Activity of Neolignans Isolated from Piper regnellii (MIQ.) C. DC. var. pallescens (C. DC.) YUNCK against Trypanosoma cruzi
作者:Patrícia Shima Luize、Tânia Ueda-Nakamura、Benedito Prado Dias Filho、Diógenes Aparício Garcia Cortez、Celso Vataru Nakamura
DOI:10.1248/bpb.29.2126
日期:——
The in vitro antiproliferative effects of 4 neolignans purified from the ethyl-acetate extract from leaves of Piper regnellii (MIQ.) C. DC. var. pallescens (C. DC.) YUNCK against Trypanosoma cruzi were investigated. These isolated compounds were identified through spectral analyses of UV, EI-MS, 1H-, 13C-NMR, H–H COSY, gNOE, HETCOR, and HMBC. The compounds eupomatenoid-5, eupomatenoid-6, and conocarpan showed considerable activity against epimastigote forms of T. cruzi, with 50% inhibition concentrations (IC50) of 7.0, 7.5, and 8.0 μg/ml respectively. After methylation, these compounds showed a lessened inhibitory activity to the growth of the protozoan, suggesting that loss of the hydroxyl group from their molecules reduces the activity. The compound eupomatenoid-3 showed lower activity than the hexane fraction. Eupomatenoid-5 was significantly more active than benznidazole, the antiparasitic drug of choice for treatment of Chagas' disease. The crude extract, hexane fraction, and eupomatenoid-5 caused no lysis in sheep blood at concentrations which inhibit the growth of epimastigote forms. The compound eupomatenoid-5 showed low cytotoxic effects against Vero cells. These results provide new perspectives on the development of novel drugs obtained from natural products with trypanocidal activity. However, the extracts and active compound isolated from P. regnellii var. pallescens should be further studied in animal models for in vivo efficacy.
研究了从 Piper regnellii (MIQ.) C. DC. var. pallescens (C. DC.) YUNCK 叶子的乙酸乙酯提取物中纯化的 4 种新木质素对克鲁斯锥虫的体外抗增殖作用。通过紫外光谱、EI-MS、1H-、13C-NMR、H-H COSY、gNOE、HETCOR 和 HMBC 等光谱分析鉴定了这些分离化合物。化合物 eupomatenoid-5、eupomatenoid-6 和 conocarpan 对 T. cruzi 的表皮原虫具有相当高的活性,其 50% 抑制浓度(IC50)分别为 7.0、7.5 和 8.0 μg/ml。甲基化后,这些化合物对原生动物生长的抑制活性减弱,表明其分子中羟基的缺失降低了活性。化合物 eupomatenoid-3 的活性低于正己烷馏分。Eupomatenoid-5 的活性明显高于苯并咪唑,后者是治疗南美锥虫病的首选抗寄生虫药物。粗萃取物、正己烷馏分和 eupomatenoid-5 在绵羊血液中不会造成裂解,其浓度可抑制上皮细胞的生长。化合物 eupomatenoid-5 对 Vero 细胞的细胞毒性较低。这些结果为从具有杀锥虫活性的天然产物中开发新型药物提供了新的视角。然而,从 P. regnellii var. pallescens 中分离出的提取物和活性化合物还需要在动物模型中进一步研究其体内疗效。