RESUMEN
Avermectin-grafted-N,O-carboxymethyl chitosan (NOCC) derivative was obtained by esterification reaction using dicyclohexylcarbodiimide (DCC) as dehydrating agent and 4-methylaminopyridine as catalyst. The structures of the conjugate were confirmed by FT-IR, (1)H NMR, and XRD. Insecticidal activities against armyworms, carmine spider mites, black bean aphids, and brown plant hoppers were investigated at concentrations ranging from 0.16 to 1000 mg/L. At the concentration of 1000 mg/L and 500 mg/L, the lethal rate was 100%. Good insecticidal activity at 4 mg/L was still shown, especially against the black bean aphids and brown plant hoppers. Moreover, the photostability of the conjugate was evaluated and showed an apparent improvement. At 300 mins, the residual rate of the conjugate was 11.22%, much higher than 0.2% of the avermectin technical material. The conjugate we developed showed potential for further study and application in crop protection.
Asunto(s)
Áfidos/efectos de los fármacos , Quitosano/farmacología , Insecticidas/farmacología , Ivermectina/análogos & derivados , Aminopiridinas/química , Animales , Quitosano/química , Diciclohexilcarbodiimida/química , Diciclohexilcarbodiimida/farmacocinética , Esterificación , Insecticidas/química , Ivermectina/química , Ivermectina/farmacología , Espectroscopía de Resonancia Magnética , Espectroscopía Infrarroja por Transformada de FourierRESUMEN
The inhibition of membrane ATPase from the marine alkalotolerant bacterium Vibrio alginolyticus by DCCD, triphenyltin and venturicidin was studied. DCCD proved to be an irreversible inhibitor, while venturicidin and triphenyltin produced a reversible inhibitory effect. The DCCD-binding proteolipid was identified in the membrane preparations. The effect of the inhibitors on ATPase activity and ATP-dependent Na(+)-transport in V. alginolyticus subcellular vesicles is discussed.
Asunto(s)
Diciclohexilcarbodiimida/farmacocinética , Compuestos Orgánicos de Estaño/farmacocinética , ATPasas de Translocación de Protón/metabolismo , Venturicidinas/farmacocinética , Vibrio/enzimología , Adenosina Trifosfato/metabolismo , Membrana Celular/efectos de los fármacos , Membrana Celular/enzimología , Sodio/metabolismo , Vibrio/efectos de los fármacosRESUMEN
In order to identify functionally important amino acid residues in the chloroplast protein import machinery, chloroplasts were preincubated with amino-acid-modifying reagents and then allowed to import or form early import intermediates with precursor proteins. Incubation of chloroplasts with N-ethyl maleimide, diethyl pyrocarbonate, phenylglyoxal, 4,4'-di-isothiocyanatostilbene 2,2'-disulphonic acid (DIDS), dicyclohexylcarbodiimide (DCCD), and 1-ethyl- 3-dimethylaminopropylcarbodiimide (EDC) inhibited both import and formation of early import intermediates with precursor proteins by chloroplasts. This suggests that one or more of the binding components of the chloroplast protein import machinery contains functionally important solvent-exposed cysteine, histidine, arginine, and aspartate/glutamate residues, as well as functionally important lysine and aspartate/ glutamate residues in a hydrophobic environment.