Fitoquímica de espécies de Erythroxylum do semiárido: isolamento e determinação estrutural de alcaloides tropânicos, flavonoides e diterpenos

Abstract

This work describes the results of phytochemical studies from three species of the Erythroxylum genus: Erythroxylum caatingae Plowman, Erythroxylum subrotundum A. St.-Hil and Erythroxylum revolutum Mart, which were identified by the botany sector of the Laboratory of Pharmaceutical Technology, UFPB. The species were submitted to extraction process, followed by partition with hexane, chloroform and ethyl acetate, resulting in their respective phases. Four Tropane alkaloids were isolated by chromatography methods from the chloroformic phase of Erythroxylum caatingae, in which two were already isolated [3α, 6β dibenzoyloxytropane and 3α-(3 ,4 ,5 - trimethoxybenzoiloxi)-6β-benzoyloxytropane (Catuabine B)] and the other two were reported for the first time in the literature [3-(3 ,4 -dimethoxy)-6-hydroxytropane and 3α-(trans-3 ,4 ,5 trimethoxycinnamoyloxy)-6β-benzoyloxytropane]. From the ethyl acetate phase of Erythroxylum subrotundum, two flavonoids were isolated: Quercetin-3-O-α-L-rhamnoside and 5,7,4 -trihydroxyflavone-3-O-α-L-rhamnoside. The study of the Erythroxylum revolutum hexanic phase resulted in the isolation of six diterpenes: ent-kauran-16-ene, 13-hydroxy-8(17),14-labdadien (Manool), ent-kaur-16- en-3β-ol, 3-oxo-13-hydroxi-8(17),14-labdadien, 3,13,19-trihydroxy-8(17),14-labdadien and ent-kauran-16β, 17-diol. All the species had their chemical constituents identified through data analysis obtained from spectroscopic methods such as Infrared and Nuclear Magnetic Resonance of 1H and 13C with uni-bidimensional techniques, besides comparison with literature data. Therefore, the given results of this work contributed to the chemical study of the species from Erythroxylaceae family.