Isolation And Antioxidant Activity Of Compounds From Dendropanax Dentiger (Harms) Merr.

Dendropanax dentiger (Harms) Merr. is a species of Dendropanax from Araliaceae fanmily, is mainly distributed in the south-west of China, traditionally used as a folk medicinal plant in China for a variety of diseases, such as migraine headache, dysmenorrheal, Rheumatoid arthritis and Rheumatic arthritis[1], and is also applicable to functional health foods, food additives, beverage compositions, fodder additives, etc. in order to investigate the chemical constituents of it, we studied the stem of Dendropanax dentiger (Harms) Merr. by silica gel, ODS, Sephadax HW-40C and XAD-7HP.Dried Ethanol extract of Dendropanax dentiger (Harms) Merr.(Araliaceae) was dissolved in distilled water, and then fractioned by re-extracting with petroleum ether, ethyl acetate, and n-butanol. subsequently, 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activities of these fractions were determined, and it is disclosed that the ethyl acetate and n-butanol fractions showed greater DPPH radical scavenging activity compared to it of petroleum ether Fraction, and the ethyl acetate fraction exhibited the highest DPPH radical scavenging activity. Therefore, ethyl acetate and n-butanol fraction was subjected to further separation by chromatographic methods. Thus 11 phenolic compounds were isolated and DPPH radical-scavenging activities of these compounds were determined, among them, flavonoids and polyphenolic compounds showed strongest DPPH radical-scavenging activities. Phenolic acids had the moderate DPPH free radical scavenging activity. From these results, it can be suggested that these compounds may be used as potential antioxidants. In addition, the petroleum ether fraction was subjected to silica gel column chromatography (CC).Twenty-four compounds were isolated from the extract and identified as follows by chemical, NMR and MS spectroscopic methods:(1) Friedelan-3-one(2) Palmitic acid(3)β-Sitosterol(4) Glycerol monooleate(5) Behenic acid(6) 1-Triacontanol(7) Stearic acid(8) Syringaldehyde (9) Coniferylaldehyde(10)β-daucosterol(11) Scopoletin(12) Sinapaldehyde(13) Quercetin(14) Luteolin(15) Sinapaldehye glucoside(16) Syrigin(17) Ferulic acid(18) (E)-cinnamic acid(19) (E)-4-hydroxylcinnamic acid(20) (+)-Medioresinol di-O-β-D-glucopyranoside(21) (+)-Syringaresinol di-O-β-D-glucopyranoside(22) Eugenol rutinoside(23) Cafic acid(24) Icariside E5All the compounds, expect for 3,7,16, were obtained fom this plant for the firt time And compounds (13), (14), (23) showed significant free radical scavenging capacities with IC50 values of 0.0051±0.0001,0.0038±0.0007 and 0.0057±0.0020μM, respectively, all of which were mucl more active than L-Ascorbic (IC50=0.0059μM).