Preparation Of Conjugated Linoleic Acid From Camellia Oleifera Seed Oil And Its Antioxidant Activity

Conjugated linoleic acid?CLA?has many physiological functions such as promoting growth,improving immunity,lowering blood fat,resisting oxidation,and playing an important role in promoting human health.However,the development of conjugated linoleic acid has been obstructed by its insufficient sources.Camellia Oleifera Seed Oil is rich in oleic acid,which is the most important source of natural oleic acid in plant and can be used as a raw material for preparing conjugated linoleic acid.In this paper,conjugated linoleic acid was synthesized by using oleic acid from Camellia Oleifera Seed Oil.On the basis of this,the effect of Ag⁺silica gel column on the separation of conjugated linoleic acid was studied.Simultaneously,conjugated linoleic oil-arginine derivative was prepared,whose antioxidant activity and effect on stearoyl-CoA desaturase?SCD?activity were also studied.The specific research contents and results are as follows:?1?Camellia Oleifera Seed Oil was used as raw material to prepare Camellia oil methyl ester.The optimum conditions were determined as following:the molar ratio of Camellia Oleifera Seed Oil and methanol was 1:12,the dosage of sodium methoxide as catalyst was0.5%,the reaction temperature was 80?,and the reaction time was 150 min.Under the process conditions,the yield of Camellia oil methyl ester was 93.17%.?2?Using Camellia oil methyl ester as raw material,SeO₂ and TBHP as catalysts,Camellia oil conjugated methyl linoleate was prepared.Response surface analysis showed that the optimum conversion conditions of Camellia oil conjugated linoleic acid was:the reaction temperature was 49.8?,the reaction time was 9.6 h,the TBHP dosage was 3.7 eq.Under the optimal conditions,the conversion rate of Camellia oil conjugated methyl linoleate was 64.95%.The purity of prepared methyl conjugated linoleate was 53.45%,which specific composition was:17.33%of methyl palmitate,20.75%of oleic acid methyl;0.86%of trans oleic acid methyl;4.4%of stearate methyl,14.78%of 9c,11t-CLA methyl,8.74%of 9c,11c-CLA methyl and 29.93%of 10t,12c-CLA methyl.?3?The sample of CLA methyl ester was separated and purified by Ag⁺silica gel column.The results showed that the Ag⁺silica gel column had obvious effects on the removal of palmitic acid,stearic acid and oleic acid from CLA methyl ester sample,but the separation effect on CLA having different structures was very limited.The purification effect was best when 10%ethyl acetate-n-hexane was used as the eluent,which improved the purity of the Camellia oil CLA sample from 53.45%to 90.4%.?4?CLA-Arg derivative was prepared by using CLA methyl ester as a raw material.Through evaluating the antioxidant activity of CLA-Arg,the results showed that its IC₅₀values for DPPH,ABTS and hydroxyl groups were 2.82 mg/mL,1.37 mg/mL and 3.47mg/mL,respectively.Molecular docking simulation was used to investigate the interaction of CLA,CLA-Arg and SCD.The results showed that both CLA and CLA-Arg could inhibit the activity of SCD,and CLA-Arg had stronger inhibitory effect,which is expected to become a new kind of drug for the treatment of SCD metabolic diseases.