Determination of five phenolic compounds from fruits of Rhodomyrtus tomentosa in different regions and its antioxidant effect

Objective Five phenolic compounds in fruits of Rhodomyrtus tomentosa from six different regiones were measured by HPLC, and the ability of scavenging free radicals of five kinds of phenolics and myrtle fruits extracts in different regions was investigated. Methods The determination was performed on Inertsil ODS-SP column(150 mm × 4.6 mm, 5 μm), the mobile phase consisted of acetonitrile and 0.1% phosphate aqueous solution with gradient elution program, flow rate was 1 mL/min with 10 μL of sample quantity at 280 nm, and the antiradical efficiency of five phenolic compounds and extrcts were evaluated by DPPH radical scavenging assay. ResultsFive kinds of phenolic components showed a good linear relationship, and the precision, stability, repeatability, and sample recovery rate all met the requirements. Five phenolic compounds and extracts had good antiradical efficiency. The IC50 values of the myrtle fruits extracts from Xinfeng, Wengyuan counties in Guangdong province, Nanning, Guilin in Guangxi province, Yunnan province, and Guizhou province were 58.82, 61.57, 17.73, 7.91, 14.77, and 8.11 μg/mL, and the IC50 values of gallic acid, protocatechuic acid, catechin, ellagic acid, and resveratrol were 0.02, 0.04, 0.03, 0.05, and 5.70 μg/mL, respectively. The IC50 of positive control VC was 6.31 μg/mL.Conclusion Material basis of antiradical efficiency of fruits is preliminary identified and it provides a scientific basis for the comprehensive utilization of the resources of R. tomentosa.