HPLC测定云雾龙胆花中獐牙菜苷和异荭草苷的含量

建立云雾龙胆花中獐牙菜苷和异荭草苷含量测定的HPLC方法。采用微波辅助动态回流法进行提取,色谱条件:Fusion-RP 80 A C18柱(150×4.6 mm,5μm);流动相:甲醇-0.2%磷酸溶液梯度洗脱(0~20 min∶18∶82~30∶70;20~30min∶30∶70~40∶60;30~35min∶40∶60~50∶50);流速:1 mL/min;柱温:30℃;检测波长254 nm。云雾龙胆花中獐牙菜苷和异荭草苷的色谱峰与共存组分完全达到基线分离,线性范围分别为0.25~1.25μg(r=0.9998),0.432~2.160μg(r=0.9999),平均加样回收率分别为97.7%(RSD=0.84%),99.2%(RSD=0.76%)。     

高效液相色谱法测定2种中药片剂中紫丁香苷的含量

建立了测定2种中药制剂灭澳灵片和活络消痛片中紫丁香苷含量的高效液相色谱方法.采用KromasilC18反相色谱柱(5μm,250 mm×4.6 mm),以乙腈-1%冰醋酸溶液(体积比10∶90)为流动相,流速1.0 mL/min,检测波长265 nm,在15 min内完成分离检测.紫丁香苷在0.16~100μg/mL范围内呈良好的线性关系(r=0.9999),最低检出限0.1μg/mL(S/N=3).灭澳灵片的加样回收率为92.2%~97.6%,活络消痛片的加样回收率为94.0%~102.6%.     

高效液相色谱法测定壮骨祛风合剂中芍药苷

采用高效液相色谱法测定了壮骨祛风合剂中芍药苷的含量。色谱柱为VP-ODS;流动相为甲醇-水-冰乙酸,体积比为25∶75∶0.2,流速为1.0mL/min;检测波长为235nm。实验结果表明,芍药苷在0.2~2.0μg/mL范围内呈线性关系,线性回归方程为A=40378.02c-3310.02,相关系数r=0.9994,测定结果的相对标准偏差为0.63%,平均加标回收率为99.92%。该方法可作为壮骨祛风合剂的质量控制标准。     

HPLC法同时测定24种花中的5种活性成分含量

建立了高效液相色谱法(HPLC)同时测定24种花中绿原酸、金丝桃苷、槲皮素、木犀草素和异鼠李素含量的方法。采用C18柱(250 mm×4.6 mm,5μm),流动相为甲醇-0.2%冰乙酸溶液梯度洗脱,检测波长350 nm,柱温35℃,流速0.8 mL/min。绿原酸、金丝桃苷、槲皮素、木犀草素和异鼠李素分别在0.0208~104.00μg/mL(r=0.99993),0.017~85.00μg/mL(r=0.99998),0.0172~86.00μg/mL(r=0.99997),0.0304~152.00μg/mL(r=0.99997),0.0168~84.00μg/mL(r=0.99986)范围内与峰面积呈良好的线性关系,平均加标回收率(n=9)92.26%~99.09%,仪器精密度(n=6)RSD均小于3.1%,方法重复性(n=6)的RSD均小于3.6%。方法可同时测定这24种花中绿原酸和黄酮类物质的含量,可作为花中活性成分定量分析的方法。     

金银花不同部位中绿原酸和木犀草苷含量的测定

利用HPLC法测定金银花不同部位中绿原酸和木犀草苷。采用ODS-C18色谱柱(250 mm×4.6 mm,5μm),以甲醇-水(0.03 mol/L磷酸)为流动相进行梯度洗脱,流速:1.0 mL/min,检测波长:350 nm,柱温:室温。绿原酸浓度在0~0.4 mg/mL内与峰面积呈良好线性关系(r2=0.999 6),回收率为101.9%~105.2%,相对标准偏差为3.18%(n=6)。木犀草苷浓度在0~0.1 mg/mL内与峰面积呈良好线性关系(r2=0.999 1),平均回收率为100.5%~104.0%,相对标准偏差为3.42%(n=6)。结果表明:金银花、芽等部位绿原酸和木犀草苷的含量较高。     

HPLC法同时测定红景天中红景天苷、酪醇和没食子酸

用高效液相色谱法同时测定大花红景天中红景天苷、酪醇和没食子酸的含量.采用C18 (4.6 mm×200 mm,5 μm)色谱柱,V(甲醇)∶V(0.5%磷酸水溶液)＝5∶95为流动相,流速1.0 mL/min,柱温40 ℃,在278 nm下进行检测.大花红景天中红景天苷、酪醇和没食子酸的平均含量分别为3.06%,0.78%和0.18%.平均回收率分别为99.90% (RSD=1.86%)、100.70% (RSD=0.74%)和99.10% (RSD=1.64%).该方法可用于测定红景天中红景天苷、酪醇和没食子酸的含量.     

不同产地地黄中地黄苷D的测定

应用高效液相色谱的方法建立了地黄苷D的定量分析。色谱条件:采用Hypersil C18柱(4.6 mmi.d.×250 mm,5μm),流动相:V(乙腈)∶V(水)=10∶90,流速:1 mL/min,检测波长205 nm,地黄苷D在0.059~0.295 mg/mL范围内呈良好线性关系,r=0.9999,回收率较高RSD=0.63%,对不同产地地黄的地黄苷D进行了定量分析,不同产地和不同等级的地黄中地黄苷D含量有较大差异,在使用中应加以考虑。     

高效液相色谱法测定九味石灰华散中羟基红花黄色素A和红景天苷的含量

建立了测定中药复方制剂九味石灰华散中羟基红花黄色素A和红景天苷含量的高效液相色谱方法.采用Kromasil C18色谱柱(5μm,250 mm×4.6 mm),以乙腈∶0.1%磷酸溶液(12∶88,V/V)为流动相,流速1.0 mL/min,羟基红花黄色素A的检测波长为403 nm,红景天苷的检测波长为275 nm.羟基红花黄色素A和红景天苷分别在0.288~180μg/mL和4.8~1 200μg/mL范围内呈良好的线性关系(r值为0.999 8~0.999 9),最低检出限分别为0.03μg/mL和0.5μg/mL(S/N=3),加标回收率分别为95.7%~97.4%和95.9%~98.6%.该方法简便、准确、重现性好,可用于九味石灰华散的质量控制.     

HPLC法测定党参中烟酸和党参炔苷的含量

建立HPLC法同时测定党参中烟酸及党参炔苷含量的方法。采用Syncronis AQ色谱柱(250 mm×4.6mm,5μm),以乙腈(A)–0.2%磷酸水溶液(B)作流动相进行梯度洗脱,流量为1 mL/min,紫外检测波长为285 nm,柱温为30℃,烟酸和党参炔苷可在24 min内实现与其它成分良好分离。烟酸的质量浓度在9.6~57.6μg/mL范围内与色谱峰面积线性关系良好(r=0.999 2),检出限为0.94μg/mL,测定结果的相对标准偏差为1.5%(n=6),平均加标回收率为99.5%;党参炔苷的质量浓度在9.92~59.52μg/mL范围内与色谱峰面积线性关系良好(r=0.999 6),检出限为0.12μg/mL,测定结果的相对标准偏差为1.9%(n=6),平均加标回收率为101.1%。该方法操作简便、快速、准确,具有良好的重复性,可作为党参中烟酸、党参炔苷测定的有效方法。     

HPLC法测定红景天除鞣质后红景天苷含量的变化

建立测定红景天溶液除鞣质前后红景天苷含量变化的HPLC法。采用Thermo-C18(4.6 mm×200 mm,5μm)为色谱柱,V(甲醇)∶V(水)=15∶85为流动相,流速1.0 mL/min,检测波长275 nm,柱温25℃。红景天苷的线性范围为1.16~5.8μg;平均回收率分别为100.16%(RSD=0.62%)。所建立的HPLC法可用于测定红景天中红景天苷的含量。     

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%.     

Toward new camptothecins. Part 6: Synthesis of crucial ketones and their use in Friedländer reaction

In the context of the preparation of camptothecin and luotonin A analogs, the synthesis of some key keto-precursors and their use in Friedländer condensation are described. This paper also focuses on the stability of these keto intermediates and emphasizes the major differences between indolizinones and pyrroloquinazolinones series. Noteworthy is also the report of some original structures isolated as by-products of some experiments.     

Synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives

Different approaches for the synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives from simple amino acids have been investigated. A library of 33 precursors for the preparation of N-hydroxy pyrazinones was obtained in moderate to good yields.     

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.     

KMnO4-mediated oxidative CN bond cleavage of tertiary amines: Synthesis of amides and sulfonamides

KMnO₄-mediated oxidative CN bond cleavage of tertiary amines producing secondary amine was introduced, which was trapped by electrophiles (acyl chloride and sulfonyl chloride) to form amides and sulfonamides. The reaction could take place at mild condition, tolerating a wide range of function groups and affording products in moderate to excellent yields.     

Chemistry of heterocyclic compounds at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences, over 50 years (Review)

The review contains a concise historical account and information on the most significant researches undertaken by the staff at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences on the Chemistry of Heterocyclic Compounds. Dedicated to Academician of the Russian Academy of Sciences B. A. Trofimov on his 70th jubilee. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1443–1502, October, 2008.     

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.     

A general and convenient synthesis of 4-(tosylmethyl)semicarbazones and their use in amidoalkylation of hydrogen,heteroatom, and carbon nucleophiles

A general synthesis of previously unknown semicarbazone-based α-amidoalkylating reagents, 4-(tosylmethyl)semicarbazones, has been developed. The synthesis involved three-component condensation of semicarbazones of aliphatic or aromatic aldehydes with the same or other aldehydes and p-toluenesulfinic acid. The scope and limitations of this reaction were investigated. The compounds obtained were demonstrated to be an efficient α-(4-semicarbazono)alkylating agents. They were reacted with H- (sodium borohydride), O- (sodium methylate), S- (sodium phenylthiolate), N- (pyrrolidine, sodium succinimide), P- (trialkyl phosphites), and C-nucleophiles (sodium diethyl malonate) to give the corresponding products of the tosyl group substitution, 4-substituted semicarbazones, including analogues of nitrofurazone. Among the prepared compounds tested in vitro for antibacterial and antifungal activity, three nitrofuryl-containing semicarbazones exhibited high biological activities with minimum inhibitory concentration (MIC) values of 8–32 μg/mL.     

Synthesis of novel chiral bidentate hydroxyalkyl-N-heterocyclic carbene ligands and their application in palladium-catalyzed Mizoroki–Heck couplings and asymmetric addition of diethylzinc to benzaldehyde

A small library of new chiral bidentate hydroxyalkyl-imidazolium salts 1 is conveniently synthesized on multi-gram scale from inexpensive and commercially available chiral pool amino acids. The corresponding carbenes, generated by deprotonation of imidazolium salts 1, in combination with palladium(II) chloride were tested in the Mizoroki–Heck coupling reaction. The most significant results in terms of yields and reactivities were achieved with low catalyst loading. The catalytic activities of these imidazolium salts were also investigated in the asymmetric addition of diethylzinc to benzaldehyde. The use of MgO nanoparticles as an additive in conjunction with these ligands played a crucial role in increasing the efficiency of these reactions.