Treatment with β-sitosterol ameliorates the effects of cerebral ischemia/reperfusion injury by suppressing cholesterol overload, endoplasmic reticulum stress, and apoptosis

β-Sitosterol is a type of phytosterol that occurs naturally in plants.Previous studies have shown that it has anti-oxidant,anti-hyperlipidemic,anti-inflammatory,immunomodulatory,and anti-tumor effects,but it is unknown whetherβ-sitosterol treatment reduces the effects of ischemic stroke.Here we found that,in a mouse model of ischemic stroke induced by middle cerebral artery occlusion,β-sitosterol reduced the volume of cerebral infarction and brain edema,reduced neuronal apoptosis in brain tissue,and alleviated neurological dysfunction;moreover,β-sitosterol increased the activity of oxygen-and glucose-deprived cerebral cortex neurons and reduced apoptosis.Further investigation showed that the neuroprotective effects ofβ-sitosterol may be related to inhibition of endoplasmic reticulum stress caused by intracellular cholesterol accumulation after ischemic stroke.In addition,β-sitosterol showed high affinity for NPC1L1,a key transporter of cholesterol,and antagonized its activity.In conclusion,β-sitosterol may help treat ischemic stroke by inhibiting neuronal intracellular cholesterol overload/endoplasmic reticulum stress/apoptosis signaling pathways.

Effect of a second metal(Co,Fe, Mo and W) on performance of Ni_2P/SiO_2 for hydrodeoxygenation of methyl laurate

NiP/SiOand bimetallic Ni MP/Si O2(M = Co, Fe, Mo, W; Ni/M atomic ratio=5) catalysts were prepared by the temperature-programmed reduction method. The catalysts and their precursors were characterized by means of UV–Vis DRS, H-TPR, XRD, TEM, CO chemisorption and NH-TPD. Their performance for the deoxygenation of methyl laurate was tested on a fixed-bed reactor. The results show that the main phase was NiP in all catalysts, and M(M = Co, Fe, Mo, W) entered the lattice of NiP forming solid solution. Different from Fe and Co, the introduction of Mo and W into NiP/SiOreduced the phosphide particle size and increased the acid amount. In the deoxygenation reaction, the turnover frequency of methyl laurate increased on the catalysts in the order of NiMoP/SiO, NiP/SiO, Ni WP/Si O2, NiFeP/SiOand NiCoP/SiO, which is influenced by the size of phosphide particles and the interaction between Ni and M(M = Fe, Co, Mo or W). The introduction of the second metal(especially Mo and W) into NiP/SiOpromoted the hydrodeoxygenation pathway. This is mainly attributed to the interaction between Ni and the second metal. Finally, the Ni MoP/SiOcatalyst was tested at 340 oC, 3 MPa, methyl laurate WHSV of 14 h-1and H/methyl laurate molar ratio of 25 for 132 h, and its deactivation took place. We found that the catalyst deactivation mainly resulted from carbonaceous deposit rather than the sintering of metal phosphide crystallites.

Deoxygenation of methyl laurate to hydrocarbons on silica-supported Ni-Mo phosphides: Effect of calcination temperatures of precursor

SiO2-supported Ni-Mo bimetallic phosphides were prepared by temperature-programmed reduction （TPR） method from the phosphate precur- sors calcined at different temperatures. Their properties were characterized by means of ultraviolet-visible diffuse reflectance spectroscopy （UV-Vis DRS）, H2 temperature-programmed reduction （H2-TPR）, X-ray diffraction （XRD）, transmission electron microscopy （TEM）, CO chemisorption, H2 and NH3 temperature-programmed desorptions （H2-TPD and NH3-TPD）. Their catalytic performances for the deoxygena- tion of methyl laurate were tested in a fixed-bed reactor. When the precursors were calcined at 400 and 500 ℃, respectively, NiMoP2 phase could be formed apart from Ni2P and MoP phases in the prepared C400 and C500 catalysts. However, when the precursors were calcined at 600, 700 and 800 ℃, respectively, only Ni2P and MoP phases could be detected in the prepared C600, C700 and C800 catalysts. Also, in C400, C500 and C600 catalysts, Mo atoms were found to be entered in the lattice of Ni2P phase, but the entering extent became less with the increase of calcination temperature. As the calcination temperature of the precursor increased, the interaction between Ni and Mo in the prepared catalysts decreased, and the phosphide crystallite size tended to increase, subsequently leading to the decrease in the surface metal site density and the acid amount. C600 catalyst showed the highest activity among the tested ones for the deoxygenation of methyl laurate. As the calcination temperature of the precursor increased, the selectivity to C12 hydrocarbons decreased while the selectivity to C11 hydrocarbons tended to increase. This can be mainly attributed to the decreased Ni-Mo interaction and the increased phosphide particle size. In sum, the structure and performance of Ni-Mo bimetallic phosphide catalyst can be tuned by the calcination temperature of precursor.

The Dependence of the Miscibility, Stability and Compressibility of L-<i>α</i>Dioleoylphosphatidylcholine/Rutin Laurate Monolayer at the Air/Water on Temperature

The miscibility, stability and compressibility of L-α dioleoylphosphatidylcholine/rutin laurate mixed monolayer at the air/water were investigated by Langmuir film balance to reveal the characteristic of the molecular interaction. The two components of DOPC/RL mixed monolayer were miscible throughout the mixture composition range and at three experimental temperatures of 10°C, 25°C and 37°C. At all experimental conditions, RL increased the compressibility and elasticity of the DOPC monolayer. Both the temperature and the composition of the membrane affected the form of intermolecular forces in the mixed monolayer.

月桂酸型甘油二酯-大豆油基油泡沫的制备及其在蛋黄酱中的应用

旨在构建健康、低脂、高稳定性的新型蛋黄酱产品,以甘油和月桂酸为原料经过Novozyme 435脂肪酶催化,制备月桂酸型甘油二酯(DAG)粗产物,采用分子蒸馏和硅胶柱层析技术对粗产物进行纯化得到高纯度月桂酸型DAG(纯度>92%),以此为原料制备油泡沫,探究了搅打时间对油泡沫起泡能力、气泡粒径分布、微观结构及稳定性的影响,并将油泡沫50%部分替代或完全替代大豆油用于蛋黄酱制备,研究油泡沫对蛋黄酱流变学特性、色泽、稳定性的影响。结果表明:随着搅打时间的延长,气泡表面吸附的晶体数量明显增多,气泡粒径增大,起泡率先增大后基本保持不变,搅打时间为15 min时油泡沫起泡率最高,且此时的油泡沫储存2个月体积无明显变化;采用油泡沫部分替代及完全替代大豆油后可降低蛋黄酱的黏度,增加蛋黄酱在应力及频率扫描下的弹性模量,蛋黄酱表现出良好的塑性和稳定性,且蛋黄酱的色泽L^(*)值增加,a^(*)值和b^(*)值降低。采用月桂酸型DAG搅打获得的油泡沫可有效降低蛋黄酱的油脂含量和热量,可作为油脂替代物用于新型蛋黄酱产品的开发。

油田开发中新型酯基钻井液配方的合成优化

介绍了一种稳定的酯类化合物的合成方法,用于克服传统酯基钻井液在钻井过程中的酯水解问题。通过采用转酯化反应方法,合成的酯类化合物具有高热稳定性和水解稳定性。反应使用2-乙基己醇和月桂酸甲酯,在甲酸钠催化剂的存在下进行。通过响应面方法(RSM)和中央复合设计(CCD)评估了最佳合成条件,确定了最佳条件。结果表明:质量分数77%的2-乙基己酯与RSM模型之间存在高度一致性。该反应产物含有质量分数77%的2-乙基己酯和23%的2-乙基己醇。其运动黏度在40℃时为5 mm^(2)·min^(-1),在100℃时为1.5 mm^(2)·min^(-1);相对密度为0.854,闪点为170℃,倾点为-7℃。使用该配方的钻井液泥浆在120℃下具有优越的流变性能。

月桂酸甲酯强化低阶煤浮选的作用机制

为了探究月桂酸甲酯对低阶煤浮选的强化作用机制,以月桂酸甲酯为捕收剂,对宁东某低阶煤泥进行了浮选实验、浮选速度实验和浮选动力学分析,并与正十二烷进行对比。研究结果表明:月桂酸甲酯比正十二烷处理后煤样的可燃体回收率和浮选速率常数分别提升10.01%和1.84%;红外光谱分峰拟合分析表明,与正十二烷相比,月桂酸甲酯作用后精煤的极性官能团含量减少了8.69%,脂肪烃和芳香烃含量升高了8.69%。这说明月桂酸甲酯有效覆盖了低阶煤表面含氧官能团位点,并将自身C—C/C—H暴露出来,导致煤样疏水性增加,从而提高低阶煤的可燃体回收率和浮选速率常数,这是月桂酸甲酯强化低阶煤浮选的主要作用机制。

一种蒙脱土负载甲烷磺酸催化合成月桂酸异辛酯的研究

采用月桂酸和异辛醇为原料合成月桂酸异辛酯,通过筛选确定蒙脱土负载的甲烷磺酸为催化剂,实验结果表明该催化剂具有良好的催化活性。通过单因素优化确定最佳工艺条件,催化剂用量0.5%,反应温度150℃,摩尔比为1.3∶1,反应时间为8 h。将粗产品进行脱醇脱酸得到目标产品。月桂酸酯化率可达99.5%,催化剂可重复利用多次,使用4次后,酯化率仍可达到94%。

In-vitro cytotoxic activity of β-Sitosterol triacontenate isolated from Capparis decidua(Forsk.) Edgew

Objective:To study the isolation and characterization of the constituent responsible for the cytotoxic activity of the ethanolic extract of stem of Capparis decidua（C.decidua）.Methods:The preliminary cytotoxic effect of isolated compound（β-Sitosterol triacontenate） was investigated by MTT assay on A549 solid tumor cells.Results:IC50 value of theβ-Sitosterol triacontenate was found to be 1μM.The cytotoxic activity increased in a dose dependent manner in case ofβ-Sitosterol triacontenate.Conclusions:The data therefore provide direct evidence for the role ofβ-Sitosterol triacontenate as a potent antimetastatic agent,which can markedly inhibit the metastatic and invasive capacity of malignant cells.

DCC/DMAP mediated esterification of hydroxy and non-hydroxy olefinic fatty acids with β-sitosterol:In vitro antimicrobial activity

A new series of fatty alkenoates were synthesized using an appropriate synthetic route involving DCC and DMAP as catalysts. Compounds were characterized by their spectral data.All the synthesized compounds were evaluated for their in vitro antimicrobial activity.The minimum inhibitory concentration(MIC),minimum bacterial concentration(MBC) and minimum fungicidal concentration(MFC) were determined for test compounds as well as for reference standards.Among the compounds tested, compounds having hydroxy group at the fatty acid chain showed the most potent antibacterial as well as antifungal activities.

Response surface methodology-based optimization of ultrasound-assisted extraction of β-sitosterol and lupeol from Astragalus atropilosus(roots) and validation by HPTLC method

Objective:To optimize the ultrasonication method for efficient extraction ofβ-sitosterol and lupeol from the roots of Astragalus atropilosus using Box-Behnken design of response surface methodology(RSM),and its validation by high performance thin layer chromatography(HPTLC)method.Methods:Ultrasonication method was used to extractβ-sitosterol and lupeol from Astragalus atropilosus(roots).RSM was used to optimize the different extraction parameters viz.liquid to solid ratio(10–14 m L/g),temperature(60-80℃)and time(40–60 min)to maximize the yield ofβ-sitosterol and lupeol.The quantitative estimation ofβ-sitosterol and lupeol was done in chloroform extract of Astragalus atropilosus by validated HPTLC method on 10 cm×20 cm glass-backed silica gel 60 F254 plate using hexane and ethyl acetate(8:2,v/v)as mobile phase.Results:A quadratic polynomial model was found to be most appropriate with regard to R1(yield of total extraction;R2/%CV=0.9948/0.28),R2(β-sitosterol yield;R2/%CV=0.9923/0.39)and R3(lupeol yield;R2/%CV=0.9942/0.97).The values of adjusted R2/predicted R2/signal to noise ratio for R1,R2,and R3 were 0.9782/0.9551/48.77,0.9904/0.9110/31.33,and 0.9927/0.9401/36.08,respectively,indicating a high degree of correlation and adequate signal.The linear correlation plot between the predicted and experimental values for R1,R2,and R3 showed high values of R2 ranging from 0.9905-0.9973.β-sitosterol and lupeol in chloroform extract of Astragalus atropilosus were detected at Rf values of 0.22 and 0.34,respectively,atλmax=518 nm.The optimized ultrasonic extraction produced 8.462%w/w of R1,0.451%w/w of R2 and 0.172%w/w of R3 at 13.5 m L/g liquid to solid ratio,78℃of temperature and 60 min of time.Conclusions:The experimental findings of RSM optimized extraction and HPTLC analysis can be further applied for the efficient extraction ofβ-sitosterol and lupeol in other species of Astragalus.

Extraction and Crystal Structure of β-Sitosterol

The title compound β-sitosterol（C29H50O）, an active phytosterol in many medicinal and edible plants, was characterized by X-ray diffraction analysis and extensive nuclear magnetic resonance（NMR） data. It crystallizes in monoclinic system, space group P21 with C29H50O·1/2H2O, a = 9.4226（7）, b = 7.4824（9）, c = 36.889（3） , V = 2597.0（4） 3, Z = 4, Dx = 1.084 g/cm3, Mr = 423.70, F（000） = 948, and μ = 0.064 mm-1. The final R = 0.0886 and wR = 0.2234 for 10157 observed reflections（I 〉 2σ（I））. The molecular crystal structure of β-sitosterol shows relative stereochemistry of 24R-ethylcholest-5-en-3β-ol. The molecule is composed of one steroid nucleus（3 six-membered rings and 1 five-membered ring） and one sidechain of 10 carbons. There are two C29H50O molecules and one H2O molecule in a symmetrical unit, and the title compound is stacked into a special laminated structure through hydrogen bonds and van der Waal forces. The special laminated structure was first reported.

Isolation and identification of an isomer of β-sitosterol by HPLC and GC-MS

Phytosterols are a group of steroids alcohols which had been regarded as a functional factor. An unknown compound in phytosterol samples and phytosterol standard samples was detected by HPLC using symmetry C18 column. The quan- tity of the compound was increased with the enrichment of β-sitosterol. After being collected and analyzed by GC-MS and compared with standard diagram from Wiley and Nist standard chart library, it proved to be γ-sitosterol, a 24β epimer of β-sitosterol.

Development of a novel electrospun nanofibrous delivery system for poorly water-soluble β-sitosterol

Electrospinning was used as a novel technique for fabricating polymeric nanofibers of a serum cholesterol lowering and poorly water-soluble plant sterol, β-sitosterol. Chitosan was used as a stabilizer/carrier polymer. The mean diameters of nanofibers ranged from 150 nm to218 nm. β-sitosterol was in an amorphous form and homogeneously dispersed in the nanofibers. The β-sitosterol-loaded nanofibers were freely water-soluble and exhibited very short lag-time in releasing the plant sterol. The dissolution was associated with an immediate recrystallization of β-sitosterol in submicron level. In conclusion, electrospinning is a promising future technology for the formulation of poorly water-soluble plant sterols.

RP-HPLC method for the quantitation of β-Sitosterol in Elaeagnus Gonyanthes Benth

Objective To establish an RP-HPLC method for the determination of β-Sitosterol in Elaeagnus Gonyanthes Benth.Methods The separation was performed on a luna C8(2)(150 mm×4.6 mm,5μm)column with the mobile phase of methanol-water(88∶12,v/v)at a flow rate of 1.0 mL/min,the detection wavelength was set at 210 nm,and the temperature of the column was maintained at 35 ℃.Results The calibration curve of β-Sitosterol was linear over the concentration range of 0.075-0.375 mg/mL(r=0.9999)and the average recovery of β-Sitosterol was 96.30% with RSD of 3.60%(n=3).Conclusion The method is simple,rapid,and accurate,and can be used for the quality control of Elaeagnus Gonyanthes Benth.

Determination ofβ-sitosterol in Plumbago zeylanica L.by HPLC-ELSD

[Objectives]A method for the determination ofβ-sitosterol in Plumbago zeylanica L.was established and the content ofβ-sitosterol in different medicinal parts,different producing areas and different harvest periods were compared.[Methods]High performance liquid chromatography(HPLC)-evaporative light scattering detector assay was used.The chromatographic column was Kromasil C_(18) column(250 mm×4.6 mm,5μm);the mobile phase was pure methanol;the flow rate was 1.0 mL/min;the column temperature was 30℃.The detection parameters of evaporative light scattering detector were as follows:drift tube temperature was 40℃,carrier gas(N_(2))pressure was 3.5 bar.[Results]There was a good linear relationship betweenβ-sitosterol(1.080-4.860μg)and the natural logarithm of peak area(r=0.9995).The average recovery rate was 99.80%.The content ofβ-sitosterol in root and stem was 0.2074 and 0.4064 mg/g,respectively,but it was not found in leaves;the content ofβ-sitosterol in P.zeylanica L.in Guangxi was generally lower than that in Yunnan,and the content ofβ-sitosterol in P.zeylanica L.in Xishuangbanna was the highest;the content ofβ-sitosterol in the stem of P.zeylanica L.was stable at a relatively high level in different harvest periods.[Conclusions]The method is simple,accurate and reproducible,and can be used as one of the methods to control the quality of P.zeylanica L.

阳离子交换树脂催化合成月桂酸甲酯的动力学研究

通过对以Amberlyst 39树脂为催化剂合成月桂酸甲酯的实验研究,计算得到该反应动力学数据,为月桂酸甲酯化反应的工业化设计提供数据和理论的参考。采用PH、E-R、LHHW三种不同的动力学模型对该反应进行拟合,结果表明E-R和LHHW模型的计算值与实验值吻合度都较高,说明在该过程中水的吸附和脱附过程的动力学可忽略,因此E-R模型最适用于表达该反应过程。

经冠状动脉内注射月桂酸钠构建大鼠冠状动脉微栓塞模型

目的建立新的在体大鼠冠状动脉微栓塞模型。方法成年SD大鼠随机分为正常对照组(n=6)、月桂酸钠组(n=54)及微球组(n=27),微球组依所注射微球的数量进一步分为500、1000和3000个次3个亚组(n=9);大鼠麻醉后开胸,夹闭主动脉后经左心室内注射200μg月桂酸钠或42μm的微球达冠状动脉,以注射生理盐水为对照;分别采用病理切片、超声心动图和彩色微粒子测量技术,观察各组大鼠心肌内微血栓和微梗死形成,以及心功能和心肌局部血流量的变化。结果经左心室内注射200μg月桂酸钠后1h,大鼠心肌微小动脉内即有微血栓形成,3h以后达高峰,血栓形成率高达66.4%±18.8%,在此后的12～72h逐渐降低。与微球组相比,所形成的微血栓中不但有血小板及纤维蛋白的聚集,而且还伴有内皮损伤及较严重的炎细胞浸润;二者所形成的微梗死灶皆为锲形呈局灶性分布,但月桂酸钠组梗死部位炎症反应较重。月桂酸钠组所形成的微梗死面积、心功能和心肌局部血流量的下降程度与单次注射1000个微球相似。结论经冠状动脉内注射月桂酸钠可成功构建大鼠冠状动脉微栓塞模型,其最佳剂量和时间点分别为200μg和3h,与机械性的塑料微球栓塞相比,在病理发病机制上比较贴近于临床,可作为冠状动脉微栓塞微循环研究的理想的动物模型。

纳米二氧化钛有机化改性工艺研究

研究并筛选了最佳表面改性剂。对以月桂酸钠作改性剂进行了改性机理的探讨和工艺条件的研究 ,并对有机化纳米二氧化钛作了红外光谱 (IR)和透射电镜 (TEM)

二氢杨梅素月桂酸酯在猪油中的抗氧化性研究(英文)

用月桂酰氯对二氢杨梅素的羟基进行酯化,合成了二氢杨梅素月桂酸酯。并对二氢杨梅素月桂酸酯结构进行了红外光谱表征。通过对二氢杨梅素及二氢杨梅素月桂酸酯在猪油中抗氧化性能比较试验,证实二氢杨梅素月桂酸酯能够持久、稳定地在猪油中发挥抗氧化作用,在猪油中的抗氧化能力比二氢杨梅素强,而二氢杨梅素在猪油氧化后期起到了促氧化作用。通过对二氢杨梅素月桂酸酯在猪油中不同添加量抗氧化试验,得出二氢杨梅素月桂酸酯在猪油中的最佳添加量为1.0mmol/L。