Xiangyou In Class Limonin And Naringin Synthesis, Extraction And Purification Of Dihydro Chalcone

In this paper, ultrasonic extraction and purifying limonoids and naringin by macroporous adsorption resin method were studied on the based of a spectrophotometric method for quantifying the total limonoids and naringin in pomelo. And the affect of various factors in the reaction of dihydrochalcone synthesis were studied.The result of main research as follows:1. A spectrophotometric method was established for quantifying the limonin and naringin in the pomelo. The maxima absorbance for the limomin was found to be 500nm to dimethylamino benzaldehyde as the indicator. A regression equation was A=0.0036C+0.0129, r=0.9984. According to naringin color characteristics of the ring opening by NaOH solution, naringin standard solution of its calibration curve is A=0.0261C+0.0185, at a wavelength of 370nm, r=0.9997.2. With ethanol as extraction solvent, the ultrasonic-assisted extraction technology of limonoids from pomelo seeds was optimized throngh orthogonal test. The best conditons for the ultrasonic extraction were:the ratio of sample and solventl:10, ultrasonic time was 30minutes, 70% ethanol, times of extraction was twice. By comparing the adsorption capacity, adsorption rate, desorption rate and yield of D3520, D4020, NKA, NKA-9, AB-8 macroporous resins, D4020 selected as the resin for purification of limonoids. The technological process to purify limonin by D4020 macropore resin method were:the adsorption flow velocity was lmL·min-1, using 70% ethanol solution as desorption agent with flow velocity of 0.7mL·min-1. The purity of the obtained limonin was 83.63%. The effective separation and purification process had lower cost.3. Naringin in pomelo peel as raw material, preparation of new sweetener had been studied. The AB-8 resin was the best in integrated edtimate.The technological process to purify naringin were:the sample velocity was 3BV/h, initial concentration was 2.0 mg-mL-1,0.05mol-1 NaOH solution as the eluent, the velocity was 1BV·h-1 and purification rate of naringin was 77.26% under optimum conditions of purification.The optimum conditions of synthetic dihydrochalcone were:the reaction time of 12h, the reaction temperature of 25℃, hydrogen pressure of 0.02Mpa, and Raney nickel was used in the reaction. The yield of naringin dihydrochalcone was 44.48% by this technology. The structure of synthetic naringin dihydrochalcone was determined by a series of spectroscopic methods, such as ultraviolet (UV), nuclear magnetic resonance (NMR) and mass spectrometry (MS).