-(1 leads to 3)-6-O-sulfo-beta-D-galactosyl-(1 leads to 4)-2-acetamido-2-deoxy-6-O-sulfo-beta-D-glucosyl-(1 leads to 3)-D-galactose, respectively. These oligosaccharide structures indicate that this enzyme specifically hydrolyzes the galactosidic bonds in which nonsulfated galactose residues participate. The enzyme could also hydrolyze a small oligosaccharide such as lacto-N-neotetraitol as follows: Gal(beta 1 leads to 4)GlcNAc(beta 1 leads to 3)Gal(beta 1 leads to 4) sorbitol leads to Gal(beta 1 leads to 4)GlcNAc(beta 1 leads to 3)Gal + sorbitol AB active blood group substance could be hydrolyzed by this enzyme only after Smith degradation. After enzymatic digestion small oligosaccharides and resistant macromolecules were produced. These findings indicate that the enzyme should be useful in studying the precise structures of keratan sulfates, related glycoproteins, and oligosaccharides.     

Structures of minor ether lipids isolated from the aceticlastic methanogen, Methanothrix concilii GP6

Structures were determined for two phospholipids and three glycolipids purified from chloroform-methanol extracts of Methanothrix concilii GP6. Together they accounted for 14% of the total lipid and were based on a C20,20-diether core structure consisting of either 2,3-di-O-phytanyl-sn-glycerol or its 3'-hydroxy analog, namely, 2-O-[3,7,11,15-tetramethylhexadecyl]-3-O-[3'- hydroxy-3',7',11',15'-tetramethylhexadecyl]-sn-glycerol. These two core lipids formed phosphodiester bonds to ethanolamine and glycosidic bonds to beta-D-galactopyranose. A third glycolipid consisted of the triglycosyl head group beta-D-galactopyranosyl-(1----6)-[beta-D-glucopyranosyl-(1----3)]-beta-D - galactopyranose in glycosidic linkage to the 3'-hydroxydiether core lipid.