Antiestrogens. Synthesis and evaluation of mammary tumor inhibiting activity of 1,1,2,2-tetraalkyl-1,2-diphenylethanes
摘要:
Among the newly synthesized 1,1,2,2-tetraalkyl-1,2-diphenylethanes, 1,1,2,2-tetramethyl-1,2-bis(4'-hydroxyphenyl)ethane (23) and 1,1,2,2-tetramethyl-1,2-bis(3'-hydroxyphenyl)ethane (26) were the most active compounds regarding estradiol receptor affinity, exhibiting Ka values of 0.73 X 10(8) and 0.67 X 10(8) M-1, respectively. In vivo, 23 and 26 showed only very small uterotrophic activity in the mouse. They strongly inhibited (73%) the estrone-stimulated mouse uterine growth. Tested on the 9,10-dimethyl-1,2-benzanthracene induced hormone-dependent mammary adenocarcinoma of the Sprague-Dawley rat, compounds 23 and 26 exhibited a dose-dependent inhibition of the tumor growth, having a strong effect at a dose of 20 (mg/kg)/day (compound 23).
Mesolytic Scission of C−C Bonds as a Probe for Photoinduced Electron Transfer Reactions of Quinones
作者:Przemyslaw Maslak、William H. Chapman
DOI:10.1021/jo952102r
日期:1996.1.1
Photoinducedelectrontransfer reactions of chlorinated benzoquinones are investigated using bibenzylic donors that undergo rapid fragmentation upon oxidation. The fragmentation rates and the quantum yields are used to probe the dynamics of back-electron transfer (BET) in two types of radical ion pairs. The triplet ion pairs formed by interception of excited state quinones give products with high quantum