Studies On Chemical Constituents And Their Antioxidant Activity From Glasswort

Glasswort, also known as Salicornia herbacea, sea antler or sea cordyceps, is one of the halophytic herbs that grows in salt marshes and on muddy seashores. This plant is rich in eight kinds of necessary amino acids, vitamins, dietary fiber and trace elements such as calcium, iron, zinc, iodine and other marine minerals. Studies have shown that glasswort exerts biological effects including anti-arrhythmic, softening blood vessels, lowering blood sugar and blood lipids, antioxidant, anti-aging, increasing immunity and so on. In this thesis, chemical constituents of glasswort were systematically studied, and it also conducted a preliminary evaluation on their antioxidant activity.After washing and mincing, fresh glasswort was extracted with80%acetone three times, then fresh glasswort was extracted with ethyl acetate three times after removing acetone under vacuum concentration, then the the ethyl acetate extract was obtained after vaccum evaporation.12pure compounds were obtained after separation and purification from ethyl acetate extract by silica gel column chromatography and Sephadex LH-20. Then1D and2D nuclear magnetic resonance (1H NMR,13C NMR,1H-1H COSY, HSQC, HMBC), infrared(IR), ultraviolet(UV), mass spectrometry(MS) and other modern spectroscopic techniques as well as related literature search were used to identify the chemical structure of the compounds, which were n-octadecanoic acid,1-0-6,9,12-hexadecatrienal glyceride,6,9,12-octadecetrienoic acid, ergosta-5,22-dien-3-ol, ergosta-5,7,22-trien-3-ol, pentadecanoic ferulate,3-methoxy-4-hydroxy benzaldehyde, di(2-ethylhexyl)phthalate,4,7,10-Octadecetrienoic acid ethyl,13,16,19-eicosatrienoic acid,3-methoxy acrolein,5,6-epoxy sterol. The12compounds are all the first time isolating from glasswort and pentadecanoic ferulate is a new natural product. The results initially clear the material basis for the activity of glasswort, providing a theoretical basis to clarify the relationship between chemical constituents and the active role of glasswort for the future. In addition, total antioxidant(FRAP values) method, DPPH radical scavenging method, superoxide anion scavenging method and other antioxidant dertermination methods were used to evaluate the antioxidant activity of compounds separating from the ethyl acetate extract of glasswort, from which, a compound of higher antioxidant activity was find out. Then, the compound was further studied to evaluate the antioxidant activity in different concentrations. The results showed that pentadecanoic ferulate had a strong hydroxyl radicals and superoxide anion scavenging activity, which was the main antioxidant active ingredient. In the conditions of1mg/mL, DPPH radical scavenging rate was as high as91.3%, IC50was110.6±0.86μg/mL, Superoxide anion clearance rate was70.05%, IC50was560±1.35μg/mL,3-methoxy acrolein and4,7,10-Octadecetrienoic acid ethyl had a moderate antioxidant level, their DPPH radical scavenging rate were47.20%and34.55%, superoxide anion clearance rate were33.95%and28.35%. The rest of the compounds all had a certain degree of scavenging hydroxyl radicals and superoxide anion, but the scavenging activity was low, which showed the antioxidant activity was weak.