Biphenyls as surrogates of the steroidal backbone. Part 1: synthesis and estrogen receptor affinity of an original series of polysubstituted biphenyls.

In the course of a programme aimed at discovering new ligands of the estrogen receptor, we explored a series of substituted biphenyls. Their synthesis and binding affinity are described.

Biphenyls as surrogates of the steroidal backbone. Part 2: discovery of a novel family of non-steroidal 5-alpha-reductase inhibitors.

A new family of non-steroidal 5-alpha-reductase inhibitors was designed by replacing the steroid skeleton of an inhibitor related to estrone by a biphenyl moiety. This hypothesis originated from the reported estrogenic activity of a few biphenyl compounds (see Part 1 of this paper; Lesuisse et al. Bioorg. Med. Chem. Lett. 2001, 11, 1709). Two compounds turned out to be potent type 2 5-alpha-reductase inhibitors with IC(50)'s of inhibition in the nanomolar range. These are to our knowledge amongst the most potent non-steroidal 5-alpha-reductase inhibitors described to date.

Structure-activity relationships of a new family of steroidal aromatase inhibitors. 1. Synthesis and evaluation of a series of analogs related to 19-[(methylthio)methyl]androstenedione (RU54115).

During the course of a study aimed at the search for new potent aromatase inhibitors, several new androstenedione analogs were synthesized and evaluated. This study led to the discovery of 19-[(methylthio)methyl]androsta-4,9(11)-diene-3,17-dione (7; RU54115) already described by our laboratory. The object of the present series of papers is to disclose the result of the structure-activity relationship studies that gave rise to this compound. This first part deals mainly with the substitution in the 19-position of the steroid nucleus. Several parameters were varied, the length of the chain and its rigidity and branching, as well as the nature of the heteroatom itself and its substitution. The interaction of these new compounds with human placental aromatase in competition with the substrate androstenedione was studied by difference visible spectroscopy. The in vivo aromatase-inhibiting activities were evaluated by measuring the estradiol lowering after oral administration of the compounds to PMSG-primed female rats.