Natural cyclopeptides as leads for novel pesticides: tentoxin and destruxin

Abstract

: Difficulties in synthesis make natural cyclopeptides challenging targets for chemists. Our interest focused on two natural toxic cyclopeptide series produced by pathogenic fungi :The total syntheses of these two bioactive series were optimised, and several analogues were designed and synthesised to establish structureÈactivity relationships. The importance of synthetic analogues in the identiÐcation of molecular targets and the explanation of mechanisms of action was demonstrated. Such systematic investigations can determine the crucial features responsible for the activity of the natural compound and help the design of more powerful or more selective products.1998 SCI. ( Pestic. Sci., 52, 81È89, 1998 Key words : cyclopeptide ; cyclodepsipeptide ; tentoxin ; H`-ATPase ; herbi-F 0 F 1 cide ; destruxin ; insecticide Abbreviations : These follow the recommendations of the IUPAC-IUB Commission on Biological Nomenclature as given in Eur. J. Biochem. 138 (1984), 9È37.

Fungi as elicitors of insect immune responses

“…1) (Hung and Boucias, 1992;. Several lines of evidence indicate that overcoming the cellular defense in insects during mycosis involves mediation by secondary metabolites such as beauverolides, cyclosporins, and destruxins (Huxham et al, 1989;Cerenius et al, 1990;Cavelier et al, 1998;Vilcinskas and Götz, 1999).…”

Conformational properties of the residues connected by ester and methylated amide bonds: theoretical and solid state conformational studies

“…Methylation of amide is the one that occurs most commonly. The ester and methylated amide bonds can be separated by more than one residue, as in the case of destruxins14, polydiscamides15, somamides16, micropeptins17, oscillapeptin18, geodiamolides19 and eujavanicin A20. Very often, these modifications are present at the same residue.…”

Bulky α,β-dehydroamino acids: their occurrence in nature, synthesis, and applications

“…Accordingly, it is of interest as a potential herbicide. 21 This activity has been attributed to the high affinity of 7 for binding to the chloroplast F 1 H þ -ATPase, resulting in the inhibition of energy transfer. 22 Diketopiperazine 8 bearing a thiomethyl group (Fig.…”