LIPID-CONTENT OF MICROPARTICULATE (1-]3)-BETA-D-GLUCAN ISOLATED FROM SACCHAROMYCES-CEREVISIAE

The preparation of pharmaceutical grade (1 --> 3)-beta-D-glucans from Saccharomyces cerevisiae requires that the microparticulate glucans wh ich are employed as the starting material for drug production be of th e highest purity. Potential contaminants of the (1 --> 3)P-D-glucan is olation process are yeast cell wall lipids, which are frequently found in association with glucans. The lipid content of yeast-derived (1 -- > 3)-beta-D-glucan during various stages of the isolation process by m ethyl esterification and total ion gas chromatography and mass spectro metry (GC-MS) was examined. Following sequential alkaline and acid hyd rolyses, the total lipid content of (1 --> 3)-beta-D-glucan was 100.4 nmol/mg with 9-cis-C 18:1 fatty acid accounting for 45.3 nmol/mg gluca n (45%). Following ethanol extraction of the (1 --> 3)-beta-D-glucan, lipid was not detected. Indeed, fatty acid methyl esters were not dete ctable by total ion CC-MS in all twelve samples investigated. These da ta demonstrate that the isolation process for yeast-derived (1 --> 3)- beta-D-glucan effectively reduces contamination by yeast cell wall lip ids.