Studies on Growth Inhibition of Hiochi-bacteria,Specific Saprophytes of Sake

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.