
%0 Journal Article
%A Frahn, JL 
%A Edgar, JA 
%A Jones, AJ 
%A Cockrum, PA 
%A Anderton, NA 
%A Culvenor, CCJ 
%T Structure of the corynetoxins, metabolites of <I>Corynebacterium rathayi</I> responsible for toxicity of annual ryegrass (<I>Lolium rigidum</I>) pastures
%J Australian Journal of Chemistry
%D 1984/01/01
%V 37
%N 1
%P 165-182
%K 
%R https://doi.org/10.1071/CH9840165
%U https://www.publish.csiro.au/paper/CH9840165 
%X The corynetoxins, toxic metabolities of Corynebacterium rathayi formed in galled seed-heads of infected annual ryegrass, Lolium rigidum, are shown to be new members of the tunicamycin group of antibiotics. They consist of N-acetylglucosaminyl-tunicaminyl-uracil in amide linkage with fatty acids which differ in certain respects from those present in the tunicamycins. The corynetoxin acids are of slightly longer chain length, C15-C19, occur in a &#946;-hydroxy as well as saturated and &#945;,&#946;-un-saturated series, and have anteiso, iso and normal chain terminations. &#946;-Hydroxy acids have not been observed previously in the tunicamycin group and anteiso chains were reported only recently in the streptovirudin subgroup. Stereochemical identity of the C11-aminosugar in the corynetoxins with the tunicamine part of the tunicamycins is demonstrated by formation of a common hydrolysis product, di(N-trifluoro- acetyl)glucosaminyl-tunicaminyl-uracil. Analysis of the carbon-13 and proton n.m.r. spectra of the main components, corynetoxins H17a and U17a, confirms the stereochemistry proposed for tunicamine except that the glycosidic linkages are changed to &#945;-galactosamine, &#946;-glucosamine. 
