Pouteria campechiana leaf extract and its bioactive compound myricitrin are mosquitocidal against Aedes aegypti and Culex quinquefasciatus

ABSTRACT

Objective: To test the mosquitocidal potential of leaf extracts of Pouteria campechiana prepared with different solvents and elucidate the structure of an isolated mosquitocidal compound. Methods: The leaf extracts of Pouteria campechiana prepared with three solvents (petroleum benzene, ethyl acetate and acetone) and potential bioactive fractions were tested against various stages of Aedes aegypti and Culex quinquefasciatus by using the WHO protocols, and the chemical profile and its functional groups were identified by GC-MS and Fourier transmission-infrared spectroscopy (FT-IR). The structure of bioactive compound was characterized by nuclear magnetic resonance (NMR) spectral technique. Results: The preliminary phytochemical results revealed the presence of alkaloids, amino acids, flavonoids, quinones, saponins, steroids, tannins, and terpenoids in the acetone extract. A significant toxic potential was observed in the acetone extract against both Aedes aegypti and Culex quinquefasciatus mosquitoes. The acetone extract exhibits remarkable larvicidal (LC50 12.232 μg/mL and LC90 63.970 μg/mL), pupicidal (LC50 18.949 μg/mL and LC,0 167.669 μg/mL) and adulticidal (LC50 20.689 μg/mL and LC90 72.881 μg/mL) effects against Aedes aegypti. Furthermore, the same extract was subjected to isolation of bioactive compound by GC- MS and FT-IR analysis. GC-MS results showed the presence of 5 major compounds, and octacosane (18.440%) was detected as the predominant compound. The FT-IR result of acetone extract demonstrated the presence of various functional groups like alkanes/alkynes, ester, aromatic and amides. The NMR spectrum results of isolated compound were well matched to glycoside linked flavonoids. Based on the chromatography and spectral techniques the isolate molecule was identified as myricitrin by FT-IR and nuclear magnetic resonance spectral data. Conclusion: The isolated compound myricitrin possesses a significant toxic effect in all stages of Aedes aegypti and Culex quinquefasciatus mosquito's with lowest LC50 and LC90 values.