Studies On The Preparation And Characterization Of Corn Lecithin And Its Hypolipidemic Effects

Lecithin is a class of valuable phosphorus-containing lipids commonly found in biological communities.Lecithin is an important component of lipids in biological membranes,including nuclear membranes,cell membranes,and plastid membranes.It plays a key role in maintaining the physiological functions of biological membranes and normal body metabolism.Because lecithin molecules have a special bipolar structure,they contain both the nonpolar end of lipophilic fatty acid hydrocarbons and the hydrophilic end of the choline base and phosphate.The special molecular structure of lecithin determines that it has a variety of physiological activities and physicochemical properties.It can be widely used in cosmetics,food and pharmaceutical industries.It is an ideal material for emulsifier,conditioner,and solubilizer for the preparation and production of various pharmaceutical preparations.Because the research and development and industrialization of pharmaceutical excipients in our countryis a relatively weak link,and pharmaceutical lecithin?oral and injection level?product research and development time is relatively late,its extraction process technology is complex and difficult.Only a few foreign companies have been able to master the pharmaceutical lecithin production technology that has both high purity and activity in the world.At present,China basically all rely on imported pharmaceutical lecithin to meet the production needs of intravenous fat emulsion and liposomes.In this study,corn germ was used as raw material.After deoiling by supercritical carbon dioxide?SC–CO₂?,ultrasonic and microwave assisted extraction and freeze purification were used to prepare oral and injectable corn lecithin,and to make PC,PE and LPC contents meet the scope of Specification of Import Drugs.Then,the physicochemical characteristics,phospholipid composition,structure identification and emulsifying properties of oral and injectable corn lecithin were studied.Finally,a rat model of hyperlipidemia was established,and the lipid-lowering efficacy and acute toxicity test of oral and injectable corn lecithin were evaluated.Corn germ is rich in resources of the People's Republic of China,and its processing and utilization rate is low.This research result can be successfully implemented in practical applications,not only can greatly increase the added value of corn germ,and extend the deep processing industry chain of corn,resulting in a huge economic,social and environmental benefits,but also help to ease the long-term reliance on importation of oral and injectable lecithin,with significant application value and broad market prospects.The research content and results are as follows:?1?Corn germ,after deoiling by supercritical carbon dioxide?SC–CO₂?was used as raw material.Ultrasonic and microwave assisted extraction was used to extract crude corn lecithin with ethanol.The ratio of material to liquid,ultrasonic power,microwave temperature and synergistic time were used for the effect of extraction rate of crude corn lecithin by single factor experiment and orthogonal test.Fixed ethanol concentration is 95%.The results showed that the optimum extraction conditions were as follows:The ratio of material to liquid?g/mL?1:10,ultrasonic power 230W,microwave temperature 55°C,and synergistic time 20min.Under these conditions,the crude corn lecithin extraction rate was?81.24±2.35?%,which was significantly higher than ultrasonic assisted extraction,microwave assisted extraction and ethanol extraction alone.The results of UPLC-ELSD analysis showed that the content of PC was the highest?62.25±2.12?%and the content of PE was?26.67±0.35?%,while the content of LPC was only?1.32±0.08?%.In addition,there are still a small number of unknown components in the crude corn lecithin sample for further study.?2?Crude corn lecithin was used as raw material,and ethanol was used to freeze and purify oral and injectable corn lecithin.Through single factor experiment and orthogonal experiment,the ratio of material to liquid,ethanol concentration,freezing temperature and freezing time were used for the effect of extraction rate,PC content,and PE content of oral and injectable corn lecithin.The results showed that the optimal conditions were as follows:The ratio of material to liquid?g/mL?1:9,ethanol concentration 95%,freezing temperature-14°C,and freezing time45min.Under these conditions,the extraction rate of oral and injectable corn lecithin was?79.35±1.22?%,the PC content was?78.37±0.17?%,and the PE content was?9.86±0.07?%,which met the requirements of the Specification of Import Drugs?JX20010249?.?3?TLC and UPLC-ELSD methods were used to analyze the phospholipid composition in oral and injectable corn lecithin.The results showed that PC content was highest,PE content was the second,and LPC content was only?1.32±0.08?%.The phospholipid composition of the prepared oral and injectable corn lecithin is in the range of those reported by the Chinese Pharmacopoeia 2015 edition and the Specification of Import Drugs?JX20010249?.The physicochemical properties related to the important quality indices of the oral and injectable corn lecithin were analyzed.The results showed that all the indices of the product were within the acceptable range of the Chinese Pharmacopoeia 2015 edition,and even some indices were better than those of injection-grade soybean lecithins from previous reports.?4?The FT-IR was used to identify the structures of oral and injectable corn lecithin sample.The results showed that the intensity of the functional band of the phospholipid in the sample was strong,indicate a phospholipid content in the sample.GC-MS analysis of fatty acid compositions of oral and injectable corn lecithin sample,PC and PE components showed that the three lipids contained large amounts of linoleic acid and oleic acid.For linoleic acid,the content of PE was the highest,reaching 60.95%.The content of oral and injectable corn lecithin sample was the lowest,only 45.99%.The content of oleic acid in the PC component was the highest,reaching 24.51%.The fatty acids in oral and injectable corn lecithin sample were mainly composed of palmitic acid?18.81%?,stearic acid?3.92%?,oleic acid?22.31%?,linoleic acid?45.99%?and linolenic acid?7.66%?.The n-6/n-3 ratio?6.00?is within the acceptable range of safety values recommended by the World Health Organization.UPLC-ESI-TQ-MS/MS was used to analyze the molecular species and content of different phospholipids in oral and injectable corn lecithin.A total of 6 PC and 6 PE molecular species were detected.In PC phospholipids,the relative content of PC?36:3?,PC?34:2?,and PC?36:2?molecular species is relatively high,while in PE phospholipids,the relatively higher molecular species is PE?36:4?and PE?34:2?.In addition,the lysophospholipids of PC and PE are composed of two molecular species,LPL?16:0?and LPL?18:0?,and their relative content is very low.The characterization results of all the fatty acid chain species and their relative contents determined by UPLC-ESI-TQ-MS/MS and GC-MS analysis results were highly consistent.?5?Emulsions stabilized with the oral and injectable corn lecithin were optically characterized and microscopically inspected,and the droplet size distribution was determined.The results showed that an increase in the corn lecithin concentration led to a decrease in droplet diameter and an increase in emulsion stability.Furthermore,the oral and injectable corn lecithin created a more stable emulsion than injection-grade egg yolk lecithin.?6?A rat model of hyperlipidemia was established and the hypolipidemic effects of oral and injectable corn lecithin was evaluated.The results showed that after 2 weeks feeding,the rats with high-fat diet,blood were collected from the tail vein to determine the serum of the model group rats.The levels of TC,TG and LDL-C were significantly higher than those of the blank control group,indicating that the model of hyperlipidemia rat model was successful.By analyzing the serum index data of rats,compared with the model group,the high-dose group and the middle-dose group can be obviously reduced the serum levels of TC and TG in hyperlipidemic rats.The high-dose group significantly reduced LDL-C levels and elevated HDL-C levels,indicating that the high-dose group had a significant reduction in blood lipids in rats with high-fat diet.Oral and injectable corn lecithin can significantly reduce the rat abdominal fat accumulation coefficient,and the high-dose group is superior to other groups.By analyzing the SOD and MDA contents in rat liver,the high-dose group can significantly reduce the liver MDA content and increase the SOD level in the liver,indicating that oral and injectable corn lecithin can inhibit lipid peroxidation in the liver and improve the anti-oxidation ability of liver tissue.From the histopathological observation of rat liver,oral and injectable corn lecithin can improve hepatocyte steatosis injury in hyperlipidemic rats,with the best effect of high dose group.In summary,the oral and injectable corn lecithin can help reduce blood lipid and protect liver.?7?The results of acute toxicity test in mice showed that the maximum intragastric administration dose of oral and injectable corn lecithin was 28g/?kg.d?.This dose was equivalent to 235 times the clinical dose.The weight gain was a normal growth range,there was no evidence of poisoning or death,and no obvious changes in the tissue were found after the necropsy.Compared with the blank control group,the difference was not statistically significant in the drug-administered group,indicating that oral and injectable corn lecithin was safe and reliable,belonging to non-toxic grade.