Cytotoxicity of diospyrin and its derivatives in relation to the generation of reactive oxygen species in tumour cells in vitro and in vivo.

BACKGROUND: Alkyl ethers (D2 and D7) synthesized from diospyrin (D1), a naphthoquinonoid isolated from Diospyros montana Roxb., were evaluated for cytotoxicity and capacity to generate reactive oxygen species (ROS) in tumour cells. METHODS: The tumour inhibitory activity of the quinonoids was assessed in vivo against Ehrlich ascites carcinoma (EAC), while cytotoxicity was determined in vitro on EAC and MCF-7 cancer cells by MTT assay. ROS generated by quinonoids in MCF-7 cells was measured fluorimetrically. RESULTS: The tumour inhibitory activity, cytotoxicity and ROS generation capacity of quinonoids were found to be D7 > D2 > D1. CONCLUSION: Alkyl ethers of D1 were more cytotoxic against tumour cells in vitro as well as in vivo.

Antimycobacterial activity of diospyrin derivatives and a structural analogue of diospyrin against Mycobacterium tuberculosis in vitro.

Three derivatives and one structural analogue of diospyrin were synthesized and investigated for their inhibitory activity against Mycobacterium tuberculosis employing the rapid radiometric method in vitro. A novel aminoacetate derivative was found to be more active than the parent compound, the MICs being 50 and 100 mg/L, respectively, for a drug-susceptible strain, H37Rv, of M. tuberculosis. This derivative also exhibited an MIC of 50 mg/L for a few multidrug-resistant strains of M. tuberculosis. The other two derivatives and the analogue did not show any significant antimycobacterial activity at the highest concentration (100 mg/L) tested.