Abstract

FRACTIONATION AND EVALUATION OF ETHYL ACETATE AND N-HEXANE EXTRACTS FROM PARTITION OF CRUDE METHANOL SEED EXTRACT OF PICRALIMA NITIDA (STAPF.) T. DURAND AND H. DURAND (APOCYNACEAE) FOR LARVICIDAL ACTIVITY AGAINST AEDES AEGYPTI LARVAE

Okwubie Lambert*, Inya Agha Ifeoma Stella, Odoh Uchenn Estella, Chukwu Chigozirim Juliet and Nafor Fole

ABSTRACT

In this work fractionation of the ethyl acetate and n-hexane extracts from partition of crude methanol seed extract of Picralima nitida was carried out and the fractions evaluated for their larvicidal activities against Aedes egypti larvae. The partition extracts were fractionated using column chromatography. 12 and 13 fractions were obtained from the n-hexane and ethyl acetate extracts respectively. Evaluation of the fractions for larvicidal activities where carried in accordance to that of WHO, 2005 guideline with modifications. Two fractions from n-hexane extract, fractions 6 and 10 with mean percentage mortality of 85 and 52.5% respectively had activities of more than 50% mortality against the Aedes egypti lavae, while four fractions from ethyl acetate extract, fractions 1, 3, 5 and 12 with mean percentage mortality of 87.5, 92.5, 87.5 and 52.5% respectively had activities of more than 50% mortality against the Aedes egypti larvae. Other fractions from both extracts had very low or no activities against the larvae. In conclusion these active fractions could further be purified to isolate and characterise the active agent(s) with the larvicidal activities.

Keywords: fractionation, Ethyl acetate, n-hexane, larvicidal, extract.