期刊文献+
共找到704篇文章
< 1 2 36 >
每页显示 20 50 100
Lack of Tocopherol Inhibits Rice Growth by Triggering an Ectopic Stress Response and the Accumulation of DELLA Protein
1
作者 Di Wang Hao Gao +4 位作者 Jian Wang Baoshan Cheng Gang Li Weijun Xu Xi Liu 《Phyton-International Journal of Experimental Botany》 SCIE 2023年第4期1173-1183,共11页
Although tocopherols are essential for rice development,the molecular details by which their absence affects development remain to be determined.To study how tocopherols function during rice development,we performed a... Although tocopherols are essential for rice development,the molecular details by which their absence affects development remain to be determined.To study how tocopherols function during rice development,we performed a transcriptome deep sequencing(RNA-seq)analysis of the rice cultivar Nipponbare(Nip)and the tocopherol-deficient mutant small grain and dwarf 1-2(sgd1-2).We identified 563 differentially expressed genes that were enriched in Gene Ontology categories associated with metabolism,stress,cellular responses,and transcriptional regulation.We determined that the total fatty acid composition of Nip and sgd1-2 was comparable,although cell membrane penetrability in sgd1-2 was significantly higher than in Nip under optimal growth conditions,indicating that tocopherol deficiency induces cell membrane damage.The expression levels of dehydration-responsive element binding 1(DREB1)genes and free proline content in sgd1-2 were also higher than those in Nip.We also showed that the DELLA protein SLENDER RICE1(SLR1)accumulated in sgd1-2,resulting in significant changes in the global transcriptome.Our study confirms that the lack of tocopherol accumulation in rice induced ectopic stress responses and limited growth by enhancing SLR1 abundance through increasing SLR1 transcript levels.These results provide new insights into tocopherol during rice development. 展开更多
关键词 tocopherol deficiency ectopic stress response GIBBERELLIN rice
下载PDF
Synthesis of the dl-ξ-Thiotocopherol: Newest Derivative of the dl-a-Tocopherol
2
作者 Tuncer Mutlu Ibrahim Erol +1 位作者 Nevin Mutlu Levent Ozcan 《Journal of Chemistry and Chemical Engineering》 2012年第1期90-95,共6页
Tocopherol is the most active vitamin and natural antioxidant existing in the nature known as vitamin E. Lacking of this vitamin makes drastic exchanges on the health of the living organisms. Their active chemical for... Tocopherol is the most active vitamin and natural antioxidant existing in the nature known as vitamin E. Lacking of this vitamin makes drastic exchanges on the health of the living organisms. Their active chemical form is l-α-tocopherol substance. In this article, α-thiotocopherol a tocopherol derivative was synthesized via a precursor like dl-α-tocopherol, which has better antioxidant than natural α-tocopherol. And the last compound after separation and purification via TLC and PC procedures was analyzed by FTIR, GC-MS and elemental analysis, oxidative stability is tested with TGA method in air showing roughly antioxidant effect. Another approach is measurment of redox potential against a reference electrode under inert nitrogen atmosphere. 展开更多
关键词 tocopherol PHENOLS substitute phenols thiotocopherol redox potential thermal and oxidative stability.
下载PDF
Detection of Tocopherol in Oilseed Rape (Brassica napus L.) Using Gas Chromatography with Flame Ionization Detector 被引量:6
3
作者 Nazim Hussain Zahra Jabeen +6 位作者 LI Yuan-long CHEN Ming-xun LI Zhi-lan GUO Wan-li Imran Haider Shamsi CHEN Xiao-yang JIANG Li-xi 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2013年第5期803-814,共12页
The variation among Chinese genotypes of Brassica napus L. for seed tocopherols content and their analysis using gas chromatography has not been comprehensively reported till to date. In the present study, the tocophe... The variation among Chinese genotypes of Brassica napus L. for seed tocopherols content and their analysis using gas chromatography has not been comprehensively reported till to date. In the present study, the tocopherol contents of four Chinese genotypes of Brassica napus L., namely, Gaoyou 605, Zhejiang 619, Zheshuang 758, and Zheshuang 72, were evaluated using three modified sample preparation protocols (P1, P2, and P3) for tocopherol extraction. These methods were distinguished as follows. Protocol one (P1) included the evaporation of solvent after extraction without silylation. Protocol two (P2) followed the direct supernatant collection after overnight extraction without drying and silylation. Protocol three (P3) included trimethylsilylation with N,O-bis(trimethylsilyl) trifluoroacetamide. Genotypic comparison of tocopherol and its isoforms revealed that Gaoyou 605 was dominant over the other genotypes with (140.5+ 10.5), (316.2+ 9.2), and (559.1+ 24.3) ~tg g-~ of seed meal ct-, 7-, and total (T-) tocopherol, respectively, and a 0.44+0.04 ^- to 7-tocopherol ratio. The comparison of the sample preparation protocols, on the other hand, suggests that P3 is the most suitable method for the tocopherol extraction from Brassica oilseeds and for the analysis of tocopherols using gas chromatography flame ionization detector (GC-FID). Trimethylsilylation is the key step differentiating P3 from P1 and P2. Variations detected in tocopherol contents among the Chinese rapeseed (B. napus) genotypes signify the need to quantify a wide range of rapeseed germplasm for seed tocopherol dynamics in short and crop improvement in long. 展开更多
关键词 Brassica napus L. genotypic variation tocopherol analysis gas chromatography flame ionization detector
下载PDF
Comparative Study of Ascorbic Acid and Tocopherol Concentrations in Hydroponic- and Soil-Grown Lettuces 被引量:4
4
作者 Drew N. Buchanan Stanley T. Omaye 《Food and Nutrition Sciences》 2013年第10期1047-1053,共7页
Hydroponically-grown produce may be a way of helping to feed the world a variety of fruits and vegetables, regardless of soil quality, space availability or climate. The objective of this study was to determine whethe... Hydroponically-grown produce may be a way of helping to feed the world a variety of fruits and vegetables, regardless of soil quality, space availability or climate. The objective of this study was to determine whether hydroponicallygrown lettuce contains as much ascorbic acid and tocopherol as soil-grown lettuce. We analyzed four varieties of lettuce, including: Waldmann’s Dark Green, Red Lollo Antago, Red Romaine Annapolis, and Butterleaf. The tocopherol content of hydroponically-grown Waldmann’s Dark Green, Red Lollo Antago, and Red Romaine Annapolis was 229%, 497% and 492% higher, respectively, compared to their soil-grown counterpart. The ascorbic acid content of hydroponically-grown Waldmann’s Dark Green, Red Lollo Antago, and Red Romaine Annapolis was 93%, 171% and 216% higher, respectively, compared to their soil-grown counterparts. Hydroponically grown lettuce varieties are significantly higher in both ascorbic acid and tocopherol content than their soil-grown counterparts, and hydroponic gardening is a viable option for producing nutritious fruits and vegetables. 展开更多
关键词 HYDROPONIC LETTUCE Ascorbic Acid tocopherol LEAFY Vegetables
下载PDF
Alpha-tocopherol supplementation on chromium toxicity: a study on rat liver and kidney cell membrane 被引量:4
5
作者 Sankar Kumar Dey Prasunpriya Nayak Somenath Roy 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2003年第3期356-359,共4页
Membrane damage is one of the important consequence of chromium, an environmental toxicant, to produce cytotoxicity. α-tocopherol, a membrane protectant can be used to reduce the chromium-induced membrane damage. In... Membrane damage is one of the important consequence of chromium, an environmental toxicant, to produce cytotoxicity. α-tocopherol, a membrane protectant can be used to reduce the chromium-induced membrane damage. In the present study, the impact of chromium in presence and absence of α-tocopherol was studied on plasma membrane of liver and kidney in male Wistar rats (80—100 g body weight). Significant increase in membrane cholesterol level as well as significant decrease in membrane phospholipid level in chromium exposed ( 0.8 mg /100 g body weight/d, i.p., for 4 weeks) animals suggest structural alteration of both liver and kidney plasma memebrane. The alkaline phosphatase, total ATPase and Na +-K +-ATPase activities of plasma membrane were significantly decreased in both liver and kidney after chromium treatment. However, α-tocopherol (30 mg/100 g diet) supplementation can restrict the changes in these membrane-bound enzyme activities. Thus, the usefulness of dietary supplementation of α-tocopherol to restrain the chromium-induced membrane damage is suggested. 展开更多
关键词 CHROMIUM LIVER KIDNEY MEMBRANE Α-tocopherol
下载PDF
Separation of α-Tocopherol with a Two-Feed Simulated Moving Bed 被引量:2
6
作者 危凤 沈波 +2 位作者 陈明杰 周先波 赵迎宪 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2012年第4期673-678,共6页
A two-feed simulated moving bed(SMB) was proposed to utilize the stationary phase more effectively.Zone I is disconnected with zone Ⅱ and zone Ⅲ is disconnected with zone IV.Two feeds are added to zones I and Ⅲ,w... A two-feed simulated moving bed(SMB) was proposed to utilize the stationary phase more effectively.Zone I is disconnected with zone Ⅱ and zone Ⅲ is disconnected with zone IV.Two feeds are added to zones I and Ⅲ,while two desorbents are added to zones Ⅱ and IV separately.The investigation on the movement of concentra-tion bands indicated that the tail of the strong retained solute and the front of the weak retained solute were eluted from zones I and Ⅲ orderly,so the streams from zones I and Ⅲ could be cut into different fractions to give the products with high purity.The two-feed SMB was used to separate α-tocopherol from its homologue mixture suc-cessfully,and could double the productivity if both feeds were identical to the feed in the conventional four-zone SMB.The solvent consumption could be reduced by reusing the middle fraction without solutes. 展开更多
关键词 simulated moving bed two-feed tocopherol
下载PDF
Synthesis of d,l-α-Tocopherol Catalyzed by Heteropoly Acids 被引量:2
7
作者 Dong QIAN Jia CUI +1 位作者 Yan Zhi TAN Kai Yi WANG(Department of Chemistry. Central South University of Technology. Changsha 410083) 《Chinese Chemical Letters》 SCIE CAS CSCD 1999年第6期443-444,共2页
,d,l-a-Tocopherol (vitamin E) isfound to be synthesized by condensingtrimethylhydroquinone with isophytol catalyzed by heteropoly acids (HPA) H3:PW12O40 andH3PMo12O40 at room temperature. These HPA are efficient cata... ,d,l-a-Tocopherol (vitamin E) isfound to be synthesized by condensingtrimethylhydroquinone with isophytol catalyzed by heteropoly acids (HPA) H3:PW12O40 andH3PMo12O40 at room temperature. These HPA are efficient catalysts for the synthesis of d l-a-Tocopherol and can easily be separated from the reaction mixture and roused, 展开更多
关键词 d.l-α-tocopherol heteropoly acids SYNTHESIS
下载PDF
Preparation of natural α-tocopherol from non-α-tocopherols 被引量:1
8
作者 杨亦文 闻光东 吴彩娟 《Journal of Zhejiang University Science》 EI CSCD 2004年第12期1524-1527,共4页
Non-a-tocopherols are hydroxymethylated and hydrogenated to produce α-tocopherol in one pot process by simultaneously reacting with paraformaldehyde and hydrogen in the presence of catalysts of benzenesulfonic acid a... Non-a-tocopherols are hydroxymethylated and hydrogenated to produce α-tocopherol in one pot process by simultaneously reacting with paraformaldehyde and hydrogen in the presence of catalysts of benzenesulfonic acid and 5% Pd/C in an autoclave. Effects of various operation conditions have been studied. The preferable reaction conditions are: temperature 180 ℃ to 200 ℃, pressure 5.0 MPa, acid concentration 0.5 g/100 ml ethanol, mass ratio of Pd/C to tocopherols 7.1 g/100 g, and reaction time 5.0 h. A product with α-tocopherol content of 80% was obtained by using a raw material with a total tocopherols content of 80.54%. The conversion of non-α-tocopherols is almost 100%, and the mole yield of a-tocopherol is more than 90%. 展开更多
关键词 tocopherol CONVERSION HYDROXYMETHYLATION HYDROGENOLYSIS
下载PDF
Fatty Acid, Total Phenol and Tocopherol Profiles of Some Walnut Cultivars: A Comparative Study 被引量:1
9
作者 Ebru Kafkas Aysegul Burgut +4 位作者 Hatice Ozcan Akide Ozcan Mehmet Sutyemez Salih Kafkas Nurgül Türemis 《Food and Nutrition Sciences》 2017年第12期1074-1084,共11页
As a member of nuts, walnut is consumed from snacks to salads and desserts to entrees and an importantpart of human diet for centuries. Walnut biological and nutritional value is also enhanced by its valuable protein ... As a member of nuts, walnut is consumed from snacks to salads and desserts to entrees and an importantpart of human diet for centuries. Walnut biological and nutritional value is also enhanced by its valuable protein and rich in nutrient composition such as vitamins and minerals. The most important characteristic of walnut oil is the abundance of polyunsaturated fatty acids, which makes it a unique food because of high amount of linoleic acid. Due to having valuable protein, vitamins and minerals it enhances biological and nourishment value, also. Recent epidemiological studies showed that consumption of walnut reduce cardiovascular diseases due to the rich in antioxidant properties, valuable fatty acids and tochopherols contents. In Turkey, walnut production and consumption increases year by year. The kernel of walnut genotypes shows variability in terms of their fat, fatty acid and tocopherol profiles. In this paper, it was aimed to characterize 10 walnut (Juglans regia L.) cultivars (Bilecik, Chandler, Hartley, Howard, Maras 12, Maras 18, Midland, Pedro, Sen and Serr) based on their fatty acid profiles using GC (Gas Chromatography), tocopherol and its isomers by HPLC (High Performance Liquid Chromatography) and total phenol content with spectrometric methods. Among the walnut cultivars “Hartley” was the highest linoleic acid (64.56%) and “Howard” was the α-linolenic acid 13.26 (%). The highest values of α (38.76 μg/g), β + γ (312.19 μg/g) and δ-tocopherol (40.77 μg/g) and total phenol (349 mg GAE/100 g ext) content were detected in “Sen” cultivar. Obtained results might be significant for further breeding programme to improve rich in especially γ-tocopherol linoleic acids and total phenolic compounds. 展开更多
关键词 FATTY Acid GC HPLC JUGLANS regia L. tocopherols WALNUT
下载PDF
Protective Effects of α-Tocopherol against Brain Tissue Damage Induced by Intracerebral Hemorrhage in SD Rats 被引量:1
10
作者 Zhiyong Chen Jinfu Yang +2 位作者 Fuyin Ren Weiwei Ye Guangyong Wu 《World Journal of Neuroscience》 2016年第1期62-74,共13页
Lipid peroxidation mediated by oxygen radical is one of the main mechanisms underlying secondary brain injury. Among all vitamin E compounds, α-tocopherol shows the most prominent antioxidative effects. It plays an i... Lipid peroxidation mediated by oxygen radical is one of the main mechanisms underlying secondary brain injury. Among all vitamin E compounds, α-tocopherol shows the most prominent antioxidative effects. It plays an important role in cell aging and injury. However, there has been no report regarding the effects of α-tocopherol on changes in brain tissue morphology after intracerebral hemorrhage (ICH), cerebral edema, or the expression of Bax and Bcl-2 proteins. We use SD rats to carry out the related studies;based on the atlas of SD rats, the caudate nucleus was positioned using a stereotaxic apparatus, and 50 μl autologous tail artery blood was injected to caudate nucleus in the ICH and α-tocopherol groups to establish ICH model. Rats in the sham surgery group received the same volume of saline in the caudate nucleus. Rats in the α-tocopherol group received intraperitoneal injections of α-tocopherol at 600 mg/kg every day. Rats in the ICH group and sham surgery group received the same amount of saline at the same times as those in the α-tocopherol group. We observed some interesting results: comparisons of brain tissue sections of rats from different groups showed that brain tissue damage and functional neurological deficits among rats from the α-tocopherol group were less pronounced than in the ICH group. Wet weight/ dry weight measurement showed that rats from the α-tocopherol group exhibited less cerebral edema than those in the ICH group. Rats from the α-tocopherol group showed less Bax expression and more Bcl-2 expression than those in the ICH group. 展开更多
关键词 Α-tocopherol Intracerebral Hemorrhage (ICH) Cerebral Edema BAX BCL-2
下载PDF
Effect of Tocopherol on Antioxygenic Properties of Green Lubricating Oil
11
作者 肖志信 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2008年第3期289-292,共4页
Based on the needs of green motor oil, and in order to improve the antioxidation properties of green lubricating oil, the effect of tocopherol antioxidation properties of rapeseed oil was studied. Experiments of high ... Based on the needs of green motor oil, and in order to improve the antioxidation properties of green lubricating oil, the effect of tocopherol antioxidation properties of rapeseed oil was studied. Experiments of high temperature oxidation, antiwear and infra-red spectrum analysis were accomplished, the results show that the rapeseed oil including tocopherol can still keeps steady structure after high temperature oxidation, with a small variety of acid number, whose antioxygenic properties are improved evidently. Meanwhile, both thiocarbamate and vitamin C play an assistant role in tocopherol, which can make rapeseed oil to have better oxidation stability and keep excellent antiwear properties after high temperature oxidation. 展开更多
关键词 rapeseed oil tocopherol antioxygenic properties
下载PDF
Conversion of Non-a-Tocopherols to a-Tocopherol in a Fixed Bed Reactor
12
作者 陈明 吴彩娟 +2 位作者 任其龙 杨亦文 黄梅 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2004年第4期561-565,共5页
Since a-tocopherol has special biological and nutritional activities, it is important to convert non-a-tocopherols to a-tocopherol. This paper focuses on the effects of residence time, pressure, temperature and the ma... Since a-tocopherol has special biological and nutritional activities, it is important to convert non-a-tocopherols to a-tocopherol. This paper focuses on the effects of residence time, pressure, temperature and the mass ratio of formaldehyde to tocopherols on the content of a-tocopherol, the conversion of non-a-tocopherols, the selectivity and yield of a-tocopherol in a fixed-bed reactor. The reactor is made from φ12 (I.D.)×360mm stainless steel pipe. It is packed with a mixture of 5% Pd/C and cation exchange resin catalysts. Preliminary results indicated the suitable operation conditions are pressure 5.0 MPa, temperature 180℃, and mass ratio of formaldehyde to tocopherols 2.0. A product of more than 50% a-tocopherol content has been obtained by using 88.85% mixed tocopherols as raw material. 展开更多
关键词 tocopherol fixed bed reactor CONVERSION
下载PDF
Intratracheally Administered Liposomal α-Tocopherol Protects the Lung against Long-Term Toxic Effects of Paraquat
13
作者 Z. E. SUNTRES AND P. N. SHEK(To whom correspondencc should be addressed at Defence and Civil Institute of Environmental Medicine, 1133 Sheppard Avenue West, North York, Ontario M3M 3B9, Canada.Operational Medicine Division, Defence and Civil Institute of 《Biomedical and Environmental Sciences》 SCIE CAS CSCD 1995年第4期289-300,共12页
Paraquat is a broad-spectrum herbicide known to produce lung injury via oxidative stress-mediated mechanisms. Different pharmacological strategies have been explored to reduce the formation of these reactive oxygen sp... Paraquat is a broad-spectrum herbicide known to produce lung injury via oxidative stress-mediated mechanisms. Different pharmacological strategies have been explored to reduce the formation of these reactive oxygen species and/or prevent their toxic effects in the treatment of paraquat poisoning. The present study was carried out to investigate whether the antioxidant (L-tocopherol, incorporated into liposomes and delivered directly to the lungs of rats, could protect the organ against the long-term toxic effects of paraquat.Plain liposomes (composed of dipalmitoylphosphatidylcholine, DPPC) or α-tocopherol liposomes (8 mg α-tocopherol/kg body weight) were administered intratracheally to animals 24 h prior to an intraperitoneal injection of paraquat dichloride (20 mg/kg) and rats wefe killed 0, 1, 4, 6, 8, 10, 12, 16, 19 or 24 days after paraquat treatment. Results of this study showed that lungs of animals treated with paraquat were extensively damaged,as evidenced by significant increases in lung weight and decreases in lung angiotensin converting enzyme (ACE) and alkaline phosphatase enzyme (AKP) activities. Moreover,paraquat treatme; resulted in a significant reduction in the number of neutrophils in the blood of rats with a concurrent increase in the pulmonary myeloperoxidase activity,suggestive of neutrophil infiltration in the lungs of treated animals. Pretreatment of rats with liposomes alone did not significantly alter the paraquat-induced changes of all parameters examined. On the other hand, pretreatment of rats with (t-tocopherol liposomes,24 h prior to paraquat challenge, attenuated paraquat-induced changes in ACE, AKP and myeloperoxidase activities but failed to prevent increases in lung weight. Thus, pretreatment of rats with liposome-associated α-tocopherol appears to protect the lung against some of the toxic effects of paraquat 展开更多
关键词 LUNG Am tocopherol Protects the Lung against Long-Term Toxic Effects of Paraquat Rev Long
下载PDF
Influence of a-tocopherol on nickel induced alteration of serum lipid profile in male albino rats
14
作者 Gupta AD Dhundasi SA +1 位作者 Dhara PC Das KK 《Asian Pacific Journal of Tropical Medicine》 SCIE CAS 2008年第1期14-18,共5页
We studied the effect of the simultaneous treatment withα-tocopherol(100 mg / kg;im) and nickel sulfate (20 mg/kg,ip) on nickel-induced changes in serum lipid profiles.Nickel-treated rats showed a significant increas... We studied the effect of the simultaneous treatment withα-tocopherol(100 mg / kg;im) and nickel sulfate (20 mg/kg,ip) on nickel-induced changes in serum lipid profiles.Nickel-treated rats showed a significant increase in serum LDL cholesterol,total cholesterol,triglycerides,and a significant decrease in serum HDL cholesterol. Simultaneous administration ofα-tocopherol with nickel sulfate improved LDL-cholesterol and HDLcholesterol level when compared with rats receiving nickel sulfate alone.The results indicate thatα-tocopherol is beneficial in preventing nickel-induced lipid profile alterations. 展开更多
关键词 NICKEL SULFATE Α-tocopherol serum LIPID profile
下载PDF
Reduced expression of α-tocopherol-associated protein is associated with tumor cell proliferation and the-increased risk of prostate cancer recurrence
15
作者 Xing-Qiao Wen Xiao-Juan Li +5 位作者 Zu-Lan Su Yong Liu Xiang-Fu Zhou Yu-Bin Cai Wen-Tao Huang Xin Gao 《Asian Journal of Andrology》 SCIE CAS CSCD 2007年第2期206-212,共7页
Aim: To examine the impact and prognostic significance of α-tocopherol associated protein (TAP) expression in a series of prostate cancer patients. Methods: Tissues from 87 patients underwent radical prostatectom... Aim: To examine the impact and prognostic significance of α-tocopherol associated protein (TAP) expression in a series of prostate cancer patients. Methods: Tissues from 87 patients underwent radical prostatectomy were examined for TAP expression by immunohistochemistry. The relationships of the staining results, the clinic pathological characteristics and the recurrence times were analyzed. Results: Compared with the adjacent areas of normal and benign glands, immunoreactivity of TAP was reduced in areas of prostate cancer. A lower TAP-positive cell number per mm^2 of the largest cancer area (defined as TAP-PN) was associated with higher clinical stage (r = -0.248, P = 0.0322). Inverse associations were found among the TAP-PN and positive lymph nodes (r = -0.231, P = 0.0325), preoperative prostatespecific antigen (PSA) levels (r = -0.423, P = 0.0043), tumor size (r = -0.315, P = 0.0210) and elevated tumor cell proliferation, which was indicated by the staining of Ki-67 (r = -0.308, P = 0.0026). TAP-PN was a significant predictor of recurrence univariately (P = 0.0006), as well as multivariately, adjusted for known markers including preoperative PSA, clinical stage, Gleason score, surgical margin, extra-prostatic extension, seminal vesicle invasion and lymph node metastasis (P = 0.0012). Conclusion: Reduced expression of TAP was associated with the cell proliferation status of prostate cancer, adverse pathological parameters and the increased risk of recurrence. 展开更多
关键词 α-tocopherol associated protein prostate neoplasms RECURRENCE vitamin E
下载PDF
Neuroprotective effects of low-concentration alpha-tocopherol Confocal laser microscopy observations
16
作者 Weilun Liang Huiling Huang +4 位作者 Qiaoli Wu Chen Wang Wenzhi Zhang Xin Su Dashi Zhi 《Neural Regeneration Research》 SCIE CAS CSCD 2009年第2期135-138,共4页
BACKGROUND: Alpha-tocopherol ( α-tocopherol) can effectively relieve neuronal damage induced by oxygen-centered free radicals. However, the effective dose remains controversial. OBJECTIVE: To evaluate the protect... BACKGROUND: Alpha-tocopherol ( α-tocopherol) can effectively relieve neuronal damage induced by oxygen-centered free radicals. However, the effective dose remains controversial. OBJECTIVE: To evaluate the protective effects of low-concentration α-tocopherol on neuronal membranes. DESIGN, TIME AND SETTING: Contrast observation and in vitro study, performed at Laboratory of Neurosurgery, Tianjin Huanhu Hospital between April and September 2006. MATERIALS: Fetal cortical neurons were derived from two 14-day pregnant SD rats, and α-tocopherol was provided by Sigma, USA. METHODS: The neurons were randomly assigned to six groups: (1) normal: neurons were cultured under normal conditions; (2) oxidative damage: oxidative free radicals was damaged using the Fenton reaction; (3) α-tocopherol: neurons were cultured in different concentrations of -tocopherol 10, 20, 40, and 80 mg/L for 2 hours, respectively. MAIN OUTCOME MEASURES: Neuronal membrane damage was observed using a confocal laser microscope, and malonaldehyde production was detected using the thiobarbituric acid method. RESULTS: At normal, biological concentrations (10 mg/L), α-tocopherol induced no change in the damaged neurons (P 〉 0.05). However, at a concentration of 80 mg/L, the number of damaged neurons was significantly reduced, compared with the damage group (P 〈 0.05). Malonaldehyde levels following 80 mg/L α-tocopherol treatment were less than the oxygen free radical damage group (P 〈 0.05), but greater than the control group (P 〈 0.01). CONCLUSION: A concentration of 80 mg/L α-tocopherol can effectively protect the neuronal cell membrane from oxidative damage 展开更多
关键词 Α-tocopherol confocal laser microscopy cell membrane low-concentration
下载PDF
A Methodological Approach to Study Almond Oil Stability in Relation to <i>α</i>-Tocopherol Supplementation
17
作者 Lizette Auezova Chawki Saliba +3 位作者 Elie Hajj-Moussa Leina El Hosry Said Yammine Ramez Chahine 《Food and Nutrition Sciences》 2012年第12期1710-1715,共6页
The objectives of the present study were to identify a suitable parameter to assess the oil oxidation and to study the possibilities of delaying the oxidation of moderately oxidized unrefined almond oil by adding supp... The objectives of the present study were to identify a suitable parameter to assess the oil oxidation and to study the possibilities of delaying the oxidation of moderately oxidized unrefined almond oil by adding supplementary amounts of α-tocopherol. Three oil samples, with initial peroxide values of 13.3, 19.5 (moderately oxidized oils), and 28.9 (oxidized oil), were supplemented with 100, 250 and 500 ppm of α-tocopherol and subjected to the oxidation at 50°C for 9 days. The level of oxidation was determined by measuring peroxide value (PV), conjugated dienes (CD) and thiobarbituric acid reactive substances (TBARS). Chemometric analysis indicated that, under the conditions of the present study, PV was the most suitable indicator of oil oxidation. The results have shown that the α-tocopherol could have an anti- oxidant or pro-oxidant effects, depending on its concentration and initial level of oil oxidation. Results also show that α-tocopherol addition at all the concentrations tested resulted in pro-oxidation of the moderately oxidized oils;hence additional supplementation with α-tocopherol could not be recommended to delay oxidation of unrefined almond oil. 展开更多
关键词 Almond Oil Oxidative STABILITY Α-tocopherol PV CD TBARS Chemometrics
下载PDF
Influence of Glutaraldehyde on the Properties and Release Kinetic of α-Tocopherol from Chitosan-based Film
18
作者 Thanakorn YEAMSUKSAWAT Jun LIANG 《Agricultural Biotechnology》 CAS 2020年第1期85-88,95,共5页
A crosslinked chitosan film with α-tocopherol was produced by a solution casting method. The appearance, mechanical properties, morphology, barrier properties and release kinetics of the α-tocopherol were evaluated.... A crosslinked chitosan film with α-tocopherol was produced by a solution casting method. The appearance, mechanical properties, morphology, barrier properties and release kinetics of the α-tocopherol were evaluated. The addition of glutaraldehyde and α-tocopherol decreased the lightness and greenness and increased the yellowness of the chitosan-based film. Moreover, it also affected the compatibility of the film due to a decrease in the opacity values. The elongation at break(EB) and tensile strength(TS) values of the film decreased when the glutaraldehyde and α-tocopherol were added. In contrast, the Young’s modulus(YM) values increased. SEM micrographs showed coarse spots and pores on the surface and cross-section of the film when compared with the chitosan film. Based on the results, it was indicated that the chitosan structure was disconnected by the α-tocopherol, and the glutaraldehyde as a crosslinking agent generated a link between the chitosan network, which could be the cause of the reduced flexibility and the increased surface roughness of the film. However, the glutaraldehyde and α-tocopherol did not result in a significant difference in water vapour permeability(WVP) values. The glutaraldehyde influenced the release kinetics of the α-tocopherol as seen by the decrease of the diffusion coefficient values that were calculated using the Fickian diffusion model. 展开更多
关键词 Release kinetic GLUTARALDEHYDE Α-tocopherol CHITOSAN Active film
下载PDF
Photooxidation of α-Tocopherol in Micelles. A New Singlet Oxygen Oxidation Product
19
作者 Wei YU Li YANG Zhong Li LIU (National Laboratory of Applied Organic Chemistry, Lanzhou UniversityLanzhou, Gansu 730000) 《Chinese Chemical Letters》 SCIE CAS CSCD 1998年第9期823-826,共4页
Methylene blue sensitized singlet oxygen oxidation of dl-α-tocopherol in dodecylsulfate (SDS) or cetyl trimethyl ammonium brondde (CTAB) ndcelles led to the formation, besidesα-tocopherol quinone and its epoxide, of... Methylene blue sensitized singlet oxygen oxidation of dl-α-tocopherol in dodecylsulfate (SDS) or cetyl trimethyl ammonium brondde (CTAB) ndcelles led to the formation, besidesα-tocopherol quinone and its epoxide, of a hitherto unknown spiro compound 6-hydroxy-2,6,8,9-tetramethyl-2-phytyl- 1-oxaspiro [4, 5] dec -8 - en - 7, 10-dione. 展开更多
关键词 Α-tocopherol singlet oxygen 6-hydroxy-2 6 8 9-tetramethyl-2-phytyl-1-oxaspiro[4 5]-dec-8-en-7 10-dione
下载PDF
Immunoscreening of Alpha-Tocopherol in Breast, Prostate Cancers and in Gestational Choriocarcinoma Tissues
20
作者 Henriette Poaty Franck Arnaud Moukobolo Kinsangou +2 位作者 Alexis F. Bolenga Liboko Judith Nsonde Malanda Michel Geffard 《CellBio》 2021年第2期11-21,共11页
<strong>Background</strong>: Many literature reviews report vitamin E supplementation as a benefit chemopreventive and adjuvant therapy in breast and prostate cancers. We investigated in the present work, ... <strong>Background</strong>: Many literature reviews report vitamin E supplementation as a benefit chemopreventive and adjuvant therapy in breast and prostate cancers. We investigated in the present work, alpha-tocopherol (<span style="white-space:nowrap;">α</span>-T) expression (the current active form of vitamin E) from tissues of Congolese patients neither smokers nor alcohol drinkers and without intake antioxidant vitamins supplement. <strong>Methods</strong>: <span style="white-space:nowrap;">α</span>-T was analysed in one normal placenta of nine weeks of gestation and in nineteen cancerous tissues, including seven breast cancers, six prostate cancers, and six gestational choriocarcinomas. The study was performed by immunohistochemistry method after diagnosis confirmation by histological analysis. <strong>Results</strong>: <span style="white-space:nowrap;">α</span>-T staining in membrane cells and collagen fibers presented a moderate expression in healthy sections of tissues (positive control), but the labelling was strong in breast, prostate adenocarcinomas, and in choriocarcinomas. <strong>Conclusion</strong>: Tumors immunohistochemistry of <span style="white-space:nowrap;">α</span>-tocopherol in breast, prostate cancers and in choriocarcinoma show elevated immunostaining suggesting a probable oncogenic effect of the micronutrient. 展开更多
关键词 Vitamin E Alpha-tocopherol Immunohistochemistry Breast Cancer Prostate Cancer CHORIOCARCINOMA
下载PDF
上一页 1 2 36 下一页 到第
使用帮助 返回顶部