Estudo Químico e investigação da atividade citotóxica de quinonas isoladas do extrato acetato de etila das raízes de Pleonotoma jasminifolia ((Bignoniaceae)

Abstract

The Bignoniaceae family is recognized for producing substances with therapeutic and bioactive properties, such as antimicrobial, anti-inflammatory, and antioxidant activities. Species within this family are particularly notable as sources of quinones, which serve as taxonomic markers. Research into new bioactive substances derived from Amazonian flora has intensified, especially in the investigation of metabolites with cytotoxic potential. Therefore, the present research aims to conduct a phytochemical study of the roots of P. jasminifolia and evaluate the in vitro cytotoxicity of the isolated substances. The root, after being dried, was subjected to extraction by maceration with hexane, ethyl acetate, and methanol. The ethyl acetate extract from the roots of P. jasminifolia was subjected to chromatographic assays, using the molecular networking tool to process the data obtained by Liquid Chromatography coupled with Mass Spectrometry (LC-MS/MS), with the aim of guiding the isolation of novel substances. The structural elucidation of the substances was carried out using spectroscopic and spectrometric techniques. In this study of this botanical species, two novel substances were isolated and named pleonotoquinone A (1) and pleonotoquinone B (2), in addition to two known anthraquinones belonging to the quinone class: 7-hydroxy-8-methoxy-2-methyl anthraquinone (3) and 7,8-dimethoxy-2-methyl anthraquinone (4). Compounds 1 and 2 were found to be cytotoxic against human colon cancer cells HCT116, with IC50 values of 2.6 and 4.3 μM, respectively. Additionally, both compounds exhibited cytotoxicity against human liver cancer cells HepG2, with IC50 values of 1.9 and 6.4 μM, respectively. The results obtained confirmed that the species P. jasminifolia is a promising source of bioactive quinones.