Preparation Of Tobacco Chlorogenic Acid Nanoliposome And Its Characteristic Analysis

Chlorogenic acid is the product of plant aerobic respiration metabolism,which is widely found in tobacco,honeysuckle,eucommia and other plants.Chlorogenic acid has antibacterial,anti-tumor,anti-virus,increased white blood cells,blood pressure,blood fat,liver and gallbladder,scavenging free radicals and excitement of the central nervous system and other effects,and is widely used in medicine,food and cosmetics industries.The sensitive against the environmental factors such as light,temperature,oxygen,be hydrolyzed under alkaline would result in the unstability of chlorogenic acid and reduce its biological activity.Liposomes are formed by amphiphilic phospholipid,which could be used to encapersulate both hydrophobic and hydrophilic active ingredient.Currently,there are many reports which only focous on the preparation of chlorogenic acid liposome,but there are only few reports which involve the stability and biological activity of chlorogenic acid after encapersulation.This paper would mainly focous on the following three questions:First,compared three kinds of chlorogenic acid nanoliposomes preparation methods,the best was selected to determine the optimum process parameters,and the particle size,potential and electron microscopy of chlorogenic acid nanoliposomes were investigated.Second,the physical properties and stability of chlorogenic acid nanoliposomes were further evaluated.Third,the biological activity were studied.The main results were as follows:1.Compared with the thin film hydration and the reverse phase evaporation technique,the ethanol injection method has the highest entrapment efficiency,small diameter and good dispersion.This method not only avoids the use of toxic solvents,but also is suitable for large-scale production,and has good reproducibility.2.The effects of film（lecithin+cholesterol）/CA mass ratio,lecithin/cholesterol mass ratio and ultrasonication time on the EE and effective loading ability of liposomes were investigated.Orthogonal combination design was used to determine the best process parameters.The results showed that when film/CA mass ratio was 9:1,lecithin/cholesterol mass ratio was 4:1 and ultrasonication time was 5minutes,the CA nanoliposomes showed regular spherical,good dispersion,a particle size of approximately 77.16nm in diameter,PDI 0.23,mean zeta potential-38.46mV,an entrapment efficiency of up to 88%,and an effective loading of up to 9.69%.UV spectroscopy showed that CA was encapsulated successfully into nanoliposomes.3.The stability of chlorogenic acid solution and chlorogenic acid nanoliposomes were characterized by retention rate or DPPH removal rate under different conditions.The results showed that chlorogenic acid nanoliposomes had better thermal stability,storage stability,alkaline stability,pH stability and illumination stability than chlorogenic acid solution,indicating that chlorogenic acid can be improved by liposome embedding.4.The antioxidant activities of chlorogenic acid solution and chlorogenic acid nanoliposomes were investigated by DPPH clearance rate and reducing ability.It was found that chlorogenic acid nanoliposomes had the same DPPH clear ability compared with free chlorogenic acid,but had lower iron ion reduction ability.5.Hydroxyl radical production optimization experiments showed that Fe SO₄ concentration of8mmol/L,H₂O₂ concentration of 8mmol/L,o-phenanthroline concentration of 8mmol/L,37℃incubation for 1h were the best process conditions.Chlorogenic acid nanoliposomes have a strong ability to remove hydroxyl radicals,chlorogenic acid nanoliposomes have considerable hydroxyl radical scavenging ability as chlorogenic acid.