Studies in the biochemistry of micro-organisms

Abstract

A systematic investigation of the production of antibacterial substances by moulds is being carried out in this laboratory and has already led to the identification of a number of mould metabolic products and related substances which have striking antibacterial properties [Raistrick & Smith, 1941; Oxford, Raistrick & Smith, 1942; Oxford, 1942 a, b; Oxford & Raistrick, 1942]. In the course of this investigation it was noticed that a new species of Penicillium, P. resticulosum sp.nov., when grown on Czapek-Dox 5 % glucose solution, gives metabolism solutions which suppress completely the growth of Staphylo- coccu aureus in bullock's heart-broth containing 2 % of glucose at dilutions of 1: 320. This antibacterial substance is very sensitive towards acids so that metabolism solutions from P. resticulosum, showing full activity at dilutions of 1: 320, become entirely inactive on keeping overnight at pH 2'0 or below. Ether extraction of such inactivated meta- bolism solutions led to the isolation, in considerable yield, of a new mould metabolic product of Structure I. This substance, which may be regarded as a simple peptide of fumaric acid and dl-alanine, has, for convenience, been named fumaryl-dl-alanine im accordance with the ordinary peptide nomenclature although this name is not strictly correct, a more accurate designation being fumaromono-dl-alanide. CH3 HOOC.CH=CH'.CO.NH.(CH Structure I bOOH