Studies on Growth Inhibition of Hiochi-bacteria, Specific Saprophytes of Sake: Part VII. Structure of Muta-aspergillic Acid (1)Part VIII. Structure of Muta-aspergillic Acid (2)

The outline of this report has already been published as a short communication concerning muta-aspergillic acid, C11H18N2O3, a new growth inhibitant against hiochi-bacteria. Deoxymuta-aspergilhc acid, C11H13N2O, reduction product of muta-aspergillic acid, was converted to 2,5-diketopiperazine, C11H20N2O2, and this compound was shown to be leucyl-valine anhydride since on hydrolysis, it yielded leucine and valine. These results and physical and chemical data on muta-aspergillic acid led to draw the conclusion that formula (I) or (II) is the most possible structure for this antibiotic.