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[摘要]：Nine (1-8 and 10) new and two (9 and 11) known compounds have been isolated from roots of Euphorbia cornigera Boiss. Their structure and relative stereochemistry were acquired through NMR (H-1, C-13, COSY-45, HOHAHA, HMQC, HMBC, NOE and HMBC) spectroscopic measurements. Compounds 1-10 were identified as diesters of 13,20-O-diacyl and 11 as 13-O-acetyl of 12-deoxyphorbol. Cytotoxic activity of the compounds was investigated on human KB cells by reduction of MTT. Compounds 8-10 displayed IC50 of 0-8, 0.5, and 1.0 mu g mL(-1), respectively, whereas the activity of rest of the compounds (1-7) was either very low or (11) zero even up to 1000 mu g mL(-1). The inhibition of DNA synthesis through Trypan blue exclusion and Brd-U assay was investigation to figure out the role of compounds 8-10 and concluded that these were responsible for the death of KB cells. Significant correlation has been found between the cytotoxicity and DNA cross-link and DNA strand-break formation. (c) 2007 Elsevier Masson SAS. All rights reserved. |
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