苯乙烯基萘类化合物的合成及其CYP1B1酶抑制活性研究

目的寻找CYP1B1酶的高活性高选择性抑制剂。方法以α-萘黄酮为先导物,结合二苯乙烯类CYP1B1酶抑制剂的结构特征,设计了先导物的结构类似物α-(E)-苯乙烯基萘类(Ⅰ)及β-(E)-苯乙烯基萘类(Ⅱ、Ⅲ)化合物。目标化合物通过萘甲醛(6、7或8)及苄基膦酸酯(Ⅴ1～Ⅴ10)的Horner-Wadsworth-Em-mons反应制备。利用7-乙氧基-3H-吩口恶嗪-3-酮-脱乙基(EROD)试剂评价目标化合物对人重组CYP1A1和CYP1B1酶的抑制活性。结果合成了26个新型苯乙烯基萘类化合物,其结构通过1H-NMR确证。酶抑制活性试验表明,与阳性对照物白藜芦醇相比,大多数目标化合物对CYP1B1酶表现出较强的抑制活性及选择性。化合物Ⅰ2、Ⅰ8、Ⅲ2、Ⅲ4较α-萘黄酮显示更强的酶抑制活性及选择性。其中,化合物Ⅰ2对CYP1B1酶的抑制活性最强(IC50为0.31 nmol.L-1)。结论合成了新型苯乙烯基萘类CYP1B1酶抑制剂,并初步分析了其构效关系,为进一步的结构优化及新抑制剂的研究提供依据。

Synthesis of styrylnaphthalenes as potent inhibitors of CYP1B1

Human CYP1B1 as one member in CYP1 family could catalyze the bioactivation of certain procarcinogens. It plays a pivotal role in the carcinogenic action of 17-β-estradiol. Recent knowledge relating to the high and consistent expression of this enzyme in various tumor organs and the involvement of it in anti-cancer drug resistance, make the inhibition of CYP1B1 as a new method in cancer prevention and therapy. Resveratrol, an inhibitor of CYP1B1, has been deemed as one of the potential chemopreventive trans-stilbenes. α-Naphthoflavone (ANF) as a strong and selective inhibitor of CYP1B1, has been employed for eliminating CYP1B1-mediated anti-cancer drug resistance in vitro. Taking ANF as a lead, α-(E)-styryl-4,5,8-trimethoxy naphthalene (Ι1) and its derivatives (Ι2~Ι10) as the structural analogues of the lead were synthesized via the Horner-Wadsworth-Emmons reactions between phosphonates (Ⅴ1~Ⅴ10) and 4,5,8-trimethoxy-1-naphthaldehyde (6). β-(E)-styryl-1,4,8-trimethoxy naphthalenes (Ⅱ1~Ⅱ8) and β-(E)-styryl-1,4,5,8-tetramethoxy naphthalenes (III1~III8) were also prepared to examine the influence of the position of the styryl moiety on the naphthalene part of these new compounds towards CYP1B1 inhibition. All the candidates prepared were evaluated for their inhibitory effects on CYP1B1-mediated EROD activity. The results suggested that most of these new compounds were more potent inhibitors of human CYP1B1 enzyme than resveratrol. Compared with the lead, compounds Ι2, Ι8, III2, III4 exhibited much higher potency and selectivity towards CYP1B1 inhibition. The SARs analysis indicated that α-(E)-styryl-4,5,8-trimethoxy naphthalenes (Ι) were stronger inhibitors than the corresponding β-(E)-styryl-1,4,8-trimethoxy naphthalenenes (Ⅱ) and β-(E)- styryl-1,4,5,8-tetramethoxy naphthalenes (III). The introduction of 3’,4’,5’-OMe groups or a 4’-OMe substitution on the styryl moiety of Ι, Ⅱand III, caused sharp decrease in their inhibitory effects. On the contrary, the derivatives with the 2’-OMe substitution (Ι8, Ⅱ6, III6) exhibited increased inhibitory potency. Meanwhile, 4’-F analogues (Ι2, Ⅱ2, III2) showed more potent inhibition than the corresponding 4’-Cl and 4’-OMe analogues. Among the tested ones, Ι2 exhibited the strongest inhibition effects with the IC50 value of 0.31 nmol•L-1.