α, β-DIAMINOBUTYRIC ACID OBTAINED FROM ASPARTOCIN

α, β-Diaminobutyric acid, isolated from the acid hydrolysate of aspartocin, was resolved into two of the four possible isomers with a Technicon amino acid autoanalyzer. ORD and NMR studies of the isolated isomers indicated that one had the D-erythro and the other the L-threo configuration. The difference in NMR spectra of the two isomers was quite likely a consequence of restricted rotation about the Cα-Cβ bonds due to electrostatic repulsion of charged amino groups. Whether the antibiotic contains both isomers or one was formed by racemization during hydrolysis was not determined.