地椒抗氧化活性部位化学成分的研究?

目的研究地椒抗氧化活性成分,阐明地椒抗氧化活性化学成分组成。方法采用1,1-diphenyl-2-picrylhydrazyl(DPPH)和2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid)(ABTS)自由基清除试验筛选评价地椒5个极性部位的抗氧化活性;采用硅胶、Sephadex LH-20和MCI GEL CHP-20P等柱色谱方法进行分离纯化,并根据质谱、核磁数据和参考文献数据等鉴定化合物的结构。结果地椒乙酸乙酯层和正丁醇层显示很好的抗氧化活性。从该两萃取层中,分离鉴定18个化合物分别为野黄芩苷(1),野黄芩素(2),5,6,7-三羟基-4'-甲氧基黄酮(3),4'5-二羟基-6,7,8,-三甲氧基黄铜(xanthomicrol)(4),芹菜素(5),4'-甲氧基木犀草素(6),木犀草苷(7),木犀草素(8),芦丁(9),丹参素(10),香草酸(11),原儿茶酸(12),绿原酸(13),咖啡酸(14),阿魏酸(15),2,6-二羟基-4-异丙基-β-D-葡萄糖苷(16),齐墩果酸(17)和胡萝卜苷(18)。结论化合物1~3和16首次从百里香属植物中分离得到,化合物4~8,10~12,14~15和17~18首次从地椒植物中分离得到。

Antioxidant activities and chemical compositions of Thymus quinquecosta-tus Celak

Objective To study the antioxidant activities and chemical compositions of Thymus quinque-costatus Celak ( dijiao ) . Methods The antioxidant activities of five polar fractions of dijiao were screened and evaluated using DPPH and ABTS free radical scavenging assays. After the chemical compo-sitions were separated and purified by using silica gel chromatography, Sephadex LH-20 chromatography and MCI GEL CHP-20P column chromatography, the chemical compositions were identified by MS and NMR spectrometers, and records of literature. Results From the EtOAc and n-BuOH fractions which showed high antioxidant activity, total 18 compositions were separated and identified: scutellarin (“1 ”short for peak No. 1, the same below), scutellarein (2), 5,6,7-trihydroxy-4′-methoxyflavone (3), xanthomicrol (4), apigenin (5), 4′-methoxyluteolin (6), luteolin-7-O-β-D-glucopyranoside (7), lute-olin (8),and rutin (9), danshensu (10), vanillic acid (11), protocatechuic acid (12), chlorogenic acid (13), caffeic acid (14), ferulic acid (15), 2,6-dihydroxy-4-isopropylphenyl-β-D-glucopyranoside(16), olenolic cid (17) and daucosterol (18). Conclusion The composition 1,2, 3 and 16 were the first reported in the genus Thymus, and 4~8, 10~12, 14~15 and 17~18 were found first in dijiao.