Antibiotics Produced by Fungi, and a New Phenomenon in Optical Resolution

Abstract

IT was reported earlier¹ that a strain of Fusarium lateritium produced an antibiotic, lateritiin-I, which was representative of a group of related compounds in presenting several remarkable chemical features. These features were elaborated in a communication to the Eleventh International Congress of Pure and Applied Chemistry held in London in July 1947, in which it was stated that lateritiin-I gave rise on hydrolysis to D(—)-α-hydroxyisovaleric acid and L(+)-N-methylvaline (II). The different configurations of these products were an indication, taking their configurational stabilities into account, that these units had an individual existence in the original antibiotic. This conclusion was supported by the isolation from lateritiin-I, after mild alkaline hydrolysis, of a lactone from which a crystalline methyl ester was prepared, the properties of these compounds being compatible with the structures (III) and (IV) respectively.