Biosynthetic studies on the chitinase inhibitor, allosamidin. Origin of the carbon and nitrogen atoms

Allosamidin 1 is a potent insect chitinase inhibitor produced by Streptomyces sp. The biosynthesis of compound 1 was studied by feeding experiments with labelled precursors. Incorporation experiments using [1-13C]- and D-[6-13C]glucose as well as doubly labelled D-[1-13C,2-15N]-glucosamine revealed that each skeleton of N-acetyl-D-allosamine and allosamizoline 2 was derived from D-glucosamine. Further experiments with L-[guanidino-13C,15N2]arginine and [methyl-l3C]-methionine clarified the origin of the dimethylaminooxazoline moiety of compound 2.