抗凝血硫酸化微晶纤维素钠构效关系的初步研究

采用UV、IR、13CNMR和元素分析对3种由不同制备工艺参数所获得的硫酸化微晶纤维素钠(Na-MCS)进行结构分析,并研究其抗凝血活性。IR、UV揭示Na-MCS结构中含有硫酸酯基;13CNMR表明,3种Na-MCS的硫酸基取代模式相似,即C6取代占主导,C2位部分取代,C3位不发生取代;元素分析测得其硫酸取代度(DS)不同,即DSNa-MCS1=1 70、DSNa-MCS2=1 45、DSNa-MCS3=1 19;抗凝血研究表明,三者均可使血浆中活化部分凝血活酶时间(APTT)和凝血酶时间(TT)延长,但凝血酶原时间(PT)不延长,三者在抗凝血活性大小上存有差异,这与DS有关,在血浆中质量浓度为5μg/mL时,高DS的Na-MCS1使APTT达到155s、TT达34s,而低DS的Na-MCS3使APTT达到85s、TT达18s。构效关系分析表明,DS的差异不改变Na-MCS的抗凝血途径,但影响其抗凝血活性大小,DS越高,抗凝血活性越强。     

玉米芯木聚糖硫酸酯化条件的研究

用碱提法从玉米芯中提取木聚糖,采用氯磺酸吡啶法进行硫酸酯化,通过正交试验确定最佳工艺条件为:吡啶与氯磺酸摩尔比1∶1,温度65℃,时间6h;木聚糖硫酸酯wisX-S通过DEAESepharoseFF层析柱分离得到一个相对分子量为1.3×104的组分,硫酸基取代度为2.24。对此木聚糖硫酸酯进行红外光谱分析,结果显示在波数1259、1228和813cm-1处分别有S=O和C-O-S键的特征吸收峰。     

玉米芯木聚糖硫酸酯的合成、表征及其抗凝血活性

以碱法提取的玉米芯木聚糖为原料,LiCl为催化剂,在非质子溶剂中,采用三氧化硫-吡啶法合成了玉米芯木聚糖硫酸酯（XS）,通过正交试验对合成工艺进行了优化,并采用凝胶渗透色谱（GPC）、红外光谱（FT-IR）、元素分析和¹³C NMR对其结构与性能进行了表征,进一步考察了其体外抗凝血活性。结果表明：在DMF溶剂中,当三氧化硫-吡啶络合物与木糖羟基单元的物质的量之比为1.5：1时,于55℃反应3 h,木聚糖的酯化效果最好,所制备的XS的取代度（D_S）为1.53,得率为78.2%,重均相对分子质量为36 754,分散系数为1.191。结构表征发现,硫酸酯基已经成功引入木聚糖中。体外抗凝血活性结果表明：XS可以延长APTT和TT,具有一定的抗凝血活性;当取代度为1.53、质量浓度为20 mg/L时,XS的APTT、PT和TT分别为36.37、14.22和14.70 s,与阳性对照肝素钠基本相当。     

丝素膜上接枝褐藻多糖硫酸酯及其体外抗凝血性能的研究

以戊二醛为交联剂,将褐藻多糖硫酸酯接枝在NH3等离子体处理的丝素膜的表面上。主要探讨了pH、反应温度、反应时间对丝素膜接枝效果的影响。用XPS分析了丝素膜表面化学元素。采用部分凝血活酶时间(APTT)、凝血活酶时间(PT)、凝血酶时间(TT)评价了接枝膜的体外抗凝血活性。得出最佳接枝工艺为:pH=2,反应温度40℃,反应时间6h。在该工艺条件下,接枝丝素膜APTT的最佳值为72s,APTT、TT凝血时间比空白对照分别延长37s和6s以上,具有抗凝血性能。经稳定性测试,固定的褐藻多糖硫酸酯基本上不脱落,从而获得了一种具有抗凝血性的新颖生物材料。     

地衣芽孢杆菌发酵土鳖虫前后水溶性活性物质含量比较及抗凝血活性

目的:比较未发酵和经地衣芽孢杆菌发酵后蛋白质、多糖含量的差别,并研究土鳖虫经地衣芽孢杆菌发酵后的抗凝血活性;方法:通过改良Lowry法、苯酚-硫酸法分别测定蛋白质、多糖含量,以凝血酶原时间(PT)、部分活化凝血活酶时间(APTT)、凝血酶时间(TT)为指标评价抗凝血活性。结果:水溶性蛋白质发酵前后含量为65.2061 mg/g,55.9015 mg/g,多糖为46.9724 mg/g,84.8736 mg/g;发酵后能显著延长小鼠的APTT、TT值,但对PT值则无明显影响。结论:土鳖虫经地衣芽孢杆菌发酵后能显著提高多糖含量,明显降低蛋白质含量,并且发酵后具有更强的抗凝效果。     

褐藻多糖硫酸酯/甲基丙烯酸甲酯接枝聚合及抗凝血性能研究

研究了Cu(Ⅱ)离子存在时,褐藻多糖硫酸酯与甲基丙烯酸甲酯(MMA)的接枝聚合反应。主要探讨了V(MMA)/V(H2O)、Cu(Ⅱ)浓度、反应时间、温度对接枝率的影响。采用FT-IR对接枝共聚物进行了表征。接枝共聚物的体外抗凝血活性采用部分凝血活酶时间(APTT)、凝血活酶时间(PT)、凝血酶时间(TT)来评价。结果表明,褐藻多糖硫酸酯的水溶液在Cu(Ⅱ)离子存在时,可以引发MMA的自由基聚合反应。当褐藻多糖硫酸酯的质量浓度为5 6g/L,V(MMA)/V(H2O)=0 20,Cu(Ⅱ)浓度为3 26mmol/L,反应温度85℃,反应时间为3h时,接枝率为197.0%。APTT、TT、PT实验证明,接枝产物的APTT、TT比空白对照物分别延长20s和5s以上,具有抗凝血性能。     

AoGDW肽抑制血小板聚集的活性及特异性

目的研究精氨酸-甘氨酸-天门冬氨酸(RGD)肽衍生物——ω-氨基辛酸-甘氨酸-天门冬氨酸-色氨酸(AoG-DW)抗血小板聚集的活性及特异性。方法采用比浊法测定AoGDW肽抑制人血小板聚集的活性,体外细胞脱黏附试验及MTT法检测AoGDW对人脐带静脉内皮细胞(HUVEC)的脱黏附作用。结果AoGDW和RGDS抑制人血小板聚集的IC50分别为(4.71±2.51)μmol/L和(61.82±8.08)μmol/L,AoGDW使HUVEC产生脱黏附的IC50为(16.50±0.68)mmol/L。结论AoGDW具有高活性的抗血小板聚集作用,并保留了其特异性,有可能避免或减少毒副作用的发生。对于抗血小板药物的临床应用将具有重要的现实意义。     

PBS结晶影响因素的研究

采用偏光显微镜对聚丁二酸丁二醇酯(PBS)的结晶影响因素进行了研究。结果表明:在等温结晶时,PBS的最佳结晶温度随着分子量的增大而提高,当分子量增到一定值后,最佳结晶温度受分子量的影响很小。结晶温度一定时,PBS的晶体尺寸随着结晶时间的延长而增大。结晶时间一定时,PBS的晶体尺寸随着结晶温度的提高而先增大后减小。数均分子量为1×103、8×103、6×104、1×105的PBS最佳结晶温度分别为40℃~50℃、80℃、80℃、90℃。低分子量的PBS在较短的结晶时间内晶体尺寸就已较大,而高分子量的PBS在较长的时间内才能形成较大尺寸的晶体,数均分子量为8×103、6×104、1×105的PBS在最佳结晶温度形成较好结晶的时间分别为10min、20min、25min。     

蔗渣木聚糖醋酸酯的合成与表征

以蔗渣木聚糖为原料,醋酸酐为酯化剂,对甲基苯磺酸为催化剂,在冰醋酸体系中合成了蔗渣木聚糖醋酸酯。考察了诸因素对产品取代度的影响。在m(木聚糖)∶m(醋酸酐)=4∶5,m(木聚糖)∶m(催化剂)=4∶0.2,m(木聚糖)∶m(冰醋酸)=4∶10.49,酯化温度为70℃,酯化时间为4 h的条件下,合成了取代度为0.20的蔗渣木聚糖醋酸酯。采用FTIR、XRD和SEM对蔗渣木聚糖醋酸酯结构进行了表征。分别测定了蔗渣木聚糖醋酸酯的糊化性能和热黏度,表明蔗渣木聚糖醋酸酯比蔗渣木聚糖糊化温度低,热黏稳定性显著改善。     

新型蔗渣木聚糖醋酸酯的合成与表征

摘要：以蔗渣木聚糖为原料,醋酸酐为酯化剂,对甲基苯磺酸为催化剂,在冰醋酸体系中合成了蔗渣木聚糖醋酸酯。考察了诸因素对产品取代度的影响。在m(木聚糖)∶m(醋酸酐)=4∶5,m(木聚糖)∶m(催化剂)=4∶0.2,m(木聚糖)∶m(冰醋酸)=4∶10.49,酯化温度为70℃,酯化时间为4h的条件下,合成了取代度为0.20的蔗渣木聚糖醋酸酯。采用FTIR、XRD和SEM对蔗渣木聚糖醋酸酯结构进行表征。分别测定蔗渣木聚糖醋酸酯的糊化性能和热黏度,表明蔗渣木聚糖醋酸酯比蔗渣木聚糖糊化温度低,热黏稳定性显著改善。     

Synthesis and anticoagulant activity of pectin sulfates

In this article, we describe the first use of trisulfonated sodium amine as a sulfating reagent for preparing pectin sulfate in aqueous solution. The main reaction parameters that were expected to affect the degree of substitution (DS) were studied. The optimal reaction conditions for the synthesis of pectin sulfate were found to be as follows: the pH of the reaction medium, the reaction temperature, the reaction time, and the ratio of the mole of sodium nitrite (n_NaNO2) to the mass of pectin (m_pectin) were 6, 60°C, 12 h, and 2.5/190 mol/g, respectively. Pectin and pectin sulfate were characterized by Fourier transform infrared (FTIR) spectroscopy and ¹³C‐NMR. The FTIR spectra showed the characteristic absorptions of sulfate ester bonds at 1264 and 830 cm^?1. Furthermore, the anticoagulant activity of pectin sulfates with different DSs, concentrations, and molecular weights were investigated with respect to the activated partial thromboplastin time (APTT), thrombin time (TT) and prothombin time. The clotting assay indicated that the pectin sulfate prolonged APTT and TT through inhibition of the activity of antithrombin. These results suggest that the introduction of sulfate groups into the pectin structure improved its anticoagulant activity. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

玉米麸质阿拉伯木聚糖对香豆酸酯的制备及性能研究

通过对水溶性玉米麸质阿拉伯木聚糖(CAX)进行改性,使CAX具有抗氧化性。将CAX溶解到DMA/Li Cl体系中,以三乙胺为缚酸剂,与对香豆酸酰氯进行酯化反应得到阿拉伯木聚糖对香豆酸酯(p-CA-CAX)。用红外、核磁对其结构进行了鉴定,表明对香豆酸(p-CA)以酯键的形式连接在CAX上。用高效液相色谱确定了p-CA的取代度,p-CA与CAX的糖苷键的摩尔比分别为1∶5,1∶4,1∶3,1∶2和1∶1时,取代度分别为0.38,0.51,0.63,0.83和0.94。用凝胶渗透色谱确定了不同取代度的p-CA-CAX的分子量,p-CA-CAX-0.38,p-CA-CAX-0.51和p-CA-CAX-0.63的分子量分别为3.52×10~5,3.85×10~5和3.93×10~5。脂质过氧化物的检测和抗氧化能力指数(ORAC)的测定表明,p-CA-CAX具有较好的抗氧化性,而且p-CA含量越高,p-CA-CAX的抗氧化性越好。     

Synthesis,characterization, and anticoagulant activity of carboxymethyl starch sulfates

To develop a renewable and compatible anticoagulant as potential heparin alternative, carboxymethyl starch sulfate (CMSS) was prepared by the reaction of carboxymethyl starch (CMS) and sulfating reagent [N(SO₃Na)₃]. The chemical structures of CMS and CMSS were characterized by Fourier transform infrared spectroscopy and ¹³C nuclear magnetic resonance. The influences of reaction parameters, including the pH of sulfating reagent, the molar ratio of sulfating reagent to CMS, reaction time, and temperature on the degree of substitution of sulfate groups (DS) of CMSS were studied. Meantime, the DS of each CMSS was determined by barium sulfate–glutin nephelometery method. Moreover, the anticoagulant activity of CMSS was investigated by the coagulation assays of activated partial thromboplastin time, thrombin time, and prothrombin time. The results revealed that the anticoagulant activity of CMSS was closely related to the DS value and concentration. The anticoagulant activity was promoted with the increasing of the DS and concentration. The molecular weight (M_w) in measured range had little impact on anticoagulant activity in contract to the DS and concentration. In this article, the CMSS with the DS of 1.91, concentration of 75 μg/mL and the M_w of 2.61 × 10⁴ had the best blood anticoagulant activities. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

川芎嗪-丁苯酞衍生物的设计、合成及抗血小板聚集活性研究

以邻苯二甲酸酐和川芎嗪为原料,经自由基取代、正丁基锂亲核加成、对甲基苯磺酸催化脱水、Pd/C加氢还原、水解、酯化等反应合成了3个川芎嗪与丁苯酞拼合衍生物,其结构经1HNMR、13CNMR和HR-MS确证.其中(3,5,6-三甲基吡嗪-2-基)甲基-2-戊酰基苯甲酸酯对由腺苷二磷酸(ADP)诱导的血小板聚集活性抑制率IC50为0.26 mmol/L,优于母体化合物川芎嗪和丁苯酞,是具有良好开发前景的候选化合物.     

菊粉季铵盐的合成及性能

该文用菊粉、环氧氯丙烷和十二烷基二甲基叔胺为原料合成了一种菊粉季铵盐表面活性剂。考察了原料摩尔比、催化剂用量、反应温度和反应时间对菊粉季铵盐取代度的影响。最佳反应条件为:n(菊粉)∶n(环氧氯丙烷)∶n(十二烷基二甲基叔胺)=1∶3∶3,催化剂硫酸0.6mL(质量分数26%),70℃反应7h,取代度最高达到1.33。该菊粉季铵盐的CMC=2.78×10-4mol/L,γCMC=29.27mN/m,临界溶解温度Krafft点<0℃,质量浓度3g/L时乳化时间为30min,浓度0.01mol/L时的增溶能力为680mL/mol。与其他生物质资源的阳离子衍生物相比,该菊粉季铵盐具有更强的降低表面张力的能力。     

Preparation, characterization and antimicrobial activity of quaternized carboxymethyl chitosan and application as pulp-cap

Quaternized carboxymethyl chitosan (QCMC) was prepared from which carboxymethyl chitosan (CMC) was prepared from chitosan first, then N-quaternary ammonium group was introduced by the reaction of CMC with 2, 3-epoxypropyl trimethylammonium. The structures of the derivatives were characterized by FT-IR, XRD, ¹³C NMR, ¹H NMR and gel permeation chromatography. In vitro antimicrobial activities of QCMC were evaluated against Escherichia coli, which is a Gram-negative bacterium, and Staphylococcus aureus, which is a Gram-positive bacterium. In compared with carboxymethyl chitosan (CMC) and quarternary chitosan (QC) of the same degree of substitusion (DS), we found that QCMC has stronger antimicrobial activity. Then we went deep into study of the relationship between their structure and antimicrobial activity, found that the DS of CMC do little effect to their antimicrobial activity, but as the increase of their DS of quaternization or the decrease of their molecular weight, the antimicrobial activity of QCMC become stronger. QCMC was complexed with calcium hydroxide as pulp-cap. Animal experiment results indicated that QCMC can strongly induce reparative dentine formation and showed a better ability in dentin inducing compared with calcium hydroxide.