10 たばこ緑葉より単離された新アミノ酸の構造

抄録

During our studies of nitrogen metabolism in tobacco leaves, a new amino acid (1), C_<12>H_<23>N_3O_7, was isolated from green leaves of N. tabacum L. var. Hicks. In mass spectra of methyl and ethylesters, parent peaks were observed at m/e 345 and m/e 387 respectively, indicating that (1) has three carboxyl groups and exsists as a monohydrate. By deutero labeling method, it became clear that the methylester has three active hydrogen atoms. Neutral behaviours in column chromatography and paper eleatrophoresis suggested that the three nitrogen atoms in (1) are all basic. KMnO_4 oxidation of (1) afforded azetidine-2-carboxylic acid in addition to aspartic acid. In mass spectrum of the methylester, base peak, m/e 128(C_6H_<10>NO_2) and its fragmentation pattern confirmed the existence of azetidine-2-carboxylic acid in (1). In the U.V. spectrum of the DNP-derivative of (1), λ_<max> 360mμ and A_<390>mμ/A_<360>mμ=0.61 suggested that (1) has one NH_2 group. KMnO_4 oxidation of this compound yielded DNP-aspartic acid together with azetidine-2-carboxylic acid. In addition to these data, studies on n.m.d.r. and fragmentation pattern in the high resolution mass spectrum established the amino acid as (A).