Sugars biogenesis

Studies on the biogenesis of several components of bacterial cell-walls led to the discovery, in 1965, of lipophilic compounds containing sugar... 

Dickinson, D.B., Hopper, J.E., and Davies, M.D., 1973, A study of pollen enzymes involved in sugar nucleotide formation. In Loewus, F. (ed.), Biogenesis of Plant Cell Wall Polysaccharides. Academic Press, NY, pp. 29 48. 

The biogenesis of the polyene MACROLIDE candicidin (a heptaene) is mostly from acetate and propionate with the additional presence in the structure of p-am1noacetophenone and mycosamine (3-ami no-3,6-dideoxy D-mannopyranose) 43. The biosynthesis of the candidin and candihexin complexes (heptaene and hexaene, respectively) seems to be via sugar-free aglycones which are within the producing mycelium. Glycosylation may take place during secretion of the final products. 

The )8-(1 2)- and a-(1 5)-linked arabinose residues are incorporated into the polymer from the activated polyprenyl sugar phosphate 10, which is in turn synthesized from glucose via 5-phosphoribose pyrophosphate (pRpp) [46-48]. Elongation of the polymer chain is believed to involve a family of arabinosyltransferases (AraT s) that recognize both 10 and arabinofuranoside-based acceptors of differing structures (Fig. 5) [18,19,49,50]. In AG biosynthesis, the entire polysaccharide appears to be assembled as a polyprenol diphosphate intermediate, which is transferred to peptidoglycan prior to the addition of the mycolate esters [18]. In LAM biogenesis, the arabinan portion is believed to be synthesized as a polyprenol phosphate that is transferred to lipomannan [51]. 

Similarities in structure commonly reflect similarities in biogenesis. Consideration of the architectural patterns and structural relationships of natural products enabled Collie, Robinson, Ruzicka and others to discern the biogenetic units from which certain phenolic compounds, alkaloids and terpenes were formed. A survey of the antibiotics indicates that one large collection of these substances can be derived mainly from amino acid residues, another mainly from acetate (or, on occasion, propionate) and a third from simple sugars. Some structures can be dissected into two or more different fragments that are derived from different types of biogenetic unit. 

This acid is a secondary product of the metabolism of sugars. In fact, there is a significant lag time before obtaining radioactive tartaric acid from the incorporation of " 002 in the leaves. This phenomenon only occurs in the presence of light. Ascorbic acid is considered to be the main intermediate in the biogenesis of tartaric acid and small... 

Butte, J. C., and J. W. Corcoran The biogenesis of desosamine, an amino-trideoxy-sugar in erythromycin. Federation Proc. 21, 89 (1962). 

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