Branched chain fatty acid, occurrence

Tyrrell, D. and Weatherstone, J. (1976) The fatty acid composition of some Entomoph-thoracae IV. The occurrence of branched-chain fatty acids in Conidiobolus species. Can. 

This chapter describes the case reports of these enzyme deficiencies and the underlying biochemistry of the disorders and their associations. It is not the intention to discuss keto acidosis associated with other diseases, for example juvenile diabetes, or ketogenesis and its control which are reviewed elsewhere (Wildenhoff, 1975, 1977 McGarry and Foster, 1976 Halperin, 1977). In addition to the common occurrence of 3-hydroxybutyrate and acetoacetate in body fluids of patients with keto acidosis, secondary organic acids have been observed in urine, including adipic and suberic acids (Pettersen et aL, 1972), 3-hydroxyisovaleric acid (Landaas, 1974), 3-hydroxyisobutyric acid and 2-methyl-3-hydroxybutyric acid (Landaas, 1975). The dicarboxylic acids occur as a result of initial co-oxidation of accumulating long-chain fatty acids followed by )8-oxidation (Pettersen, 1972), and metabolites of the branched-chain amino acids occur because of inhibition of their metabolic pathways by 3-hydroxybutyrate and acetoacetate (Landaas and Jakobs, 1977). 

Garton, G. A., Scaife, J. R., and Smith, A. (1975). Effect of vitamin B12 status on the occurrence of branched-chain and odd-numbered fatty acids in the liver lipids of the baboon. 

Reviews of fungal fatty acid composition (, 7, ) reveal that their primary constituents are 12- to 20-carbon chain length unbranched compounds, with even-numbered chains predominant. Both saturated and unsaturated compounds occur, with palmltolelc (C-16 l), oleic (C-18 l), llnolelc (C-18 2) and llnolenlc (C-18 3) acids the most common unsaturated moieties ( ). As with most naturally occurring fatty acids (9), monounsaturated compounds usually contain a els oleflnlc bond and polyunsaturated acids have methylene-interrupted els double bonds. Although rare In occurrence and subjected to limited study, branched chains, hydroxy, oxo and epoxy acids are also synthesized ( 5). Lists of the structures of unusual fatty acids which can be employed In structure activity studies are presented In detail elsewhere (9-14). 

Free fatty acids Long-chain carboxylic acids variation in branching, occurrence of other functional groups and number of double bonds atypical as the free form and usually found esterified as waxes or glycerides Complex lipids Usually occur in small amounts in plant and animal tissues free fatty acid turnover is very rapid in plasma free fatty acids may serve as indicators of spoilage in food... 

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