Detlef Manns

Linalool and cineole type glucosides from Cunila spicata.

The leaves of Cunila spicata yielded a monoterpenetriol and six glycosidic terpenoids derived from linalool, hydroxylated linalool and 1,8-cineole: 3,7-dimethyl-oct-1-ene-3,6,7-triol, linalool-O-beta-D-glucopyranoside, 3,7 dimethyl-octa-1,6-diene-3,8-diol-3-O-beta-D-glucopyranoside as well as 3,7-dimethyl-octa-1,5-diene-3,7-diol-3-O-beta-D-glucopyranoside, 3,7-dimethyl-octa-1,7-diene-3,6-diol-7-O-beta-D-glucopyranoside, 3,7- dimethyl-oct-1-ene-3,6,7-triol-6-O-beta-D-glucopyranoside and (1S,4R,6R)-1,3,3-trimethyl-2-oxabicyclo[2.2.2]octan-6-O-beta- glucopyranoside. The structures of the glucosides were established by chemical and spectroscopic methods especially high field NMR techniques.

Homoditerpene peroxides fromArtemisia absinthium

Abstract Two new diastereomeric homoditerpene peroxides have been isolated from the aerial parts of wormwood ( Artemisia absinthium ). The mixture of both compounds showed antimalarial activity in vitro with an EC 50 of 1 μg ml −1 .

Triterpenes with a new 9-epi-cucurbitan skeleton from Senecio selloi

From the fresh aerial parts of Senecio selloi (Asteraceae), two diastereomeric triterpenes with a hitherto unknown skeleton have been isolated. The structure has been elucidated mainly by advanced NMR experiments, including inverse techniques, HMQC, HMBC, ROESY.

Allergenic sesquiterpene lactones from Eupatorium cannabinum L. and Kaunia rufescens (Lund ex de Candolle)

From Eupatorium cannabinum L., a hitherto unknown alpha-methylene-gamma-butyrolactone, 3 beta-peroxyeucannabinolide, was isolated. This compound and eupatoriopicrin from the same plant showed a weak sensitizing capacity in guinea pigs. 2-oxoludartin and dehydroleucodin, isolated from Kaunia rufescens (syn. Eupatorium rufescens), were strong sensitizers in the same sensitizarian procedure.

Screening of Brazilian plants for the presence of peroxides

Chloroform or dichloromethane extracts of 357 southern Brazilian plant species were tested for the presence of peroxides by thinlayer chromatography, using the spray reagent from Huber & Frohlke. From the species tested, 71 (20%) showed positive results and most of them (56%) are Asteraceae species. The species tested were mainly from Asteraceae, but 55 more families were screened, in a total of 77 genera surveyed.