Stimulatory effects of silibinin and silicristin from the milk thistle Silybum marianum on kidney cells.

The biochemical influence of flavonolignans from the milk thistle Silybum marianum has been tested on kidney cells of African green monkeys. Two nonmalignant cell lines were selected, with the focus of the work on the fibroblast-like Vero line. Proliferation rate, biosynthesis of protein and DNA, and the activity of the enzyme lactate dehydrogenase (as a measure of the cellular metabolic activity) were chosen as parameters for the effect of the flavonolignans.

A new antioxidative vitamin B6 analogue modulates pathophysiological cell proliferation and damage.

The new large scale synthesis of the yellow colored vitamin B6 analogue 5'-O-phosphono-pyridoxylidenerhodanine (2) (B6PR) leads to oligohydrates of its monosodium salt (4). The light-red hemiheptadecahydrate (8 1/2 hydrate) (4a) was crystallized and its three-dimensional structure determined by X-ray crystallography. Special nucleotide and protein interaction properties together with scavenging antioxidative function are combined in this simple water-soluble vitamin B6 analogues B6PR.

Formation of 4,4-dialkoxycyclohexa-2,5-dienone N-(thiol-S-yl)imine during reaction of 4-alkoxynitrosobenzenes with thiols in alcoholic solvents.

During the interaction of nitrosoarenes with glutathione in aqueous media, intermediate generation of a highly resonance-stabilized sulfenamide cation has been repeatedly suggested. Most intermediates and end products could be explained by reactions of this sulfenamide cation with different nucleophiles such as excess thiol, solvent water, and metabolically produced arylamine. The present paper presents evidence for adduct formation of the sulfenamide cation with solvent alcohol at neutral pH.

Additional pathways of S-conjugate formation during interaction of 4-nitrosophenetole with glutathione.

The rapid reactions of nitrosoarenes with cellular SH groups have proved to be main metabolic conversions during detoxication. Interactions of the phenacetin metabolite 4-nitrosophenetole with glutathione have been investigated in detail during the last years, revealing a complex pattern of products depending on the stoichiometry of the reactants and reaction conditions. Eight metabolites have been identified hitherto, and the present work extends this medley by six additional products.

Isolation and characterization of dolichol-linked oligosaccharides from Haloferax volcanii.

Biosynthesis of procaryotic glycoproteins has been studied in some detail only in the extreme halophile Halobacterium halobium. To extend these studies for a moderate halophile, dolichol phosphate-linked oligosaccharides were isolated and characterized from Haloferax volcanii. Mannosyl (beta 1-->4)galactosyl phosphodolichol could be characterized as a main component by GC/MS permethylation analysis, mass spectrometry and 1H-NMR-spectroscopy.