The phytochemical investigation of L. macrophylla Benth led to the isolation of a new flavanol named licanol: (-)-4'-O-methyl-epigallocatechin-3'-O-α-L-rhamnoside, along with nine known compounds, identified as: (-)-4'-O-methyl-epigallocatechin, pheophytin A, 13²-hydroxy-(13²-S)-pheophytin A, pheophytin B, sitosterol, stigmasterol, sitosterol-β-O-glucoside, betulinic alcohol and oleanolic acid. The structures were established based on IR, HR-ESI-MS, and NMR spectrometric data analysis with the aid of 2D techniques. The methanolic extracts of leaves and stem bark as well as the compounds licanol, 13²-hidroxi-(13²-S)-feofitina A, and betulinic alcohol demonstrated antimicrobial activity against several bacterial strains.

Pradosia huberi (Ducke) Ducke (Sapotaceae), espécie Amazônica popularmente conhecida como "casca-doce" é utilizada na medicina tradicional no tratamento de gastrite. O extrato etanólico de suas cascas é rico em polifenóis que podem apresentar um grande número de atividades, incluindo efeito vasorelaxante e cardioprotetor. O objetivo deste estudo foi avaliar as propriedades farmacológicas do extrato etanólico (EPH), de frações e da 2,3-diidromiricetina-3-O-α-L-raminosídeo isolados de P. huberi, em artéria mesentérica isolada de rato. O EPH foi fracionado resultando nas seguintes frações: CHCl3, CHCl3:AcOEt (1:1), AcOEt, AcOEt:MeOH (1:1) e MeOH. Da fração MeOH foi isolada a 2,3-diidromiricetina-3-O-α-L-raminosídeo e identificada através de espectro de RMN de ¹H e 13C, além de comparações com os dados de literatura. EPH (1-100 µg/mL) promoveu relaxamento dependente de concentração no tônus vascular induzido por 10 µM de fenilefrina (CE50=17,1±2,9 µg/mL; Emax=87,4±2,9 %, n=8). A fração MeOH também relaxou os anéis mesentéricos (CE50=31±2,0µg/mL; Emax=54±12,5%, n=6), porém com menor eficácia quando comparado ao efeito de EPH. Tanto o efeito de EPH com de MeOH foram completamente abolidos após a remoção do endotélio vascular. A fração AcOEt:MeOH (1:1) e o flavonoide isolado induziram vasorelaxamento. O estudo demonstrou que o EPH e a fração MeOH de Pradosia huberi apresentam propriedade vasorelaxante que pode ser completamente dependente da presença do endotélio. O flavonoide isolado não é o responsável por este efeito vasorelaxante.

Pradosia huberi (Ducke) Ducke (Sapotaceae), an Amazonian species, is popularly known as "casca-doce" and used in the folk medicine for the treatment of gastritis. The ethanol extract of the bark contains mainly polyphenolic compounds, which are known to show a large number of activities, including cardioprotective and vasorelaxant effects. The aim of this study was to evaluate the pharmacological properties induced by P. huberi ethanol extract (PHEE) and fractions and 2-3-dihydromyricetin-3-O-α-L-rhamnoside derived from this extract, in isolated rat mesenteric arteries. PHEE was separated and the following fractions were obtained: CHCl3, CHCl3:AcOEt (1:1), AcOEt, AcOEt:MeOH (1:1) and MeOH. We isolated 2-3-dihydromyricetin-3-O-α-L-rhamnoside from the MeOH fraction, which was identified by¹H and 13C NMR spectra and compared with data in the literature. PHEE (1-100 µg/mL) induced concentration-dependent relaxations of 10 µM phenylephrine-induced tone (EC50=17,1±2,9 µg/mL; Emax=87.4±2.9 %, n=8). The MeOH fraction also relaxed mesenteric rings (EC50=31±2.0 µg/mL; Emax=54±12.5%, n=6) but less effectively when compared to PHEE. Both effects were completely abolished after removal of the vascular endothelium. The AcOEt:MeOH (1:1) fraction and the isolated flavonoid were ineffective in eliciting vasorelaxation. The study demonstrates that PHEE and MeOH fraction of Pradosia huberi possess a vasorelaxant effect, which may be completely dependent upon endothelium. The isolated flavonoid is not responsible for this vasorelaxant effect.