RT Journal Article SR Electronic(1) A1 Russell, D. W.YR 1967 T1 Effects of Stereoisomeric Isoleucines on Sporidesmolide Biosynthesis by Pithomyces chartarum JF Microbiology, VO 47 IS 3 SP 335 OP 346 DO https://doi.org/10.1099/00221287-47-3-335 PB Microbiology Society, SN 1465-2080, AB SUMMARY As well as the known sporidesmolides I, II and III, Pithomyces chartarum produces sporidesmolides or similar compounds which contain residues of erythro-isoleucine and α-hydroxyisocaproic acid. When erythro-L-isoleucine was added to the growth medium, synthesis of sporidesmolides I and III was inhibited and synthesis of isoleucine-containing sporidesmolides, mainly Sporidesmolide II, was promoted. Threo-L-isoleucine in the medium was poorly utilized, but its presence resulted in production of a very complex mixture of sporidesmolides containing a higher proportion of isoleucine residues than the control. Epimerization of erythro-D-isoleucine occurred in the medium. Neither epimer was well utilized, and this isomer had little effect on sporidesmolide production or composition; it promoted some increase in the synthesis of isoleucine-containing sporidesmolides. Threo-D-isoleucine had effects qualitatively similar to but less pronounced than those of erythro-L-isoleucine, probably because of extracellular epimerization. The use of epimeric pairs of amino acids as tools for investigating biochemical processes involving inversion of configuration at an amino acid α-carbon atom is suggested., UL https://www.microbiologyresearch.org/content/journal/micro/10.1099/00221287-47-3-335