Insecticidal Activity of Phytochemicals and Extracts of the Meliaceae

Abstract

Limonoids, characteristic natural products of the Meliaceae, Rutaceae, and other Rutales, have marked biological activity against a variety of insects. In particular, the well-known compound azadirachtin is under development as a possible commercial insecticide owing to its potent antifeedant and growth-regulating properties. This compound inhibits the feeding, growth and survival of the variegated cutworm, Peridroma saucia, with an EC 50 and LC 50 of 0.36 and 2.7 ppm in diet, respectively. In contrast, azadiracntin has no antifeedant activity against nymphs of the migratory grasshopper, Melanoplus sanguinipes, but does inhibit molting in a dose-dependant manner with an oral ED 50 of 11.3 μg/g insect fwt.The ED 50 via intrahemocoelic injection is 3.2 μg/g, indicating that the gut poses a physical or physiological barrier to azadiracntin bioavailability. The lesser toxicity via the oral route may be largely due to local metabolism, as the oral toxicity can be synergized by piperonyl butoxide, an inhibitor of mixed-function oxidases. The topical ED 50 is 4.5 μg/g insect, indicating that azadirachtin is well absorbed through the integument. Azadirachtin toxicity in this insect does not involve inhibition of sterol reductases or sterol transport. Of nine other limonoids tested, only cedrelone, anthothecol, and bussein inhibit larval growth of P. saucia, and only cedrelone inhibits the molting of the milkweed bug, Oncopeltus fasciatus. Foliar extracts of species in the subfamily Melioideae are on average more insecticidal than extracts from the Swietenioideae; some deserve further attention as sources of insecticidal phytochemicals.In recent years much effort has been devoted to the search for alternatives to the current arsenal of pest-control chemicals. Plant-derived extracts and phytochemicals, which once formed the basis of pest-control technology, are again being scrutinized for potentially useful products or as models for new classes of synthetic insecticides (1, 2). Amongst the most promising of the natural products investigated to date are the limonoids, characteristic

Effect of aqueous extract of Azadirachta indica A. Juss (neem) leaf on oocyte maturation, oviposition, reproductive potentials and embryonic development of a freshwater fish ectoparasite Argulus bengalensis Ramakrishna, 1951 (Crustacea: Branchiura)

“…In insects, it was observed that even the lower concentrations of azadirachtin interfered with the animal physiology with the largest effect being fully inhibiting the feeding process, thereby allowing control of them (Warthen 1989). It inhibits feeding and growth of insects belonging to several orders like Lepidoptera (Koul et al 1987), Diptera (Champagne et al 1989), Orthoptera (Rao and Subrahmanyam 1986;Ascher et al 1989), Hemiptera (Dorn 1986;Dorn et al 1986), Coleoptera (Meisner and Mitchell 1982;Ladd et al 1984), Hymenoptera (Rembold et al 1982), etc. through intervention in endocrine events (Sieber and Rembold 1983; and Blackwell 1993; Malczewska et al 1988;Subrahmanyam et al 1989;Barnby and Klocke 1990).…”

ISOLASI DAN ELUSIDASI STRUKTUR TRITERPENOID KULIT BATANG SURIAN Toona sinensis DAN UJI TERHADAP HAMA Crosidolomia pavonana

“…Dari kajian literatur diperkirakan triterpenoid hasil isolasi memiliki kerangka euphan dengan jumlah atom karbon dua puluh delapan, tidak munculnya satu signal diperkirakan adanya signal yang overlap, terjadinya overlap diperkirakan pada puncak karbon metil pada C-25 dan C-26, hal ini disebabkan karena lingkungan kimia kedua karbon metil hampir sama, kasus ini juga sering terjadi pada spektrum triterpenoid lainnya [16] . Selanjutnya diketahui adanya satu substituen hidroksi dengan munculnya signal karbon pada pergeseran kimia 71,8 ppm dan juga ditemukan satu ikatan rangkap yaitu muncul signal karbon pada pergeseran kimia 121,7 dan 140,7 ppm, maka senyawa triterpenoid hasil isolasi memiliki atom karbon dua puluh delapan dan satu atom oksigen dan memiliki satu ikatan rangkap.…”

Effect of extracts of Trichilia silvatica C. DC., on development and reproduction parameters of Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae)

“…The limonoids of Meliaceae are very complex with a high degree of oxidetion and rearrangement exhibited in the parent limonoid structure. Compounds belonging to this group express a wide range of biological activities like insecticidal deterrence, insect antifeedant and growth regulating capacity on insects (Champagne et al, 1989;Kubo and Klocke, 1982;Mikolajczak and Reed, 1987;Mikolajczak et al, 1989;Nakatani et al, 1981;Simmonds et al, 2001;Xie et al, 1994) as well as antiviral and analgesic, and several other pharmacological effects on humans (Romin et al, 1992;Vaz et al, 1997).…”

“…Some previous studies have focused on nortriterpenoids (limonoids) from the family Meliaceae because of their potent effects on insect pests linked to low toxicity (Carpinella et al, 2002;Champagne et al, 1989;Klocke et al, 1989;Kubo and Klocke, 1982).…”