In vitro isolation and characterization of biolarvicidal compounds from micropropagated plants of Spilanthes acmella
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Spilanthes acmella (Family: Asteraceae) commonly known as “toothache plant” is known to possess strong insecticidal and larvicidal properties. Experiments have been conducted to isolate and characterise the biolarvicidal compounds from the flower head extract of micropropagated S. acmella plants employing various tools like FT-IR, TLC, CC, NMR. FT-IR spectroscopy of the crude hexane extract sample revealed the presence of amide (secondary metabolite) as functional group in S. acmella flower heads. The crude extract was separated into 85 fractions (100 ml each) through silica gel column chromatography using hexane-ethyl acetate mobile phase. All fractions were tested for their larvicidal activity against late III/early IV instar Anopheles stephensi larvae and fraction showing maximum bioefficacy against aforesaid larvae was further resolved into three separate bands on Preparative TLC plate, the respective Rf values being (a) 0.18, (b) 0.23 and (c) 0.27. Based on Proton NMR spectrum of the eluted compounds and their comparison with published results, three different compounds were identified: N-isobutyl-2,6,8-decatrienamide (compound 1), undeca-2E,7Z,9E-trienoic acid isobutylamide (compound 2) from band a and (2E)-N-(2-methylbutyl)-2-undecene-8,10-diynamide (compound 3) from band b. The amount of the compounds obtained were 338 mg (compounds 1 and 2) and 188.4 mg (compound 3), respectively. This is the first report of biolarvicidal compounds isolation and characterisation from micropropagated S. acmella plants.
KeywordsMalaria Crude Extract Larvicidal Activity Flower Head Micropropagated Plant
Fourier transform infrared spectroscopy
Nuclear magnetic resonance
Preparative thin-layer chromatography
Veena Agrawal is grateful to University Grants Commission, New Delhi for financial assistance and Vibha Pandey to CSIR, New Delhi for JRF and SRF. Thanks are also due to Dr. A.P. Dash and Dr. K. Raghavendra, National Institute of Malaria Research, Delhi for kindly providing us the mosquito larvae for bioassay tests.
- Crouch NR, Langlois A, Mulholland DA, Nair JJ (2005) A novel alkylamide from the leaves of Acmella caulirhiza (Asteraceae), a traditional surface analgesic. S Afr J Bot 71:228–230Google Scholar
- Jondiko IJO (1986) A mosquito larvicide in Spilanthes mauritiana. Phytochemistry 25:2289–2290Google Scholar
- Ndung'u MW, Kaoneka B, Hassanali A, Lwande W, Hooper AM, Tayman F, Zerbe O, Torto B (2004) New mosquito larvicidal tetranortriterpenoids from Turraea wakefieldii and Turraea floribunda. J Agric Food Chem 52:5027–5031Google Scholar
- Pandey V, Agrawal V (2009) Efficient micropropagation protocol in Spilanthes acmella L. possessing strong antimalarial activity. In Vitro Cell Dev Biol Plant 45:491–499Google Scholar
- Pandey V, Agrawal V, Raghavendra K, Dash AP (2007) Strong larvicidal activity of three species of Spilanthes (Akarkara) against malaria (Anopheles stephensi Liston, Anopheles culicifacies, species C) and filaria vector (Culex quinquefasciatus Say). Parasitol Res 102:171–174CrossRefPubMedGoogle Scholar
- World Health Organization (2005) Resolution WHA. 58.2. Malaria control. In: Fifty-eight World Health Assembly, Resolutions and Decisions Annex. GenevaGoogle Scholar