Human cytochrome P450 2B6 is an important hepatic enzyme for the metabolism of xenobiotics and clinical drugs. Recently, more attention has been paid to P450 2B6 because of the increasing number of drugs it metabolizes. It has been known to interact with terpenes, the major constituents of the essential oils used for various medicinal purposes. In this study, the effect of monoterpenes on P450 2B6 catalytic activity was investigated. Recombinant P450 2B6 was expressed in Escherichia coli and purified using Ni-affinity chromatography. The purified P450 2B6 enzyme displayed bupropion hydroxylation activity in gas-mass spectrometry (GC-MS) analysis with a k_cat of 0.5 min⁻¹ and a K_m of 47 μM. Many terpenes displayed the type I binding spectra to purified P450 2B6 enzyme and α-terpinyl acetate showed strong binding affinity with a K_d value of 5.4 μM. In GC-MS analysis, P450 2B6 converted α-terpinyl acetate to a putative oxidative product. The bupropion hydroxylation activity of P450 2B6 was inhibited by α-terpinyl acetate and its IC₅₀ value was 10.4 μM α-Terpinyl acetate was determined to be a competitive inhibitor of P450 2B6 with a K_i value of 7.6 μM. The molecular docking model of the binding site of the P450 2B6 complex with α-terpinyl acetate was constructed. It showed the tight binding of α-terpinyl acetate in the active site of P450 2B6, which suggests that it could be a competitive substrate for P450 2B6.

人细胞色素P450 2B6是异种生物和临床药物代谢的重要肝酶。最近，由于P450 2B6代谢的药物数量越来越多，因此引起了更多关注。已知与萜烯相互作用，萜烯是用于各种医学目的的精油的主要成分。在这项研究中，研究了单萜对P450 2B6催化活性的影响。重组P450 2B6在大肠杆菌中表达，并使用镍亲和色谱法纯化。纯化的P450 2B6酶在气相色谱（GC-MS）分析中显示安非他酮的羟基化活性，k _cat为0.5 min ^-1，K _m为47μM。许多萜烯显示出与纯化的P450 2B6酶的I型结合光谱，α-乙酸叔丁酯显示出很强的结合亲和力，K _d值为5.4μM。在GC-MS分析中，P450 2B6将乙酸α-叔丁基酯转化为推定的氧化产物。P450 2B6的安非他酮羟基化活性被乙酸α-叔丁基酯抑制，其IC ₅₀值为10.4μMα-乙酸叔丁酯被确定为具有K _i的P450 2B6的竞争性抑制剂。值为7.6μM。构建了P450 2B6复合物与α-乙酸叔丁酯的结合位点的分子对接模型。它表明乙酸α-叔戊酯在P450 2B6的活性位点上紧密结合，这表明它可能是P450 2B6的竞争底物。