Two new spirooxindole alkaloids from rhizosphere strain Streptomyces sp. xzqh-9

Two new spirooxindole alkaloids spindomycins A (1) and B (2) were isolated from rhizosphere strain Streptomyces sp. xzqh-9. Their structures were elucidated by comprehensive spectroscopic analyses of NMR and MS data. The absolute configurations of 1 and 2 were determined by experimental and theoretical calculation of electronic circular dichroism (ECD). Antitumor, lactate dehydrogenase, and tyrosine kinase inhibitory activities of two compounds were evaluated, while only spindomycin B (2) exhibited weak inhibitory activity against tyrosine kinase Bcr-Abl.