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The ‘guaco’ lianous herb Mikania laevigata, which is widespread in Southern Brazil, is traditionally used to treat bronchitis, asthma and cough. This work investigates the influence of the extraction method, solvent:drug ratio, ethanol proportion, harvest season (summer or winter) and solvent heating on the physicochemical profile of the extracts (dry weight, density, pH) and the coumarin (1,2-benzopyrone) content determined by LC. Among the results obtained, it is observed that higher ethanol content increases the amount of coumarin in the extract. Leaves harvested in summer also produce an extract with a high coumarin yield. The most efficient method of extraction is percolation, independent of the solvent used.

Phytochemical survey of stems and leaves of the South Brazilian endemic Raulinoa echinata Cowan, Rutaceae led to the isolation of five limonoid derivatives: the widespread limonin, limonexic acid, kihadalactone B, a methoxylated limonexic acid derivative and a degraded limonoid structurally related to fraxinellone. The two latter compounds have been isolated for the first time. These compounds displayed weak inhibitory activity when assayed in vitro against trypomastigote forms of Trypanosoma cruzi. In this paper, the isolation, structure elucidation and bioactivity of these compounds are reported

We have isolated two phytoconstituents present in the B. forficata leaves, a medicinal plant employed in folk medicine specially for the treatment of diabetes. These compounds were isolated by column chromatography and identified as β-sitosterol and kaempferol-3,7-dirhamnoside (kaempferitrin) by spectroscopical data and comparison with authentic samples. A comparative study with different parts of the plant indicated that the latter is present only in the leaves, suggesting that it might be useful for a suitable quality control of phytotherapeutics which contain this organ of B. forficata in its composition.