Crataegus monogyna Jacq. : a source of oleanolic acid, a potential angiotensin-converting enzyme inhibitor

Abstract

Crataeugus monogyna Jacq., a local wild medicinal plant, contains several compounds that possess various pharmacological properties, including effects on the cardiovascular system. The compound of interest in this dissertation was oleanolic acid, a penacyclic triterpenoid present in the free state of salt form. This investigation was aimed at the extraction of oleanolic acid and determination of its quality and quantity by several analytical assays. Oleanolic acid (0.0496%) was extracted from air-dried fruit. This involved Soxhlet extraction, partitioning of the compound in diethyl ether, dissolution in acetone and preparative layer chromatography, successively. The purity of oleanolic acid was determined by TLC, IR and UV spectroscopy. The ethanolic extract was tested for other compounds by spectrophotometric and colorimetric techniques. It resulted that this extract contained favonoids and coumarins, but no catecholamines or organic acids. The quantity of triterpenoids obtrained from the plant material was 0.8976%, of which oleanolic acid constituted only 5.53%. Therefore the yield of oleanolic acid by the ripe fruit was low.