Jadwiga Maj

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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. They induce concentration-(More)
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(More)
β-Carotene ethenolysis under promotion of well-defined ruthe-nium catalysts were examined as a novel method of synthesis of vitamin A derivatives. Efficient reaction was promoted by the second-generation Hoveyda catalyst. The products of ethenolysis in positions C15-C15 , C11-C12, and C9-C10 were detected, but cleavage of the C11-C12 double bond(More)
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(More)
Background: The aim of our investigation was to estimate the stability of α-tocopheryl O-glycosides in relation to activity of exoglycosidases in selected rat tissues. Material and Methods: Acetylated glycosides were obtained in glucosidation of α-tocopherol using the Helferich method. The activity of exoglycosidases was determined by the Zwierz et al.(More)
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(More)
A group of biologically active 4-azasteroids was studied by C-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(More)
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