Insecticides in Chinese medicinal plants: survey leading to jacaranone, a neurotoxicant and glutathione-reactive quinol.
Sixty-two plant species from central China were purported to have insecticidal activity. Adult house fly (Musca domestica) toxicity assays were used to identify the two most active plants and guide the chromatographic isolation of the insecticidal components. The active ingredient of Senecio palmatusPall. (Asteraceae) was characterized as methyl (1-hydroxy-4-oxocyclohexa-2,5-dien-1-yl)acetate (jacaranone) (1), previously known to have insect antifeedant activity. Mono- and bisglutathione (GSH) adducts are formed on incubation of 1 with GSH and rat liver GSH S-transferase. The toxic action of 1 in mice (intraperitoneal LD(50) = 150-200 mg/kg) is associated with both neurological signs and GSH depletion in liver 90 min after treatment. Paeonia suffruticosa var. papaveracea (Andr.) Kerner (Paeoniaceae) was the other active plant found here to have 2'-hydroxy-4'-methoxyacetophenone (paeonol) (2) as an insecticidal ingredient in the root and in one case, for the whole plant, contaminated with S-tert-butylthiomethyl O,O-diethyl phosphorodithioate (terbufos) (3), a synthetic anticholinesterase insecticide.
Xu
Hanhong
H
Environmental Chemistry and Toxicology Laboratory, Department of Environmental Science, Policy and Management, University of California, Berkeley, CA 94720-3112, USA.
Zhang
Nanjing
N
Casida
John E
JE
D000818:Animals; D016227:Benzoquinones; D002800:Cholinesterase Inhibitors / Q000302:isolation & purification / Q000494:pharmacology; D004365:Drugs, Chinese Herbal / Q000302:isolation & purification* / Q000494:pharmacology; D005260:Female; D005978:Glutathione / Q000378:metabolism; D006793:Houseflies; D020128:Inhibitory Concentration 50; D007306:Insecticides / Q000302:isolation & purification* / Q000494:pharmacology; D008297:Male; D051379:Mice; D029596:Paeonia / Q000737:chemistry*; D010946:Plants, Medicinal / Q000737:chemistry; D010947:Plants, Toxic / Q000737:chemistry; D011809:Quinones / Q000302:isolation & purification* / Q000494:pharmacology; D012674:Senecio / Q000737:chemistry*
D016227:Benzoquinones; D002800:Cholinesterase Inhibitors; D004365:Drugs, Chinese Herbal; D007306:Insecticides; D011809:Quinones; C013077:jacaranone; D005978:Glutathione