Chemical characterization and bioactivity of secondary metabolites of the stem of Melochia villosa (Sterculiaceae)

Abstract

Melochia villosa (Mill.) Fawc. & Rendle is one of the species belonging to the Sterculiaceae family that has been little studied phytochemically. The objective of the research was to perform phytochemical analysis and characterization of the alcoholic and ethereal extracts of the stem of this species, in order to identify secondary metabolites present in this botanical part with properties of application as possible drugs, as well as contributing to the chemotaxonomy of the species. For structural elucidation, techniques such as infrared spectroscopy, nuclear magnetic resonance, and gas chromatography coupled to mass spectrometry were used. In the chromatographic fractionation of the alcoholic extract, nine fractions were obtained, of which only fractions 3, 5, 8 and 9 could be tested, with antifungal activity against Fusarium vercillioides, and F. poae for fractions 3 and 9 respectively. Fractions 5 and 8 produced lethality on nauplios of Artemia salina. Eight fractions were obtained from the fractionation of the ethereal extract, mostly with the presence of unsaturated sterols, where fractions II, VII and VIII lethal activity. The presence of the carbonyl group and the ester bond was evidenced, as well as the diisoctylic ester of 1,2-benzenedicarboxylic acid. The presence of hexadecanoic acid, mono-(2-ethylhexyl) ester of 1,2-benzenedicarboxylic acid, undecyl ester of undecanoic acid, as well as cholestan-3-one and spinasterone, both compounds derived from unsaturated sterols, were also observed.

Keywords

• cholestan-3-one
• gas chromatography coupled to mass spectrometry
• hexadecanoic acid
• infrared spectroscopy
• nuclear magnetic resonance
• spinasterone
• structural elucidation
• undecyl ester of undecanoic acid.