Actinolactomycin,a New 2-Oxonanonoidal Antitumor Antibiotic Produced by Streptomyces flavoretus 18522,and its Inhibitory Effect on the Proliferation of Human Cancer Cells

摘要

Actinolactomycin 1, a new 2-oxonanonoidal antitumor antibiotic, was isolated from the fermentation broth of Streptomyces flavoretus 18522 through a bioassay-guided separation procedure. The structure of 1 was determined as 4,7-dihydroxy-3,9-dimethyl-2-oxonanone by the spectroscopic methods. Compound 1 inhibited the proliferation of A2780, K562, HCT-15, A549 and HeLa cells with the IC50 values of 1.4 ± 0.4 μmol/L, 8.4 ± 4.7 μmol/L, 9.4 ± 2.2 μmol/L, 15.4 ± 5.6 μmol/L and 13.7 ± 2.0 μmol/L, respectively. Flow cytometric analysis indicated that 1 could inhibit the cell cycle of tsFT210, A2780 and K562 cells mainly at the G0/G1 phase and could also induce apoptosis in K562 cells.