Toxic tunicaminyluracil antibiotics identified in water-damaged wheat responsible for the death of pigs

Abstract

A unique mixture of toxic tunicaininyluracil antibiotics, closely related to the corynetoxins which causc annual ryegrass toxicity and to the tunicamycins, has been identified in rain-damaged, stored wheat implicated in a fatal intoxication of pigs. The toxins, present at a level of approximately 4.5 mg per kg, were isolated by preparative t.1.c. They displayed specific inhibition of uridine diphospho-N-acetylglucosamine : dolichol-phosphate N-acetylglucosamine-1-phosphate transferase and bacterial inhibition consistent with this type of antibiotic, and produced symptoms in rats identical with those associated with the tunicamycin and corynetoxin complexes. Chemical identification, based on t.l.c., h.p.l.c., co-chromatography with authentic toxins and catalytic hydrogenation, was confirmed by fast atom bombardment mass spectrometry. The origin of these toxins is unknown, but the unique mixture of components detected suggests a previously unreported tunicaminyluracil antibiotic-producing microbial source.