Regulation of fermentative ergot alkaloid prodn. - by adding precursor or stimulant for isoleucine biosynthesis

摘要

A process is claimed for regulating the amt. and proportions of alkaloids obtained by culturing mutant strains of Claviceps purpurea which produce principally ergocornine (Ia), alpha- ergocryptine (Ib) and beta-ergocryptine (Ic). The process comprises using a cpd. which acts as a precursor for isoleucine biosynthesis, or which stimulates isoleucine formation by biochemical control, as a regulator during conventional fermentation. The regulator can be methyloxalacetic acid, alpha-ketobutyric acid, threonine, homoserine, homocysteine and/or methionine. It can be used in an amt. of 0.01-10 (pref. 0.05-5.0) g/l. The proportions of (Ic) can be increased to the level required for prodn. of dihydroergotoxine, which is used as the (m)ethanesulphonate for treatment of peripheral and cerebral circulatory disorders.