Molecular Dynamics Simulation Of Diffuse Properties In Supercritical Fluid & Extraction Of Active Components From Antler Velvet

Molecular dynamics simulation was used in this work to explore the diffusion mechanism of supercritical fluid extraction. Extraction of anti-aging components from antler velvet with supercritical fluid was also carried out to find the optimum experimental parameters.Molecular dynamics simulation was carried out by Material Studio 3.1 modeling software, including Amorphous Cell module, Discover module and COMPASS force-field. It can be divided into four parts (1) Benzene molecule was chosen as the target solute molecule to fix the simulation parameter of aroma compounds in supercritical CO2 : NVT ensemble with Hoover-Nose thermostat method; the number of equilibration steps was 1.0×105 and that of the production steps was 2.0×105; time step of the calculation was 0.5 fs; cut-off radius was half length of the simulation cell, long-range correction was applied; 303 molecules with charge group in a cubic box with periodic boundary conditions, 3 solute molecules,300 solvent molecules.(2) Diffusion coefficient comparison between experimental data and simulation data of benzene, toluene and ethylbenzene at different T,P shown the feasibility of the simulation parameters.(3) Methanol with percentage of 5% and 10% was used as the cosolvent in supercritical CO2 .Based on the Aalto density correlation, diffusion coefficient of tert-butylbenzene was explored in this mixture fluids and further discussion of the microstructure gave a good explanation to diffusion coefficient of tert-butylbenzene in the methanol-CO2 fluid (4) Molecular dynamics simulation of supercritical fluids extraction of caffeine from plant matrix was carried out, solid-fluid diffusion was explored with cellulose as the simple module of matrix.Antler velvet is one of the important tradition Chinese medicines with many active components and effects. From anti-aging aspect, that is preventing the oxidization of free radical, the yields of hypoxanthine and other anti-aging components extracted by supercritical CO2 were explored. With orthogonal and uniform array design, experiment parameters were fixed.