Preference for<i>O</i>-demethylation reactions in the oxidation of 2′-, 3′-, and 4′-methoxyflavones by human cytochrome P450 enzymes
作者:Haruna Nagayoshi、Norie Murayama、Masaki Tsujino、Shigeo Takenaka、Jun Katahira、Vitchan Kim、Donghak Kim、Masayuki Komori、Hiroshi Yamazaki、F. Peter Guengerich、Tsutomu Shimada
DOI:10.1080/00498254.2020.1759157
日期:2020.10.2
2'-, 3'-, and 4'-Methoxyflavones (MeFs) were incubated with nine forms of recombinant human cytochrome P450 (P450 or CYP) enzymes in the presence of an NADPH-generating system and the products formed were analyzed with LC-MS/MS methods.CYP1B1.1 and 1B1.3 were highly active in demethylating 4'MeF to form 4'-hydroxyflavone (rate of 5.0 nmol/min/nmol P450) and further to 3',4'-dihydroxyflavone (rates
在产生NADPH的系统中,将2'-,3'-和4'-甲氧基黄酮(MeFs)与9种形式的重组人细胞色素P450(P450或CYP)酶一起孵育,并用LC- MS / MS方法.CYP1B1.1和1B1.3在4'MeF脱甲基形成4'-羟基黄酮(5.0 nmol / min / nmol P450的速率)和进一步生成3',4'-二羟基黄酮(速率为5%的活性)方面具有很高的活性。分别为2.1和0.66 nmol / min / nmol P450)。发现3'MeF被P450氧化为m / z 239(M-14)产物(大概为3'-羟基黄酮),然后氧化为3',4'-二羟基黄酮。P450还将2'MeF催化氧化为m / z 239(M-14)和m / z 255(M-14,M-14 + 16)产品,可能分别是单羟基和二羟基产品。将这些MeF与P450一起孵育时,至少形成了两种类型的具有m / z 269片段的环