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Mikania laevigata Schultz Bip. ex Baker, M. involucrata Hook. et Arn. and M. hirsutissima DC. (Asteraceae), commonly occurring in the southern Brazilian State of Rio Grande do Sul, were submitted to biological tests to evaluate their potential antiinflammatory activity. Decoctions from the leaves and stems were analysed by the induced rat paw oedema and pleurisy models. The animals were treated orally with different decoction doses. In the induced rat paw oedema test, the animals treated with leaf decoctions from M. laevigata (200 mg/ kg) and M. involucrata (50 mg/ kg) presented an oedema inhibition of 81.56% and 81.67%, respectively, 3 h after the administration of the phlogistic agent. Leaf decoctions from M. hirsutissima (400 mg/ kg) did not show such an activity. Stem decoctions displayed lower antiinflammatory activity when compared with the same doses and response time of the leaf decoctions for all analysed species. In the pleurisy assay, leaf decoctions from M. laevigata (400 mg/ kg) and M. involucrata (200 mg/ kg) inhibited leukocyte migration to the pleural exudate by 28.26% and 54.35%, respectively.

Brachycerine (1), an unusual alkaloid from the leaves of Psychotria brachyceras, was characterized through spectroscopic data interpretation and its stereochemistry established by NOE difference techniques. Brachycerine (1) was found to be restricted to shoots in rooted cuttings of P. brachyceras (0.018 +/- 0.004% dry weight), and accumulation was unaffected by root induction treatment with auxin.

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