The glycolipids from the non-capsulated strain of Pneumococcus I-192R, A.T.C.C. 12213.
1. The total lipid was extracted from the non-capsulated strain of Pneumococcus I-192R, A.T.C.C. 12213, with chloroform-methanol mixtures. Two glycolipids were isolated by chromatography on silicic acid and DEAE-cellulose (acetate form). 2. The major glycolipid was obtained pure in a yield of 640mg./34g. dry wt. of cells and represents about 34% of the total lipid. It contained galactose, glucose, glycerol and fatty acid ester residues in the proportions 1:1:1:2, and yielded on saponification a crystalline non-reducing glycoside. 3. The structure of the glycoside was shown to be O-alpha-d-galactopyranosyl-(1-->2)-O-alpha-d-glucopyranosyl-(1-->1)-d-glycerol. The fatty acids obtained on saponification were identified by gas-liquid partition chromatography of their methyl esters. 4. The minor glycolipid was obtained as a 1:1 (w/w) mixture with the major component, but after saponification the two glycosides were separated by paper chromatography. Evidence was obtained for the structure of the glycoside derived from the minor glycolipid as 1-O-alpha-d-glucosylglycerol. 5. A general method is described for determining the stereochemistry of the glycerol moiety in 1-linked glycerol glycosides.