ABSTRACT
Objective To compare chemical composition in the different parts (leaf, branch, and fruit) of Rhodomyrtus tomentosa, and to study the chemical constituents from fruits of R. tomentosa. Methods High performance liquid chromatography/time-of-flight mass spectrometry (HPLC-TOF-MS) method was executed to analyze the samples. Principle component analysis (PCA) and partial minimum variance discriminant analysis (OPLS-DA) in MassLynx XS software were used to analyze the obtained data. The chemical constituents of fruits were isolated and purified by column chromatography, including silica gel, Sephedex LH-20 and re-HPLC, and the structures were elucidated based on their NMR and MS data. Results The PCA results indicated that the constituents existed in leaf were significantly different from those in branch and fruit, while constituents in branch and fruit were similar. Furthermore, based on OPLS-DA, combined with chromatographic retention regulation, accurate molecular mass, isotopic matching and literature searching, four marker compounds from leaves had been found and identified as myricitrin (1), myricitrin-3-O-L-furanoarabinoside (2), iridin (3), and 3,3’-didemethyl-9-oxo-pinoresinol (4). Besides, five compounds were isolated from fruits and identified as maslinic acid (5), ethyl gallate (6), gallic acid (7), resveratrol (8), and piceatannol (9). Conclusion This research provides an effective strategy for analyzing chemical difference from different parts of R. tomentosa, which can be applied to study the chemical difference from different parts of other species.