Handroanthus chrysotrichus Leaves: A Renewable and Sustainable Source of Ursolic and Oleanolic Acids

Abstract

Background: Information on the phytochemical composition and cytotoxicity of Handroanthus chrysotrichus leaves remains limited, although other plant parts and related species have been investigated. Aims: Handroanthus chrysotrichus is a tree species belonging to the Bignoniaceae family. This family and genus have been investigated for their bioactive compounds, although less is known about the phytochemical profile and biological activities of its species, particularly its leaves. Study Design: The leaves were collected in Petrolina-PE; subsequently, crude hexanolic extract (CHE) and crude methanol extract (CME) were prepared through exhaustive maceration. The CME was partitioned by vacuum liquid chromatography (VLC) yielding the following fractions: hexane (HEX), chloroform (CHCl3), ethyl acetate (EtOAc) and methanol (MeOH). Place and Duration of Study: Núcleo de Estudos e Pesquisas de Plantas Medicinais (NEPLAME), Universidade Federal do Vale do São Francisco, between March 2024 and September 2024. Methodology: Extracts and fractions were characterised in terms of their triterpene content and chemical composition by gas chromatography–mass spectrometry (GC-MS) analysis and nuclear magnetic resonance spectroscopy (NMR) 1H and 13C, and cytotoxicity profiles. Results: High triterpene contents were recorded in CHE, CHCl3 and EtOAc with the latter exhibiting the highest content of 8.36 ± 0.89 mgEqUA.g-1. The CHE GC-MS analysis enabled the identification of 13 compounds, with E-squalene as the predominant compound. The NMR experiments revealed that ursolic and oleanolic acids were the main constituents of the EtOAc fraction. Further isolation of compound 1 from EtOAc enabled its identification as ursolic acid, reported for the first time in the leaves of H. chrysotrichus. Regarding cytotoxicity, only EtOAc exhibited moderate activity against human glioblastoma cells (SBN-19), with an inhibition of 51.75 ± 6.78 %. Conclusion: The leaves of Handroanthus chrysotrichus were identified as a potential renewable source of ursolic and oleanolic acids, which are compounds with pharmacological activities.