IG-105, N-(2, 6-dimethoxypyridine-3-yl)-9-methylcarbazole-3-sulfonamide, a novel antimicrotubule agent, showed potent anticancer activity in a variety of human tumor cells in vitro and in vivo. In order to characterize the metabolism and the possible drug-drug interaction of IG-105, we carried out a series of experiments. Drug metabolizing enzymes involved in IG-105 metabolism were investigated by using pooled human liver microsomes (HLMs) and recombinant cytochrome P450 isoforms (rP450s) respectively. The possible metabolites were analyzed by liquid chromatography-orbitrap-mass spectrometry (LC-Orbitrap-MS). The inhibitory effect of IG-105 on main P450 enzymes was also evaluated. The results showed that IG-105 can be metabolized by a series of rP450s, including CYP1A2, CYP2B6, CYP2C9, CYP2C19, CYP2D6, CYP3A4 and CYP3A5, with the major contribution enzymes being CYP1A2, CYP2B6, CYP2C19, and CYP3A. Three metabolites (M1-M3) were identified and demethylation was the major phase I metabolic reaction for IG-105. IG-105 moderately inhibited CYP1A2, CYP2C9, CYP2C19, CYP2D6, and CYP3A enzyme activities with IC50 values of 6.42, 23.64, 0.39, 1.4, and 3.14 μmol·L-1, respectively. Since the biotransformation of IG-105 involves multiple enzymatic pathways, the compound is less likely to be a victim of a concomitantly used medicine which inhibits activity of one of the CYPs. However, as IG-105 showed medium to strong inhibition on CYP1A2, CYP2D6, CYP3A, and CYP2C19, caution is particularly needed when IG-105 is co-administrated with other anticancer drugs which are mainly metabolized by the above enzymes.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |