PHRM 221 Lecture Notes - Lecture 4: Thiamine Pyrophosphate, Thiamine, Cyanocobalamin
Document Summary
Thiamin (b1), riboflavin (b2), niacin (b3), pantothenic acid (b5), pyridoxine (b6), biotin (b7), folic acid (b9), cyanocobalamin (b12) Sources : whole grain cereals, legumes (e. g. beans and lentils), nuts, meat and yeast. Lost during production of white flour and polished (white) rice. Essential coenzyme in several decarboxylation reactions in cho and aa metabolism. Required for atp generation by mitochondria and in pentose phosphate pathway. Diuretic-induced in elderly (due to excess excretion) If suspected, immediate treatment with thiamine is required. Can progress to wernicke-korsakoff syndrome (wks) with dementia and psychosis. No ul for thiamine has been set. Sources : found in many foods in relatively low amounts. Physiological function : converted to flavin mononucleotide (fmn) and flavin adenine dinucleotide (fad) Coenzymes for flavoproteins, in redox reactions in fa/aa metabolism and tca cycle. Fad: part of the mitochondrial electron transport chain. Involved in metabolism of vit b6, folic acid and niacin. Uncommon and rarely occurs alone due to efficient recycling .
