Análise da composição do óleo essencial e da fração hexânica do extrato das folhas de Tibouchina aspera aubl

Abstract

Plants are used as source for medicine production since the oldest civilizations. Those medicaments obtained by isolated substances from plants gained greater notoriety in the XIX century, and still being researched and used for this purpose nowadays. In this context, Brazil with its biodiversity has a lot of species used popularly as empiric treatment for diseases, a knowledge passed through generations. Many of these plants, however, do not have scientific studies about its chemical composition, which is very important to comprehend the mechanism of action of these plants therapeutically. One of the most abundant plant family in Brazil is the Melastomatacea family, the sixth largest in Brazilian grounds and it has plants used both as ornamental and medicinal purposes. Plants from Tibouchina Aubl. genus are used empirically as analgesics and sedatives. The present work studies one of the species from the Tibouchina Aubl. genus, Tibouchina aspera Aubl., which despite been used to describe the genus, little is known about its chemical composition. From T. aspera leaves was obtained its essential oil by hydrodistillation, and dry extract by alcoholic maceration. The extract was fractionated and a hexane fraction obtained, which along with the essential oil was analyzed in a gas chromatography apparatus with coupled mass spectrometer. In the study, was identified in the plant extract the intermediate triterpene squalene and two simple alkanes. In the essential oil was identified two substances, 1-hexanol and 3-hexenol. This is the first scientific study in the literature to identify chemical substances in T. aspera Aubl.