Chemical characterization and evaluation of the biological activity of bourreria huanita (llave & lex.) hemsl. (Esquisuchil or brother Pedro's tree)

Abstract

The extraordinary plant biodiversity of the region and the limited existing scientific technical information on native flora suggest the need to conduct studies on poorly studied plant species that are attributed medicinal properties. A particular case is that of esquisuchil (Bourreria huaiiita), a Boraginaceae recognized in Mesoamerica for its medicinal properties since pre-Hispanic times. Commonly used in a traditional and popular way for its antimicrobial and anti-inflammatory effect of the flower infusion, to cure bacterial or viral skin lesions, for fever, as a tranquilizer and anxiolytic, in heart disease, blood pressure, used as a disinfectant choline, relieves menstrual pain and anti-abortion, and is also attributed analgesic and anticancer properties. According to the review carried out, there is no information on its chemistry and biological activity, so the characterization through chemical and biological assays of plant extracts and essential oils of the flower was carried out. The sample was collected in Antigua Guatemala, identified by a botanist and morphoanatomical, organoleptic and physicochemical tests were performed to evaluate the quality and purity of the plant drug. The total solids test was performed to select the best solvent, resulting in 50% ethanol with an extract yield of 38.1%. The essential oil was extracted by hydrodistillation using a Neoclevenger type apparatus, presenting 30 constituents, the majority being farnesyl ketone (8.38%), 2OH-phenylene benzoic acid (8.37%), ≤ phenylethylsalicylate (5.60%), 6,10 dimethyl 2-undecanone (5.29%) and heneicosane (5.20%), which could be of interest in the food industry. Liquid-liquid partitions were performed from the crude ethanolic extract using solvents of different polarities (hexane, chloroform, and ethyl acetate). The partition with the highest yield was hexane (4.0%). Phytochemical screening revealed that the secondary metabolites present in B. huanita were: alkaloids, flavonoids and anthocyanins, tannins, and coumarins. According to phytochemical screening, the secondary metabolites present in ethanolic extracts were: flavonoids and anthocyanins, sesquiterpene lactones, steroids and triterpenoids, tannins, coumarins, saponins, and volatile oils. In dichloromethane extracts, the metabolites detected were steroids and triterpenoids, coumarins, and volatile oils. Biological activity was assessed, revealing that the ethanolic extract exhibited antibacterial activity against E. co/i at 0.5 mg/mL. None of the plant extracts tested showed antifungal, cytotoxic, or larvicidal activity. We hope to establish contact with other research centers to conduct pharmacological tests on the nervous system.