[Serologic demonstration of the activity of a Mycobacterium leprae antigen obtained by chemical synthesis]. / Comprobación serólogica de la actividad de un antígeno del Mycobacterium leprae obtenido por síntesis química.

Following the chemical isolation and characterization of the glycolipid phenolic I by Hunter and Brennan in 1981, derived from infected armadillo liver, studies were continued to achieve the chemical synthesis of this trisaccharide, which is part of the glycolipid and, as it has been demonstrated, was the major antigenic determinant of this substance. The synthetic antigen obtained by Fujiwara in 1984 and Gigg in 1985, was conjugated with bovine albumin. Immunodominance of the terminal residue 3,6-Di-O-methyl-glucose was confirmed by the use of ELISA, monoclonal and polyclonal antibodies. In Cuba, Mariño and Verez, based on this knowledge obtained the antigen by another way of synthesis conjugated with acrylamide against positive and negative (71%) control sera, as well as its specificity in the reaction with sera from tuberculous patients and children vaccinated with BCG (89%).

Chemical synthesis of an artificial antigen containing the trisaccharide hapten of Mycobacterium leprae.

The trisaccharide allyl O-(3,4-di-O-methyl-beta-D-glucopyranosyl)-(1----4)-O-(2,3-di-O-methyl-al pha-L- rhamnopyranosyl)-(1----2)-3-O-methyl-alpha-L-rhamnopyranoside was synthesized from partially methylated monosaccharide derivatives. Condensation of 1,4-di-O-acetyl-2,3-di-O-methyl-alpha-L-rhamnopyranose promoted by boron trifluoride etherate with the appropriate alcohol proceeded stereoselectively and with very high yields. Selective deacetylation and glycosylation with 2,4-di-O-acetyl-3,6-di-O-methyl-alpha-D-glucopyranosyl bromide led to a trisaccharide. The acrylamide copolymers of mono-, di-, and tri-saccharide were compared in their ability to specifically bind antibodies from leprosy patients.