Study On The Cause Of Brazilin Inactivation And Optimization Of Its Extraction Process

Brazilin is one of the main active components extracted from the heartwood of hematoxylin,which is traditional Chinese medicine.In recent years,studies on the pharmacological activities of brazilin have shown that brazilin has antitumor,hypoglycemic,and vasodilatory activities.However,oral or intravenous injection of brazilin has little effect,and its aqueous solution exposed to the air is easy to turn from colorless to yellow,then to red,and the color gradually deepens.At present,there is no report on the cause of deactivation and discoloration of brazilin.In this work,the discoloration behavior of brazilin was studied,the discoloration product and its structure transformation behavior were determined,a new simple and rapid method for determining the content of brazilin was established,and the extraction technology of brazilin was optimized.The follows are contents and conclusions:1.Study on the discoloration(inactivation)behavior of brazilinThe extraction of hematoxylin was separated by TLC,the natural color change process of brazilin was studied,and the accelerated color change behaviors were observed.The results showed that the discoloration(inactivation)of brazilin was mainly due to the fact that the chemical structure of brazilin was easily oxidized and the color change can be expressed in the following formula.The results provided a theoretical basis for the optimization of extraction process and the study on pharmacology of brazilin.2.The establishment of TLC method for the determination of brazi linA new method for the determination of brazilin by external standa rd one point method was established based on the study of TLC separ ation,color development,stability improvement and methodology of the extract of hematoxylin.The results showed that: on GF254 silica gel pl ate,the developer solution was chloroform: acetone: formic acid ratio was 8:4:1,fumigated with ammonia,sprayed with Al Cl3 solution,and t hen determined the content of brazilin by TLC scanner at 508 nm.Th ere was a good linear relationship between brazilin content and its abs orbance in the range of 0-6?g(R2 = 0.9962),RSD ? 3.40%,and the a verage recovery was 101.75%.This method can be used for the determ ination of brazilin.It provides an effective experimental method for the study of extraction processoptimization,product quality control and ph armaceutical pharmacology of brazilin.3.Optimization of extraction process of brazilinTaking the yield of dry powder and the content of brazilin as the examination index,the single factor and response surface analysis were carried out for the extraction conditions of brazilin,such as solvent,e xtraction times,degreaser ratio and so on.The extraction process of br azilin was optimized.The steps were as follows: take the pieces of Ch inese herbal drink as the raw material,use the alcohol solution with th e volume fraction of 56%,the ratio of material to liquid is 1:8,soak f or 1h,heat and refluxe for 1.8h,extract for 4 times respectively,comb ine the decoction,spin and steam under the negative pressure until 1g of the medicine is equivalent to 0.5m L of the solution,store at 0-4 ? for 48 h,then filter the filtrate,degrease the filtrate with the solvent o f twice the amount of petroleum ether: ethyl acetate = 3:1,stir it at th e speed of 450 r/min for 15 min,stand for 20 min to obtain the aque ous phase,then extract the impurities with twice the amount of ethyl acetate in the aqueous phase,stir it at the speed of 450 r/min for 15 m in,stand for 60 min to obtain the organic phase,fully dry it with anh ydrous sodium sulfate,and spinthe organic phase to obtain the crude e xtract,Then add 4 times of distilled water to the crude extract to diss olve and filter,add 4 times of ethyl acetate: petroleum ether = 2:1 ext ractant to the filtrate,extract twice,stir at 450r/min for 15 minutes,aft er standing and layering,separate the oil and water,add anhydrous sod ium sulfate to the organic phase for drying,and then transfer to the ro tary evaporator.The dry powder refined products are obtained by rotar y evaporation under negative pressure(temperature?40?,vacuum degre e?0.08mpa).The yield of dry powder and the content of brazilin were 1.9%,52.1%,respectively.The organic phase in the process can be re cycled.The process is simple in operation,low in cost and suitable for industrial production.