中文名称 | 英文名称 | CAS号 | 化学式 | 分子量 |
---|---|---|---|---|
(-)-表没食子儿茶素没食子酸酯 | (-)-epigallocathechin gallate | 989-51-5 | C22H18O11 | 458.378 |
—— | (-)-(2R,3R)-5,7-dihydroxy-2-(3,4,5-trihydroxyphenyl)chroman-3-yl acetate | 183209-70-3 | C17H16O8 | 348.309 |
—— | epigallocatechin hexaacetate | 21731-10-2 | C27H26O13 | 558.496 |
(-)-表没食子儿茶素 | epigallocatechin | 970-74-1 | C15H14O7 | 306.272 |
—— | (-)-epigallocatechin penta(tertbutyldimethylsilyl)ether | —— | C45H84O7Si5 | 877.585 |
An enzyme catalyzing the methylation of phenolic hydroxyl groups in polyphenols was identified from mycelial cultures of edible mushrooms to synthesize O-methylated polyphenols. Enzyme activity was measured to assess whether methyl groups were introduced into (−)-epigallocatechin-3-O-gallate (EGCG) using SAM as a methyl donor, and (−)-epigallocatechin-3-O-(3-O-methyl)-gallate (EGCG3″Me), (−)-epigallocatechin-3-O-(4-O-methyl)-gallate (EGCG4″Me), and (−)-epigallocatechin-3-O-(3,5-O-dimethyl)-gallate (EGCG3″,5″diMe) peaks were detected using crude enzyme preparations from mycelial cultures of Flammulina velutipes. The enzyme was purified using chromatographic and two-dimensional electrophoresis. The purified enzyme was subsequently analyzed on the basis of the partial amino acid sequence using LC–MS/MS. Partial amino acid sequencing identified the 17 and 12 amino acid sequences, VLEVGTLGGYSTTWLAR and TGGIIIVDNVVR. In database searches, these sequences showed high identity with O-methyltransferases from other mushroom species and completely matched 11 of 17 and 9 of 12 amino acids from five other mushroom O-methyltransferases.