Study On Antioxidant Constituents From Ardisia Crenata Sims.

Ardisia crenata Sims.(A. crenata) has been used as a medicinal shrub for hundreds years. In recent years, there were a lot of researches for A. in pharmacological action and clinical application. A. crenata was reported to possess relieving cough and asthma, anti-inflammatory, antibacterial, antineoplastic, anti-fertility, lower blood pressure, anticoagulant, cAMP phosphodiesterase inhibitory effect. The research indicated that A. crenata contains triterpenoid saponins, coumarins, phenols, quinine, volatile oil, cardiac glycoside, saccharide, organic acid, etc. According to a literature search found that studies on the constituents and the antioxidant for A. crenata have not been related. Based on the above study and literature retrieval results, Thus, this study is carried out on antioxidant activity and chemical constituents of A. crenata.In this research, A. crenata was extracted by 90% ethanol, and then was suspended in water and successively partitioned and extracted with dichloromethane and ethyl acetate. The ethanol extract and other extracts were screened for antioxidant activity. And the active sites of the ethyl acetate fraction were separated by different chromatographic methods, such as Silica gel column chromatography, RP silica gel column chromatography and other means. Four compounds were isolated from A. crenata, and their structures were elucidated by their physical and chemical properties and Nuclear Magnetic Resonance (NMR) techniques (such as 1H-NMR, 13C-NMR.). Their structures were identified as kudzusapogenol-C(l),2a-Hydroxyursolic acid(2), 3β,6β,19α,23-tetrahydroxyurs-12-en-28-oic acid(3), cyclamiretinA-3β-O-β-D-glu-copyridineanosyl-(1â†'2)-a-L-arabinopyridineanoside(4). To the best of our know-ledge, compound 1,2 and 3 were isolated from the A. crenata for the first time.In vitro screening experiments, using DPPH assay experiment on four different solvents partition layers and the four compounds separated from A. crenata were investigated for their free radical scavenging activity. The results showed that ethyl acetate extract of A. crenata has a higher free radical scavenging activity. And compound 4 showed a higher free radical scavenging activities; compound 1, compound 2 and compound 3 showed that have the free radical scavenging activities.In vitro experiments shows that current researches on antioxidant activity of A. crenata are still less. Therefore, it is of important theoretical and practical significance on the separation of antioxidant active ingredient of A. crenata and further identify the structure of antioxidant active ingredient.