Synthesis and biological evaluation of a series of gem-dichlorocyclopropanes as antitumor agents.

As part of our continuous effort to produce non-steroidal antiestrogens demonstrating less intrinsic estrogenicity and greater antagonism than those in use, a series of Analog II (1,1-dichloro-2,3-diphenylcyclopropanes) derivatives was synthesized. The compounds were tested for their ability to inhibit the growth-stimulating action of estradiol in the immature mouse uterus and estrogen receptor (ER) (+) MCF-7 human breast cancer cells in vitro. Like Analog II, the derivatives were found to have no intrinsic estrogenicity (except 30) and they antagonized estradiol action less completely than the lead compound. Polarity improved the ER binding affinity of Analog II, but was quite small for all compounds, except 30, for which it was comparable to tamoxifen. Six compounds (8, 10, 14, 23, 29 and 30) demonstrated antiproliferative activity toward MCF-7 cells, in vitro, and the mean inhibition period over 6 days ranged from 20 to 37%. Only compound 30 was reversed by estradiol.

Synthesis and biological evaluation of a series of 1,1-dichloro-2,2,3-triarylcyclopropanes as pure antiestrogens.

A series of 1,1-dichloro-2,2,3-triarylcyclopropanes (DTACs) was synthesized and evaluated as pure antiestrogens. Addition of 4-methoxy- or 4-(benzyloxy)phenyl Grignard reagents to p-methoxy, p-benzyloxy, or unsubstituted deoxybenzoins, followed by dehydration of the resulting carbinols produced a mixture of E and Z olefins, which were reacted with dichlorocarbene to give O-protected DTACs. The E and Z isomers were separated by fractional crystallization and the central or geminal phenyl ring was deprotected to provide phenolic DTACs. Alkylation with (N,N-dimethylamino)ethyl chloride yielded basic cyclopropanes. Two chlorodiarylindenes were isolated as thermolysis products of the DTACs, and one was converted to a phenol by hydrogenolysis. All DTACs and indenes were competitive inhibitors of [3H]estradiol binding in the immature rat uterine cytosol receptor assay, with relative binding affinities of 0.1-3.6% of estradiol. None of the new compounds were estrogenic in the 3-day immature mouse uterotrophic assay at doses up to 750 micrograms. In the 3-day immature mouse antiuterotrophic assay, five DTACs with either a methoxy (5a), benzyloxy (4d, 5c), or (dimethylamino)ethoxy (7a, 7b) central ring side chain produced significant decreases in uterine weight at doses up to 750 micrograms. One compound, (Z)-1,1-dichloro-2-[4-[2-(dimethylamino)ethoxy]-phenyl]-2-(4- methoxyphenyl)-3-phenylcyclopropane (7b), elicited a dose-dependent decrease in vivo comparable to MER 25. These same five compounds, as well as the lead compound Analog II, were active in vitro against the estrogen-dependent MCF-7 human breast tumor cell line in a dose-dependent fashion.

The influence of calmodulin antagonists on calcium transport and uptake in the rat intestine.

The effects of calmodulin (CaM) antagonists on calcium transport, tissue retention and the cell-associated calcium space were determined in duodenal segments of intestine and isolated duodenal enterocytes from young male rats. The CaM antagonists trifluoperazine (TFP) and chlorpromazine (CPZ) which were added separately to the media bathing both the mucosal and serosal surfaces of duodenal segments decreased calcium transport and tissue uptake in a dose-related fashion over a concentration range of 0.1-1 mM. Both TFP and CPZ reduced active transport to a greater extent than calcium retention in the duodenal segments. In addition, TFP and CPZ produced a dose-related decrease in the observed intracellular calcium space in duodenal tissue and reduced calcium uptake into isolated enterocytes. The TFP-induced antagonism of calcium transport was greater when TFP was at the mucosal surface than at the serosal surface of the intestinal tissue. Although TFP and CPZ are not entirely specific CaM antagonists at the concentrations used in this study, the results indicate that CaM antagonism by TFP and CPZ decreases active calcium transport and calcium uptake in duodenal segments of rat intestine in a dose-related fashion. Therefore, the present study together with the reports of other investigators suggests that CaM is involved in the mediation of calcium translocation in intestinal tissue in a fashion which is similar to that reported in other biological tissue.

Biodistribution of a novel antiestrogen (Analog II) in the mouse and rat.

The biodistribution of a novel antiestrogen Analog II was determined in the mouse and rat. The tritiated product, [3H]-Analog II was prepared by New England Nuclear and was purified by preparative chromatography using silica gel and petroleum ether/methylene chloride (80:20). The fat tissue had the highest uptake due to the hydrophobic nature of Analog II. The second highest uptake was in the mouse uterine tissue which was greater than that observed in the rat. The differences in biodistribution between the mouse and rat may partially explain the differences in biological activity of Analog II previously observed in these two animal species.

Time-dependent deterioration of active transport in duodenal segments of rat intestine.

In this study, a time-dependent deterioration of the active transport in duodenal segments of rat intestine was observed. The everted gut-sac technique was used to quantitate both calcium and glucose transport in intestinal segments. The results indicate that both calcium and glucose transport decreased significantly in intestinal segments of animals killed by cervical dislocation 10-20 min prior to tissue removal. It was further determined that animal anesthesia permitted excision of intestinal segments prior to death and thus avoided transport deterioration.