白芍总苷体外抗氧化活性研究

目的研究白芍总苷体外对不同化学体系和生物体系的抗氧化活性。方法通过Fenton反应生成·OH自由基,采用DPPH·自由基,观察不同质量浓度的白芍总苷溶液对化学体系自由基的清除作用。利用邻二氮菲-Fe2+-H2O2产生的·OH自由基造成红细胞膜破裂,以及肝、脑细胞脂质的过氧化,观察不同质量浓度的白芍总苷溶液对生物体系自由基的清除作用。结果白芍总苷对·OH有一定的清除作用,其IC50为0.62 g/L。白芍总苷对DPPH·自由基有较强的清除作用,IC50为6.6 mg/L;对·OH自由基引发的红细胞膜破裂有一定的抑制作用,其IC50为30.17 mg/L,对肝、脑匀浆脂质过氧化有一定的抑制作用,其IC50分别为6.9、16.3 mg/L。结论白芍总苷具有清除自由基作用,在不同体外实验体系中抗氧化量效关系存在差异。     

Anthocyanin profile and antioxidant capacity of black carrots (Daucus carota L. ssp. sativus var. atrorubens Alef.) from Cuevas Bajas,Spain

The present work deals with the study of the anthocyanin profile of two different black carrots (Daucus carota L. ssp. sativus var. atrorubens Alef.) cultivars, associated with Antonina and Purple Haze varieties, from Cuevas Bajas (Málaga, Spain) and some of their antioxidant features. The main anthocyanins detected by LC–MS were found to correspond to five cyanidin-based anthocyanins: cyanidin 3-xylosylglucosylgalactoside, cyanidin 3-xylosylgalactoside and the sinapic, ferulic and coumaric acids derivative of cyanidin 3-xylosylglucosylgalactoside. The anthocyanins present in the black carrots were essentially acylated and their levels were found to correspond to 25% and 50% of the total phenolic content for the Purple Haze and Antonina varieties, respectively. Moreover, the reducing capacity of the two black carrots extracts (86.4 ± 8.0 and 182.0 ± 27 μM TE/100 g fw) and the radical scavenging ability (17.6 ± 9.0 and 240.0 ± 54.0 μM TE/100 g fw) expressed in Trolox equivalents units were determined. The antioxidant features of the black carrot extracts were shown to be significantly higher than those of orange carrots used herein for comparison. Overall, this work highlights the Cuevas Bajas black carrots as rich sources of anthocyanins with significant antioxidant capacities and good nutritional value.     

Evaluation of yield,quality and antioxidant activity of essential oil of in vitro propagated Kaempferia galanga Linn.

ObjectiveTo determine chemical constituents and antioxidant properties of essential oil from rhizome of the medicinal plant, Kaempferia galanga (K. galanga) Linn. (Zingiberaceae) in conventionally propagated (CP) and in vitro propagated (IVP) plants.MethodsIn vitro (micro) propagation of K. galanga was done by inoculating explants on to Murashige and Skoog agar medium, supplemented with suitable combinations of phytohormones; the regenerants were transferred to soil for further growth. Essential oil preparations of both CP and IVP rhizomes grown in soil, obtained by the hydro-distillation method were analyzed by gas chromatography-mass spectrometry. Antioxidant activities of essential oil samples were monitored.ResultsMaximum numbers of regenerated shoots were found in the medium supplemented with 1 mg/L benzyl adenine and 0.5 mg/L indole-3-acetic acid. A total of 6 compounds were identified from rhizomes from CP and IVP plants that yielded 96.9% and 97.81% of the total oil contents, respectively. The major compound of rhizome oil identified from CP and IVP rhizomes was ethyl p-methoxy cinnamate in quantities, 82.01% and 71.77%, respectively, without any compositional variation. Antioxidant properties of essential oil preparations were assessed by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) and hydrogen peroxide radical scavenging assays. Moreover, antioxidant activities of rhizome-oil from IVP plants were better than that of CP oil samples.ConclusionsAs IVP rhizomes had better oil yield, those could be used for a large scale commercial propagation for sustainable use of essential oil. The principal chemical in the essential oil, ethyl p-methoxy cinnamate could help apothecary, for several ailments.     

等离子接枝处理超高分子量聚乙烯纤维

利用等离子接枝法对超高分子量聚乙烯纤维进行表面处理，在纤维表面产生活性官能团，并用紫外分析、红外分析探讨了纤维表面官能团的产生及变化。通过测定纤维复合材料层间剪切强度验证结构与性能的关系。     

Evaluation of free radical scavenging and antityrosinase activities of standardized longan fruit extract.

The protective effects of fruits and vegetables against chronic diseases have been attributed to the antioxidant properties of some secondary metabolites present in these foods. Plant polyphenols have been reported to exhibit bioactive properties, and in particular antioxidant activities. Longan seeds are found to contain high levels of some beneficial polyphenolic compounds such as corilagin, gallic acid and ellagic acid. The present study examined the free radical scavenging activity of longan seed extract by using three different assay methods. Longan extracts contained corilagin ranging from zero to 50.64 mg/g DW, gallic acid from 9.18 to 23.04 mg/g DW, and ellagic acid from 8.13 to 12.65 mg/g DW depending on the cultivars. Dried longan seed extracts of cultivar Edor contained high levels of gallic acid and ellagic acid and also exhibited the highest radical scavenging activities when comparing fresh seed and dried pulp extracts. For scavenging activity of DPPH and superoxide radicals, longan seed extract was found to be as effective as Japanese green tea extract while dried longan pulp and mulberry green tea extracts showed the least scavenging activities. In the ORAC assay, both fresh and dried longan seed also had higher activity than dried pulp and whole fruit. However, the results demonstrate that three polyphenolics may not be the major contributors of the high antioxidant activity of longan water extracts but this high activity may be due to other phenolic/flavonoid glycosides and ellagitannins present in longan fruit. In addition, longan seed also showed tyrosinase inhibitory activity with IC(50) values of 2.9-3.2 mg/ml. Therefore, the preliminary observations suggest that longan seed extract could be another potential source of potent natural dietary antioxidants and also in an application as a new natural skin-whitening agent.     

沙蚕提取物的抗氧化活性研究

目的探讨沙蚕提取物的抗氧化活性。方法采用DPPH法观察沙蚕提取物的抗氧化活性，通过Sephadex LH-20凝胶过滤，对沙蚕提取物中的抗氧化物质进行了初步分离纯化。结果与结论沙蚕提取物具有较强的清除自由基（DPPH）的能力，通过定性分析方法确定该物质为一类小分子量的多肽类物质。     

黄芩抗氧化化学成分的研究

目的研究黄芩(Scutellaria radix)的化学成分及其抗氧化活性。方法采用硅胶和反相硅胶柱色谱方法进行分离,核磁共振等波谱学方法进行结构鉴定,抗氧化活性评价采用体外二苯代苦味酰肼(DPPH)自由基清除实验。结果从黄芩中分离鉴定了4个黄酮类化合物:汉黄芩素,黄芩苷元,5,7,2,′5′-四羟基-8,6′-二甲氧基黄酮和5,7,2,′6′-四羟基黄酮,其中黄芩苷元(化合物2)对DPPH自由基的清除率50%时的浓度(IC50)为19μmol/L。结论黄芩苷元具有抗氧化活性作用,是黄芩具有抗氧化作用的主要物质成分之一。     

海洋微藻抗肿瘤及抗氧化活性初筛

目的 对90株海洋微藻的提取物进行了体外抗肿瘤和抗氧化活性筛选,从中寻找活性微藻藻株.方法以细胞凋亡诱导、细胞坏死以及自由基清除为活性指标,采用SRB,TLC自显影技术和DPPH方法进行抗肿瘤以及抗氧化活性筛选,并对活性藻株代谢产物进行了HPLDUV分析.结果与结论发现5株微藻的提取物具有抗肿瘤活性、1株微藻的提取物具有抗氧化活性.HPLC-UV分析表明,其抗氧化活性可能与具有400nm最大紫外吸收的化合物有关.     

Antitumor and antioxidant activity of protocatechualdehyde produced from Streptomyces lincolnensis M-20

We characterized the biological functions of protocatechualdehyde (PA) isolated from the butanol extract of culture supernatant from Streptomyces lincolnensis M-20. Following butanol extraction, it was purified by silica gel and Sephadex LH-20 column chromatography. PA was analyzed by Furier Transform Infrared Spectroscopy (FT-IR), Gas chromatograph-Mass Spectrometer (GC-MS), and Nuclear Magnetic Resonance (NMR). PA had potent antioxidant activity, as measured by 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity. Antitumor activity against MCF-7 human breast cancer cells was evaluated by the 3-(4,5-dimethylthazol-2-yl)-2,5-diphenyl tetrazolium-bromide (MTT) assay. PA treatment (0∼150 μM) dose-dependently blocked apoptosis, as shown by improved cell viability and inter-nucleosomal DNA fragmentation. Our findings suggest that Streptomyces lincolnensis M-20, a lincomycin producer, also produces protocatechualdehyde.     

荜茇清除DPPH自由基能力的研究

目的:研究中药材荜茇清除DPPH自由基(DDPH·)能力.方法:用DPPH法对荜茇七种不同溶剂提取物体外抗氧化活性进行筛选,与抗坏血酸(VitC)比较.结果:荜茇95%乙醇的提取物对DDPH·的清除率最高;清除DDPH·50%时,荜茇95%乙醇提取物折算成药材荜茇所需用量与VitC相比相差约2×103倍.结论:荜茇具有一定的清除DPPH自由基能力.