Abstract

Couroupita guianensis Aubl. (Lecythidaceae), commonly known in Vietnam as “Ngoc ky lan”, is a plant species widely used in traditional medicine to treat various ailments such as colds, stomachaches, malaria, and skin diseases due to its antibacterial, anti-inflammatory, and analgesic properties. Although numerous studies on the biological activities and chemical constituents of this species have been published worldwide, research data on C. guianensis distributed in Vietnam remain highly limited. In this study, by using normal-phase silica gel column chromatography with elution systems of increasing polarity, five pure compounds were isolated from the leaves of Couroupita guianensis. The chemical structures of these compounds were elucidated through one-dimensional (1D) and two-dimensional (2D) nuclear magnetic resonance (NMR) spectroscopy, mass spectrometry (MS), and comparison with the literature data. The study successfully isolated two triterpenoid esters, namely 23-O-trans-p-coumaroyl-2α,3β-dihydroxyolean-12-en-28-oic acid (1) and 23-O-trans-feruloyl-2α,3β-dihydroxyolean-12-en-28-oic acid (2). Additionally, three phenolic acids were identified, including trans-ferulic acid (3), trans-caffeic acid (4), and trans-p-coumaric acid (5). The presence of these triterpenoid esters and phenolic acids enriches the phytochemical profile of C. guianensis, and provides a crucial database to guide further studies on its pharmacological effects.