Biotransformation of 6-methoxy-3-(3',4',5'-trimethoxy-benzoyl)-1H-indole (BPR0L075), a novel antimicrotubule agent, by mouse, rat, dog, and human liver microsomes.
6-Methoxy-3-(3',4',5'-trimethoxy-benzoyl)-1H-indole (BPR0L075) is a novel synthetic indole compound with microtubule binding activity. Incubation of BPR0L075 with mouse, rat, dog, and human liver microsomes in the presence of NADPH resulted in the formation of six metabolites. Liquid chromatography-tandem mass spectrometry and comparison with the synthetic reference standards identified two metabolites (M1 and M5) as the products derived from hydroxylation on the indole moiety of the molecule. M3 was also identified as a product derived from hydroxylation, but the structure of this metabolite was not identified because of the lack of a reference standard. M2, M4, and M6 were identified as the products derived from O-demethylation. M2, 6-desmethyl-BPR0L075, was the major metabolite formed by the liver microsomes of the four species. No qualitative species difference in the metabolism of BPR0L075 was observed. There was quantitative species difference in the metabolism of BPR0L075 among the four species. Whereas mouse and rat liver microsomes metabolized BPR0L075 predominantly via O-demethylation, dog liver microsomes metabolized BPR0L075 by O-demethylation and hydroxylation to about the same extent. The rank order of intrinsic clearance rates for the conversion of BPR0L075 to 6-desmethyl-BPR0L075 was mouse > rat > human > dog. Incubation of BPR0L075 with baculovirus-insect cell-expressed human cytochrome P450 (P450) isozymes showed that CYP1A2, 2C9, 2C19, 2D6, 2E1, and 3A4 all catalyzed the O-demethylation and hydroxylation of BPR0L075 but to a different degree. Among the six P450 isozymes tested, CYP1A2 and 2D6 were most active on catalyzing the metabolism of BPR0L075. CYP1A2 catalyzed mainly the formation of M1, M2, and M3. M2 was the predominant metabolite formed by CYP2D6.
Yao
Hsien-Tsung
HT
Division of Biotechnology and Pharmaceutical Research, National Health Research Institutes, Zhunan Town, Miaoli County, Taiwan, Republic of China.
Wu
Yu-Shan
YS
Chang
Yi-Wei
YW
Hsieh
Hsing-Pang
HP
Chen
Wei-Cheng
WC
Lan
Shih-Jung
SJ
Chen
Chiung-Tong
CT
Chao
Yu-Sheng
YS
Chang
Ling
L
Sun
Hsu-Yi
HY
Yeh
Teng-Kuang
TK
D000818:Animals; D001711:Biotransformation; D002851:Chromatography, High Pressure Liquid / Q000592:standards; D019388:Cytochrome P-450 CYP1A2 / Q000378:metabolism; D019389:Cytochrome P-450 CYP2D6 / Q000378:metabolism; D003577:Cytochrome P-450 Enzyme System / Q000235:genetics / Q000378:metabolism*; D003640:Dealkylation; D004285:Dogs; D005260:Female; D006801:Humans; D006900:Hydroxylation; D066298:In Vitro Techniques; D007211:Indoles / Q000737:chemistry / Q000378:metabolism*; D008297:Male; D051379:Mice; D008862:Microsomes, Liver / Q000201:enzymology / Q000378:metabolism*; D015394:Molecular Structure; D009249:NADP / Q000378:metabolism; D051381:Rats; D011994:Recombinant Proteins / Q000378:metabolism; D012015:Reference Standards; D013045:Species Specificity; D053719:Tandem Mass Spectrometry / Q000592:standards; D050257:Tubulin Modulators / Q000737:chemistry / Q000378:metabolism*
C488735:6-methoxy-3-(3',4',5'-trimethoxybenzoyl)-1H-indole; D007211:Indoles; D011994:Recombinant Proteins; D050257:Tubulin Modulators; D009249:NADP; D003577:Cytochrome P-450 Enzyme System; C504573:CYP1A2 protein, human; D019388:Cytochrome P-450 CYP1A2; D019389:Cytochrome P-450 CYP2D6