Separation, Purification And Inhibitory Effect On AGEs Formation Of Flavonoids From Artemisia Selengensis Haulm

Artemisia Selengensis belongs to Asteraceae Artemisia plants, edible for medicine. It is widely planted in "Eight Diagrams" district of Nanjing. As a vegetable, The tender stems of Artemisia Selengensis were mainly edible for people in winter and spring. But the old stems, leaves and the haulm could not be used due to the lack of deeply processing technology. In order to promote the utilization of Artemisia Selengensis and the comprehensive development of traditional Chinese medicine, we take Artemisia Selengensis haulm as the research object in this dissertation. The chemical constituents were extracted by 75% ethanol, and isolated by column chromatography. Their structures were determined by modern methods of identification. The inhibitory activity against the formation of advanced glycation end products (AGEs) was studied in the paper. The main contents and conclusions in this dissertation were summarized as follows:1 Considering overall absorption and desorption properties, AB-8 resin was selected out of eight kinds of macroporous resins (NKA-Ⅱ, AB-8, HPD417, DM130, D101, HPD826, ADS-17 and polyamide) to purify the crude flavonoids extract from Artemisia Selengensis haulm. The optimum process conditions for purifying the crude flavonoids extract using AB-8 resin were determined as follows:sample concentration 1.476mg/mL, pH 4.0, flow rate 1mL/min, adsorption volume 2.5BV, elution solvent 60% ethanol (v/v), elution volume 1.5～2.0BV. Under these conditions, the purity of total flavonoids was improved from 5.80% to 30.26%, and achieved a goal of enrichment and purification, which had certain value of application.2 The compounds were isolated from the haulm of Artemisia Selengensis by column chromatography on AB-8 resin, octadecylsilanized silica-gel (ODS), silica-gel and sephadex LH-20. Their structures were determined by chemical evidence and MS spectra,1H-NMR,13C-NMR, HMBC and HQBC. Four compounds were identified as: compound 1, kaempferol-3-O-glucuronide, rutin and luteolin. Three isomers were identified as 3,5-dicaffeolquinic acid,4,5-dicaffeolquinic acid,3,4-dicaffeolquinic acid. Except rutin and luteolin, all the compounds were obtained from Artemisia Selengensis for the first time. Compound 1 was a new compound.3 Rutin and luteolin were isolated from the two elutions (30% EtOH elutions and 50% EtOH elutions) which contain highest flavonoids contents; they exhibited the strong inhibitory activities against the formation of AGEs. Rutin had showed significant inhibitory activities at a concentration of 2.5mmol/L with 89% inhibition on the formation of AGEs in BSA-MGO model and 77% inhition in BSA-GO model. The inhibitory effect of luteolin on the formation of AGEs in BSA-MGO model was 81% inhibition at a concentration of lmmol/L. Luteolin could trap reactive carbonyl species at low concentrations, suggesting that it could be used as a new inhibitor for preventing and alleviating diabetes and diabetes-related complications.4 There were total 4 elutions (F-10(10% EtOH elutions), F-30(30% EtOH elutions), F-50(50% EtOH elutions) and F-70(70% EtOH elutions)) obtained by AB-8 resin. All elutions were found with significant inhibitory activities against the formation of AGEs. The ability of inhibitory was F-50>F-30>F-10>F-70, which was consistent with the effects of rutin and luteolin on the significant inhibitory activities against the formation of AGEs. Meanwhile, the inhibitory activities of elutions were found to be highly correlated with their total flavonoids contents. Thus, the F-50 component could be used in industrial production of healthy food because of the significant inhibitory activity against the formation of AGEs.