Triterpenes, steroids and phenolic isolated from Minquartia guianensis Aubl. (Coulaceae) and antibacterial activity

This work aimed to carry out a chemical study of Minquartia guianensis branches and leaves extracts (Coulaceae) and to evaluate their antibacterial potential. The collection of plant material was carried out at Reserva Ducke, Manaus, Amazonas. The plant material was dried, ground, and extracted with hexane (Hex) and methanol (MeOH). The extracts obtained were submitted to chromatographic analysis and showed characteristics mainly of terpenes and phenolics. The chemical fractionation of branches methanol extract allowed the isolation of the triterpenes: lupen-3-one, β-amyrone, lupeol, β-amyrin; the steroids: β-sitosterol and stigmasterol, and a phenolic derivative: methyl gallate. From the leaf’s methanol extract, the triterpene: taraxerol was identified. These same methanol extracts were active against gram-positive bacteria: Staphylococcus aureus and gram-negative bacteria: Aeromonas hydrophila and Pseudomonas fluorescens, with an inhibition percentage of 63 to 70%. Based on the results, this work contributed to the chemical and biological knowledge of the species M. guianensis, this being the first report of the substances: β-amyrin, β-amyrone and methyl gallate for the Coulaceae family.