| Nitraria tangutorum Bohr.is a plant of Zygophyllaceae which is edible and medicinal in local.In addition, its fruits are often used in folk medicines such as antispasmodic, antineuropathic, and antiarrhythmicagent to cure weaknesses in the spleen and stomach. In this study, N. tangutorum fruit was extracted by column chromatography and TLC,and it will provide scientific evidence for the development of natural antioxidants.The main conclusions were showed as follow:1.The dried friuts (4.5kg) were extracted under reflux at 65℃with three 25L portions of 95% ethanol. The primary extract was evaporated to dryness in vacuo. The crude ethanol extract was suspended in water and subjected to sequential liquid-liquid extraction with petroleum ether, chloroform, ethyl acetate and n-butanol. The resules were crude ethanol extract(CEE) 1168.93g, petroleum ether fraction(PEF) 26.63g, chloroform fraction(CF) 25.40g, ethyl acetate fraction (EAF) 44.04g, n-butanol (BF) 120.67g, and aqueous fraction (AF) 952.19g.2.In this study, the antibiotic activities of N. tangutorum fruit against Escherichia coli, Bacillus subtilis and Staphyloccocus aureus were tested by the method of drug sensitive slips.The results showed that extracts from N. tangutorum fruit were effective to E. coli, B. subtilis and S. aureus.EAF showed the biggest inhibitory effect in the all inhibition tests.The inhibitory effect of PEF was close to EAF in the inhibition of E. coli test.3.The antioxidant activities were evaluated by the ABTS+ and DPPH·scavenging capacity. The antioxidant activity of ethyl acetate fraction was the highest which was slightly above VE. The others were significantly lower than the EAF. The results of DPPH·scavenging were consistent with ABTS+ scavenging. It has been shown by experimentation that the antioxidant activity of EAF was close to VE.4. The PEF were purified by column chromatography and mixed the same fraction by TLC and HPLC. Finally, there are 22 fractions were obtained. The antioxidant activity of compound 4 was higher than that of vitamin C and vitamin E.EAF was purified also, and there are 21 fractions were obtained. The antioxidant activity ofⅢ-4,Ⅲ-10 andⅢ-20 were close to vitamin C and vitamin E.5.12 compounds were isolated from the extract of N. tangutorum fruit. On the basis of spectroscopic methods including 1H NMR,13C NMR and ESI-MS, and comparison with literature, their structures were elucidated as Stigmasterol (3); Ethyl Hydroxybenzoate (5); myricetin (10). All the three compounds were isolated from N. tangtorum for the first time. |
