title: Insect antifeedant sesquiterpene acetals from the liverwort Lepidolaena clavigera. 2. structures, artifacts, and activity.
abstract: Clavigerin A ( 1) was isolated from the New Zealand liverwort Lepidolaena clavigera and shown to be a polyoxygenated bergamotane sesquiterpene with an unusual ring system. L. clavigera shows infraspecific variation, since 1 was the only clavigerin detected in a North Island collection, whereas the previously reported clavigerins B ( 2) and C ( 3) were found in South Island collections with no sign of 1. Three new clavigerins, 4- 6, were identified, but these are artifacts formed by alcoholysis of the acetoxy acetal group of the clavigerins 2 and 3, with either the extraction solvent ethanol or the RP column eluent methanol. The insect antifeedant and cytotoxic activities of these compounds are reported, and it is proposed that they act as hidden 1,4-dicarbonyl compounds.
authors.affiliation: New Zealand Institute for Crop & Food Research Ltd, Dept of Chemistry, University of Otago, P.O. Box 56, Dunedin, New Zealand. perryn@crop.cri.nz
authors.forename: Nigel B
authors.initials: NB
authors.lastname: Perry
authors.forename: Elaine J
authors.initials: EJ
authors.lastname: Burgess
authors.forename: Lysa M
authors.initials: LM
authors.lastname: Foster
authors.forename: Philippa J
authors.initials: PJ
authors.lastname: Gerard
authors.forename: Masao
authors.initials: M
authors.lastname: Toyota
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Asakawa
mesh_terms: D000080:Acetals / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D000818:Animals; D000972:Antineoplastic Agents, Phytogenic / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D001517:Coleoptera / Q000187:drug effects; D004354:Drug Screening Assays, Antitumor; D005247:Feeding Behavior / Q000187:drug effects; D000882:Haplorhini; D035926:Hepatophyta / Q000737:chemistry*; D015394:Molecular Structure; D009036:Moths / Q000187:drug effects; D009520:New Zealand; D010946:Plants, Medicinal / Q000737:chemistry*; D012717:Sesquiterpenes / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*
chemical_list: D000080:Acetals; D000972:Antineoplastic Agents, Phytogenic; D012717:Sesquiterpenes; C528139:clavigerin A; C528137:clavigerin B; C528138:clavigerin C