Phytochemical analyses as well as antimicrobial and antioxidant activities of the extracts of
C. sumatrensis
aerial parts were investigated in this study.
METHODS: The aerial parts of
C. sumatrensis were air dried, weighed and exhaustively extracted with hexane, ethyl acetate and
methanol successively. The crude extracts were screened for metabolites. These extracts of
the plant were evaluated for antimicrobial and antioxidant activities using agar diffusion and
DPPH method respectively. The extracts were also analysed using Gas chromatography –
Mass spectrometry, and the chromatogram coupled with mass spectra of the compounds were
matched with a standard library.
RESULTS: Preliminary phytochemical investigation of
crude n-hexane, ethyl acetate and methanol extracts of the aerial parts of
Conyza sumatrensis
revealed the presence of anthraquinones, flavonoids, terpenoids, phenolics, tannin, glycosides
and carbohydrate. All the crude extracts gave a clear zone of inhibition against the growth of
the test bacteria (
Staphylococcus aureus
,
Escherichia coli
,
Bacillus subtilis
,
Pseudomona aeruginosa,
Salmonella typhi
,
Klebsiellae pneumonae
) at moderate to high concentrations, as
well as test fungi (
Candida albicans
,
Aspergillus niger
,
penicillium notatum
and
Rhizopus stolonifer
) at high concentration. Methanolic extract exhibited significant radical scavenging
property with IC
50 of 17.08 μg/mL while n-hexane and ethyl acetate extracts showed no
significant antioxidant activity. GC-MS of N-hexane extract showed a total number of eleven
chemical constituents with α-Farnesene and spathulenol being the most abundance
compounds constituting 20.27 and 22.28% of the extract respectively. Ethyl acetate extract
revealed thirteen compounds with two most abundant compounds, cis-β-farnesene (16.64 %)
and cis-pinane (21.09 %). While methanolic extract affords seventeen compounds with Ephytol
being the most abundant compound (19.36 %).
