Isolation and Characterisation of an Αlpha-amyrin Acetate Isolated from the Leaves of Microtrichia perotitii DC (Asteraceae)

摘要

Aims: Microtrichia perotitii DC belongs to the family Asteraceae and is widely distributed in West African countries of Nigeria, Senegal, Mali, Port of Guinea, Sieraleone, Ivory Coast, Ghana and Dahomey. In Nigeria it is found in northern part of the country where it is known as Maijankai or Sawun keke in Hausa, Osete in Igbira and Shaware pepe in Yoruba languages. The herb is locally used for treating pain related diseases which includes toothaches, cuts and burns, rashes in children, skin diseases, rheumatism, diarrhea and jaundice. It is on the basis of its significance in trado-medicinal usage that an attempt was being made to isolate the active compounds in the herb. Previous phytochemical screening of the leaves of the herb has confirmed the presence of carbohydrates, tannins, cardiac glycosides, triterpenes, proteins, flavonoids, alkaloids, and steroids.Methods: The leaves of the herb were extracted in methanol in a soxhlet apparatus. The crude extract obtained that is Microtrichia perotitii methanol extract (MPME) was fractionated in methanol, ether, aqueous, and n-butanol. Each of these soluble fractions was tested for analgesic and anti-inflammatory activities against laboratory animals (mice and rats). The most active fraction was n-butanol which was obtained as a white milky solid A(C_(1)) and its melting point range was 224 – 226°C. The compound after re-crystallisation` was subjected to spectroscopic analyses with Infrared, proton and carbon-13 Nuclear Magnetic Resonance spectroscopy .Results: The data obtained for the compound when compared with literature value was found to be an alpha-amyrin acetate.Conclusion: An alpha-amyrin acetate was isolated from the leaf of Microtrichia perotitii for the very first time. Alpha-amyrin acetate has been reported to have broad spectrum of biological activities against some diseases and ailments and could therefore be the leading principle behind many of the ethnomedicinal applications of Microtrichia perotitii .