Lactonamycin Z, an antibiotic and antitumor compound produced by Streptomyces sanglieri strain AK 623

Abstract

In summary, the structure elucidation revealed 1 to be closely related to lactonamycin, differing solely by the presence of an hydroxy group at C-3′ and the relative stereochemistry at C-4′ of the sugar moiety. Further differences are possible with respect to the absolute configuration, which has been determined for lactonamycin by X-ray crystallographic and optical rotation analysis). The antibacterial activities of 1 were determined by an agar plate diffusion assay. A weak activity against Gram-positive bacteria was detected as shown in Table 2. The antitumor activity of 1 was tested according to NCI guidelines) with human cell lines from gastric adenocarcinoma (HMO2), breast carcinoma (MCF 7), and hepatocellular carcinoma (Hep G2). 1 strongly inhibited the proliferation of HMO2 (IC50 value: 0.19 μg/m1), whereas the effects on MCF 7 and Hep G2 cell lines were less pronounced. The growth is inhibited in the G2/M cell cycle phase.