Study On The Extraction, Separation And Purification Of Iridoids And Yellow Pigment From Gardenia Fruit

Objective: To study the technology of extraction, separation and purification of iridoids and Gardenia yellow pigment from Gardenia fruits, as well as the technology of water as solvent to replace the traditional organic solvent in the process of the extraction. The extraction conditions were determined by single-factor experiments, and then the feasibility of separating Gardenia yellow pigment and iridoids with the macroporous resin adsorption method was investigated in order to provide a basis for further industrialized extraction, separation and purification.Methods: Water was used as the solvent to extract the active ingredients and Gardenia yellow pigment at the same time, under single-factor experiments. Optimum extraction was chosen by using orthogonal design. Based on this, the static rate of adsorption, absorption curve, the velocity of adsorption, eluting solvent and the velocity of elution in affecting the separation and purification of different macroporous resins were investigated. Therefore, the proper macroporous resin was selected for purifying iridoids and Gardenia yellow pigment fromg Gardenia fruit, and the best process of adsorption and deadsorption was formed under the single-factor experiments.Results: From this study, the conditions of the extraction by water were obtained as follows: temperature of extraction was 50℃, time of extration was 2 hours, and the ratio of Gardenia fruit to sovent was 1:10. Under these conditions, the extraction rate of iridoids was 88.81%, while the extraction rate of Gardenia yellow pigment was 92.32%.X-5 macroporous resin was chosed as a adsorbent for separating iridoids from Gardenia yellow pigment through the study on static volume adsorption capacity and selectivity of different kinds of resinss. With this adsorption and separation technology, iridoids and Gardenia yellow pigment could be separated very well, only less than 1% Gardenia yellow pigment remained in the solution of iridoids after separation.Through the study of macroporous resin on Gardenia yellow pigment purification, we found that macroporous resin X-5 was more suitable for the purification process. The proper conditions include sample concentration 0.033g/ml; adsorption velocity 1.5mL/min, and elution flow rate 2ml/min by using 50% ethanol as eluate. From the study of bleaching power of activated carbon on the solution of iridoids, we found that 1% of activated carbon totally adsorbed the residues of Gardenia yellow pigment in the solution of iridoids. We also found that the neutral alumina was the best absorbing for iridoids after comparison of it with silica and polyamide resin. The proper conditions were as follows: sample concentration was 0.045'g/ml, adsorption velocity was 1.5mL/min, and elution flow rate was 1.5ml/rnin by using 70% ethanol as eluate.Conclusions: Water can be used as the solvent to extract iridoids and Gardenia yellow pigment from Gardenia at the same time. Macroporous resin X-5 can effectively separate iridoids from Gardenia yellow pigment, and also can be used for Gardenia yellow pigment purification. Activated carbon can be used to remove Gardenia yellow pigment in the solution of iridoids, and neutral alumina may have a better effect on the purification of iridoids.