Abstract

The aerial parts of Mikania micrantha H. B. K. were prepared with different polarities solvents by the associated ultrasonic extracting method. The screening antimicrobial activities assays were designed against fungi (Fusarium solani, Phytophthora parasiticaDestur, Pythium aphanidermatum, and Rhizoctonia solani Kühn) and bacteria (Ralstonia dolaanacearum, Xanthomonas oryzae pv. Oryzae). The results show that the leaves extracts were higher bioactivity than the stem extracts, and the chloroform extracts were observed the highest bioactivity. The antimicrobial potential of the leaves extracts of M. micrantha were also assessed. The results show that concentration for 50% of maximal effect (EC₅₀) values was 1313.92, 2493.63, 1718.97, and 1084.91 mg/l respectively at 48h against the five fungi tested. Determination of Minimum Inhibitory Concentration (MIC) values were found to be 250 and 500 mg/l respectively against the two bacteria tested. The result of Gas Chromatography-Mass Spectrometer (GC-MS) analysis indicated that 13 compounds, which represented 87.03% of total, were present in the leaves extract, and 1-(4-chlorophenyl)-2- hydroxyethanone (57.44%) was the major chemical constituent.

Key words: Mikania micrantha H.B.K., leaves extracts, chloroform extracts, fungistasis efficacy, bacteriostatic efficacy, GC-MS analysis