Synthesis of novel galeterone derivatives and evaluation of their in vitro activity against prostate cancer cell lines.

Prostate cancer is one of the main causes of male cancer-related deaths worldwide and the suppression of androgen receptor signalling is established as an effective strategy for the treatment. A series of galeterone analogues including several steroid-fused azacycles, as well as 17-(benzimidazol-1-ylimino), 16α-(benzimidazol-2-ylamino), and 16α-(benzothiazol-2-ylamino) steroid derivatives, were synthesized and tested against prostate cancer cell lines. Candidate compound 3f was shown to reduce AR-regulated transcription in a dose-dependent manner in nanomolar ranges and suppress expression of AR-regulated proteins Nkx3.

Synthesis and biological activity of 22-deoxo-23-oxa analogues of saponin OSW-1.

Analogues of the potent cytotoxic saponin OSW-1 were prepared from the readily available steroidal 16β,17α,22-triol. The new 22-deoxo-23-oxa analogues of OSW-1 were screened against eight cancer cell lines and normal human fibroblasts. The analogues proved to be slightly less active than OSW-1 but also less toxic to normal cells.

Decomposition of alpha-Tocopheryl Glycosides in Rat Tissues.

BACKGROUND: The aim of our investigation was to estimate the stability of alpha-tocopheryl O-glycosides in relation to activity of exoglycosidases in selected rat tissues. MATERIAL AND METHODS: Acetylated glycosides were obtained in glucosidation of alpha-tocopherol using the Helferich method. The activity of exoglycosidases was determined by the Zwierz et al.

Colon cancer releases alpha-tocopherol from its O-glycosides better than normal colon tissue.

Background/aims: Free radicals, in a colon, may damage DNA, make difficult DNA repair and change course of post-translational modifications of regulatory proteins, which promote tumor initiation and progression. Therefore risk of colon cancer is closely related to diet and other lifestyle factors. Dietary antioxidants, such as vitamin E, should reduce the levels of harmful oxidation products.

New analogues of the potent cytotoxic saponin OSW-1.

Saponin OSW-1 (5e-G2; 3 beta,16 beta,17 alpha-trihydroxycholest-5-en-22-one 16-O-{O-[2-O-(4-methoxybenzoyl)-beta-D-xylopyranosyl]-(1-->3)-2-O-acetyl-alpha-arabinopyranoside}) analogues: with modified side chain (5a/d-G2), 22-deoxo-23,24,25,26,27-pentanor- (14), 22-deoxo-23-oxa- (17), glycosylated with various monosaccharides (5e-G4/G6/G8), and OSW-1 structural isomer (10) were obtained. The analogues were synthesized using a previously published method for the synthesis of OSW-1. The structures of analogues were fully confirmed by spectroscopic methods, and the S-chirality at C-22 of the structural isomer was established by conformational analysis combined with the NMR spectrometry.

13C-NMR study of 4-azasteroids in solution and solid state.

A group of biologically active 4-azasteroids was studied by 13C-NMR spectroscopy in solution and in the solid phase. A full assignment of signals in the spectra of samples in chloroform was performed for thirteen 4-azasteroids using two-dimensional techniques. Substituent and steric effects of a nitrogen atom, and their influence on chemical shifts of the neighboring carbon atoms are discussed.