Phenolic glycolipids

Some alcohols, arylamines, and phenols are sulfated. The sulfate donor in these and other biologic sulfation reactions (eg, sulfation of steroids, glycosaminoglycans, glycolipids, and glycoproteins) is adenosine 3 -phos-phate-S -phosphosulfate (PAPS) (Chapter 24) this compound is called active sulfate. ... 

The derivatives 3-<9-methyl-D-olivose (D-oleandrose, 3-<9-methyl-2,6-dideoxy-D-arabino-hexose), and 3-0-methyl-D-oliose (3-<9-methyl-2,6-dideoxy-D-/yvo-hexose) are components of steroidal glycosides obtained from Cynanchum othophyllum Schneid, a traditional Chinese medicine.148 A derivative 4-O-me-thyl-D-olivose has been identified as the terminal sugar of the tetrasaccharide moiety in the phenolic glycolipid of Mycobacterium kansasii.149... 

M. Gilleron, A. Venisse, J. J. Foumie, M. Riviere, M. A. Dupont, N. Gas, and G. Puzo, Structural and immunological properties of the phenolic glycolipids from Mycobacterium gastri and Mycobacterium kansasii, Eur. J. Biochem., 189 (1990) 167-173. 

Smith et al x had described glycolipids that are devoid of amino acids, terming them glycosides of phenolphthiocerol dimycocerostate. These were renamed as phenolic glycolipids (10) by Hunter and Brennan71,74 when they discovered the... 

Structures of Major Phenolic Glycolipids from Mycobacterium... 

PGL-I, homogeneous by thin-layer chromatography, through reverse-phase HPLC showed heterogeneity based on fatty acid content, and PD-MS analysis demonstrated the existence of the C3o,C3o mycocerosate glycolipid, the C32,C32 species, and the species.27 Two other minor phenolic glycolipids isolated from M. 

The seroreactivity of a synthetic monoglycosyl NGC related to the major phenolic glycolipid of M. bovis BCG has provided strong confirmatory evidence for revision of the enantiomeric configuration of the glycosyl residue in the so-called mycoside B 78 to that of 2-O-methyl-a-L-rhamnopyranose. The NGC with the glycosyloxynonanoyl linker-arm was suitable for the serodiagnosis of bovine tuberculosis. 

Other syntheses directed toward NGPs related to other mycobacterial glyco-lipids include those of the common inner-core trisaccharide fragment of the phenolic glycolipids of M. kansasii.154-155 In one of these syntheses,155 the tyramine moiety in the spacer-arm is suitable for conjugation to protein, and the trisaccharide segment in 112 has been prepared for the subsequent attachment of strain-specific terminal sugar residues.156-158... 

Information on the biosynthesis of the phenolic glycolipids is very limited.220 The carbon atoms in the methyl-branched structures in mycocerosic acids are derived from propanoate.221-222 So also are those in phthiocerol.223 224 The aromatic ring can be derived from tyrosine.224 The methoxyl residue in phenolphthiocerol presumably comes from methionine, by analogy with the known source in the related lipid phthiocerol.225 226 Rainwater and Kolatukuddy226 demonstrated two steps in the biosynthesis of mycocerosic acids, and isolated the enzymes involved, but the biosynthetic steps leading to phenolphthiocerol itself are not known. 

As concerns the chemistry of these glycolipids, they contain either an eater linkage between the sugar moiety and the lipid moiety, as in cord factor and in wax D of Mycobacteria, or they are glycosides of phenolic alcohols (as in mycoside B) or of inositol (as in the phosphoglycolipids), or they can be linked to the carboxyl group of D-alanine (as in mycoside C). 

The lipid moiety of the glycolipids under consideration is either composed of branched-chain fatty acids (for example, mycolic acids in cord factor and in wax D) or can be a wax formed by the union of a phenolic alcohol with branched-chain fatty acids of the mycocerosic acid type, as in mycosides A and B. In the phosphoglycolipids, simple normal fatty acids have been found, accompanied by some methyl branched acids. 

Phenolic glycolipids from Mycobacterium bovis (top) and M. leprae (bottom)... 

Other glycolipids are carbohydrate esters of fatty acids (such as mycolic acids). Mycosides are also part of this group and they contain a branched aliphatic chain with hydroxyl groups esterified by fatty acids and terminated at one end by a phenol group to which the carbohydrate moiety is linked. 

Both D-and L-rhamnose may be present in the same oligosaccharide, as reported for the glycopeptidolipids of Mycobacterium avium.232 The surface antigens of all serovars examined present the inner disaccharide a-L-rhainnopyranosyl(l—>2)-6-deoxy-a-L-talopyranose. L-Rhamnose is also part of the highly immunogenic phenolic glycolipids from Mycobacterium 33... 

Goodnow Why do you assume that this is acting only on the innate response Could phenolic glycolipids be having an effect on T cell differentiation, and memory versus exhaustion issues ... 

Goodmw If you test the same phenolic glycolipids, do they have direct effects on lymphocytes themselves ... 

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