A32390A, a new biologically active metabolite. I. Discovery and fermentation studies.

Abstract

A32390A is an isonitrile-containing derivative of diacyl D-mannitol. The compound is produced in fermentation as the major component of a metabolic complex known as A32390. A32390A inhibits dopamine-.beta.-hydroxylase, reduces heart and adrenal norephinephrine levels, lowers blood pressure in hypertensive rats, and possesses antibiotic activity vs. gram-positive bacteria and fungi, including Candida albicans. A32390 is produced in submerged culture by a mold, a Pyrenochaeta sp., NRRL-5786. Glucose and surose are among the best C sources for the biosynthesis of A32390. Mannitol, although a substituent of the A32390A molecule, supports little or no biosynthesis of the compound when employed as the major C source for the fermentation. The addition of crotonic acid derivatives, ethanol, or L-histidine to the fermentation medium enhances the level of A32390 produced.