Characterization and in vivo production of three glycolipids from Candida bogoriensis: 13-glucopyranosylglucopyranosyloxydocosanoic acid and its mono- and diacetylated derivatives

[摘要] Three glycosides of 13-hydroxydocosanoic acid isolated from Candida bogoriensis were characterized by quantitating the amount of carbohydrate, acetate, and hydroxy acid in each, and by gas–liquid chromatography and mass spectrometry of their methyl ester, trimethylsilyl ether derivatives. One of the glycosides was the diacetylated derivative of 13-glucosylglucosyloxydocosanoic acid previously characterized by Tulloch, Spencer, and Deinema (Can. J. Chem., 46: 345 [1968]), in which the disaccharide had the β(1 → 2) sophorose linkage and the acetyl groups were attached to the 6′ and 6″ positions of the glucose residues. The other two glycosides were 13-glucosylglucosyloxydocosanoic acid and its monoacetylated derivative. A comparison of the mass spectra of derivatives indicates that the acetyl group of the monoacetyl lipid is on the internal glucose. Methyl 13-glucosyloxydocosanoate was produced by acid hydrolysis of the methyl ester of the unacetylated glycolipid and was characterized by the same techniques as the other glycolipids.Time course of production of the three glycolipids is consistent with the diacetylated derivative being the first extracellular product and the other two glycolipids being formed by deacetylation. 13-Hydroxy[13-3H]docosanoic acid, methyl 13-hydroxy[13-3H]docosanoate, and 9-hydroxy[11,12-3H]-stearic acid were each incorporated into the glycolipid fraction.

[关键词] mass spectrometry;13-hydroxydocosanoic acid;hydroxy acid glycosides