The changes of Trp-deficient linusorb during the oxidation and the influence ofγ-tocopherol on their oxidative stability

Linusorbs(LOs),particularly the Methionine(Met)-containing yet Tryptophan(Trp)-free LO(CLB and CLP),play a significant role in shaping the quality and sensory attributes of flaxseed oil.To investigate the stability of these LOs and their oxidized forms during accelerated oxidation,the polar fractions of crude flaxseed oil were selectively removed using silica absorption and then reintroduced separately into the oil matrix along with LOs andγ-tocopherol(γ-T).Through comprehensive analysis of oxidative stability indexes,LOs content changes,oxidation kinetics,and the correlation between LOs and oxidative stability indexes,we observed that the LOs fraction alone exhibited a moderate antioxidant effect on the peroxide value(PV)but a weaker effect on the panisidine value(p-AV)of flaxseed oil.However,upon addition ofγ-T,we observed a weak synergistic effect betweenγ-T and LOs in suppressing PV,while a stronger effect in suppressing p-AV.Additionally,a comparison of the oxidation kinetics of different LOs indicated thatγ-T preferentially protected the oxidation of CLP over CLB.Similar protective trends ofγ-T towards the methionine sulfoxide(MetO)and methionine sulfoxide(MetO2)form of LOs were also observed,albeit to a lesser extent.Correlation analysis revealed that changes in Metcontaining LOs,particularly CLP,showed a high correlation with PV in the tested matrices,while MetOcontaining LOs better depicted changes in p-AV.Importantly,CLP demonstrated higher susceptibility to the influence of antioxidants,making it more suitable for evaluating the peroxide value in flaxseed oil samples.

Klebsiella as an α-tocopherol source facilitating Lactobacillus plantarum fermentation in rice straw silage

Silage serves as the indispensable diet of ruminants,the increasing mechanism of α-tocopherol during silage making is unclear.Rice straw lacks chlorophyll after harvesting the grain,this can eliminate the impact of tocopherols formed by the breakdown of chlorophyll.Here,we explored the α-tocopherol source,its influencing factor,and its relationship with dominant lactic acid bacteria in rice straw silage treated without or with different additives(sodium benzoate,Lactobacillus plantarum,cell wall degrading enzymes,the combination of L.plantarum and cell wall degrading enzymes)and vacuum times(5,8,11,and 14 s)after ensiling for 42 d.We found that the pathogenic Klebsiella was traced as the source of increasedα-tocopherol in rice straw silage.The residue air in the silo,pH value,and additive variety had impacts on Klebsiella activity,which was strongly active at levels of residue air in the silo and pH that were high.As an acidic niche creator,L.plantarum was more effective than sodium benzoate in restraining Klebsiella.Despite having a low acidity tolerance,Klebsiella was still present in rice straw silage treated with L.plantarum.The relationship between Klebsiella and L.plantarum was that Klebsiella could affordα-tocopherol to the multiplication of L.plantarum and residue capsular polysaccharide protected Klebsiella from escaping the extinction in rice straw silage.

Alpha-tocopherol supplementation on chromium toxicity: a study on rat liver and kidney cell membrane

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.

Synthesis of d,l-α-Tocopherol Catalyzed by Heteropoly Acids

,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,

Protective Effects of α-Tocopherol against Brain Tissue Damage Induced by Intracerebral Hemorrhage in SD Rats

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.

Influence of a-tocopherol on nickel induced alteration of serum lipid profile in male albino rats

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.

Reduced expression of α-tocopherol-associated protein is associated with tumor cell proliferation and the-increased risk of prostate cancer recurrence

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.

Maternal reproductive health: Expression patterns of antioxidant enzyme selenoproteins of post-implantation embryos conceived by ethanol-treated murine mothers supplemented with α-tocopherol

Objective:To investigate if the protective effect ofα-tocopherol against the impact of ethanol on brain morphogenesis involved the activity of the selenoproteins phospholipid hydroperoxide glutathione peroxidase (PHGPx;GPx4) and selenoprotein P (SelPP) that have roles against oxidative stress.Methods:Forty female mice were randomly assigned into natural control (CON), positive control (ETOH), low-, medium-, and high-α-tocopherol-supplemented-ethanol groups (LTOC, MTOC, HTOC, respectively). CON received drinking water without ethanol while ETOH, LTOC, MTOC and HTOC groups received 20% ethanol in drinking water. The supplemented groups were given respective dosages ofα-tocopherol, 0.410, 0.819, and 1.640 mg/g body weight, at day 14 before mating onwards to the day 9 of gestation. At 10.5 ED of gestation (1100 h), the pregnant females were sacrificed by cervical dislocation and the embryos were harvested. Total RNA were extracted, cDNA synthesis and qRT- PCR analyses were carried out.Results: The level of expression of PHGPx in the positive control was significantly lower than that of the natural control. Among the threeα-tocopherol-supplemented groups, only the medium dose- group was significantly higher than the positive control. The level of expression of SelPP in the positive control was significantly lower than those of the natural control, the low- and medium- dose -tocopherol supplemented groups. In the high dose-α-tocopherol supplemented group, the level of expression was not significantly different from the positive control but significantly lower than the natural control.Conclusions: The activity of the selenoproteins PHGPx and SelPP are involved in the internetwork of antioxidative enzymes with vitamin E when given up to a medium dose only and is one of the possible pathways of shielding embryonic development against the impact of ethanol on brain morphogenesis. This study strengthens the impact of dietaryα-tocopherol and Selenium supplement during the critical period of pregnancy.

Neuroprotective effects of low-concentration alpha-tocopherol Confocal laser microscopy observations

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

A Methodological Approach to Study Almond Oil Stability in Relation to <i>α</i>-Tocopherol Supplementation

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.

Influence of Glutaraldehyde on the Properties and Release Kinetic of α-Tocopherol from Chitosan-based Film

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.

Effect of Polysaccharide Species on Storage Stability of Alginate Capsules Containing <i>α</i>-Tocopherol

Alginate capsules containing α-tocopherol were prepared adding polysaccharide species such as κ-carrageenan, gellan gum, pectin, curdlan and ghatti gum. The effects of polysaccharide species and the diameters of α-tocopherol on storage stability of the capsules were investigated and characterized in detail. As the contact angle of α-tocopherol to the capsule shell strongly affected storage stability, the contact angle was measured on the model sheet made of calcium alginate with polysaccharide species. The leakage ratio decreased with the contact angle and increased with the diameter of α-tocopherol. The capsules made of calcium alginate with gellan gum showed the largest contact angle and the highest storage stability. The capsules made of calcium alginate with curdlan, ghatti gum and pectin were harder than other capsules and showed higher storage stability. All the capsules showed the almost similar swelling ratio in the acidic solution with pH 4, but showed the different swelling ratios according to the polysaccharide species in the alkali solution with pH 9. The tablets were prepared with the wet and the dried capsules. The tablets prepared with the dried capsules showed higher storage stability.

Photooxidation of α-Tocopherol in Micelles. A New Singlet Oxygen Oxidation Product

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.

生育酚及甾醇含量对大豆油氧化稳定性及贮藏稳定性的影响

植物油是生育酚、甾醇等活性物质的最主要的膳食来源之一,但现有的过度精炼的工艺造成了生育酚和甾醇的大量损失,大大降低了食用植物油的营养价值。随着人们对营养健康的日益关注,加上行业内对植物油适度精炼工艺的号召,需要提高精炼后植物油中生育酚、甾醇的保留量,但植物油中生育酚和甾醇的最低含量的确定缺乏基础研究依据。因此,本文分别利用Rancimat法和Schaal烘箱法比较了不同生育酚及甾醇含量的大豆油的氧化稳定性和贮藏稳定性的差异,结果表明,生育酚和甾醇能够显著提高大豆油贮藏过程中的稳定性,但并不是剂量越高效果越强。当大豆油中生育酚及甾醇分别保留至0.12%、0.35%时,大豆油的氧化稳定性最强;当大豆油中生育酚及甾醇分别保留至0.12%、1.29%时,大豆油的贮藏稳定性最佳。本研究结果为植物油适度精炼工艺中相应产品标准(草案)的制修定提供基础数据,为探究以营养物质含量高低作为植物油新分级指标之一的可行性提供借鉴。

紫花苜蓿γ-生育酚甲基转移酶(γ-TMT)基因的克隆与逆境下的表达分析

紫花苜蓿是目前全国乃至世界上种植最多的牧草,在畜牧业生产中发挥着重要的作用。γ-生育酚甲基转移酶(γ-TMT)是维生素E合成途径中一种重要的合成酶,催化γ-生育酚向α-生育酚的转化,改变维生素E组成,利于动物和人体的吸收。本实验通过RACE-PCR技术,得到紫花苜蓿γ-TMT基因的全长cDNA序列,命名为MsT-MT。测序和生物信息学分析表明,此序列全长1 306bp,包含1个长为939bp的完整开放阅读框(ORF),编码312个氨基酸。MsTMT属于甲基转移酶家族(AdoMet-MTases),有1个腺苷脱氨基酶信号(SLSTDDP),包含有2个保守的S-腺苷甲硫氨酸结合结构域(XXDXGCGIG,VXXPGGXXIX)。Real-time PCR检测结果表明MsTMT基因在紫花苜蓿各组织中均有表达,叶片中表达量最高。受NaCl、PEG以及黑暗诱导后,该基因表达上调;低温胁迫后该基因表达下降;外源ABA不影响该基因的表达。

γ-维生素E甲基转移酶基因转化花生研究

采用携带γ-TMT和bar基因表达载体pGBVE的根癌农杆菌(Agrobacteriumtumefaciens)菌 株GV3101对花生栽培品种鲁花11和丰花2号的成熟胚小叶片及胚生长点进行遗传转化。受体基因型及外 植体类型对转化效率影响很大,以鲁花11胚生长点的转化率最高。试验获得14株PPT抗性苗,经PCR检测 证明,γ-TMT基因已整合在花生基因组中。

大豆γ-生育酚的混合遗传分析与QTL定位

【目的】通过对大豆γ-生育酚进行混合遗传和QTL定位分析,了解其遗传机制,定位其主效QTL,为高γ-生育酚含量大豆品种的选育奠定基础。【方法】以栽培大豆晋豆23为母本,以山西农家品种大豆灰布支黑豆为父本杂交衍生的重组自交系作为供试群体构建遗传图谱。图谱全长2047.6 cM,平均图距8.8 cM,包括227个SSR标记,232个标记位点。重组自交系试验群体及亲本材料分别于2011年、2012年和2015年夏季在河南省农业科学院原阳试验基地种植,冬季在海南省三亚南繁试验基地种植。田间试验采取随机区组设计,2次重复。从6个环境中每个家系选取15.00 g籽粒饱满,大小一致的大豆种子,利用高效液相色谱法定性、定量测定样品中的γ-生育酚含量。采用主基因+多基因混合遗传分离分析法,对大豆γ-生育酚含量进行混合遗传分析;采用WinQTLCart 2.5复合区间作图法,对大豆γ-生育酚含量进行QTL定位分析。【结果】主基因+多基因混合遗传分析表明,γ-生育酚受2对重叠作用主基因×加性多基因控制。遗传基因分布在双亲中。三亚试验数据检测出2对主基因间上位性效应值为0.4010—0.5169和多基因的加性效应值为0.1797—0.2146,主基因遗传率为11.27%—13.05%,多基因遗传率为82.51%—86.55%,多基因效应大于主基因效应。原阳试验数据检测到2对主基因间上位性效应值为0.9646—1.8455,主基因遗传率为39.51%—58.96%,没有检测出多基因效应。采用WinQTLCart 2.5复合区间作图(CIM)共检测到9个影响γ-生育酚的QTL,分布于A1(Chr.5)、A2(Chr.8)、C1(Chr.4)、K(Chr.9)、M(Chr.7)和G(Chr.8)6条染色体中,单个QTL的贡献率为7.29%—29.55%。qγ-G-1同时在2011年原阳、2012年三亚、2015年三亚3个环境下检测到,且均定位在G(Chr.18)染色体Satt275—Satt038标记区间0.01 cM处,解释的表型变异分别为8.97%、8.12%和7.91%。qγ-A1-1同时在2011年原阳和2015年原阳2个环境下检测到,且均定位在A1(Chr.5)染色体Satt276—Satt364标记区间0.01 cM处,解释的表型变异分别为29.54%和28.23%。qγ-G-1和qγ-A1-12个QTL能够稳定遗传。【结论】γ-T最适遗传模型符合MX2-Duplicate-A,即2对重叠作用主基因×加性多基因模型。其遗传同时受到基因型、环境和上位性的影响。检测到γ-T的2个稳定主效QTL,Satt275—Satt038和Satt276—Satt364是共位标记区间。

不同保藏方法对高温下桃仁中维生素E稳定性的影响

观察高温环境下用常规包装、真空包装和可食用膜包装保藏方法对桃仁中维生素E稳定性的影响。结果:三种包装方式中,真空包装的桃仁中维生素E的稳定性最好,可食用膜包装次之,常规包装最差。对于同一种包装方法的桃仁样品,其中维生素E的稳定性顺序为:γ 生育酚>α 生育酚>δ 生育酚。

油棕等植物γ-生育酚甲基转移酶的生物信息学分析

油棕果实中含有丰富的维生素E,而提高其中高活性的维生素E组分是改善棕油品质的关键。油棕γ-生育酚甲基转移酶(Gen Bank登录号为AEU17779)能将低活性的γ-生育酚三烯催化生成高活性的α-生育酚和α-生育酚三烯,是控制油棕维生素E组分和活性的关键酶,其功能在油棕等许多植物中极其保守。本研究利用生物信息学相关软件对以油棕VTE4基因为主要分析对象的一些植物VTE4基因的核酸和相应的氨基酸序列的组成成分、疏水性/亲水性、跨膜结构域以及功能结构域等进行分析。结果表明:VTE4属于不具有信号肽的亲水性蛋白,可能作为转运蛋白在叶绿体中发挥作用,α-螺旋和无规则卷曲大量散布于整个蛋白质二级结构中,具有S-腺苷甲硫氨酸结合位点和PLN02244保守结构域。这一结果可为油棕等植物VTE4的功能和分子机制研究提供更多详细的参考。

α-及γ-生育酚对玉米油回色的影响

为了研究不同生育酚异构体对油脂回色的影响,分别将α-生育酚、γ-生育酚及α-和γ-生育酚添加到中链脂肪酸甘油酯(MCT)和玉米油甘油三酯中,通过105℃烘箱加热10 h来考察回色情况。结果表明,在MCT和玉米油三酰甘油中,虽然α-生育酚损失量远大于γ-生育酚,但微小的γ-生育酚的变化对油脂回色的影响却更显著。加热之后,玉米油甘油三酯中生育酚的损失量大于MCT中的损失量。尽管α-生育酚单独存在的情况下对玉米油的回色几乎没有影响,但当α-及γ-生育酚共同存在的情况下,α-生育酚对γ-生育酚引起的玉米油的回色起到抑制作用。