Estudo Químico de Marcetia mucugensis Wurdack (Melastomataceae)

Abstract

This work describes the chemical composition of Marcetia mucugensisis (Melastomataceae), a plant restricted to rocky fields and that can be found in Mucugê, Bahia. Several species of this family are used for medicinal purposes, such as Miconia albicans (Sw.) Tr. Used against rheumatism; Mouriri guianensis Aubl. Used against ulcers, postpartum baths and vaginal infections and Macairea radla (Bonpl.) DC. used against scabies and skin diseases. Besides presenting plants with proven pharmacological activities such as antimicrobial activity of ethanol extracts of Miconia albicans and Miconia rubiginosa and cytotoxic and antioxidant activity of flavonoids present in Melastoma malabathricum L.The phytochemical investigation of this plant was carried out through the isolation and characterization of secondary metabolites present in the hydroalcoholic extract from the leaves collected in the Chapada Diamantina, Bahia. The triterpene squalene, four polimethoxyflavones 5,3'-dihydroxy-3,6,7,8,4',5'-hexamethoxyflavone (digicitrin), 5-hydroxy-3,6,7,8,3',4',5'- heptamethoxyflavone (gardenin A), 5-hydroxy-3,6,7,8,3',4'-hexamethoxyflavone, and 5,7-dihydroxy-3,6,8,3',4',5'-hexamethoxyflavone alone with quercetin were isolated. The isolation of chemical constituents was performed by conventional chromatographic methods, while the structural determination was carried out by means of spectrometric techniques such as infrared (IR), mass spectrometry (MS) as well as nuclear magnetic resonance hydrogen (1H NMR) and carbon-13 (13C NMR), including two-dimensional techniques (COSY, HSQC, and HMBC) and comparison with the data described in the literature. This work is the first report about the phytochemical study of M. mucugensis.