Abstract
A strain of streptolmycete isolated from a soil sample was found to produce a novel amino acid metabolite. The compound was purified from the culture fluid by column chromatography, using cation exchange resin, a synthetic adsorbent, and finally by preparative HPLC with a reverse-phase column. The structure of the compound was established as Nσ-(5-methyl-4-oxo-2-imidazolin-2-yl)-L-ornithine on the basis of an analysis of the spectral data and chemical degradation. This was confirmed by comparing the NMR spectrum of the metabolite with that of the compound synthesized by treating methylglyoxal and Nx-acetyl-L-arginine. The substance did not show any antimicrobial activity against bacteria, fungi and yeasts by the agar plate method, but exhibited a weak preventive effect on cucumber powdery mildew disease in a pot test.
