Identification of Renin Inhibiting Natural Products from Nauclea latifolia

Abstract

Natural products, particularly plants have been an important source of food and medicine throughout the history of mankind. High blood pressure has become a growing health burden all over the world. There is an obvious need to discover better therapeutic agents to tackle this problem. Exploitation of natural products is one important option. This thesis describes the results obtained from the phytochemical, and bioassay studies, on Nauclea latifolia of Nigerian origin that are summarized as follows: Chemical studies on the crude methanolic extract of the stem/bark of N. latifolia resulted in the isolation of seven new indole alkaloids, latifoliamide A-G (46-52), along with one known alkaloid, angustoline (45). The structures of compounds (45-52) were elucidated using extensive NMR and mass spectral studies. Compounds (45-52) were evaluated for their in vitro renin inhibitory activity. Compounds (45, 46, 49-51) were found to exhibit a wide range of anti-renin activity, while 47 and 52 were inactive in the bioassays. Based on these bioactivity data, it appears that previously reported anti-hypertensive property of this plant in the literature might be due to the presence of these bioactive alkaloids.