Structure elucidation of sphingolipids from the mycopathogen Sporothrix schenckii: Identification of novel glycosylinositol phosphorylceramides with core Man alpha 1 -> 6Ins linkage

Acidic glycosphingolipid components were extracted from the mycelium form o f the thermally dimorphic mycopathogen Sporothrix schenckii. Two fractions from the mycelium form (Ss-M1 and Ss-M2), having the highest Rf values on H PTLC analysis, were isolated and their structures elucidated by 1- and 2-D C-13- and H-1-nuclear magnetic resonance spectroscopy, and electrospray ion ization mass spectrometry with lithium adduction of molecular ions, The str uctures of Ss-M1 and Ss-M2 were determined to be Man alpha1-->Ins1-P-1Cer a nd Man alpha1-->3Man alpha1-->Ins1-P-1Cer, respectively (where Ins = myoino sitol, P = phosphodiester). The Man alpha1-->6Ins motif is found normally i n diacylglycerol-based glycophosphatidylinositols of Mycobacteria, but this is the first unambiguous identification of the same Linkage making up the core structure of fungal glycosylinositol phosphoryl-ceramides (GIPCs). The se results are discussed in relation to the structures of GIPCs of other my copathogens, including Histoplasma capsulatum and Paracoccidioides brasilie nsis. (C) 2001 Academic Press.