甘露糖赤藓糖醇脂对冷冻熟面品质的影响

为改善冷冻熟面在冻藏过程中易产生冰晶、品质劣变的现象,本研究以蔗糖酯(sucrose ester,SE)为对照添加剂,探究甘露糖赤藓糖醇脂(mannosylerythritol lipids,MELs)对冷冻熟面中可冻结水含量、水分分布、成品品质特性以及小麦粉糊化特性、蛋白二级结构的影响。结果表明,添加0.30%~1.10%MELs能够促进冷冻熟面中的自由水向结合水转化,降低可冻结水的含量,使水与蛋白、淀粉等大分子结合更牢固。与空白组和添加SE组样品相比,添加0.70%MELs制作的冷冻熟面品质较好,此时的硬度为(4335.317±48.047)g,比空白组增加25.36%;拉断力和拉断距离分别达到(11.22±0.15)g和(69.09±1.34)mm;吸水率显著增大,蒸煮损失率最小,优于SE的改善效果。同时,MELs可以有效延缓小麦粉淀粉老化速度,提升蛋白质二级结构中的β-折叠和α-螺旋含量,强化面筋网状结构。

甘露糖赤藓糖醇脂的发酵代谢调控、特性及应用研究进展

甘露糖赤藓糖醇脂(mannosylerythritol lipids,MELs)是一种新型的生物表面活性剂,除了具有与化学表面活性剂相似的界面活性、表面活性和乳化性外,还具有环境兼容、安全低毒的特点以及抑菌、诱导细胞凋亡及分化等生物活性,使其在医疗、食品、农业及生态修复等领域都具备巨大的应用潜力。但由于菌株的发酵代谢调控、生物安全等因素制约着其产业化,多数MELs的应用现今仍处于实验室研究阶段。因此,本文系统地回顾和总结了MELs的结构、主要来源、生物化学特性以及应用方面的研究现状,并从发酵条件优化、代谢调控和群体感应现象的角度对MELs的发酵代谢调控进行评述并作出展望,为未来降低MELs的生产成本,加快实现其规模化应用提供参考。

甘露糖赤藓糖醇脂生产及应用研究进展

甘露糖赤藓糖醇脂(mannosylerythritol lipids,MELs)是一种生物表面活性剂,除具有可降解、毒性低、生物兼容性好等优点,还因其特有的代谢、合成途径与结构特性,而具有基因转染、广谱抗菌、皮肤修复等多种功能。MELs在医疗、日化、食品、农业、生态修复等各领域应用前景巨大,被公认为是现今最有潜力的生物表面活性剂。然而,不同种属所生产的MELs之间结构差异性大且生产方式较落后,合成与作用机制尚不清晰,因而无法实现规模商业化生产。从结构特性、生产纯化、应用途径等方面重点阐述了MELs相关研究进展,以期阐明其结构与功能的多样性,为实现靶向MELs的定制生产,降低生产成本,加快实现其规模化应用提供参考。

甘露赤藓糖醇脂的微生物生产

甘露糖亦藓糖醇脂（ＭＥＬ）是一种新型的非离子生物表面活性剂。近年来的研究发现，ＭＥＬ不仅具有比较确定的分子结构和优良的界面性能，更重要的是它还具有一些特异性能，如：抗菌性、高安全性和良好的生物降解性。在ＭＥＬ的脂肪酸生物合成及其生理机能方面的研究取得很大进展的同时，采用优于传统发酵法的休止细胞法以及随程提取和改进反应器设计等手段大幅度提高了ＭＥＬ的生产强度。ＭＥＬ极有可能成为新型生物表面活性剂中最具潜力的一种，随着应用范围的不断扩大，可以预见其巨大的社会效益和经济效益。

氮源对蚜虫拟酵母生物合成新型乳化剂——甘露糖赤藓糖醇脂的影响

以蚜虫拟酵母为试验菌株,探究不同氮源对合成甘露糖赤藓糖醇脂(MELs)的影响。选择硝酸钠、酵母提取粉、硫酸铵和硝酸铵为氮源,以MELs产量和生物量为评价指标进行试验,结果发现酵母提取粉最有利于菌体生长,硝酸钠最有利于MELs的合成。针对酵母提取粉和硝酸钠开展复配添加研究,分析发酵过程中生物量、MELs产量、pH、发酵液中还原糖和胞外多糖含量的变化,测定不同组MELs产物在25℃时的临界胶束浓度。结果表明:以添加2.0 g/L硝酸钠和2.0 g/L酵母提取粉为氮源时,发酵后期生物量和MELs产量均为最高,此时最有利于蚜虫拟酵母菌体生长和MELs的合成。分离纯化后的MELs产物临界胶束质量浓度为12.50 mg/L,此时水溶液表面张力降低为(31.45±0.66) mN/m,与其它组产物表面活性无明显差异,说明硝酸钠和酵母提取粉的复配对菌体生长和MELs的合成具有促进作用,合成MELs最高产量达(54.00±1.63) g/L,而对MELs产物的表面活性影响不明显。

湖北拟酵母发酵制备甘露糖赤藓糖醇脂的研究

甘露糖赤藓糖醇脂(MELs)是一种糖脂类生物表面活性剂。以湖北拟酵母(Pseudozyma Hubeiensis)为发酵菌株,探究不同碳源、有机氮源及二者的添加量对微生物合成甘露糖赤藓糖醇脂的影响,结果表明橄榄油和酵母提取物分别是最佳的碳源和有机氮源。此外以硝酸钠和酵母提取物进行氮源复配,进一步探究复合氮源对湖北拟酵母发酵合成甘露糖赤藓糖醇脂的影响。结果表明最优培养基组成为:橄榄油120 g/L、酵母提取物3.0 g/L、NaNO_(3)1.0 g/L、MgSO_(4)·7H_(2)O 0.30 g/L、KH_(2)PO_(4)0.30 g/L,发酵培养168 h后,甘露糖赤藓糖醇脂产量达到55.0 g/L。

糖脂生物表面活性剂——甘露糖赤藓糖醇脂的研究进展

甘露糖赤藓糖醇脂是一种糖脂类生物表面活性剂,主要由霉菌和酵母菌等微生物发酵生产,具有良好表面活性和特殊生物活性,其在食品、医药、化妆品等领域有着潜在的应用前景。近年来,其研究在国外备受关注,而国内却鲜有报道。文中综述了甘露糖赤藓糖醇脂的发酵生产、多样性结构及活性、构效关系、生物合成途径等方面的相关研究,对存在问题进行了分析,并探讨了今后的研究重点。

一株产甘露糖赤藓糖醇脂菌株的筛选及其产物分析

【目的】解决石油长链烃类物质引起的环境污染问题,筛选可以高效降解石油烃的产糖脂类生物表面活性剂菌株。【方法】采用血平板、油平板法,从葡萄皮表面分离到6株产糖脂类的真菌,比较各菌株的排油性能,通过PCR扩增合成糖脂类表面活性剂的关键基因,筛选到一株具有emtl序列的真菌K6。经形态学、生理生化测定和分子系统发育分析(5.8S,ITS1,ITS2)对菌株进行鉴定,而且通过TLC和HPLC分析该菌株的代谢产物。【结果】经鉴定,该菌为Pseudozyma churashimaensis,可产甘露糖赤藓糖醇脂。石油烃降解实验表明,菌株K6具有很强的乳化性能和降解石油烃的能力,其石油烃降解率可达70.17%。【结论】菌株K6具有产生物表面活性剂和降解长链石油烃类的能力,其对石油污染环境的生物修复具有重要的现实意义。

酶法合成糖及糖醇酯

以脂肪酸为酰基供体,糖和糖醇为酰基受体,利用吸附到涤棉布上的假丝酵母脂肪酶作催化剂,在含叔丁醇的系统中,研究了酯化反应条件。酯化最适温度和pH值分别为40℃～45℃和50～75。在酰基供体中,以亚油酸和油酸最好,C8到C22的饱和脂肪酸的酯化程度相仿。在23种糖和糖醇中,果糖、木糖、海藻糖、山梨糖、木糖醇、甘露醇以及异丙基葡萄糖和甲基葡萄糖比其它酰基受体的酯化率高。糖醇的酯化程度明显高于相应的糖。此外,酰基供体与受体的摩尔比大于2∶1时,有利于酯化。在由30mmol(085g)油酸,02mmol山梨醇(0036g),3mL叔丁醇和30mg固定化酯肪酶(600u)组成的反应系统中,40℃震荡反应48h,以等摩尔的底物计算,酯化程度达到90%以上。反应产物经薄层色谱鉴定为单酯和双酯。

MEL-A-ZnONPs的制备、表征及抗菌活性研究

为提高纳米氧化锌(zinc oxide nanoparticles,ZnONPs)的分散性和抗菌活性,该研究将绿色、无毒的A型甘露糖赤藓糖醇脂(mannosylerythritol lipids-A,MEL-A)用于ZnONPs的制备和修饰,并利用紫外可见光谱、X射线衍射、傅里叶红外光谱、纳米粒度、Zeta电位和透射电镜-能谱等方法进行表征。结果表明,MEL-A添加浓度为0.250 mmol/L时,制备出的0.250MEL-A-ZnONPs平均粒径及多分散系数(polydispersity index,PDI)值最小,分别为(78.25±27.26)nm和0.155,Zeta电位的绝对值达到最大,为-22.89 mV,且透射电镜形貌及分散性最好,显著优于未修饰的对照组(N-ZnONPs)。利用最小抑菌浓度(minimum inhibitory concentration,MIC)、最小杀菌浓度(minimum bactericidal concentration,MBC)、生长曲线、抑菌圈等实验评价ZnONPs的抗菌性能,发现N-ZnONPs和0.250MEL-A-ZnONPs对金黄色葡萄球菌的MIC均为12.0 mg/L,MBC分别为24.0 mg/L和16.0 mg/L,对大肠杆菌的MIC分别为24.0 mg/L和20.0 mg/L,MBC分别为32.0 mg/L和24.0 mg/L,表明MEL-A-ZnONPs对金黄色葡萄球菌具有更好的抗菌效果。

木糖醇（C_（5－9））酸酯的研制及其应用

本文介绍是以液体木糖醇和Ｃ_（５～９）混合脂肪酸直接酯化生成的木糖醇Ｃ_（５～９）酸酯。它是一种新型耐热增塑剂，其特点是综合性能优良，热稳定性、力学性能、耐寒性均较好，而且本身无毒，可代替环氧类增塑剂使用于塑料制品中。

RP-HPLC Determination of Pinoresinol Diglucopyranoside in Qing′e Pill Extract

Aim To develop and determine pinoresinol diglucopyranoside in Qing'e Pill, atraditional Chinese compound preparation containing Eucommia ulmoides Oliv. as the principal drug,by a reverse-phase high-performance liquid chromatographic method (RP-HPLC) . Methods The extract ofQing'e Pill was refluxed with 75% ethanol, purified on an AB-8 macroporous adsorption resin columnand then injected into HPLC system. The HPLC assay was performed on an ODS analytical column with amixture of methanol-acetonitrile-water (24:3:78, V/V/V) as the mobile phase at a flow-rate of 1.0mL·min^(-1), and a UV detector set at 227 nm. Results Good linearity between peak area andconcentration was found in the range of 5.5 - 170 μg·mL^(-1) for pinoresinol diglucopyranoside ( r> 0.9998) . The average recovery was 99.3%. The intra-day assay RSD and the inter-day assay RSDwere 1.3% and 2.8%, respectively (n = 5). The content of pinoresinol diglucopyranoside in Qing'ePill was determined to be 0.446 +- 0.012 mg·g^(-1) (n = 10). Conclusion The RP-HPLC method wasproved to be sensitive, specific, accurate and precise for the determination of pinoresinoldiglucopyranoside in Qing' e Pill.

Magnolol attenuates sepsis-induced gastrointestinal dysmotility in rats by modulating inflammatory mediators

AIM： To investigate the protective effects of magnolol on sepsis-induced inflammation and intestinal dysmotility. METHODS： Sepsis was induced by a single intraperitoneal injection of lipopolysaccharide （LPS）. Male Wistar rats were randomly assigned to one of three treatment groups： magnolol prior to LPS injection （LPS/Mag group）; vehicle prior to LPS injection （LPS/Veh group）; vehicle prior to injection of saline （Control/Veh）. Intestinal transit and circular muscle mechanical activity were assessed 12 h after LPS injection. Tumor necrosis factor-α （TNF-α）, interleukin-10 （IL-10）, monocyte chemoattractant protein-1 （MCP-1） and inducible nitric oxide synthase （iNOS） mRNA in rat ileum were studied by RT-PCR 2 h after LPS injection. Nuclear factor-κB （NF-κB） activity in the intestine was also investigated at this time using electrophoretic mobility shift assay. In addition, antioxidant activity was determined by measuring malondialdehyde （MDA） concentration and superoxide dismutase （SOD） activity in the intestine 2 h after LPS iniection.RESULTS： Magnolol significantly increased intestinal transit and circular muscle mechanical activity in LPS- treated animals. TNF-α, MCP-1 and iNOS mRNA expression in the small intestine were significantly reduced after magnolol treatment in LPS-induced septic animals, compared with untreated septic animals. Additionally,magnolol significantly increased IL-10 mRNA expression in septic rat ileum. Magnolol also significantly suppressed NF-κB activity in septic rat intestine. In addition, magnolol significantly decreased MDA concentration and increased SOD activity in rat ileum. CONCLUSION： Magnolol prevents sepsis-induced suppression of intestinal motility in rats. The potential mechanism of this benefit of magnolol appears to be modulation of self-amplified inflammatory events and block of oxidative stress in the intestine.

Attainment of multifactorial treatment targets among the elderly in a lipid clinic

Objective To examine target attainment of lipid-lowering, antihypenensive and antidiabetic treatment in the elderly in a specialist set- ting of a University Hospital in Greece. Methods This was a retrospective study including consecutive subjects 〉 65 years old （n = 465） with a follow-up 〉 3 years. Low-density lipoprotein cholesterol （LDL-C）, blood pressure （BP） and glycated hemoglobin （HbAlc） goal achievement were recorded according to European Society of Cardiology/European Atherosclerosis Society （ESC/EAS）, European Society of Hypertension （ESH）/ESC and European Association for the Study of Diabetes （EASD） guidelines. Results The LDL-C targets were attained by 27~,4, 48% and 62% of very high, high and moderate risk patients, respectively. Those receiving statin ＋ ezetimibe achieved higher rates of LDL-C goal achievement compared with those receiving statin monotherapy （48% vs. 33%, P 〈 0.05）. Of the diabetic sub- jects, 71% had BP 〈 140/85 mmHg, while 78% of those without diabetes had BP 〈 140/90 mmHg. A higher proportion of the non-diabetic individuals （86%） had BP 〈 150/90 mmHg. Also, a higher proportion of those with diabetes had HbAlc 〈 8% rather than 〈 7% （88% and 47%, respectively）. Of note, almost one out of three non-diabetic individuals and one out of ten diabetic individuals had achieved all three treatment targets. Conclusions Even in a specialist setting of a University Hospital, a high proportion of the elderly remain at suboptimal LDL-C, BP and HbAlc levels. The use of drug combinations could improve multifactorial treatment target attainment, while less strict tar- gets could be more easily achieved in this population.

Effect of Cu^(2+) concentration on hydrogen fermentation

The results of the study on the effect of Cu2+ concentration on hydrogen production using a glucose solution and mixed microorganisms from a 9 2 L laboratory-scale digester operated at 35 ℃ indicated the productions of hydrogen, volatile fatty acids （VFAs）, ethanol and biogas were inhibited by the added Cu2+ which caused a reduction in the glucose degradation efficiency. The specific yields of hydrogen, ethanol and acetate decreased with increased Cu2+ concentration in the mixed microorganisms. When the Cu2+ concentration in the mixed microorganisms was almost an constant, the specific yields of hydrogen, ethanol and acetate were very similar. A 50% inhibition of hydrogen yield (EC50) occurred at a Cu2+ dosage of 0 50 mg/L in the present investigation. Cu2+ in the external environment is accumulated in the mixed microorganisms. The Cu2+ speciation, using a sequential extraction technique, showed that the Cu2+ was present mainly bound to organic sites in the mixed microorganisms in the present investigation.

Enzymatic reaction of ethanol and oleic acid by lipase and lignin peroxidase in rhamnolipid(RL) reversed micelles

An environment friendly bio-surfactant of rhamnolipid(RL) was used as a solvent. The enzymatic reaction of oleic acid catalyzed by lipase and lignin peroxidase(lip) was evaluated. The optimum conditions of enzymatic reaction catalyzed by lipase(lip) were water to amphiphile molar ratio of 30(20), RL of 60(60) critical micelle concentration(CMC), pH of 7.0(3.0) and temperature of 40(30) °C, respectively. The change of enzyme conformation indicates that, for catalytic of lipase, water content is the most important factor of the enzymatic reaction of oleic acid, and p H for lip. With individual optimum conditions, the enzymatic efficiency of oleic acid catalyzed by lipase is higher than that by lip. In the presence of ethanol, the enzymatic reaction of oleic acid catalyzed by lipase suits Ping-Pong Bi-Bi mechanism. As an alternative to chemical reversed micelles, the RL reversed micelles are promising methods to enzymatic reaction of oleic acid.

Number of medications is associated with outcomes in the elderly patient with metabolic syndrome

Background The diagnosis of metabolic syndrome indicates a clustering of metabolic imbalances which in sum have been recognized as a major predictor of cardiovascular and all-cause mortality. The aim of this study was to assess the level of under-pharmacy and poly-pbarmacy and its prognostic impact in elderly patients with metabolic syndrome. Methods Retrospective chart-review at a tertiary medical center, of 324 patients greater than 65 years of age who met the International Diabetes Foundation criteria for metabolic syndrome diagnosis [Body Mass Index （BMI） 〉 30 kg/m2, diagnosis of type 2 diabetes, hypertension, and dyslipidemia]. Results There were 60 （18.5%） patients in the low （〈 5） medication burden group, 159 （49.1%） in the medium （〉 5 and 〈 10） medication burden group, and 105 （32.4%） in the high （〉 10） medication burden group. At baseline, the groups differed only by systolic blood pressure. At two years follow-up, the medium group had significantly better improvement in high density lipoprotein cholesterol （HDL-C）, low density lipoprotein cholesterol （LDL-C）, HbAlc, and systolic blood pressure compared to the low medication burden group and significantly better improvement in triglycerides, Haemoglobin Alc （HbAlc） and systolic blood pressure compared to the high medication group. Decrease in HDL-C was the only variable associated with strokes. High medication burden predicted hospitalization burden. The number of anti-hypertensives, history of tobacco use, low and high medication burdens and decrease in HDL-C were all associated with death. Conclusions Both poly-pharmacy and under-pharmacy are associated with a decreased therapeutic benefit among patients with metabolic syndrome in terms of important laboratory measurements as well as clinical outcomes such as myocardial infarctions, hospitalization, and death.

Clinical Observation and Experimental Study on Compound Hypoglycemic Decoction for Hyperglycemia

Purpose: To observe the clinical efficacy of Compound Hypoglycemic Decoction (CHD) and its effect on serum total cholesterol in model mice. Method: The paired t test was used to analyze the data recorded before and after administration of drugs for hyperglycemia induced by intraperitoneal injection of 75% egg yolk emulsion in experimental mice. CHD and Fenofibrate were administered as prevention measures. Results: The total effective rate of serum total cholesterol (TC) decrease in 60 cases of hyperglycemia was 86.66% and that of serum total triglyceride (TG) decrease was 81.81%. The total effective rate of high-density lipoprotein-cholesterol (HDL-C) increase was 75%. The decrease in TC and TG, and the increase of HDL-C after treatment by in-group comparison were all significant (P<0.05). 21.9% and 22.2% decrease in the total cholesterol was respectively found in the CHD and Fenofibrate groups (both P<0.05), with no significant difference. Conclusion: The hypoglycemic action of Compound Hypoglycemic Decoction was remarkable in clinical practice, and it is very effective in preventing hyperglycemia in experimental mice.

Chemical constituents from the red alga Symphyocladia latiuscula

The extraction and solvent fi＇actionation of red alga Symphyocladia latiuscula, and repeated column chromatography led to isolation of 17 compounds： cholesterol （1）, 313,5β-dihydroxy-B-norcholestan-6βcarboxaldehyde （2）, 6β-hydroxy-cholest-4-ene- 3-one （3）, 1-O-myristoyl-3-O-（6＇-sulfo-α-D-quinovopyranosyl）glycerol （4）, 1-O-palmitoyl-3-O-（6＇-sulfo-u-19-quinovopyranosyl） glycerol （5）, 1-O-palmitoyl-3-O-[α-D-galactopyranosyl（1→6）β-D-galactopyranosyl] glycerol （6）, 1-O-palmitoyl-3-O-β-D- galactopyranosylglycerol （7）, methyl hexadecanoate （8）, methyl stearate （9）, hexadecanoic acid （10）, γ-n-butyl cis-aconiate （11）, α-n-Butyl cis-aconiate （12）, phenethylamine （13）, 3,5-dibromo-L-tyrosine （14）, 3-methylbutylamine （15）, methyl pyroglutamate （16）, n-butyl pyroglutamate （17）. The structures of these compounds were identified by NMR spectroscopy and mass spectrometry, and compared with those reported in the literature. All the compounds were isolated from Symphyocladia genus for the first time. These compounds were investigated for their inhibitory effects on human recombinant aldose reductase in vitro. Of the compounds, 1-O-palmitoyl-3-O-β-D-galactopyranosylglycerol （7） demonstrated moderate enzyme inhibition.

Effects of Danqidihuang Granules on glucolipid metabolism in insulin-resistant rats

OBJECTIVE： To explore whether the insulin resis- tance （IR） model could be established through feed- ing Sprague-Dawley （SD） rats high-sugar and high-fat diets and to further observe the preven- tive and treatment effects of different doses of Dan- qidihuang Granules in rats. METHODS： Thirty-two SD rats were divided ran- domly into control group A （given regular feed）, model group B （food high in sugar and fat）, inter- vention group C （food high in sugar and fat as well as regular doses of Danqidihuang Granules）, and in- tervention group D （food high in sugar and fat as well as double doses of Danqidihuang Granules）. The interventions were for 8 weeks. Motion, change in color, body weight, and food intake, as well as plasma lipids （including low-density lipopro- tein-cholesterol （LDL-C）, high-density lipopro- tein-cholesterol （HDL-C）, total cholesterol （TC） and triglyceride （TG）, fasting blood glucose （FBG）, fast-ing insulin （FINs） levels, insulin sensitivity index （ISI）, and insulin resistance index （HOMO-IR） were observed. RESULTS： At the end of the second week of the ex- periment, the appetite and activities of rats in groups B, C and D decreased significantly com- pared with group A. The fur of the rats in those three groups was curly. After the fourth week, the activities, food intake and color of rats in group B were worse than those in groups C and D, but there were no significant differences in weight （P〉0.05）. Compared with group A, LDL-C, TC, FBG and HO- MO-IR in model group 13 were increased significant- ly （P〈0.05）, whereas the FINs and ISI increased obvi- ously （P〈0.05）. The levels of LDL-C and TC in group D was decreased obviously compared with those in group C, and HOMO-IR in group D was less than that in group B CP〈0.05）. CONCLUSION： Danqidihuang Granules helped to prevent and improved the insulin resistance of rats.