高速逆流色谱法对独角莲中有效成分皂苷的分离纯化

本文采用高速逆流色谱法对独角莲中的有效成分皂苷进行分离纯化.分别以乙酸乙酯∶正丁醇∶乙腈∶水=5∶1∶1∶5(V/V)及乙酸乙酯∶正丁醇∶乙醇∶水=5∶10∶2∶20(V/V)为溶剂系统,用下相作流动相,上相作固定相,分别采用2 mL/min及1.5 mL/min 的流动相流速、800 r/min的转速对独角莲中的有效成分皂苷进行分离,得到纯度98%的胡萝卜苷6 mg.     

指纹图谱结合化学模式识别评价吉祥草的质量以及高效液相色谱法测定吉祥草中4种化学成分的含量北大核心CSCD

基于吉祥草高效液相色谱(HPLC)指纹图谱,结合化学模式识别评价20批吉祥草(S1~S20)的质量,并测定其中芦丁、人参皂苷Rb1、薯蓣皂苷、薯蓣皂苷元等4种化学成分的含量。吉祥草样品经75%(体积分数)乙醇溶液回流提取2次,过滤、合并滤液、旋转蒸发至干,得到的残渣用甲醇溶解并定容至10 mL,过0.45μm微孔滤膜,滤液供HPLC分析。采用中药色谱指纹图谱相似度评价系统(2012A版)建立20批吉祥草HPLC指纹图谱,并对其进行相似度评价。结合化学模式识别,进行聚类分析、主成分分析和偏最小二乘判别分析,并筛选差异性成分。结果表明:从20批吉祥草HPLC指纹图谱中,选取了13个共有峰,指认其中4个成分,分别为芦丁(峰5)、人参皂苷Rb1(峰11)、薯蓣皂苷(峰12)、薯蓣皂苷元(峰13);20批吉祥草图谱与对照图谱相似度为0.546~0.942;经聚类分析和偏最小二乘判别分析,20批吉祥草均被分成3类,其中S7、S10、S12、S16、S18、S17、S15、S3、S4、S1、S13、S2、S14、S19、S6、S8、S20、S9为第1类,S11为第2类,S5为第3类;经主成分分析,主成分1~4的累积方差贡献率为85.374%,20批吉祥草中S5的综合得分较高,其次是S11;采用变量重要性投影法筛选出7个差异性成分,分别为峰13(薯蓣皂苷元)、峰2、峰7、峰5(芦丁)、峰12(薯蓣皂苷)、峰1和峰6;芦丁、人参皂苷Rb1、薯蓣皂苷、薯蓣皂苷元的质量在一定范围内与其对应的峰面积呈线性关系,检出限(3S/N)为0.005~0.020 mg·g^(-1);对S2进行加标回收试验,4种化学成分的回收率为97.4%~102%,测定值的相对标准偏差(n=6)为1.1%~2.6%;方法用于20批吉祥草分析,芦丁、人参皂苷Rb1、薯蓣皂苷和薯蓣皂苷元的测定值分别为0.249~0.984 mg·g^(-1),0.431~5.851 mg·g^(-1),0.007~0.261 mg·g^(-1)和0.003~0.095 mg·g^(-1)。     

分光光度法测定薯蓣皂苷元

采用高氯酸反应使薯蓣皂苷元显色 ,对影响显色反应的主要因素进行了考察 ,于 41 0nm波长处对穿山龙中薯蓣皂苷元的含量进行测定 ,测定结果与高效液相色谱法相近。方法的线性范围为 3.1 2～2 1 .84μg mL ,适用于薯蓣皂苷元提取过程中的常规检测     

薯蓣皂苷元-葡萄糖C-苷类似物的合成

采用汇集式合成策略,以葡萄糖为原料,经乙酰化、 溴代、消除、硅炔基化、脱除保护基制得(2R,3R) -6-乙炔基-2-(羟甲基) -3,6-二氢-2H-吡喃-3-醇(5);以薯蓣皂苷元为原料,经磺酰化、叠氮化制得叠氮化薯蓣皂苷元8;以5和8为原料,经Click反应合成薯蓣皂苷元-葡萄糖C-苷类似物(9),收率74%,其结构经¹H NMR, ¹³C NMR以及HR-MS(ESI)表征。      

薯蓣皂苷元抗肿瘤衍生物的合成及其生物活性的研究

以薯蓣皂苷元为先导物,设计并合成了9个新的薯蓣皂苷元含氮衍生物,其结构经过~1H NMR,~(13)C NMR,IR和HRMS鉴定.所有衍生物采用噻唑蓝(MTT)法进行抗肿瘤活性(A549,A431,H1975,HCT-116,Aspc-1,Ramos)的测定以及细胞毒性(HBE,LO-2)的研究.研究结果表明,大部分薯蓣皂苷元衍生物具有显著的抗肿瘤活性和低细胞毒性.     

高效液相色谱法测定人血浆中奥氮平的浓度

 用高效液相色谱法测定了人血浆中奥氮平的浓度。色谱条件 :采用岛津LC 6A型高效液相色谱仪 ;色谱柱为ZorbaxODS (15 0mm× 4 6mmi d ,粒径 5 μm) ;流动相为V(5 0mmol/L磷酸钠缓冲液 ,pH 7 2 )∶V(甲醇 )∶V(乙腈 ) =12∶10∶3的溶液 ;检测波长为 2 70nm ;流速为 1 0mL/min ;柱温 40℃ ;灵敏度 0 0 0 5AUFS ;纸速 2mm/min。实验结果显示 ,在上述条件下 ,该方法的线性范围为 15 μg/L～ 12 0 0 μg/L(r =0 9988) ,最低检测限为 3μg/L ,血浆中奥氮平的平均回收率为 (97 0 2± 3 11) % ,测定结果的日内平均相对偏差为 3 86 % (n =15 ) 。     

穿龙薯蓣化学成分的液相色谱-质谱联用分析

穿龙薯蓣(DiosoreanipponicaMakino)为薯蓣科薯芋属植物,产于内蒙古,黑龙江等省区,其根茎俗称穿山龙,既是生产治疗心血管疾病药物地奥心血康的原料药材,又是用于合成多种甾体激素类药物的原料薯蓣皂苷元的重要来源之一。临床报道穿龙薯蓣总皂苷对治疗冠心病、抗动脉粥样硬化、降血脂、平喘、抗炎和抗肿瘤有一定疗效,其有效部位为穿龙薯蓣甾体皂苷.我们采用高效液相与电喷雾串联质谱联用方法分析穿龙薯蓣中主要的皂苷成分,并发现一种未见报道的甾体皂苷元。     

反相高效液相色谱法测定穿山龙中的薯蓣皂甙元

利用超临界CO2萃取技术从穿山龙中提取薯蓣皂甙元,建立了反相高效液相色谱法测定穿山龙中薯蓣皂甙元的方法.采用Shim-pack CLC-ODS(150 mm×4.6 mm,5 μm)色谱柱,流动相为V(甲醇):V(水)=99:1,流速为1.0mL/min,UV检测波长为206 nm.在0.2～2.0 mg/mL范围内,薯蓣皂甙元峰面积与其质量浓度呈良好的线性关系,r=0.9997.进行了高、中、低3个不同浓度的加标回收率测定,相应的回收率分别为101.5%,99.88%,98.45%,平均值99.94%,RSD为1.7%.     

毛细管电泳-电化学检测法测定淮山中薯蓣皂苷和腺苷含量

建立了毛细管电泳-电化学检测(CE-ED)法测定淮山中薯蓣皂苷和腺苷的含量。考察了检测电位、运行缓冲液浓度和pH、分离电压及进样时间等的影响。在优化的实验条件下,对0.1mg/L薯蓣皂苷、腺苷在9min内实现了分离,其线性范围分别为0.1~1 000μg/L和0.1~1 200μg/L;检出限分别为0.04μg/L和0.03μg/L,峰电流的相对标准偏差(RSD,n=6)分别为1.7%、1.5%,迁移时间的RSD分别为0.7%、0.6%。该方法已用于淮山样品中薯蓣皂苷和腺苷的测定,样品加标回收率在98.0%~102.5%之间,RSD≤2.3%。     

α-萘乙酸的高效液相色谱分析

采用高效液相色谱法 ,hypersil 5μmC1 8柱 ( 4 .6× 2 50mm) ,以pH =3～ 4的V(甲醇 )∶V(水 )∶V(磷酸 )=60∶40∶0 .35为流动相 ,检测波长 2 72nm ,测定α -萘乙酸的含量。在 0 .0 1 6～ 1 .0 0 0 g/L范围内 ,浓度与峰面积线性关系良好 (r =0 .9997) ,精密度RSD为 0 .8% (n =5) ,方法简便 ,准确。     

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.     

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.     

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.     

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.