Evaluation of gamma irradiation on medicinal plants for both qualitative and quantitative analysis of phenolic acid

Abstract The aim of this study is to assess how gamma irradiation affects the chemical profiles of medicinal plants. Two different forms; methanol leaf extracts and dried leaves, of the three medicinal plants were investigated. Utilising FTIR, HPLC, and LCMS techniques, the qualitative measurement of gallic acid (GA) in three different medicinal plants for both plant extract and dried plant before and after the gamma radiation treatment was carried out. In the meantime, HPLC has been used to do a quantitative analysis of GA in these plants in order to show the percentage concentration of phenolic acid. For these medicinal herbs, the FTIR study revealed that both plant extract and dried plant had comparable functional groups both before and after gamma radiation therapy. The chromatogram of the HPLC profile for these medicinal plants was similar in chemical constituents before and after gamma irradiation, but the samples that were treated with gamma irradiation had a slight increase in intensity (between 0.0002-0.0009 Au). Additionally, gamma irradiation at levels of 6-12 kGy and 9-13 kGy caused the mass peak of GA to deteriorate in mass spectrometry analysis. Furthermore, the percentage concentration of GA increased significantly as the gamma radiation dose increased for both forms. GRAPHICAL ABSTRACT