Estudo químico e biológico de Warszewiczia coccinea (Vahl) Klotzch (Rubiaceae).

Abstract

The Rubiaceae family is recognized for having a chemodiversity of metabolites, indole alkaloid, triterpenes, iridoids, anthraquinones and other classes of metabolites which have biological activity. The specie in study Warszewiczia coccinea (Vahl) Klotzsch (Rubiaceae) presents reports in the literature of in vitro antileishmania activity, antioxidant and acetylcholinesterase inhibition, also described the isolation of triterpenes and an anthocyanidin, respectively: 6β, 19α-dihydroxyursolic acid, sumaresinolic acid and cyanidin 3-O-glucoside. However, so far, the characterization of alkaloids or other classes involved, nor the evaluation of other biological activities of this specie has not been reported. Leaves, branches and bracts were collected, dried, crushed and extracted in maceration assisted by ultrasound bath with hexane and methanol solvents, following the order of increasing polarity. To evaluate the biological activities in vitro, the following methodologies were used: broth microdilution (antimicrobial sensitivity), method of free radical inhibition DPPH and Fe3+/phenanthroline (antioxidant activity), toxicity against the brine shrimp Artemia salina and the chorioallantoic embryo model of a chicken egg embryo (Gallus domesticus) (angiogenic activity in vivo). After fractionation of the methanolic extract of leaves, it was possible to isolate a coumarin, the scopoletin (substance I). The extract was also active for antimicrobial activity against four strains evaluated: Escherichia coli (ATCC 11775), Pseudomonas aeruginosa (ATCC 10145), Staphylococcus aureus (ATCC 12600) and Candida albicans (ATCC 10231). The hexane extract of branches has antiangiogenic activity and both the hexane and methanol extracts of leaves show toxicity in all concentrations evaluated. The results show the antimicrobial and antiangiogenic activity for Warszewiczia coccinea extracts and isolation of scopoletin from the leaves, which demonstrates the first report of this coumarin for the entire genus.