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.
1. Total lipid was extracted from Mycoplasma laidlawii strain B with chloroform-methanol mixtures and fractionated into neutral lipid, glycolipid and phospholipid components by chromatography on silicic acid. 2. Saponification of the glycolipid fraction, which represented nearly half of the total lipid, yielded two glycosides for which the structures O-alpha-d-glucopyranosyl-(1-->1)-d-glycerol and O-alpha-d-glucopyranosyl-(1-->2)-O-alpha-d-glucopyranosyl-(1-->1)-d-glycerol were established. 3. The ratio of monoglucosyl diglyceride to diglucosyl diglyceride increased with the age of the culture, though the total glycolipid concentration remained virtually constant. The glycolipid concentration was unaffected by the addition of cholesterol to the culture medium. 4. The phospholipid fraction consisted of two components, phosphatidylglucose and phosphatidylglycerol. Organisms harvested at acidic pH also contained O-amino acyl esters of phosphatidylglycerol. No lipids containing inositol could be detected.
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