Feeding-induced phenol production in Capsicum annuum L. influences Spodoptera litura F. larval growth and physiology.

We studied the role of induced plant phenols as a defense response to insect herbivory. Phenolic compounds were induced in Capsicum annuum L., the source of many culinary peppers, after feeding by different stages of the insect pest, Spodoptera litura F.

New seco-limonoids from Cipadessa baccifera: Isolation, structure determination, synthesis and their antiproliferative activities.

A comprehensive reinvestigation of chemical constituents from CHCl-soluble extract of Cipadessa baccifera led to the isolation of two new limonoids 1, 2 together with six known compounds 3-8. Their structures were established on the basis of extensive analysis of spectroscopic (IR, MS, 2D NMR) data. Further, a series of cipaferen G (3) derivatives were efficiently synthesized utilizing Yamaguchi esterification (2, 4, 6-trichlorobenzoyl chloride, EtN, THF, DMAP, toluene) at the C-3 position of the limonoids core, which is being reported for the first time.

Identification of naphthol derivatives as novel antifeedants and insecticides. 1.

A series of β-naphthol-derived 2-aminobenzothiazolomethylnaphthol derivatives (4a-4q) were synthesized and purified in excellent yields (86-94%) using green protocols and screened for their antifeedant and toxic activities against tobacco caterpillar (Spodoptera litura) and castor semilooper (Achaea janata) using no-choice leaf disk and topical bioassay methods. Four of them, 4d, 4f, 4i, and 4j, were identified to be potent antifeedants with ED50 values of 16.4, 19.

Vapor-phase toxicity of Derris scandens Benth.-derived constituents against four stored-product pests.

The vapor-phase toxicity of Derris scandens Benth.-derived constituents was evaluated against four stored-product pests ( Callosobruchus chinensis L., Sitophilus oryzae L.

Synthesis and insect antifeedant activity of plumbagin derivatives with the amino acid moiety.

A series of plumbagin derivatives (4a-4k) containing an amino acid moiety were synthesized under mild esterification conditions in excellent yields (35%-80%) and screened for their antifeedant activities in tobacco caterpillar (Spodoptera litura) and castor semilooper (Achaea janata) using a no-choice laboratory bioassay. The parent compound plumbagin lacked significant activity, but the analogues were effective in reducing feeding by two insect species. The introduction of an N-acetyl-l-amino acid side chain to the Michael adduct of plumbagin at the third position of the quinone moiety significantly increased antifeedant activity.