Phytochemical composition and green insecticides from Citrus aurantifolia fruit peels against whitefly, Bemisia tabaci

Abstract

Insecticidal potential of extracts of Citrus aurantifolia, family Rutaceae, was evaluated to control whiteflies, Bemisia tabaci. Biocidal activity directed chromatographic separation of chloroform and butanol fractions, with spectral identification (1D-NMR, 2D-NMR, ESIMS) of the active fractions have been resulted in separation and structural elucidation of for previously described coumarins (bergapten 1, limettin 2, isopimpinellin 3, oxypeucedanin hydrate 4) in addition to a new dimeric coumarin (12R, 12’R)-aurantifolin 5, two known limonoids; 21,23-dihydro-23-methoxy-21-oxolimonin 6, 21,23-dihydro-23-methoxy-21-oxonomilin 7, and two known flavonoid glycosides; scoparin 8, and narcissin 9. Amongst these compounds, narcissin 9 was the most effective after 24 h. of treatment while, (12R, 12’R)-aurantifolin 5 was the most potent against B. tabaci, 3rd instar nymphs after 72 h. of treatment and under laboratory conditions, with LC₅₀ values of 33.31and 15.92 ppm, respectively comparing with the positive control azadirachtin.