fenugreek (trigonella foenum-graecum l.) has a long and respected history of medicinal uses in middle east and persian medicine. the hypocholesterolaemic and hypoglycaemic effects of fenugreek were attributed to its major steroidal sapogenin, diosgenin and its major alkaloid, trigonelline. the knowledge of diosgenin and trigonelline biosynthesis is derived from studies of cholesterol and nicoti...

Previous studies from our laboratory indicated that the initial step in the biosynthesis of nicotinamide adenine dinucleotide from nicotinamide in mammalian liver involves the enzymatic deamidation of nicotinamide to nicotinic acid (1, 2). The nicotinic acid is then converted to NAD via the pathway described by Preiss and Handler, involving the intermediate formation of nicotinic acid mononucle...

A soluble yellow CO dehydrogenase from CO-autotrophically grown cells of Pseudomonas carboxydohydrogena was purified 35-fold in seven steps to better than 95% homogeneity with a yield of 30%. The final specific activity was 180 mumol of acceptor reduced per min per mg of protein as determined by an assay based on the CO-dependent reduction of thionin. Methyl viologen, nicotinamide adenine dinuc...

Native amine dehydrogenases (nat-AmDHs) catalyze the ( S )-stereoselective reductive amination of various ketones and aldehydes in presence high concentrations ammonia. Based on structure Cfus AmDH from Cystobacter fuscus complexed with Nicotinamide adenine dinucleotide phosphate (NADP + ) cyclohexylamine, we previously hypothesized a mechanism involving attack at electrophilic carbon carbonyl ...