Anthranilic diamides derivatives as potential ryanodine receptor modulators: Synthesis, biological evaluation and structure activity relationship.

A series of novel anthranilic diamides derivatives (7a-s) containing halogen, trifluoromethyl group and cyano group were designed, synthesized, and characterized by melting point, 1H NMR, 13C NMR and elemental analyses. The bioactivity revealed that most of them showed moderate to excellent activities against oriental armyworm (Mythimna separata) and diamondback moth (Plutella xylostella). Above all, the larvicidal activity of 7o against oriental armyworm was 100% and 40% at 0.25 and 0.1 mg L-1, comparable to that of the standard chlorantraniliprole (100%, 0.25 mg L-1 and 20%, 0.1 mg L-1). What is more, 7o against diamondback moth displayed 90% insecticidal activity at 0.01 mg L-1, superior to chlorantraniliprole (45%, 0.01 mg L-1). The experiments 7o on the American cockroach (Periplaneta Americana) heart beating rates (Dorsal vessel) and contractile force were compared with chlorantraniliprole. In addition, 7o could affect the calcium homeostasis in the central neurons of the third larvae of oriental armyworm, which revealed that the ryanodine receptor is the potential target of 7o. The density functional theory (DFT) calculation results revealed the amide bridge, the benzene ring of anthraniloyl moiety and pyrazole ring might play an important role in the insecticidal activity through hydrophobic interactions and π-π conjugations.

Microbial transformation of bufotalin by Alternaria alternata AS 3.4578.

The microbial transformation of a cytotoxic bufadienolide, bufotalin (1), was carried out. Three transformed products from 1 by Alternaria alternata were isolated. Their structures were characterized as 3-keto-bufotalin (2), 12 beta-hydroxyl-bufotalin (3), and 3-keto-12 beta-hydroxyl-bufotalin (4) based on the extensive NMR studies. Among them, 3 and 4 were new compounds with strong in vitro cytotoxic activities against HeLa cells.