Glycerophosphoryl diglucosyl diglyceride, a new phosphoglycolipid from Streptococci

Abstract

1. 1. From Streptococcus faecalis var. faecalis, Streptococcus faecalis var. zymogenes, and Streptococcus hemolyticus (serogroup A) the more polar phosphoglycolipids were isolated. They were chromatographically identical and contained lucose, glycerol, fatty acid ester, and phosphate in a molar ratio of 2:2:2: I. 2. 2. The structure of all three compounds was shown to be 1(3)-O-[6''-(snglycero-1-phosphoryl)-2'-O-(α- d-glucopyranosyl)-α- d-glucopyranosyl]-diglyceride . The sn-glycerol- I-phosphate residue is heretofore unique in bacterial phosphoglycolipids. 3. 3. The deacylated core was studied by periodate oxidation, Smith degradation, alkaline hydrolysis, and enzymatic degradation. The location of the acyl groups was established by periodate oxidation and Smith degradation as well as by cleavage of the phosphodiester with HF (60%). 4. 4. The fatty acid composition was such as known for Lactobacillaceae. In the phosphoglucolipid from S. hemolyticus the fatty acids were randomly distributed, whereas the compounds from S. faecalis showed positional specificity with preference for longer-chain fatty acids in Position I and for shorter-chain fatty acids in Position 2 of the glycerol moiety. 5. 5. Methods are given for the determination of Smith degradation products and polyolphosphates by gas-liquid chromatography.