Thermal chemistry of podophyllotoxin in ethanol and a comparison of the cytostatic activity of the thermolysis products.
Podophyllotoxin (1) in buffered ethanolic solution is degraded by two pathways. One leads to (a) picropodophyllin (2), which undergoes dehydration to give alpha-apopicropodophyllin (5), which rearranges to give beta-apopicropodophyllin (6), (b) the ethyl ether of picropodophyllotoxin, 8, and (c) the ethyl ether of epipicropodophyllotoxin, 7. The other pathway leads directly to epipodophyllotoxin (10) and the corresponding ethyl ether, 9, and possibly, via a transient 3,4-dehydropodophyllotoxin (5'), to beta-apopicropodophyllin (6). The 1H NMR spectra of these compounds are described, their in vitro cytostatic activity compared, and their syntheses, including that of podophyllotoxin ethyl ether, reported.
D000970:Antineoplastic Agents / Q000138:chemical synthesis* / Q000494:pharmacology; D002478:Cells, Cultured; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D000431:Ethanol; D006358:Hot Temperature; D009374:Neoplasms, Experimental / Q000473:pathology; D011034:Podophyllotoxin / Q000032:analysis* / Q000494:pharmacology
D000970:Antineoplastic Agents; D000431:Ethanol; D011034:Podophyllotoxin