Phytochemicals from Ophiorrhiza exigua and their Chemotaxonomic Significance

Background: The Ophiorrhiza plants are an important group of medicinal herbs worldwide. However, many species of the genus Ophiorrhiza, including Ophiorrhiza exigua were not investigated for their chemical constituents and bioactivities. Objective: The objective of this study is to isolate and identify the secondary metabolites from the plant O. exigua, discuss their chemotaxonomic significance, and evaluate their α-glucosidase inhibitory activities. Methods: The compounds were isolated and purified by column chromatography, and their structures were identified by spectroscopic analyses and comparison with the literature data. Based on the extensive literature survey, their chemotaxonomic importance was analyzed. Moreover, their α- glucosidase inhibitory activities were evaluated by the colorimetric method. Results: The phytochemical study of the plant O. exigua led to the isolation of nine compounds (1–9) of different structural groups. Importantly, the chemotaxonomic importance of these isolated compounds was discussed, suggesting compounds 2–5 as four chemotaxonomic markers for the species O. exigua. In the α-glucosidase inhibitory bioassay, the compounds did not exhibited potent effects. result: This phytochemical study of O. exigua led to the isolation of ten compounds (1–10) with diverse structure features. Importantly, the chemotaxonomic importance of isolated compounds has been extensively discussed, suggesting compounds 2–5 as four chemotaxonomic markers for O. exigua. Moreover, compounds 5, 7, and 9 exhibited moderate α-glucosidase inhibitory activities with IC50 values of 31.0, 27.9, and 50.3 mg/mL, respectively. Conclusion: All compounds except 1 and 9 were isolated from the genus Ophiorrhiza for the first time. Compounds 2–5 showed chemotaxonomic importance for the species O. exigua. This work filled the gap in the knowledge of the phytochemical and biological profiles of the plant O. exigua.