Content of multiple components (neochlorogenic acid,L-tryptophan,vicenin-2,isoquercitrin,and astragalin) in Moringa oleifera leaves was determined by high-performance liquid chromatography (HPLC),and the absolute content-time curves were plotted.Based on Fick's law of diffusion and Higbie's penetration theory,the parameters of the equations were calculated,and the measured results were substituted into the mathematical model to fit the equations.The n and a obtained from the equations on the decocting time factor and the solvent volume were close to each other.The dynamic models of the five components are as follows:■.The variation of the content of multiple components in M.oleifera leaves with time and solvent volume was explored.It was found that the content of the components was the highest when the leaves were decocted for 30 min with solvent volume 12 folds of the medicinal material.The dissolution and destruction of components and the diffusion movement of components are the main causes of the content change of M.oleifera leaves at different time and with different solvent volumes.The R~2of the linear equations on the content and the equations on the decocting process (5-30min and solvent volume 12-20 folds of the medicinal materials) was≥0.999 8 and≥0.9,respectively.Thus,the content determination and the decocting kinetic model had high accuracy,which can reflect the change law of the content of key components in M.oleifera leaves during the decoction.This study is expected to serve as a reference for optimizing the decocting technology.
Keywords: Moringa oleifera leaves; content determination; decocting kinetic model; decoction with water; high-performance liquid chromatography.