The technical problem to be solved by the present invention is to overcome the shortcomings such as low conversion rate, serious environmental pollution, and high energy consumption in the chemical synthesis method of the above-mentioned Tocopheryl Acetate Ewg, and provide a method with high conversion rate, mild production reaction conditions, low energy consumption, and environmental protection. Synthesis method of natural α-tocopheryl acetate with low pollution.
The technical solution adopted to solve the above-mentioned technical problems comprises the following steps:
1, prepare immobilized lipase [0012] The lipase measured by the addition of every gram of natural α-tocopherol 700 ~ 900U is dissolved in pure water, and the lipase solution that is made into a concentration of 8.5mg/ml is measured. Textile carrier, the quality of textile carrier is 5 times of lipase quality, 4 ℃ is soaked in the lipase solution, soaks 16 hours, dries, repeats above steps until lipase solution absorbs completely, obtains immobilized lipase.
2. Modified immobilized lipase
The prepared immobilized lipase is soaked in dimethyl sulfoxide, the mass ratio of immobilized lipase and dimethyl sulfoxide is 1: 1.5~5, 28~45 DEG C are incubated 1~3 hour, carry out modification treatment .
3. Immobilized lipase catalyzed reaction
Mix the natural α-tocopherol with the acetyl donor in a molar ratio of 1: 1.5~55, add the modified immobilized lipase in the mixture, 28~45°C, 180~200 rpm in a shaker React for 12 to 24 hours.
4. Filtration and purification
Filtration and recovery of immobilized lipase, vacuum distillation at -0.09MPa, 95 to 160°C to recover the acetyl donor until no condensate is generated, and film evaporation and dehydration at a vacuum of 200Pa and 170 to 180°C Degassing, vacuum tightness is 1～3Pa, 250～260 ℃ carries out molecular distillation with molecular distillation device, gets natural α-tocopheryl acetate.
The above-mentioned acetyl donor is 25% acetic acid-n-hexane solution in mass percent concentration, and the molar ratio of natural α-tocopherol to acetic acid is 1: 1.5~3; the acetyl donor is ethyl acetate or acetic acid Methyl ester, the mol ratio of natural α-tocopherol and ethyl acetate or methyl acetate is: 1: 25～55.
The lipase of the present invention is Candida lipolytica lipase or Candida plicata lipase.
In step 2 of the modified immobilized enzyme of the present invention, the prepared immobilized enzyme is soaked in dimethyl sulfoxide, the optimum mass ratio of immobilized lipase and dimethyl sulfoxide is 1: 3, 28 ~ 35 ° C Insulated for 1 to 3 hours for modification.
In step 2 of the modified immobilized lipase of the present invention, the prepared immobilized lipase is soaked in dimethyl sulfoxide, and the optimum temperature is kept at 30° C. for 2 hours to perform modification treatment.
The fabric carrier of the present invention is cotton fabric, silk, hemp fabric, nylon fabric.
The synthetic method of natural α-tocopherol acetate of the present invention carries out esterification or transesterification under the catalysis of modified immobilized lipase through natural α-tocopherol and acetyl donor, and reaction product is filtered, reduced pressure Distillation and molecular distillation to obtain Tocopheryl Acetate Ewg, the amount of catalyst used is less, no corrosion to equipment, easy to recycle, less chemical reagents are introduced in the reaction process, no side reactions occur, and the conversion rate of reactants is high, up to 90%, making the separation It is simple, does not generate a large amount of waste water, and does not need to recover a large amount of extraction solvents, is environmentally friendly and energy-saving, and meets the requirements of large-scale continuous industrial production.
The present invention will be described in further detail below in conjunction with the accompanying drawings and embodiments, but the present invention is not limited to these embodiments.
The method for the synthesis of natural Tocopheryl Acetate Ewg in this embodiment consists of the following steps:
1. Preparation of immobilized enzyme
Measure Candida lipolytica lipase (45700U/g) 2.45g by the addition amount of every gram of natural α-tocopherol 800U and be dissolved in 288.2ml pure water and be made into the enzyme solution that concentration is 8.5mg/ml, natural α-tocopherol is a commodity sold on the market, sold by Zhejiang Huayuan Pharmaceutical Technology Development Co., Ltd. Candida lipolytica lipase (Lipase P30000U/g), purchased from Imperial Jade Bio-Technology Co., Ltd, by weighing Silk textile carrier 12.26g is soaked in this enzyme solution, and the quality of textile carrier is 5 times of Candida lipolytica lipase quality, and textile carrier also can adopt cotton textile, also can adopt hemp textile, also can adopt Nylon textiles were used, stored in a refrigerator at 4°C for 16 hours, dried in the air, soaked again according to the above method, until the enzyme solution was completely absorbed, and the Candida lipolytica lipase was immobilized.
2. Modified immobilized enzyme
The immobilized Candida lipolytica lipase that above-mentioned step 1 obtains is soaked in the dimethyl sulfoxide of 40.1ml, and the mass ratio of immobilized Candida lipolytica lipase and dimethyl sulfoxide is 1: 3, 30 ℃ of insulations 2 hours for finishing treatment.
3. Immobilized enzyme catalyzed reaction
107g of natural α-tocopherol (1200IU) was added in 3 times and mixed with 96g of acetic acid-n-hexane solution with a mass percentage concentration of 25%, and 32g of acetic acid-n-hexane solution with a mass percentage concentration of 25% was added every 6 hours. The mol ratio of natural α-tocopherol and acetic acid is 1: 2, and the immobilized Candida lipolytica lipase after adding modification is added in the mixture, 32 DEG C, 180～200 rev/mins react in shaker for 20 hours, get natural Tocopheryl Acetate Ewg, the conversion rate is 98.1%.
4. Filtration and purification
Filtration and recovery of immobilized Candida lipolytica lipase, in a vacuum of -0.09MPa, 95 ~ 160 decompression distillation reclaimed acetic acid, until no condensate is generated, in a vacuum of 200Pa, 170 ~ 180 ° C film evaporation dehydration Degassing, vacuum degree is 1~3Pa, 250~260°C molecular distillation is carried out with a molecular distillation device to obtain 87.0 g of natural α-tocopheryl acetate with a purity of 96.9%, and a yield of 90%.
