Studies On Bioactive Components From Limonium Gmelinii

In this paper, ten chemical constitutes were isolated by various chromatographic and recrystallized methods from Limonium gmelinii in Xinjiang. On the basic of analysis of NMR data and measurement of physico-chemical characters, the structures of 8 compounds were identified as Myricetin(C-1), β-sitosterol(C-2), dihydromyricetin(C-3), gallic acid(C-4), myricetin-3-O-α-L- rhamnoside(C-5), quercetin(C-6), daucosterol(C-7) and rutin(C-8). Among them, compunds C-3、C-6、C-7 and C-8 were isolated from this plant for the first time.To get the total flavonoids from Limonium gmelinii, it was extracted with 50% ethanol by using heat reflux extraction combined with flash extraction. The best conditions were as follows: material to liquid was 1:70 g/m L, flash extraction time was 15 minutes and the temperature of heat reflux extraction was 90℃. Finally, 5 kinds of macroporous resins were tested to purify the flavonoid parts, among them AB-8 had high ratios both at adsorption and desorption for total flavonoids. In addition, AB-8 was studied to the static adsorption curve of total flavonoids. Two factors including the concentration and dosageof solvent were optimized.A RP-HPLC analytical method for simultaneous determination of four flavonolsmyricetin3-O-α-L-rhamnoside, rutin, myricetin and quercetin in the aeries parts of Limonium gmelinii was established. Analysis was performed on Kromasil C18 column(250mm ′ 4.6mm,5μm) with methanol-water- phosphoric acid(40:60:0.4)as mobile phase. The detection wavelength was 265 nm. The methodology validation shows that this method is accurate, simple and reliable, which is applicable for the simultaneous determination of four flavonols in the aeries parts of Limonium gmelinii.In addition, the inhibitory activity of free radicals, ACE and the protection effect on acute alcohol-induced liver damage of the extracts or total flavonoids were investigated in vitro and in vivo. The experiments showed the total flavonoids at concentrations of 50, 100, 200μg/m L had the inhibitory activities for DPPH? free radicals, and the activity was dependent on the concentration, while the inhibitory activity for ?OH was not good. The extracts from ethanol, ethyl acetate, n-Bu OH and water had high inhibitory activities of ACE at concentrations of 100μg/m L. We have also studied the effect of total flavonoids on acute alcohol-induced liver damage, the results showed that total flavonoids could reduce the liver index; decrease ALT, AST activity in liver tissue, elevate SOD activity, reduce the content of MDA, LDH, TC and TG to protect the liver in mice. The mechanism may be related to the antioxidant activities of total flavonoids.