The microbial transformation of (+)-catechin (1) and (−)-epicatechin (2) by endophytic fungi isolated from a tea plant was investigated. It was found that the endophytic filamentous fungus Diaporthe sp. transformed them (1, 2) into the 3,4-cis-dihydroxyflavan derivatives, (+)-(2R,3S,4S)-3,4,5,7,3′,4′-hexahydroxyflavan (3) and (−)-(2R,3R,4R)-3,4,5,7,3′,4′-hexahydroxyflavan (7), respectively, whereas (−)-catechin (ent-1) and (+)-epicatechin (ent-2) with a 2S-phenyl group resisted the biooxidation.
研究了从茶树中分离的内生真菌对(+)-
儿茶素(1)和(−)-
表儿茶素(2)的微
生物转化作用。发现内生丝状真菌Diaporthe sp.能将它们分别转化为3,4-顺式二羟基黄烷衍
生物,即(+)-(2R,3S,4S)-3,4,5,7,3′,4′-六羟基黄烷(3)和(−)-(2R,3R,4R)-3,4,5,7,3′,4′-六羟基黄烷(7),而具有2S-苯基的(−)-
儿茶素(ent-1)和
(+)-表儿茶素(ent-2)则抵抗
生物氧化。