中药烧烫伤凝胶质量标准的色谱研究

建立烧烫伤凝胶的色谱(TLC和HPLC)质量标准.采用薄层色谱法(TLC)对烧烫伤凝胶中黄连、黄柏、大黄、黄芩进行了定性鉴别,并用高效液相色谱法(HPLC)对烧烫伤凝胶中有效成分盐酸小檗碱进行含量测定.盐酸小檗碱含量测定的线性范围为26.64~133.20μg/mL,r=0.9997,平均回收率为96.77%,RSD为1.6%.定性鉴别和含量测定方法简便可靠,重复性好,可有效的控制烧烫伤凝胶的质量.     

益气通痹胶囊质量标准研究

采用薄层色谱法对益气通痹胶囊中黄芪、何首乌、五味子、赤芍、延胡索进行定性鉴别,采用高效液相色谱法测定了制剂中淫羊藿苷的含量. 所用薄层色谱具有鉴别特征,色谱斑点清晰,专属性强. 淫羊藿苷在0.55~3.30 μg范围内呈良好的线性关系(r =0.99996),平均回收率为98.4%,RSD为0.62 %. 所建立的定性和定量方法,操作简便可靠,专属性强,重现性好,能较全面反映该制剂内在质量,可作为益气通痹胶囊新药研发质量控制标准.     

精芪参固本胶囊薄层鉴别及芍药苷含量测定

为制定精芪参固本胶囊的质量标准,采用薄层色谱法鉴别处方中的黄芪和人参,用高效液相色谱法测定精芪参固本胶囊中芍药苷的含量。以乙腈–0.4%的磷酸溶液(20∶80)为流动相,流量为1.0 mL/min,柱温为35℃,检测波长为230 nm。芍药苷的质量浓度分别在9.236～55.416μg/m L范围内与色谱峰面积呈良好的线性关系,相关系数为0.999 8,检出限为180 ng/g。样品加标回收率为98.87%,测定结果的相对标准偏差为1.76%(n=6)。该方法操作简单、快速,结果准确,重现性好,可为精芪参固本胶囊的质量控制提供依据。     

不同采收期苗药土党参中党参炔苷、总多糖和总黄酮含量的测定以及土党参最佳采收期的确定北大核心CSCD

分别采用高效液相色谱法(HPLC)和紫外-可见分光光度法(UV-Vis)测定不同采收期(1~12月)土党参中党参炔苷、总多糖、总黄酮含量,并用总评归一化法确定其最佳采收期。在土党参样品中加入甲醇,超声提取40 min,过0.45μm滤膜,用HPLC测定滤液中的党参炔苷含量。在土党参样品中加入80%(体积分数)乙醇溶液,回流2次,每次1 h,过滤后,滤渣以水为介质在微波炉中消解2次,每次5 min,稀释后加入50 g·L^(-1)苯酚溶液和硫酸,于100℃水浴加热10 min,冰水浴中冷却20 min,用UV-Vis在490 nm下测定总多糖含量,用葡萄糖作为对照品绘制标准曲线。在土党参样品中加入60%(体积分数,下同)乙醇溶液,回流2次,每次1 h,过滤、浓缩并稀释,加入50 g·L^(-1)亚硝酸钠溶液、100 g·L^(-1)硝酸铝溶液和40 g·L^(-1)氢氧化钠溶液,用60%乙醇溶液稀释至10 mL,用UV-Vis在509 nm下测定总黄酮含量,用芦丁作为对照品绘制标准曲线。以Hassan法计算党参炔苷、总多糖和总黄酮的归一值,以总归一(OD)值确定最佳采收期。结果显示:党参炔苷、总多糖和总黄酮的质量浓度均在一定范围内与其对应的峰面积(党参炔苷)和吸光度(总多糖和总黄酮)呈线性关系,党参炔苷的检出限(3S/N)、总多糖的检出限(3.143s)、总黄酮的检出限(3.143s)分别为0.131,0.046,0.071 mg·L^(-1)。方法用于实际样品的分析,峰面积(党参炔苷)和吸光度(总多糖和总黄酮)的相对标准偏差(n=6)均不大于3.0%,平均加标回收率分别为98.8%,99.1%,98.5%;10月份的OD值较高,可将其确定为土党参最佳采收期,此时党参炔苷、总多糖和总黄酮的质量分数分别为3.08,185.15,5.85 mg·g^(-1)。     

间二氯苯纯度的测定

通过测定间二氯苯中的杂质含量得到间二氯苯的纯度。分别采用高效液相色谱法(HPLC–UVD)和气相色谱法(GC–FID)测定间二氯苯中主要杂质邻、对二氯苯的含量,结果表明两种方法所得杂质含量一致;用高效液相色谱法(HPLC)测定间二氯苯中杂质苯的含量,卡尔费休(Karl Fischer)法测定水分含量,热重法(TGA)进行灰分测定,电感耦合等离子体质谱(ICP–MS)法测定无机杂质含量。最终确定间二氯苯的纯度为99.60%,扩展不确定度为0.03%(k=2)。该方法测定结果准确可靠,具有可溯源性。     

蒸发光散射高效液相色谱法测定黄芪饮片中的黄芪甲苷含量

采用蒸发光散射高效液相色谱法测定黄芪饮片中黄芪甲苷的含量。黄芪饮片分别用甲醇和正丁醇提取,以Na OH溶液洗涤,蒸干,再用甲醇溶解,采用Agilent SB–C18柱(250 mm×4.6 mm,5μm)分离测定,流动相为乙腈–水(32∶68),流量为1.0 m L/min,漂移管温度为80℃。方法检出限为1.5μg/m L,黄芪甲苷溶液的质量浓度在2~12μg/m L范围内与色谱峰面积线性关系良好(r2=0.999 6),测定结果的相对标准偏差为0.65%(n=6),平均加标回收率为99.6%。该方法稳定可靠,可用于黄芪药材及其生物制品中黄芪甲苷含量的测定。     

薄层色谱法分离菠菜色素及胡萝卜素含量测定

采用薄层色谱法分离菠菜叶片中的色素,并对其胡萝卜素的鉴别和含量测定.以硅胶G作为吸附剂,石油醚/乙醇/丙酮=3/2/1(体积比)的混合溶液为提取剂,石油醚/丙酮=2/1(体积比)的混合溶液为展开剂为最佳条件,提取和分离菠菜色素.菠菜中的胡萝卜素用薄层扫描仪在波长464.5nm条件下进行测定.结果表明,胡萝卜素在0.03～0.21μg范围内呈现良好的线性关系(r=0.999 8),加标回收率为95.25%～96.44%,相对标准偏差为0.59%.该方法的重复性、稳定性均满足分析的需要.     

毛细管气相色谱法测定香烟烟气中苯酚

建立毛细管气相色谱法(FID)测定香烟烟气中苯酚含量的方法。用5 mL磷酸三丁酯–三乙酸甘油酯混合液(体积比为1∶150)为吸收剂收集香烟烟气中苯酚,用毛细管气相色谱法(FID)测定烟气吸收液中苯酚含量。苯酚的质量浓度在1.6~160 mg/L的范围内与色谱峰峰面积呈良好的线性关系,线性相关系数r=0.999 5,方法的检出限为0.2 mg/L。加标回收率在91%~107%之间,测定结果的相对标准偏差为2.1%~4.3%(n=5)。该方法简单可行,可以满足烟气中苯酚含量的分析要求。     

HPLC法测定地胆草中绿原酸的含量

建立了用高效液相色谱法测定地胆草中绿原酸含量。选择Agilent TC-C18色谱柱(250 mm×4.6 mm,5μm),甲醇-0.1%磷酸溶液(20∶80)为流动相,流速1.0 mL/min,检测波长328 nm,进样量10μL。结果表明,绿原酸0.044 9~4.488 0μg范围内线性关系良好(r=0.999 9),平均加样回收率为99.63%,RSD为0.61%(n=9)。所用方法专属性强、快速准确,可作为地胆草中绿原酸含量的测定方法。     

中药材黄芪与红芪的色谱鉴别法

目的：鉴别中药材黄芪和红芪．方法：高效液相色谱法,数据分析用waters公司．Patten Mattch软件．结果：黄芪和红芪药材的区别是在高效液相色谱指纹图谱中黄芪药材有26个特征峰,红芪药材有23个特征峰;红芪中毛蕊异黄酮的含量低于芒炳花素,黄芪中毛蕊异黄酮的含量高于芒炳花素;红芪中不含黄芪甲苷,黄芪中含有黄芪甲苷．结论：可以用色谱法准确、可靠地鉴别黄芪和红芪药材．     

二氧化碳和丙烯直接合成甲基丙烯酸的NiPMo/TiO2催化剂的研究

用溶胶-凝胶法以磷钼酸(MPA)的镍盐溶液水解钛酸四丁酯制备了NiPMo/TiO2催化剂.使用ICP、 XRD、 TG-DTA、 IR、 TPD-MS和微反应技术研究了催化剂的化学组成、热稳定性、化学吸附性质和催化反应性能.杂多钼酸盐与TiO2通过O2-在TiO2表面发生了键合.在623 K下,杂多阴离子仍保持原有的Keggin结构.CO2在Lewis酸位Ni(Ⅱ)和Lewis碱位Ni-O-Mo的桥氧协同作用下生成CO2卧式吸附态Ni(Ⅱ)←O-(CO)←(O--Ni).丙烯有多种吸附态在催化剂上吸附.在563 K、 1 MPa和空速1500 h-1的反应条件下,丙烯的摩尔转化率为3.2%,产物MAA选择性为95%.     

CoFe2O4自形成磁性液体场致结构化对磁化的影响

The Langevin paramagnetic theory can’t describe the relation between magnetization of ferrofluids and applied magnetic field. The structuralization of ferrofluids, which is considered the main influence factor of the magnetization, is regarded. The part of magnetization works is deposited when the structure is forming. This action influences the magnetization of ferrofluids directly or indirectly. On the base of the “compressing” model, the Langevin function that usually describes the magnetization of ferrofluid is modified, and a well-fitted curve is obtained. An equation of the relation between the equivalent volume fraction after being “compressed” and the intensity of magnetic field is discovered, which approximately describes the process of magnetization. The relation between the approximate initial susceptibility and the volume fraction can be obtained from modified formula.     

Highly regioselective Buchwald–Hartwig amination at C-2 of 2,4-dichloropyridine enabling a novel approach to 2,4-bisanilinopyridine (BAPyd) libraries

The highly regioselective Buchwald–Hartwig amination at C-2 of the cheap and readily accessible reagent, 2,4-dichloropyridine with a range of anilines and heterocyclic amines is described. This new methodology is robust and provides a facile access to 4-chloro-N-phenylpyridin-2-amines on 0.25 mol scale. These intermediates undergo a further Buchwald–Hartwig amination at higher temperature to enable rapid exploration of the chemical space at C-4 and to provide a library of 2,4-bisaminopyridines.     

Sulfur-directed metal-free and regiospecific methyl C(sp3)–H imidation of thioanisoles

Regiospecific and direct imidation of the methyl C(sp³)–H bond of thioanisoles is realized under mild and metal-free conditions with N-fluorobis(benzenesulfonyl)imide as an oxidant and nitrogen source. Proposed mechanism suggests that thionium ion intermediates and a Pummerer-type reaction are involved. The imidation has advantages such as high step-economy, excellent functionality tolerance, and regiospecificity, giving structurally diverse imidation products.     

Selective syntheses of 2H-1,3-oxazines and 1H-pyrrol-3(2H)-ones via temperature-dependent Rh(II)-carbenoid-mediated 2H-azirine-ring expansion

The Rh(II)-catalyzed reaction of 2-carbonyl-substituted 2H-azirines with ethyl 2-cyano-2-diazoacetate or 2-diazo-3,3,3-trifluoropropionate provides an easy access to 2H-1,3-oxazines and 1H-pyrrol-3(2H)-ones. These compounds can be selectively prepared from the same starting material using temperature as the only varied parameter. The 2-azabuta-1,3-diene intermediate, a common precursor for both heterocyclic products, isomerizes into 2H-1,3-oxazine under kinetic control, while 1H-pyrrol-3(2H)-one is the sole product of the reaction at elevated temperatures. According to DFT-calculations a one-atom oxazine ring contraction involving ring-opening to a 2-azabuta-1,3-diene intermediate, followed by a 1,5- and 1,2-prototropic shift leads to the consecutive formation of imidoylketene and azomethine ylide, which then further undergo cyclization to the pyrrole derivative.     

Copper catalyzed/mediated synthetic methodology for ebselen and related isoselenazolones

Scope of the copper catalyzed/mediated selenium-nitrogen coupling reaction has been studied for the synthesis of isoselenazolones. It is noticed that the 2-chloro, 2-bromo-, and 2-iodo-aryl amides substrates can be exploited in the selenium-nitrogen coupling reaction by employing 25-100 mol % of CuI/1,10-phenanthroline (L) and potassium carbonate as a base in DMF. Furthermore, electron rich 2-chloro-arylamides also underwent selenium-nitrogen coupling reaction to give biologically important selenium-nitrogen heterocycles. Also, copper-catalyzed selenium-nitrogen coupling reaction has been meticulously applied for the synthesis of diaryl diselenides having methoxy, amine, and amide functionality from respective aryl iodides in the presence of stoichiometric amount of succinimide as an external Se-N coupling partner.     

Knoevenagel condensation catalyzed by novel Nmm-based ionic liquids in water

A series of novel N-methyl morpholine (Nmm) based ionic liquids with 1,2-propanediol group were synthesized and used as catalysts for Knoevenagel condensation at room temperature in water. Under the effect of the catalyst, various aldehydes or aliphatic ketones could react with a wide range of activated methylene compounds well, including malononitrile, alkyl cyanoacetate, cyanoacetamide, β-diketone, barbituric acid, 2-arylacetonitrile and thiazolidinedione. Furthermore, most of the products could be separated just by filtrating and washing with water. Additionally, the catalyst is recyclable and applicable for the large-scale synthesis.     

Construction of polyheterocyclic spirotetrahydrothiophene derivatives via sulfa-Michael/aldol cascade reaction

A series of polyheterocyclic spirotetrahydrothiophene derivatives were obtained in moderate to excellent yields via a catalyst-free sulfa-Michael/aldol cascade reaction of chalcones 1 and commercially available 1,4-dithiane-2,5-diol 2 under mild conditions. We also present the first asymmetric sulfa-Michael/aldol cascade reaction of chalcones 1 and commercially available 1,4-dithiane-2,5-diol 2 with moderate to good enantioselectivities catalyzed by readily available chiral phase-transfer catalysts (PTCs).     

Suzuki-Miyaura reactions of the soluble guanylate cyclase inhibitor NS2028: a non-product specific route to C-8 substituted analogues

Both soluble guanylate cyclase (sGC) inhibitors ODQ 1 and NS2028 2 are synthesized via improved protocols. In the former case treating 3,4-dihydroquinoxalin-2(1H)-one oxime 8, which can be prepared in two steps from 1,2-benzenediamine, with 1,1′-carbonyldiimidazole (CDI) gives the dihydro-ODQ 10 that in the presence of KMnO₄ oxidises to give ODQ 1 in an overall yield of 46% starting from 1,2-benzenediamine. In the latter case, the synthesis affords NS2028 2 from 2-amino-4-bromophenol 3 in three steps with an overall yield of 85% and avoids the need for chromatography. Furthermore, Suzuki-Miyaura reaction conditions are described that enable the preparation of 8-aryl and 8-heteroaryl derivatives of NS2028 directly from NS2028 2. Finally, demethylation of the 8-(methoxyphenyl) substituted analogues afforded the 8-(hydroxyphenyl) derivatives 40-42. All new products are fully characterised.