苦荞中D-手性肌醇的纯化及其抗氧化活性研究

采用超声浸提法提取苦荞D-手性肌醇（DCI）,通过高碘酸钠氧化法测定DCI含量,利用活性炭柱分离纯化苦荞粗提物,高效液相色谱法（HPLC）分析粗提物和纯化产物的组成及含量。以VC、BHT为对照,通过对DPPH自由基、羟自由基、超氧阴离子的体外抗氧化评价体系和总还原力的测定,评价对比苦荞DCI粗提物和纯化产物的抗氧化活性。结果表明,苦荞粗提物中D-手性肌醇的含量仅为0.129%,经活性炭柱纯化后,苦荞中D-手性肌醇的含量可以达到27.26%;苦荞DCI提取物对DPPH自由基、超氧阴离子自由基和羟基自由基均具有不同程度的清除作用,同时具有较好的还原性,且DCI纯化产物的抗氧化活性要明显强于DCI粗提物。      

肌醇、D-手性肌醇对大鼠酒精性脂肪肝作用的研究

酒精性脂肪肝(Alcoholic fatty liver,AFL)以及由此发展而成的严重肝脏疾病是人类健康的重大威胁。本实验以SD大鼠为实验动物模型,研究肌醇和D-手性肌醇对大鼠酒精性脂肪肝的作用。实验动物随机分为6个组,一个空白对照组,一个模型对照组,肌醇高(200mg/kg·BW·d)、低(100mg/kg·BW·d)剂量组,D-手性肌醇高(200mg/kg·BW·d)、低(100mg/kg·BW·d)剂量组。采用体积分数为40%的酒精给大鼠灌胃造酒精性脂肪肝模型,灌胃剂量9m L/kg·BW·d,每天分两次给大鼠灌胃,两次间隔大于6小时。造模同时灌胃给药。60天后,测定大鼠体重,脏器指数变化,检测血清和肝脏相关指标。结果显示,肌醇可降低大鼠的肝脏指数,降低血清中TC、TG水平。肌醇两个剂量组能显著降低肝脏TC含量(P<0.05),其中高剂量组有极显著降低作用(P<0.01),手性肌醇两个剂量组均能显著降低肝脏TC含量(P<0.05);肌醇两个剂量组和D-手性肌醇两个剂量组均能极显著降低肝脏TG含量(P<0.01)。肌醇高剂量组使大鼠肝脏GSHPx活力极显著升高(P<0.01),MDA含量极显著降低(P<0.01);D-手性肌醇高剂量组使肝脏SOD活性极显著提高(P<0.01),并极显著降低肝脏MDA水平(P<0.01)。肌醇和D-手性肌醇能降低肝脏脂质含量,预防酒精性脂肪肝,两者效果相当。     

D-手性肌醇对高糖导致氧化损伤线虫延缓衰老的作用及机制

目的:研究D-手性肌醇(D-chiro-inositol,DCI)对高糖膳食导致氧化损伤的线虫延缓衰老的作用,并探究其延缓衰老的作用机制。方法:将线虫同期化后分别培养在含有0、5、10、20 μm/L的DCI的高糖培养基中,记录线虫死亡数目,检测线虫体内脂褐素自发荧光强度及体内的活性氧(ROS)水平;试剂盒法检测线虫的体内相关抗氧化酶活力;PCR 法检测抗衰老相关基因mRNA表达水平。结果表明:DCI可以显著延长线虫的平均寿命(10、20 μm/L,p<0.05),极显著降低线虫体内脂褐素和ROS水平(20 μm/L,p<0.01)。此外,20 μm/L剂量组氧化损伤线虫体内超氧化物歧化酶(SOD)和过氧化氢酶(CAT)活力显著增加(p<0.05),age-1、daf-2基因mRNA 表达水平显著下调(p<0.05),而sir-2.1、sod-3、daf-16、ctl-1基因的mRNA表达水平显著上调(p<0.05)。结论:DCI对高糖导致氧化损伤线虫有保护作用,其延缓线虫衰老的作用机制可能与其调控抗衰老相关基因表达有关。     

D-手性肌醇及D-松醇对缓解HepG2细胞胰岛素抵抗的作用

对D-手性肌醇及D-松醇缓解胰岛素抵抗作用进行评价,选用HepG2人肝癌细胞建立胰岛素抵抗细胞模型。将实验分为正常对照组和D-手性肌醇及D-松醇实验组,分别设立50、100、200、400mg/L4个剂量。采用四甲基偶氮唑盐法(MTT法)检测受试样品对细胞增殖的影响。选用1×10-6mol/L浓度的胰岛素诱导细胞建立胰岛素抵抗模型,给予不同浓度D-手性肌醇及D-松醇,考察二者对胰岛素抵抗HepG2细胞葡萄糖消耗量的影响。实验结果表明,在200~1000 mg/L的浓度范围内D-手性肌醇和D-松醇对HepG2细胞的正常增殖无显著影响。D-手性肌醇浓度为50、100和200 mg/L时,对胰岛素抵抗HepG2细胞的葡萄糖消耗量与模型对照组相比有显著促进作用(p0.05),浓度为400 mg/L时,有极显著性差异(p0.01);D-松醇浓度为200 mg/L时,对胰岛素抵抗HepG2细胞的葡萄糖消耗量与模型对照组相比有显著促进作用(p0.05),浓度为400 mg/L时,有极显著性差异(p0.01)。因此,D-手性肌醇和D-松醇均能够缓解HepG2细胞胰岛素抵抗现象,且在1000 mg/L浓度范围内对HepG2细胞正常增殖无显著影响。     

酶法提取苦荞D-手性肌醇及体外降糖活性

该实验以苦荞籽粒为研究对象,使用酶辅助超声法提取D-手性肌醇（D-Chiro Inositol,DCI）。考察了pH值、酶解温度、酶解时间、加酶量、料液比、乙醇体积分数对DCI浓度的影响,并在此基础上,采用响应面试验设计优化了DCI最佳提取工艺。结果显示：酶解最佳pH值为6,酶解温度为36.4 ℃,酶解时间为0.5 h,加酶量为2.1%,料液比为1:10,乙醇体积分数为48%时,DCI浓度为5.87 mmol/L。进一步利用α-淀粉酶及α-葡萄糖苷酶两项指标评价提取物纯化前后的体外降糖能力。采用活性炭、固相萃取离子小柱纯化DCI,结果显示阴离子（SAX）固相萃取小柱纯化效果最好,能够将纯度提高80%。苦荞中DCI对α-葡萄糖苷酶的半抑制质量浓度（50% Inhibitory Concentration,IC50）降低,IC50值由0.68 mg/mL降到0.47 mg/mL,表明纯化效果显著。采用α-半乳糖苷酶辅助超声法可以有效的获得高浓度DCI,并证实纯化后的DCI具有较好的体外降糖活性。通过该项目的研究为苦荞的综合开发利用提供理论参考。     

D-松醇的研究与开发

D-松醇(D-pinitol,DP)是D-手性肌醇(D-chiro-inositol,DCI)的一种甲基化衍生物,在自然界中具有广泛的植物来源。近年来研究发现,D-松醇具有多种生理活性,如胰岛素增敏作用、降血糖、抗肿瘤、免疫调节、抗炎抗水肿等,因此D-松醇可以应用于医药、保健品原料和膳食补充剂。除此之外,D-松醇作为植物源杀菌剂在农业生产方面的应用也被逐渐推广。广阔的应用范围使D-松醇具备了良好的开发前景。目前对于D-松醇的制备,主要采用化学合成和从天然资源中提取这两种方法,并以后者为主。主要对D-松醇的结构、理化性质、制备、生理活性及D-松醇的应用与开发做简要概述。     

肌醇与D-手性肌醇抗氧化作用的研究

目的:肌醇、D-手型肌醇对D-半乳糖致衰老小鼠体内抗氧化能力的研究。方法:采用颈背部皮下注射D-半乳糖的方法建立衰老小鼠模型,然后分别以100、200、400mg/(kg·bw)剂量的肌醇、D-手型肌醇灌胃。给药八周后,将小鼠处死,观察其对血清、肝脏和脑组织中超氧化物歧化酶(SOD)、过氧化氢酶(CAT)的活性及丙二醛(MDA)含量和总抗氧化能力(T-AOC)的影响。结果表明:与模型组相比肌醇、D-手性肌醇各剂量组均能不同程度增加血清和组织中SOD和CAT的活性,提高T-AOC,降低MDA含量。说明肌醇和D-手型肌醇可以通过提高抗氧化酶的活性,显著提高D-半乳糖致衰老小鼠的抗氧化能力。     

荞麦手性肌醇提取及其降糖功能研究

该文报道Gr+3催导苦荞(Fagopyrium tartarian)仁发芽,整粒抽提种子中手性肌醇(D-chiro- inositol,D-CI)工艺方法;并使用SPSS软件评价D-CI抽提物对糖尿病ICR小鼠具有显著降低空 腹血糖(FBG)(P<0．05),及对糖尿病患者具有显著降低空腹血糖(FBG)和极显著降低餐后血糖 (PG)作用(P<0．01)。     

荞麦籽粒中手性肌醇的薄层层析定性检测方法研究

手性肌醇结构类似于pH2.0型胰岛素调节受体,所以糖尿病人的膳食补充手性肌醇可有效减轻糖尿病症状。在荞麦籽粒中含有手性肌醇,以经过预处理后的荞麦籽粒为原料,对其所含的手性肌醇进行薄层层析定性方法的研究。显色剂采用高碘酸钠溶液和联苯胺溶液。通过试验以选择层析时最佳的点样量、展开次数和展开剂。     

D-手性肌醇对STZ诱导的2型糖尿病大鼠糖原合成的影响

主要探究D-手性肌醇对链脲佐菌素(STZ)诱导的2型糖尿病大鼠糖原合成的影响。实验选用SPF级雄性SD大鼠作为实验动物,高脂高糖饲料配合注射STZ溶液建造2型糖尿病模型,将实验动物分为正常对照组、模型对照组、D-手性肌醇低剂量组(L,30 mg/(kg BW·d))、D-手性肌醇高剂量组(H,60mg/(kg BW·d))和D-手性肌醇正常高剂量组(NH,60 mg/(kg BW·d))。N组和NH组饲喂正常饲料,其余3组饲喂高脂高糖饲料,5周后大鼠处死,对其肝脏和骨骼肌中的糖原含量进行检测,并利用PCR技术对大鼠肝脏和骨骼肌中的PI3K、Akt、GSK-3β和GS的表达量进行检测。实验结果表明:D-手性肌醇可以显著提高肝糖原含量(p0.01)肌糖原含量有提高的趋势,且能促进肝脏和骨骼肌中PI3K、Akt和GS基因的表达,抑制GSK-3β基因的表达。     

柱前衍生化高效液相色谱法测定荞麦中D-手性肌醇含量的方法

建立了一种柱前衍生化高效液相色谱法(HPLC)测定荞麦中D-手性肌醇(D-CI)含量的方法,对衍生化试剂及方法的重复性、稳定性、精密性及加标回收率进行了考察。得到衍生化条件为:苯甲酰氯0.2 mL,吡啶0.6 mL,反应温度70℃,反应时间60 min;色谱条件为:C18柱(4.6 mm×250 mm,5 μm),以乙腈和超纯水为流动相进行梯度洗脱,流速为1.0 mL/min,柱温30℃,UV检测波长230 nm。结果表明,荞麦中的D-CI获得了很好的分离,D-CI在0.004~0.04 mg/mL内线性相关性好,R²为0.999,加标回收率为98.40%~100.67%,所建立的方法稳定、灵敏、重现性好,可用于测定荞麦中D-CI含量定量分析。     

Effect of inositol and its derivatives on diabetes: a systematic review

A growing body of research has investigated the association between inositol and diabetes. The purpose of this review is to report through a systematic way the current scientific evidence relating potential benefits of inositol isomers on diabetes/gestational diabetes. The screening of the studies published last decade was performed in 4 databases (Pubmed-Web of Science-The Cochrane Library-Lilacs). Among the 1640 studies identified in the search, only 26 studies had sufficient data to be included in the systematic review. The available literature suggests that inositol seems to be provide improvements in fasting blood glucose and other biochemical results, which are among the most important parameters in diabetic individuals. Although there are some studies demonstrating that inositol may be effective in prevention and treatment of diabetes/gestational diabetes, conduction of studies with larger sample and longer follow-up duration is required for it to be represented as an effective strategy in management of diabetes.     

Effect of slightly acidic electrolysed water on functional components,antioxidant and α-glucosidase inhibitory ability of buckwheat sprouts

The effect of slightly acidic electrolysed water (SAEW) on the accumulation of total phenolics (TP), total flavonoids (TF), rutin, quercetin and D-chiro-inositol (DCI), the antioxidant and α-glucosidase inhibitory abilities of germinated buckwheat was investigated. The buckwheat treated in low available chlorine concentration (ACC) of 10.94 mg L^-1 displayed the best accumulation of the bioactive substance, showing 63.0%, 113.07% and 128.1% higher TP, TF and rutin content on the 9th day, respectively, and 163.5% and 113.4% higher quercetin and DCI content on the 7th day, respectively, compared to control. Seven-day sprouts treated with SAEW had markedly stronger ABTS radical scavenging and α-glucosidase inhibitory capacities compared to the other treatments. SAEW with lower ACC had less adverse impact on the length and fresh weight of buckwheat than SAEW with higher ACC. Buckwheat sprouts should be treated by SAEW with lower ACC and harvested on the 7th day as for enhanced health-promoting benefits.     

Reliable identification of grapevine rootstock varieties using RAPD PCR on woody samples

Since grapevine ( Vitis spp .) rootstock material is being traded increasingly as disbudded woody material a lack of distinctive morphological features on such material necessitates an alternative and reliable means of identification. Methods described here were developed for rapid and efficient extraction of DNA from woody samples rich in phenolic compounds and polysaccharides, and for subsequent identification of varieties by RAPD PCR. Using these methods, and with the application of only one selected RAPD primer, we were able to differentiate sixteen rootstock varieties, including the seven varieties most commonly used in Germany. Problems commonly encountered with reproducibility of RAPD patterns were avoided by choosing primers with a dinucleotide sequence and a high G/C content that allowed a rather high annealing temperature of 45°C. Methods described here should also be useful for other horticultural crops, especially those with woody tissues rich in phenolic compounds and polysaccharides.     

An internet compendium of analytical methods and spectroscopic information for monomers and additives used in food packaging plastics

An internet website (http://cpf.jrc.it/smt/) has been produced as a means of dissemination of methods of analysis and supporting spectroscopic information on monomers and additives used for food contact materials (principally packaging). The site which is aimed primarily at assisting food control laboratories in the European Union contains analytical information on monomers, starting substances and additives used in the manufacture of plastics materials. A searchable index is provided giving PM and CAS numbers for each of 255 substances. For each substance a data sheet gives regulatory information, chemical structures, physico-chemical information and background information on the use of the substance in particular plastics, and the food packaging applications. For monomers and starting substances (155 compounds) the infra-red and mass spectra are provided, and for additives (100 compounds); additionally proton NMR are available for about 50% of the entries. Where analytical methods have been developed for determining these substances as residual amounts in plastics or as trace amounts in food simulants these methods are also on the website. All information is provided in portable document file (PDF) format which means that high quality copies can be readily printed, using freely available Adobe Acrobat Reader software. The website will in future be maintained and up-dated by the European Commission's Joint Research Centre (JRC) as new substances are authorized for use by the European Commission (DG-ENTR formerly DGIII). Where analytical laboratories (food control or other) require reference substances these can be obtained free-ofcharge from a reference collection housed at the JRC and maintained in conjunction with this website compendium.     

Aroma characterization of various apricot varieties using headspace–solid phase microextraction combined with gas chromatography–mass spectrometry and gas chromatography–olfactometry

The characterization of the aromatic profile of several apricot cultivars with molecular tracers in order to obtain objective data concerning the aromatic quality of this fruit was undertaken using headspace–solid phase microextraction (HS–SPME). Six apricot cultivars were selected according to their organoleptic characteristics: Iranien, Orangered, Goldrich, Hargrand, Rouge du Roussillon and A4025. The aromatic intensity of these varieties measured by HS–SPME–Olfactometry were defined and classified according to the presence and the intensity of grassy, fruity and apricot like notes. In the six varieties, 23 common volatile compounds were identified by HS–SPME–GC–MS. Finally, 10 compounds, ethyl acetate, hexyl acetate, limonene, β-cyclocitral, γ-decalactone, 6-methyl-5-hepten-2-one, linalool, β-ionone, menthone and (E)-hexen-2-al were recognized by HS–SPME–GC–O as responsible of the aromatic notes involved in apricot aroma and considered as molecular tracers of apricot aromatic quality which could be utilized to discriminate apricot varieties.     

Tests of potential functional barriers for laminated multilayer food packages. Part I: Low molecular weight permeants

The advent of the functional barrier concept in food packaging has brought with it a requirement for fast tests of permeation through potential barrier materials. In such tests it would be convenient for both foodstuffs and materials below the functional barrier (sub-barrier materials) to be represented by standard simulants. By means of inverse gas chromatography, liquid paraffin spiked with appropriate permeants was considered as a potential simulant of sub-barrier materials based on polypropylene (PP) or similar polyolefins. Experiments were performed to characterize the kinetics of the permeation of low molecular weight model permeants (octene, toluene and isopropanol) from liquid paraffin, through a surrogate potential functional barrier (25 μm-thick oriented PP) into the food simulants olive oil and 3% (w/v) acetic acid. These permeation results were interpreted in terms of three permeation kinetic models regarding the solubility of a particular model permeant in the post-barrier medium (i.e. the food simulant). The results obtained justify the development and evaluation of liquid sub-barrier simulants that would allow flexible yet rigorous testing of new laminated multilayer packaging materials.