检索结果-南通市图书馆

Antiglycation,antioxidant,antiacne,and photoprotective activities of crude extracts and triterpene saponin fraction of Sapindus saponaria ***:An in vitro study

引用

Asian Pacific Journal of Tropical Biomedicine 2022年第9期12卷 391-399页

作者： Regildo M.G.Silva Gustavo R.Martins Laura M.B.Nucci Filipe O.Granero Célia C.M.Figueiredo Patrícia S.Santiago Luciana P.Silva Laboratory of Herbal Medicine and Natural Products Department of BiotechnologyFaculty of SciencesHumanities and LanguagesSão Paulo State UniversityAssisSão PauloBrazil Institute of Chemistry São Paulo State UniversityAraraquaraSão PauloBrazil São Paulo State University Campus de RegistroRegistroSão PauloBrazil Fundação Educacional do Município de Assis AssisSão PauloBrazil

Objective:To evaluate the photoprotective,antioxidant,antiglycation,and antiacne activities of crude extract(CESs)and triterpene saponin fraction(TSSs)of Sapindus ***:HPLC-MS purification was performed on a Symmetry TM C18 *** saponins were identified by a UV *** activity was evaluated by DPPH and O_(2)^(−)radicals scavenging,and FRAP and TBARS *** activity was assessed by relative electrophoretic mobility and inhibition of advanced glycation end products(AGEs)***,antiacne activity was determined by inhibition of Cutibacterium acnes,and photoprotective effect was evaluated by Mansur’s ***:Most of the triterpene saponins detected in the fraction by HPLC-MS analysis were hederagenin as the *** and TSSs presented varying antioxidant activity in DPPH(CESs:75.69%and TSSs:83.65%),FRAP(CESs:425.39μM TE/g DW and TSSs:649.36μM TE/g DW),TBARS(CESs:42.96%and TSSs:52.16%)and O_(2)^(−)radicals scavenging(CESs:61.33%and TSSs:86.69%)*** and TSSs also exhibited antiglycation activity comparable to bovine serum albumin treated with *** addition,CESs and TSSs showed inhibition of AGE formation(34.48%and 61.85%,respectively).Antiacne activity against Cutibacterium acnes was observed with a minimum inhibitory concentration equal to minimum bactericidal concentration(CESs:36.11µg/mL and TSSs:18.34µg/mL).In photoprotective assays,CESs and TSSs showed maximum absorbance of 1.42 to 0.20 and 2.80 to 1.30,respectively,in the wavelength range of 260 to 400 ***,CESs and TSSs showed sun protection factors of 8.89 and 14.89,***:Sapindus saponaria fruit extracts show strong antioxidant potential and antiglycation activity against bovine serum albumin glycation and AGE ***,they presented antibacterial activity against Cutibacterium acnes and photoprotective effect against UV-A and UV-B.

关键词： Photoprotective AGE formation free radical Antioxidant Triterpene saponin Sapindus saponaria

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

NMR used to study the side-reactions between peroxides and antioxidants during the reactive extrusion process of the impact polypropylene

引用

Magnetic Resonance Letters 2022年第2期2卷 91-106,I0003页

作者： Chunfa Li Ting Huang Yubin Bao Zhe Chen Guangxin Lin SABIC R&D Center(China)Co. LtdShanghai201319China SABIC Mount VernonUSIN47620USA

Side reaction pathways are observed to occur between antioxidants and peroxide during the processing of multiple resin grades mediated by controlled peroxide-induced degradation of impact *** the present work,the reaction mechanism and main by-products between antioxidants and peroxides were *** results demonstrate that peroxides greatly accelerate the decomposition reactions,and the free radicals formed from peroxide decomposition react with,for example,the antioxidant AO1010 to produce dehydrogenation of phenyl propionic unit(s)at the a position(cinnamic acid ester moiety),which generates a conjugated system leading to the increased color of the *** is the first time to confirm the cinnamic acid moiety's existence and report its NMR ***,this work confirms the dehydrogenation mechanism by comparison with different sterically hindered phenolic *** also systematically summarizes the oxidation and degradation mechanism of AO168 and AO1010 under air and peroxide environments,*** on present study,clear guidelines are obtained to improve the quality of polymeric products,especially the appearance and stability,during product development.

关键词： Peroxide Antioxidant free radical Cinnamic acid ester Polypropylene

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Effects of Micelle on Pyrazoles as Antioxidants in radical-induced Oxidation of DNA

引用

Chemical Research in Chinese Universities 2013年第4期29卷 671-677页

作者： LI Yan-feng LIU Zai-qun Department of Organic Chemistry College of Chemistry Jilin University Changchun 130021 P. R. China

Effects of 4-（1,3-diphenyl-1H-pyrazol-5-yl）phenol（APP）,4-（1,5-diphenyl-lH-pyrazol-3-yl）phenol（BPP） and 4-（3,5-diphenyl-1H-pyrazol-1-yl）phenol（CPP） on 2,2＇-azobis-（2-amidinopropane hydrochloride）（AAPH）-induced oxidation of DNA were measured in the presence of various concentrations of Triton X-100,cetyltrimethylammonium bromide（CTAB）,or sodium dodecyl sulfate（SDS） in order to clarify the influence of neutral,cationic and anionic microenvironments on antioxidant capacities of APP,BPP and *** these surfactants can protect DNA against AAPH-induced oxidation,the pyrazoles in the presence of these surfactants functioned as prooxidants when the concentrations of Triton X-100 and CTAB ***,CPP exhibited antioxidant property with the increase of the concentration of *** the contrary,APP,BPP and CPP were antioxidants in the presence of various concentrations of *** added surfactants resulted in the complication of the microenvironments around DNA,pyrazoles and peroxyl radical（ROO＊） derived from *** anionic charge of SDS was beneficial to enhancing the antioxidant effectiveness of these *** can be concluded that the charge property of surfactants markedly influenced the behavior of an antioxidant in AAPH-induced oxidation of DNA.

关键词： Pyrazole Surfactant Oxidation DNA free radical Microenvironment effect

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

The damage effects of oxy free radicals and fulvic acid on chondrocytes

引用

Journal of Environmental Sciences 1991年第4期3卷 48-54页

作者： Zhang Fahao, Wang Kui and Xu ShanjinSchool of Pharmaceutical Sciences and research Laboratones of Natural and Biomimetic Drugs.Beijing Medical Universi-ty,Beijing,100083,China

The damage effects of oxy free radical and fulvic acid on cultivated chicken embryo chondrocytes were studied. The results show that the growrth of chondrocytes is inhibited and the morphology of the cells altered. The collagen synthesizing capability of the damaged cell changes somewhat. A noteworthy change of the type of collagen synthesized by the abnormal cells was observed by CMC-chromatography and amino acid analysis. The results indicated that the abnonml cells tend to synthesize type I instead of type II collagen, which is synthesized and secreted by the intact chondrocyte.

关键词： free radical fulvic acid chondrocyte collagen Kaschin-Beck disease.

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Recent Advances in Types and Generation Mechanism of Intracellular free radicals

引用

Agricultural Biotechnology 2015年第4期4卷 25-28页

作者： Xin LI Zhi FANG Bo XUE Longzhou LIU Ye YANG College of Animal Science Yangtze University Yichang Chia Tai Co. Ltd.

The overproduction of free radicals is the main reason for the peroxidation damage, metabolic disturbance and antioxidant imbalance in animals. This paper summarized the types and generation mechanism of intracellular... 详细信息

关键词： free radical Type Generation mechanism

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Restraining effect of nitrogen on coal oxidation in different stages:Non-isothermal TG-DSC and EPR research

引用

International Journal of Mining Science and Technology 2020年第3期30卷 387-395页

作者： Tongyu Zhao Shengqiang Yang Xincheng Hu Wanxin Song Jiawen Cai Qin Xu State Key Laboratory of Coal Resources and Safety Mining China University of Mining and TechnologyXuzhou 221116China School of Safety Engineering China University of Mining and TechnologyXuzhou 221116China Key Laboratory of Gas and Fire Control for Coal Mines(China University of Mining and Technology) Ministry of EducationXuzhou 221116China Department of Civil&Environmental Engineering University of AlbertaEdmonton T6G 2W2Canada

Nitrogen is widely used to prevent the spontaneous combustion of coal in underground coal mines. A spontaneous combustion-prone coal seam was studied to investigate the restraining effect of nitrogen on coal oxidation in different oxidation stages, based on non-isothermal thermogravimetry-differential scanning calorimetry(TG-DSC) and electron paramagnetic resonance(EPR) experiments. We found that the key feature temperatures grow steadily with increasing nitrogen in the oxidation environment,resulting in longer oxidation stages. The most significant finding is that there is a stagnation of the inhibitory effect of nitrogen on coal oxidation in the range of 85.0–95.0% nitrogen in the slow and the rapid oxidation stages, owing to the competitive adsorption of coal by nitrogen and oxygen. However, the restraining effect cannot be reflected by the kinetic parameters of the coal before it reaches the thermal decomposition and combustion stage. Nitrogen can also affect free radical types and free radical concentrations during coal oxidation: the higher the concentration of nitrogen in the oxidation environment, the greater the number of free radical types and the lower the free radical concentration. This experimental study improves the understanding of the restraining effect of nitrogen on coal oxidation in different oxidation stages and provides an important reference for coal fire prevention in spontaneous combustionprone coal seams.

关键词： Reaction heat Non-isothermal TG-DSC Activation energy Pre-exponential factor free radical

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Dose rate effects on shape memory epoxy resin during 1 Me V electron irradiation in air

引用

Journal of Materials Science & Technology 2021年第8期67卷 61-69页

作者： Longyan Hou Yiyong Wu Debin Shan Bin Guo Yingying Zong State Key Laboratory of Advanced Welding and Joining Harbin Institute of TechnologyHarbin 150001China National Key Laboratory of Materials Behavior and Evaluation Technology in Space Environments Harbin Institute of TechnologyHarbin 150001China

The effects of 1 Me V electron irradiation in air at a fixed accumulated dose and dose rates of 393.8,196.9,78.8,and 39.4 Gy s^(-1)on a shape memory epoxy(SMEP)resin were *** low-dose-rate irradiation,accelerated degradation of the shape memory performance was observed;specifically,the shape recovery ratio decreased exponentially with increasing irradiation time(that is,with decreasing dose rate).In addition,the glass transition temperature of the SMEP,as measured by dynamic mechanical analysis,decreased overall with decreasing dose *** dose rate effects of 1 Me V electron irradiation on the SMEP were confirmed by structural analysis using electron paramagnetic resonance(EPR)spectroscopy and Fourier transform infrared(FTIR)*** EPR spectra showed that the concentration of free radicals increased exponentially with increasing irradiation ***,the FTIR spectra showed higher intensities of the peaks at 1660 and 1720 cm^(-1),which are attributed to stretching vibrations of amide C=O and ketone/acid C=O,at lower dose *** intensities of the IR peaks at 1660 and 1720 cm^(-1) increased exponentially with increasing irradiation time,and the relative intensity of the IR peak at 2926 cm^(-1)decreased exponentially with increasing irradiation *** solid-state13 C nuclear magnetic resonance(NMR)spectra of the SMEP before and after 1 Me V electron irradiation at a dose of 1970 k Gy and a dose rate of 78.8 Gy s^(-1) indicated damage to the CH_(2)–N groups and aliphatic isopropanol *** result is consistent with the detection of nitrogenous free radicals,a phenoxy-type free radical,and several types of pyrolytic carbon radicals by *** the subsequent propagation process,the free radicals produced at lower dose rates were more likely to react with oxygen,which was present at higher concentrations,and form the more destructive peroxy free radicals and oxidation products such as acids,amides,and *** increase in peroxy

关键词： Shape memory epoxy resin Shape memory effect Electron irradiation Dose rate effect free radical Chain scission

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Quantum Chemistry Study on Dissociation of Oxalyl Bromide

引用

Chinese Journal of Structural Chemistry 2005年第11期24卷 1334-1339页

作者： GENG Zhi-Yuan WANG Dong-Mei WANG Yong-Cheng DAI Guo-Liang LU Ling-Ling WANG Han-Qing College of Chemistry and Chemical Engineering Northwest Normal University Lanzhou 730070 China Lanzhou Institute of Chemistry and Physics The Chinese Academy of Sciences Lanzhou 730000 China Department of Chemistry Baoji College of Arts ＆ Sci. Baoji 721007 China

The multi-bond dissociation dynamics of oxalyl bromide （（BrCO）2） has been investigated by DFT and CIS calculations. Upon the results, conclusion could be drawn that dissociation of C-Br bond of oxalyl bromide at the ground state （So） is of barfierless. After the absorption of a photon, （BrCO）2 is excited to the first excited state and one of its C-Br bonds is broken to yield Br ·＊ and BrCOCO· ＊ free radicals. In addition, BrCOCO · ＊ with high energy is apt to release energy, and ultimately, turns into BrCOCO ·of the ground state. The energy is adequate for BrCOCO· to break down into Br · and 2CO; at the same time the C-C and C-Br bonds of BrCOCO · free radicals dissociate.

关键词： oxalyl bromide multi-bond dissociation BrCOCO free radical DFT

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Short-term effects of di-（2-ethylhexyl） phthalate on testes,liver, kidneys and pancreas in mice

引用

Asian Journal of Andrology 2007年第2期9卷 199-205页

作者： Yumi Miura Munekazu Naito Maira Ablake Hayato Terayama Shuang-Qin Yi Ning Qu Lin-Xian Cheng Shigeru Suna Fumihiko Jitsunari Masahiro Itoh Department of Anatomy Tokyo Medical University Tokyo 160-8402 Japan Department of Histology and Embryology Xin Jiang Medical University Xinjiang 830001 China Department of Hygiene and Public Health Faculty of Medicine Kagawa University Kagawa 761-0783 Japan

Aim： To determine the biochemical effect of di-（2-ethylhexyl） phthalate （DEHP） on testes, liver, kidneys and pancreas on day 10 in the process of degeneration of the seminiferous epithelium. Methods： Diets containing 2% DEHP were given to male Crlj：CDI（ICR） mice for 10 days. The dose of DEHP was 0.90±0.52 mg/mouse/day. Their testes, livers, kidneys and pancreata were examined for detection of mono-（2-ethylhexyl） phthalate （MEHP）, nitrogen oxides （NOx） produced by peroxidation of nitric oxide （NO） with free radicals, and lipid peroxidation induced by the chain reaction of free radicals. Results： Histological observation and serum analysis showed the presence of severe sperrnatogenic disturbance, Leydig cell dysfunction, liver dysfunction and dehydration. Unexpectedly, the concentration of MEHP in the testes was extremely low compared with that in the liver. However, the concentration of the NOx in the testes was as high as the hepatic concentration. Furthermore, free radical-induced lipid peroxidation was histochemically detected in the testes but not in the liver. Conclusion： The results indicate that DEHP-induced aspermatogenesis is caused by the high sensitivity of the testicular tissues to MEHP rather than the specific accumulation or uptake of circulating MEHP into the testes.

关键词： phthalatc nitrogen oxide free radical testis

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Neuroprotective effects of rutaecarpine on cerebral ischemia reperfusion injury

引用

Neural Regeneration Research 2013年第22期8卷 2030-2038页

作者： Chunlin Yan Ji Zhang Shu Wang Guiping Xue Yong Hou Department of Pharmacology Hebei North University

Rutaecarpine, an active component of the traditional Chinese medicine Tetradium ruticarpum, has been shown to improve myocardial ischemia repeffusion injury. Because both cardiovascular and cerebrovascular diseases are forms of ischemic vascular disease, they are closely related. We hypothesized that rutaecarpine also has neuroprotective effects on cerebral ischemia reperfusion injury. A cerebral ischemia reperfusion model was established after 84, 252 and 504 pg/kg rutae- carpine were given to mice via intrapedtoneal injection, daily for 7 days. Results of the step through test, 2,3,5-triphenyl tetrazolium chloride dyeing and oxidative stress indicators showed that rutae- carpine could improve learning and memory ability, neurological symptoms and reduce infarction volume and cerebral water content in mice with cerebral ischemia reperfusion injury. Rutaecarpine could significantly decrease the malondialdehyde content and increase the activities of superoxide dismutase and glutathione peroxidase in mouse brain. Therefore, rutaecarpine could improve neu- rological function following injury induced by cerebral ischemia reperfusion, and the mechanism of this improvement may be associated with oxidative stress. These results verify that rutaecarpine has neuroprotective effects on cerebral ischemia reperfusion in mice.

关键词： neural regeneration traditional Chinese medicine rutaecarpine cerebral ischemia reperfusion learning and memory infarct volume free radical glutathione peroxidase superoxide dismutase malondialdehyde grants-supported paper neuroregeneration

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：