Estrada Omar, González-Guzmán Juan M, Salazar-Bookman María M, Cardozo Alfonso, Lucena Eva, Alvarado-Castillo Claudia P
Nat Prod Commun. 2015 Feb;10(2):281-4.
The Aspidosperma genus (Apocynaceae) represents one of the largest sources of indole alkaloids widely associated with cardiovascular effects. Aspidosperma fendleri, a plant found mainly in Venezuela, has a single phytochemical report in which is revealed the presence of alkaloids in its seeds. This study explored the cardiovascular effects of an ethanolic extract of A. fendleri leaves (EEAF) in spontaneously hypertensive rats (SHR) and its potential bioactive compounds. Using bioguided fractionation, fractions and pure compounds were intravenously administered to SHR and their effects on mean arterial blood pressure (MABP) and heart rate (HR) monitored over time. EEAF induced hypotensive and bradycardic effects as shown by significant reductions in mean arterial blood pressure (MABP) and heart rate (HR), respectively. Bioactivity-guided fractionation led to the isolation of a mixture of two known isomeric triterpenoid glycosides identified by spectral evidence as quinovic acid 3-O-β-rhamnopyranoside and quinovic acid 3-O-β-fucopyranoside. This mixture of triterpenoid saponins induced reductions in MABP and HR similar to those induced by propranolol. Together, these findings indicate that the two quinovic acid glycosides are responsible for the hypotensive and bradycardic effects which suggest their potential use in cardiovascular therapy.
阿氏长春花属（夹竹桃科）是吲哚生物碱的最大来源之一，这些生物碱广泛具有心血管效应。芬德勒氏阿氏长春花是一种主要生长在委内瑞拉的植物，仅有一份植物化学报告揭示了其种子中存在生物碱。本研究探讨了芬德勒氏阿氏长春花叶片乙醇提取物（EEAF）对自发性高血压大鼠（SHR）的心血管效应及其潜在的生物活性化合物。采用生物导向分级分离法，将分级分离物和纯化合物静脉注射给SHR，并随时间监测它们对平均动脉血压（MABP）和心率（HR）的影响。EEAF分别使平均动脉血压（MABP）和心率（HR）显著降低，从而产生降压和心动过缓作用。生物活性导向分级分离法导致分离出两种已知的异构三萜糖苷混合物，通过光谱证据鉴定为奎诺酸3 - O-β-鼠李吡喃糖苷和奎诺酸3 - O-β-岩藻吡喃糖苷。这种三萜皂苷混合物引起的MABP和HR降低与普萘洛尔引起的相似。总之，这些发现表明这两种奎诺酸糖苷是降压和心动过缓作用的原因，提示它们在心血管治疗中的潜在用途。
