Constituintes químico de Cochlospermum regium (Martius e Schrank) Pilger (Bixaceae)

Abstract

The medicinal plants have been a rich source for obtaining bioactive molecules, constituting one of the most successful strategies in the discovery of novel medicines. The specie Cochlospermum regium (Martius and Schrank) Pilger (Bixaceae), popularly known as algodãozinho-do-campo is a native plant, abundant in Brazilian Cerrado. After an ethnobotanical and ethnopharmacological research carried out at Tocantins State it was showed that this plant is used in folk medicine to treat several illnesses. Among the therapeutic indications the most frequents are: gynecological and renal inflammations, prostatitis, a few kinds of pains, fever, gastritis and skin affections, among others. This study aimed to contribute to the knowledge of the chemical constituents of C. regium. For this, extracts solutions were obtained by an exhausting way maceration of this plants roots in the solvents: hexane, dichloromethane, ethyl acetate and methanol, in this sequence increasing polarity, obtaining the following income rude mass macerated: 1,78%, 0,23%; 0,51% and 12,16%, respectively. The phytochemical investigation of the hexane extract (CrRH) allowed the isolation of substance initially identified as SA (7,0 mg), an unpublished chemical compound, still in characterization process and Substance SB (20,0 mg), identified as excelsina, a lignan reported for the first time in this specie. From the CrRH1 fraction originated by the fractionating chromatography column of the hexane extract was isolated the substance SC (6,0 mg) identified as a steroid, still in structural elucidation. From the dichloromethane extract (CrRD) the substance SD (9,0 mg) was isolated and identified as phidroxicinamic acid stereate, whose structures are not yet fully defined. Data obtained so far indicate the existence of a mixture of p-hidroxicinâmic acids, probably varying the size of the side chain ester. On the fractionation of ethyl acetate extract was obtained the substance SE (23mg) originated from the CrRAc1 fraction and identified as naringenin, a common flavanone in the genus Cochlospermum, have been also isolated in the stalk bark of this specie, not having, however, reports the presence of this flavanone in roots of C. regium. And finally, the SF substance (15,0 mg), originated of the CrRAc2 fraction, which was also identified as excelsina.