Peter Mende

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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)
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)
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)
An analytical procedure previously developed for the trace determination of nitrosamides was applied to a screening of nitrosated foodstuffs for nitrosoureas. Different types of foodstuffs were nitrosated both under chemical conditions using a high nitrite concentration, and under simulated gastric conditions. Methylating activity corresponding to(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)
Popular vegetables, condiments and some Nigerian staple foods were evaluated for their relative methylating potential due to nitrosamide formation following nitrosation under standardized conditions. Methylating activity of nitrosated foodstuffs, expressed as N-nitroso-N-methylurea equivalents, was determined by gas chromatography-thermal energy analysis.(More)
Based on a method for trapping direct-alkylating intermediates with scavenger reagents possessing a nucleophilic side-chain and an N-nitroso group as a marker, a sensitive test system for the detection of N-nitrosamides and related compounds has been developed. N-Nitroso-N-tert-butylglycine is an effective scavenger reagent for this purpose. It reacts(More)