Synthesis Of Oil Hydroperoxide Catalyzed By Soybean Lipoxygenase

Oil hydroperoxides are very important intemediates of pharmaceutical synthesis or chemical synthesis. They can be used to prepare epoxide, hydroxyl compound, ketones and polyfunctional compound. Also, oil hydroperoxides can be decomposed to aldehydes, aldehyde acids and dicarboxylic acids. Lipoxygenase (LOX) (linoleate:oxygen reductase; EC 1.13.11.12) is a dioxygenase, which catalyzes the oxidation of linoleic acid and other polyunsaturated fatty acids and fatty acid esters, containing a cis,cis-1,4-pentadiene moiety, into hydroperoxides. The reaction of soybean lipoxygenase catalyzing-o- xidizing corn oil and soybean oil were studied. The process conditions of sodium sulfite reducing soybean oil hydroperoxide were optimized. The main contents and results are as follows:1. The process conditions which affect the yield of corn oil hydroperoxide were investigated. A yield of 53.8% was obtaind under following conditions: 5 oC, 4%(v/v体系) of solvent ethanol concentration, 100 g/L of corn oil concentration, borate buffer solution(pH9.0), 15 mL/min flow rate of oxygen, 3.05×105 U/mL of soybean lipoxygenase activity, and reaction time 1.5 h.2. The synthesis of corn oil hydroperoxide catalyzed by defatted soybean flour was studied. A yield of 72.1% was obtained under following conditions: 100 g/L of corn oil concentration, 80 mesh of defatted soybean flour, 200 g/L of defatted soybean flour concentration, 15 oC, pH9.0, 6% (v/v体系)of ethanol concentration and 0.13 g/L of BHT concentration, 83%(v/v体系) of borate buffer concentration, and reaction time 3h.3. The synthesis of soybean oil hydroperoxide catalyzed by defatted soybean flour was studied. A yield of 75.1% was obtained after 3 h under following conditions: 150 g/L of soybean oil concentration, 80 mesh of defatted soybean flour, 200 g/L of defatted soybean flour concentration, 15 oC, pH9.0, 6%(v/v体系) of ethanol concentration, 0.14 g/L of BHT concentration, 83%(v/v体系) of borate buffer concentration. The defatted soybean flour was reused for three times and the yields of soybean oil hydroperoxide were 75.1%, 70.9% and 39.1%, respectively.4. Soybean oil hydroperoxides were reduced to hydroxy soybean oil by sodium sulfite. Solvent type, solvent concentration, temperature, the dosage of sodium sulfite and reaction time were investigated. A conversion of 95.8% was obtained under following conditions: 15 oC, 88.2% (v/v体系) of solvent ethanol concentration, n(Na2SO3):n(-OOH) is 1.2:1, and reaction time 1.5 h.