Chemical and Biological Investigation on the Potential Ornamental Plant Ophiorrhiza chinensis

Abstract

An investigation of the potential ornamental plant Ophiorrhiza chinensis H.S. Lo (Rubiaceae) was conducted, which resulted in the discovery of eight structurally diverse compounds, including two triterpenes, two steroids, two anthraquinones, one alkaloid, and one coumarin. These chemical constituents were isolated by repeated column chromatography and identified by analysis of their NMR spectral data. All of these substances were found in this species for the first time, and four of them were first isolated from the genus Ophiorrhiza. The chemotaxonomic importance of these isolates was discussed, indicating four chemotaxonomic markers for O. chinensis. The tyrosinase inhibitory activity of these isolates was evaluated by a colorimetric method. As a result, six phytochemicals demonstrated moderate tyrosinase inhibitory effects with IC50 values ranging from 25.7 μM to 68.1 μM. Moreover, the binding modes between the active compounds and the mushroom tyrosinase were analyzed preliminarily assisted by molecular docking calculations. This study filled up the knowledge gap of the unreported phytochemical and pharmacological profiles of secondary metabolites from the species O. chinensis.