| Artemisia sphaerocepdala Krasch(ASK)is a unique and arid plant resource in the northwest region.The seed,rich in hydrophilic colloid,is an edible and medicinal resource.It is used as a legal food additive,and widely added to flour.However,the other biologically active constituents of the seed are not yet fully understood.Therefore,the active components of Artemisia sphaerocepdala Krasch seeds(ASKS)were isolated and identified.Besides,their antioxidant activity and antitumor activity were analyzed,and the fatty acid composition was detected.The results provided scientific basis for the further development and utilization of ASKS.The main results are as follows:We extracted the flavonoids from(ASKS)by methanol,acetone,ethyl acetate and chloroform.The extracts which from methanol had the highest scavenging activity of DPPH and ABTS in all of the solvent extracts.In addition,the contents of total flavonoids and polyphenols were relative to the different polarity of solvents.In this study,methanol extracts had higher contents of flavonoids(33.30 mg/g)and polyphenols(80.1 mg/g)than other solvent extracts,followed by acetone and ethyl acetate extract,and chloroform extract had the lowest flavonoids and polyphenols.Next,we detected quercetin and catechins from extracts by HPLC.Furthermore,we leached first by ethanol and extracted afterward by petroleum ether,chloroform,ethyl acetate and n-butanol to analyze the chemical composition of flavonoids in ASKS.The contents of total flavonoids and polyphenols in ethyl acetate extracts were 32.64 and 73.56 mg/g,respectively,and the contents in chloroform extracts were 7.50 mg/g and 15.22 mg/g,respectively.We next detected the antioxidant activity of the extracts,and the results showed that all of the extracts had antioxidant activity,and ethyl acetate extracts had the best antioxidant ability due to the fact that the scavenging activity of DPPH was 92.16%and the scavenging activity of ABTS was 99.76%at 1 mg/mL.Besides,we analyzed quercetin,catechins and caffeic acid in ethyl acetate extracts by HPLC.Layer and columncancer chromatography were used to separate the active components,and the structures were identified by nuclear magnetic resonance spectroscopy.Three compounds were obtained from ASKS,they are identified as stigmasterol,β-sitosterol and eriodicumol-7-methylether by the above isolation method.Human hepatoma cell(HepG2),cervical cancer cells(Hela)and colon cancer cells(Caco-2)were used as tumor models to further explore the inhibitory activity of three compounds on the proliferation of cancer cells.MTT assay showed that different concentrations of three compounds had significant inhibitory activity,the results of DAPI staining and AO/EB double staining showed that the cell morphology of treated group changed into round and irregular morphology when compared to the control group,and the cells appeared cell apoptosis characteristics,such as rupture shrinkage,extent of cell gap etc.Response surface methodology(RSM)was used to optimize method of supercritical CO2 extraction of ASKS Oil.The best yield was 18.6%when the extraction pressure,temperature and time were 41.2 MPa,48.2℃ and 78.24 min,respectively.The results showed that the content of unsaturated fatty acids was 81.27%and the content of unsaturated fatty acids was more than 90%.P/S value of ASK oil was 5,higher than the common commercially available edible oil,it is beneficial to reduce blood cholesterol content of human body,and thus has a high food value.This study indicated that the extracts from ASKS by different solvents all had antioxidant activity in vitro,and the monomer compounds separated from ASKS inhibited the proliferation of cancer cells.Moreover,the oil of ASKS was rich in unsaturated fatty acids,which had the high edible value.These all provided the basis for the further research of ASKS in food and medicinal field. |
