Detection of mycobacterial lipids in skin biopsies from leprosy patients

Abstract

Lipids were extracted from small skin biopsies obtained from 5 lepromatous leprosy patients by employing a procedure designed to produce separate non-polar and polar fractions. The defatted tissue was subjected to alkaline hydrolysis and the total fatty acids in the hydrolysate were converted to methyl esters by a phase transfer reaction using iodomethane. The composition of free lipids and methyl esters of fatty acids was analysed by special thin-layer chromatographic systems. The presence of dimycocerosates of phthiocerol A, phthiocerol B and phthiodiolone A, phenolic glycolipid-I, two phosphatidyl inositol mannosides and 2 mycolates − alpha- and keto-mycolate − was demonstrated using reference lipid samples.