Estudo fitoquímico da fração hexânica das cascas do caule de Terminalia argentea Mart & Zucc (Combretaceae)

Abstract

The species of the genus Terminalia are distributed throughout tropical regions around the globe and are used for medicinal purposes by various cultures in the treatment of diseases, bacterial infections, sore throats, ulcers, conjunctivitis, heart disease, skin diseases, pneumonia, hookworm, diarrhea, hypertension, nosebleeds, leprosy and jaundice. The species Terminalia argentea Mart e Zucc occurs naturally in the cerrado, the Atlantic forest, the Amazon forest and the caatinga, its bark is popularly used to treat canker sores, tumors and to calm coughs, the infusion of its leaves is used to treat ulcers. This work describes the phytochemical study of the hexanic fraction of the stem bark that led to the isolation of three substances, being two special metabolites not yet reported in Terminalia argentea. Two substances were identified through comparative CCDA with substance standards as the saponin 3-O-β-D-glycopyranosyl sitosterol (GHT_23PH) and the steroid β-sitosterol (GHT_8A1V). The third substance (GHT_23P) was partially elucidated by one and two-dimensional 1H and 13C NMR spectroscopy as being another saponin, whose aglycone is still in the phase of structural determination.