| ?-polyglutamic acid is a new type of biopolymer made by glutamic acid monomer through ?-amino and ?-carboxy dehydration condensation,because it has excellent water absorption,biocompatibility and biodegradability,has been widely used in cosmetics,agriculture,environmental protection,medicine and biomedical materials and other fields.In cosmetics,?-polyglutamic acid can be used as supporting materials,skin moisturizers,skin factor slow-released agent,natural beauty mask and so on.The hydrogel is a colorless,odorless,transparent and soft gum,which is highly hygroscopic and moisturizing because of its three-dimensional polymer network structure.It is especially suitable for improving the moisturizing effect of the product in cosmetics.In addition,the powerfully water absorption capacity and sustained-release ability of ?-polyglutamic acid in the soil can be used as the accelerator of seed germination,and it has obvious drought-promoting seedling effect,which can effectively improve the germination rate and seed vigor of the crop.In this study,we researched the moisturizing property,human safety and its antioxidant activity of ?-polyglutamic acid,and solved the problem of the decrease of carbomer viscosity in cosmetics caused by ?-polyglutamic acid.Meanwhile the effects of different molecular weight of ?-polyglutamic acid on the seed germination and seedling growth of mung bean were discussed.?-PGA samples with different molecular weights(Mw)and different percentage(0.1-0.5%)were prepared,and the moisture retention capacity of the samples were determined by using an skin moisturizing evaluation method.The skin safety evaluation was investigated by the human skin patch test method.The results showed that ?-PGA with different average molecular weight and different concentration displays different moisturizing properties,and 0.1%?-PGA with average molecular weight 1200 KDa has better moisture retention capacity.After treatment with the?-PGA for 2 h,the percentage of skin moisture content change was 103.93 ± 0.24;After treatment with the ?-PGA for 4 h,the percentage of skin moisture content change was 112.23 ± 0.23,nearly equal to the value of sodium hyaluronate treatment(positive control group,114.01 ± 0.34).The results of the human skin patch test showed that ?-PGA is safe.Taking IC50 as the evaluating criterion of DPPH free radical scavenging capability by determining the scavenging rate curves of ?-polyglutamic acid,Vc phosphate and ?-arbutin were used to be compared with.The inhibitory activity of?-polyglutamic acid on hyaluronidase was determined by DNS method.The results showed that the IC50 value of 1.4 million Mw ?-polyglutamic acid was 25.5 mg/mL,slightly better than that of 100000 Mw ?-polyglutamic acid(IC50 30.5 mg/mL).The effects of scavenging free radicals were about half that of Vc magnesium phosphate(IC50 13 mg/mL),but lower than ?-arbutin(IC50 0.016 mg/mL).The components of the cosmetics containing ?-PGA,such as glutamic acid,sodium glutamate and sodium chloride,can lead to a decrease in the viscosity of the thickener carbomer,and the higher the ion concentration,the lower the carbomer viscosity.In order to keep the viscosity of 0.2%carbomer 941 more than 1000 cp in the cosmetic system,the ?-PGA concentration of 100,000 and 800,000 molecular weight can not exceed 0.05%.If the concentration of 0.1%?-PGA is added to the cosmetic formulation,the minimum mass fraction of carbomer 941 should be 0.3%and 0.25%for 100,000 and 800,000 molecular weight ?-PGA to maintain the viscosity of the system 1000 cp above,can be used for skin care cream and emulsion production.The effects of different molecular weight ?-polyglutamic acid on the seed germination and seedling growth of mung bean were studied.The results showed that?-polyglutamic acid with different molecular weights could increase seed germination rate and increase plant height,root length and fresh weight.Correspondingly,the amylase,catalase and peroxidase activity of the seeds also increased in varying degrees.Among them,the relative molecular weight of 120 kD y-polyglutamic acid had the best effect of the seed.In summary,y-polyglutamic acid has a good moisturizing property and moderate antioxidant activity,safey,non-irritating,can be widely used as a good additive in cosmetics and other skin products;solved the problem of reducing the viscosity of carbomer in cosmetics by y-polyglutamic acid.The water retention can improve seed germination rate,promote seedling growth,have obvious drought-resistant seedling effect,and has wide application prospect in agriculture. |
PDF Full Text Request