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Salted tea prepared in Kashmir by adding sodium bicarbonate shows high methylating activity (equivalent to 3 p.p.m. N-methylnitrosourea) upon in vitro nitrosation. Pure caffeine treated under conditions of the tea preparation formed caffeidine and caffeidine acid. We report here the formation of two new compounds, mononitrosocaffeidine, an asymmetric(More)
In the present study, Brassica a dried green vegetable from Kashmir, which is a major constituent of the local diet, was analysed for nitrosatable aliphatic amines, N-nitrosamines prior to and after nitrosation) and alkylating activity due to N-nitrosamides following nitrosation. The cooked vegetable contained 11 micrograms/kg nitrosodimethylamine and 21(More)
The phosphate carrier of pig heart mitochondria has been isolated and reconstituted in liposomes. The highest specific activity for [32P]phosphate exchange was obtained with hydroxyapatite eluate from mitochondria, extracted with Triton X-114 in the presence of cardiolipin. This fraction, which is free from the ADP ATP-carrier, had a specific activity of 30(More)
Three varieties of kola nut, Cola acuminata, C. nitida and Garcinia cola, of Nigerian origin, were analysed for their content of primary and secondary amines, and assessed for their relative methylating potential due to nitrosamide formation. Primary and secondary amines were determined as benzene sulfonamides by gas chromatography/thermal energy analysis(More)
The in vitro nitrosation of sun-dried red chillies (Capsicum annuum) and of its constituents capsaicin and dihydrocapsaicin was studied. The nitrophenols 4-nitroguaiacol, 4,6-dinitroguaiacol, nitrocapsaicin and nitrodihydrocapsaicin were detected as final products, whereas no formation of nitrosamides was observed though this is expected from the amide(More)
The ethylmaleimide-sensitive phosphate-transport system of heart mitochondria was isolated and the activity reconstituted in liposomes. The identification of the phosphate-carrier protein was complicated by several factors. 1. The phosphate-carrier fraction, isolated through different procedures in different laboratories, contains 4-5 protein components of(More)
Epidermis of steins and petioles of LUPINUS POLYPHYLLUS accumulates quinolizidine alkaloids at a concentration of about 30 mM. Since lupanine is synthesized mainly in green mesophyll tissue and not in the epidermis, the alkaloids have to be transported into the epidermal cells. Uptake of [ (3)H]-lupanine into isolated epidermis was 3 to 20 times higher in(More)
The phosphate carrier of pig heart mitochondria was solubilized with Triton X-100 and purified by chromatography on hydroxylapatite. Incubation of the phosphate carrier fraction with cardiolipin stimulated the reconstituted [32P]phosphate exchange activity in liposomes, whereas increased Triton X-100 concentrations inhibited it. The effects of cardiolipin(More)
Caffeine on alkaline hydrolysis produces caffeidine [1-methyl-4-(methylamino)-5-(N-methylcarbamoyl)imidazole] and caffeidine acid [N-[4-(5-carboxy-1-methylimidazolyl)]-N,N'-dimethylurea]. We now report the synthesis and chemical characterization of mononitrosocaffeidine [1-methyl-4-(N-methyl-N-nitrosoamino)-5-(N-methylcarbamoyl)i midazole],(More)