Investigação fitoquímica e atividade biológica em resíduos madeireiros de Dalbergia spruceana Benth

Abstract

In the scientific literature, the vegetative parts commonly used in phytochemical and pharmacological studies are leaves, barks, fruits, branches, roots, and flowers. Wood, on the other hand, is not frequently explored in these studies due to its scarcity in research groups, justified by environmental protection laws. Thus, in collaboration with the Wood Technology Laboratory, the remnants (sawdust) of Dalbergia spruceana Benth, derived from studies on the technological properties of wood, were made available for phytochemical investigation. They underwent grinding and cold extraction with hexane and methanol solvents to obtain crude extracts. The isolation of substances was carried out through fractionation using open column chromatography with different supports (sephadex LH-20, silica gel 70-230, and 230-400 mesh) and preparative-scale planar chromatography (silica gel 60 F254, normal phase). Phytochemical studies of hexane and methanol extracts from D. spruceana resulted in substances of different classes, such as fatty acid (lignoceric), steroids (β-sitosterol and stigmasterol), phenylpropanoid (elemicin), neoflavonoid (dalbergin), and flavonoids (maackiain, 8-hydroxy-7-methoxy-3',4'-methylenedioxypterocarpan, 8,4,2'-trihydroxy-7,4'-dimethoxyisoflavone, and 3',4'-dihydroxy-7,8,2'-trimethoxyisoflavan), the last two having no reports in the literature. The substances were characterized by 1D and 2D Nuclear Magnetic Resonance, Mass Spectrometry, and comparison with models in the literature. The biological evaluation of the major substance (maackiain) against the Bemisia tabaci insect resulted in a 35% mortality rate, showing a difference of only 7% compared to Evidence 700 WG® (42%), a commercial drug used in insect control.