Synthesis of 3,4-cis-[3H]leucocyanidin and enzymatic reduction to catechin.
A novel method is presented for the synthesis and purification of (+)-2,3-trans-3,4-cis-[4-3H]leucocyanidin. Soluble enzyme extracts from developing barley grains and leaves of the forage legume Onobrychis viciifolia (sainfoin) catalyzed the NAD(P)H-dependent reduction of (+)-2,3-trans-3,4-cis-[4-3H]leucocyanidin to (+)-[4-3H]catechin. NADPH was the preferred substrate. With extracts of barley the rate of reaction with 1 mM NADH was 20% of the rate found with NADPH. With extracts from both tissues there was a broad pH optimum around pH 6.6.
Tanner
G J
GJ
CSIRO Division of Plant Industry, Canberra, ACT, Australia.
Kristiansen
K N
KN
D000429:Alcohol Oxidoreductases / Q000737:chemistry*; D002392:Catechin / Q000737:chemistry*; D007887:Fabaceae / Q000737:chemistry / Q000201:enzymology; D005419:Flavonoids / Q000096:biosynthesis / Q000138:chemical synthesis* / Q000737:chemistry; D001467:Hordeum / Q000737:chemistry / Q000201:enzymology; D006863:Hydrogen-Ion Concentration; D009249:NADP / Q000737:chemistry; D010084:Oxidation-Reduction; D010946:Plants, Medicinal; D013379:Substrate Specificity; D014316:Tritium
D005419:Flavonoids; D014316:Tritium; D009249:NADP; D002392:Catechin; D000429:Alcohol Oxidoreductases; C001532:leucocyanidin