01839nas a2200301   4500000000100000008004100001260001600042653002900058653002400087653003000111653002600141653001600167653001100183653002100194653002800215653001200243653002500255653002100280100001500301700001700316700001500333700001600348245012000364300001000484490000800494520102100502022001401523       1987                            d  c1987 Jun 0110aAntigen-Antibody Complex10aAntigens, Bacterial10aCarbohydrate Conformation10aCarbohydrate Sequence10aGlycolipids10aHumans10aImmunoglobulin M10aIndicators and Reagents10aleprosy10aMycobacterium leprae10aOligosaccharides1 aFujiwara T1 aAspinall G O1 aHunter S W1 aBrennan P J00aChemical synthesis of the trisaccharide unit of the species-specific phenolic glycolipid from Mycobacterium leprae.  a41-520 v1633 a<p>O-(3,6-Di-O-methyl-beta-D-glucopyranosyl)-(1----4)-O-(2,3-di-O-methyl- alpha-L-rhamnopyranosyl)-(1----2)-3-O-methyl-L-rhamnopyranose, the haptenic trisaccharide of the Mycobacterium leprae-specific phenolic glycolipid I (PGL-I) antigen, and related trisaccharides, were synthesized by allylation of O-2 of benzyl 4-O-benzyl-alpha-L-rhamnopyranoside using phase-transfer catalysis, methylation of the product, deallylation, and coupling to O-(2,4-di-O-acetyl-3,6-di-O-methyl-beta-D-glucopyranosyl)-(1----4)-2,3- di-O-methyl-L-rhamnopyranosyl bromide or related disaccharides. Anomeric mixtures of the trisaccharide derivatives were separated by preparative t.l.c., deacetylated, and hydrogenolyzed, to give the pure trisaccharides. It had already been demonstrated that only those trisaccharides containing an intact, terminal 3,6-di-O-methyl-beta-D-glucopyranosyl unit are effective in inhibiting the specific binding between PGL-I and anti-PGL-I immunoglobulin M antibodies in human lepromatous leprosy sera.</p>  a0008-6215