Antifeedant and phytotoxic activity of cacalolides and eremophilanolides.
The antifeedant effect of six cacalolides and six eremophilanolides was tested against the herbivorous insects Spodoptera littoralis, Leptinotarsa decemlineata, and Myzus persicae. The test compounds included several natural products isolated from Senecio madagascariensis (14-isovaleryloxy-1,2-dehydrocacalol methyl ether, 4), S. barba-johannis (13-hydroxy-14-oxocacalohastine, 5; 13-acetyloxy-14-oxocacalohastine, 6) and S. toluccanus [6-hydroxyeuryopsin, 7; 1(10)-epoxy-6-hydroxyeuryopsin, 9; toluccanolide A, 11] and the derivatives cacalol methyl ether (1); cacalol acetate (2); 1-acetyloxy-2-methyloxy-1,2,3,4-tetradehydrocacalol acetate (3); 6-acetyloxyeuryopsin (8); 6-acetyloxy-1(10)-epoxyeuryopsin (10), and toluccanolide A acetate (12). Compound 11 and its derivative 12 exhibited moderate antifeedant activity against S. littoralis; 2, 7-10, and 12 showed strong activity against L. decemlineata, while the aphid M. persicae was moderately deterred in the presence of compounds 1, 4, 8, 10, and 12. The phytotoxic activity of 1-12 on Lactuca sativa was also evaluated. Compounds 2 and 4-12 moderately inhibited seed germination at 24 h, while compounds 1-4, 6, 9, and 10 had a significant inhibition effect on L. sativa radicle length (over 50%).
Burgueño-Tapia
Eleuterio
E
Departamento de Química Orgánica, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Prolongación de Carpio y Plan de Ayala, Col. Santo Tomás, México DF, 11340 Mexico.
González-Coloma
Azucena
A
Martín-Benito
Darío
D
Joseph-Nathan
Pedro
P
D000818:Animals; D000935:Antifungal Agents / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology; D001042:Aphids / Q000187:drug effects*; D001517:Coleoptera / Q000187:drug effects*; D005247:Feeding Behavior / Q000187:drug effects; D007306:Insecticides / Q000737:chemistry* / Q000302:isolation & purification / Q000633:toxicity; D008958:Models, Molecular; D010936:Plant Extracts / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology; D012639:Seeds / Q000737:chemistry; D012717:Sesquiterpenes / Q000302:isolation & purification* / Q000494:pharmacology*; D018411:Spodoptera / Q000187:drug effects*
D000935:Antifungal Agents; D007306:Insecticides; D010936:Plant Extracts; D012717:Sesquiterpenes; C497192:cacalol