Preliminary Study On Premature Bolting Mechanism And The Activity Of Skin-whitening Of Angelica Dahurica

Angelica dahurica[Angelica dahurica（Fisch.ex Hoffm.）Benth.et Hook.f.var.formosana（Boiss.）Shan et Yuan]is one of the edible Chinese herbal list released by China’s Ministry of Health.It is also one kind of the traditional skin-whitening herbs.Based on our previous selection of varieties of Angelica dahurica,the selection of the improved variety with the lowest bolting rate of Angelica dahurica was carried out more systematically.After the original region of field cultivation experiment,we measured a few physiological and biochemical indexes and selected the best Angelica dahurica root.Based on that,combining with the traditional application of Angelica dahurica,we need to make scientific excavation of its whitening and skin-protecting ingredients.Our study provided a reference for a better development of Angelica dahurica in the application of beauty cosmetics.The main results are as follows:1.The effect of seed harvested by different parts of Angelica dahurica on early bolting.The determination of physiological and biochemical indexes such as seed germination was carried out by different parts of Chuan zhi No.2.Soluble sugar and soluble protein content were the highest in the seeds from lateral branches,which reached the highest germination rate at 78.33%,indicating that higher content of soluble sugar and soluble protein provided necessary conditions for seed germination.The germination rate of seeds from different parts of the plant was inversely proportional to their C/N ratio.On the whole,the seeds form lateral branches were riched in nutrients,which had the maximum thousand-grain weight（3.12 g）,the seed vigor index reached 88.16%with a minimum moisture content of11.20%.2.The effect of seed harvested at different time of Angelica dahurica on early bolting.Taking seeds harvested at different period of Chuan zhi No.2 as material,the later seeds were harvested,the lower C/N ratio and germination ratio were.The offspring’s height and diameter of stem were higher and lower with the different mature stage of the parent seed,and the index of June 28 was the highest.The C/N ratio of the leaf of offspring was related to the harvested time of the parent seeds.The later the seed harvested,the lower C/N ratio in the offspring was,and the premature bolting rate was lower.It was worth noting that different parent seed harvested had some influence on the offspring yield and quality.The offspring of seed harvested on June 28 which had the highest yiled and the best root3.Effects of exogenous sugar treatment on the growth and lichen of Angelica dahurica.Through spraying exogenous sugar on the leaves of Chuan zhi No.2,it was found that exogenous sugar treatment could increase the level of endogenous soluble sugar at the early stage,but it had little effect for a long time,and even resulted in the decrease of sugar content.Exogenous sugar treatment did not lead to early flowering of Angelica dahurica.However,it can significantly improve the plant height and yield of Angelica dahurica,the starch content decreased,with the increased of concentration sugar treatment,but the total content is higher than that of the control.4.Transcriptome analysis of different bolting qualities Angelica dahurica.Transcriptome analysis was carried out for different characteristics of leaves premature bolting and normal material,the results showed a by MADS box and FUL genes expression level was higher in premature bolting materials,it means that the two genes related with premature bolting..5.Optimization of extraction method of water extract from radix angelica dahurica and analysis of whitening active ingredients.Dry root of Chuan Zhi No.2 was selected as experimental material,and various solvents were choosed for extraction.Combined with tyrosinase inhibitory test,we found the same concentration of water extraction was bigger than alcohol extraction in tyrosinase inhibition.And the tyrosinase inhibition rate was proportional to the concentration of water extraction.Through the human skin-whitening efficacy evaluation experiment,the value of L was increased gradually after smearing Angelica dahurica water extraction liquid for one week.At the third week,the value of△E_ab enhanced significantly.At the same concentration,the effect of skin-whitening of water extraction liquid was better than kojic acid.Two kinds of furocoumarin could not be detected in water extraction by HPLC.And the alcohol extract had a higher content of imperatorin.Furthermore,the water extract contained less photosensitive material,which was verified to be directly applied to the skin and had no any other allergy.We chose the dry root of Chuan Zhi No.2 as materials.The extraction time,temperature,solid-liquid ratio and extraction times were chose as the influence factors of tyrosinase inhibition test.Box-Behnken method was used to optimize the main factors which influencing the tyrosinase activity,the design for this experiment included 3 factors and 3 levels,with tyrosinase inhibition rate as the evaluation index,and we established the tyrosinase inhibition rate of quadratic polynomial mathematical model.The best extraction conditions was extracting temperature 30℃,liquid-solid ratio was 25 ml/g,extraction time for 30 min.The tyrosinase inhibition rate was 24.20%.Considering the water extraction part of Angelica dahurica contain considerable polysaccharide composition,tyrosinase activities were detected before and after the removal of polysaccharides.It was found that there was little difference between the IC₅₀ of the two samples,indicating that the existence of polysaccharide in the water extract had little contribution to the tyrosinase inhibitory activity,the main active substances mainly existed in the part without polysaccharides.Using different organic solvents with pH from small to large,the extraction method was optimized with response surface disign.The IC₅₀0 of ethyl acetate phase was minimum（9.58 mg/mL）,showing that the skin-whitening active existed in ethyl acetate.6.Use molecular docking technology to predict effective whitening ingredients.Using molecular docking technology,the literature reported in Angelica dahurica coumarin with a light toxicity component respectively with tyrosinase docking experiment.It was found that 5-methoxy-8-hydroxypsoralen had the strongest binding force to tyrosinase,the conjugated interactions the same with kojic acid,which is bonding withπ-πof HIS-263,the Cu²⁺,the hydrogen bonding in HIS-61 and HIS-296.The follow is oxypeucedanin,which forces between oxypeucedanin and tyrosinase was hydrogen bonding withπ-πconjugate,and like the kojic acid had the same action site with the ASN-260,VAL-283.It was speculated that the skin-whitening role of Angelica dahurica might be 5-methoxy-8-hydroxypsoralen and oxypeucedanin.In conclusion,this paper studied the C/N ratio and bolting rate between the was studied and the relationship between the rate of bolting,in Angelica dahurica,was shown by test that the different parts of the harvested seeds and harvest the seeds in different period,their C/N ratio was directly related to the bolting rate,to guide the production of a certain theoretical basis.In addition,the determination of solvent in the whitening active site of Angelica dahurica was studied,and the water extraction effect was better.The active fraction was in the ethyl acetate part,which was the foundation for the reentry of Angelica dahurica in the cosmetics market.