On Glumamycin, a New Antibiotic. V. The Steric Configuration of α,β-Diaminobutyric Acid

Abstract

Abstract Glumamycin has been treated with nitrous acid to convert the free amino group into hydroxyl, and the resulting deamino-glumamycin has been hydrolyzed with hydrochloric acid. A mixture of threonine and allothreonine has then been isolated from this hydro-lysate. The DNP derivative of the product shows an optical rotation [M]D24=−294°±14 (c 0.48, 4% sodium bicarbonate). This fact shows that the above product is a mixture of d-threonine and d-allothreonine. Further, as the α, β-diaminobutyric acid obtained from the hydrolysate of deaminoglumamycin and that obtained from the hydrolysate of glumamycin have the same optical rotation, it may be concluded that the two moles of α, β-diaminobutyric acid in glumamycin have the same steric configuration. On the other hand, the product obtained by the oxidation of α, β-diaminobutyric acid with hydrogen peroxide is in agreement with d-alanine. Thus, it has been found that the α- and β-carbons of α, β-diaminobutyric acid belong to the d series and that, consequently, α, β-diaminobutyric acid takes the d-erythroconflguration.