百合知母汤的高效液相色谱指纹图谱及其与组方药味的相关性

研究和建立了百合知母汤的高效液相色谱(HPLC)指纹图谱,为研究百合知母汤的药效物质基础及配伍变化提供了手段。采用Agela Venusil XBP-C18色谱柱(250 mm × 4.6 mm,5 μm),以乙腈和0.1%甲酸为流动相二元梯度洗脱,流速1 mL/min,检测波长315 nm,柱温25 ℃。以芒果苷为参照物,在相同的色谱条件下测定了10批不同产地的百合与知母制备的百合知母汤的指纹图谱,获得了16个共有指纹峰,通过与对照品的保留时间及紫外光谱比较,标定了5-羟甲基糠醛(5-HMF)、新芒果苷、芒果苷、异芒果苷、王百合苷B的出峰位置。该方法得到的百合知母汤的指纹图谱特征性和重现性较好,方法稳定、可靠,可以为百合知母汤的质量控制提供参考。通过实验归属了百合知母汤指纹图谱中的主要色谱峰,并确定了煎煮过程中的主要变化成分为5-HMF。     

高效液相色谱指纹图谱法分析南方红豆杉药材的氯仿提取物

建立了南方红豆杉药材氯仿提取物的高效液相色谱(HPLC)指纹图谱分析方法。采用Eurospher 100 C18色谱柱(250 mm×4 mm, 5 μm),以甲醇和水为流动相进行梯度洗脱,流速为1 mL/min,检测波长为232 nm,柱温为30 ℃。以10-脱乙酰巴卡亭III(10-DABIII)为参照物,在相同的色谱条件下测定了10批不同产地的南方红豆杉药材氯仿提取物的指纹图谱,获得了11个共有指纹峰,并利用主成分分析法(PCA)对指纹图谱进行统计分析。结果表明南方红豆杉药材的质量与种植区域有关。该方法稳定、可靠,可用于南方红豆杉药材的质量控制。     

不同产地金银花药材的HPCE指纹图谱分析

以40mmoL/L硼砂溶液为缓冲液,利用高效毛细管电泳(HPCE)法,建立不同产地金银花的HPCE指纹图谱并测定其中绿原酸的含量。工作电压为17kV,温度为25℃,压力进样时间为6s。不同产地金银花药材中绿原酸的含量为3.2%4.4%。通过对HPCE指纹图谱共有峰数据进行判别分析和聚类分析,可以将不同产地的金银花进行判别分类。HPCE指纹图谱可以用于较全面地考察金银花药材的质量。     

丹参药材水溶性成分的高效液相色谱指纹图谱研究

采用高效液相色谱法(HPLC)对贵州铜仁丹参基地的丹参药材进行了指纹图谱研究。实验采用Zorbax SB-C18色谱柱 (5 μm, 4.6 mm i.d.×250 mm),以乙腈-0.4%(体积分数)冰醋酸水溶液为流动相,乙腈的体积分数在70 min内由0线性 增加到40%;流速1.0 mL/min;柱温25 ℃;检测波长254 nm。以19个主要共有峰为评价指标,采用国家药品监督管理局推荐 的“计算机辅助中药指纹图谱相似度计算软件”计算处理,建立了铜仁地区丹参药材的HPLC共有指纹图谱。该法操作简单 ,精密度、稳定性和重现性良好,有助于加强丹参药材的质量控制。     

高效液相色谱法研究当归指纹图谱

目的:研究当归药材的指纹图谱.方法:高效液相色谱法,Hypersil ODS柱(4.6 mm×250 mm,5μm),Kromasil ODS保护柱(4.6 mm×10 mm,5μm).甲醇-1%醋酸梯度流动相,流速1.0 mL/min,柱温25℃.以当归对照药材为对照品,色谱峰光谱采集范围:190~400 nm;以阿魏酸为参照物并测定了阿魏酸的含量,检测波长:323nm,流动相:甲醇-1%醋酸(40∶60,V/V),流速0.7 mL/min.结果:找出了22个共有峰,其中5号峰为阿魏酸,11个样品与当归对照药材之间的相似度均在90%以上,平均相似度为96.77%.结论:样品处理方法简单,研究所得的当归指纹图谱稳定性、重复性好,可以作为当归极性部分的特征性指纹图谱.     

不同产地金银花药材HPLC指纹图谱的研究

研究并建立不同产地的金银花药材的指纹图谱,并应用系统聚类分析和主成分分析建立金银花药材的化学模式识别方法,以期为金银花药材品质评价与质量控制提供参考。CP-C_(18)色谱柱(5μm,4.6mm×150mm),以乙腈-0.2%磷酸水溶液为流动相进行梯度洗脱,流速为1.0 mL·min~(-1),柱温25℃,检测波长为254nm。16批不同产地的金银花药材有13个共有峰,相似度在0.916~0.990。聚类分析能对不同产地的金银花药材进行有效识别,主成分分析结果与聚类分析结果类似。建立的方法能够成功应用于金银花药材的质量控制与评价及产地识别,可为制定金银花药材质量控制与评价模式提供新的参考依据。     

秦艽花的指纹图谱研究

建立秦艽花的HPLC指纹图谱。采用Fusion-RP 80A C18柱(150×4.6mm,5μm),以甲醇-0.2%H3PO4为流动相,梯度洗脱,检测波长240 nm,对11批不同产地秦艽花药材进行HPLC测定,以龙胆苦苷为参照峰。结果秦艽花药材共有20个共有峰。本实验建立的HPLC指纹图谱和测定方法为有效控制秦艽花的质量提供了依据。     

不同产地龙葵药材的高效液相色谱-蒸发光散射检测指纹图谱

采用高效液相色谱-蒸发光散射检测器(HPLC-ELSD)来研究不同产地龙葵药材品质的差异,为龙葵药材质量标准的制定提供参考依据。使用Phenomenex C₁₈色谱柱,流动相为乙腈-20%(v/v)甲醇水溶液(含0.03%(v/v)三乙胺),梯度洗脱,蒸发管温度为40 ℃。利用"中药色谱指纹图谱相似度评价系统"对所采集的色谱图进行相似度比对,选择相似度在0.9~1.0之间的色谱图归一化拟合成龙葵的标准指纹图谱,并利用对照品进行色谱峰指认。研究结果表明,不同产地来源的龙葵药材之间具有显著的差异,依据HPLC-ELSD采集到的非挥发类成分可对中药材进行区分。该方法为龙葵药材的真实性、优良性和稳定性评价提供了一种新的、具有广阔应用前景的技术手段。     

桑叶HILIC特征指纹图谱研究

应用亲水色谱法(HILIC)建立了桑叶药材的指纹图谱,并对10批桑叶样品进行分析,为桑叶药材的真伪鉴别及质量控制提供了新方法。采用HILIC XBridgeTMAmide色谱柱,以乙腈-水(含0.2%甲酸、20mmol/L甲酸铵、20%甲醇)为流动相,梯度洗脱,流速为0.8 mL/min,柱温为25℃,检测波长为322 nm,进样量为20μL。该方法具有良好的精密度、重现性和稳定性,检测的10批桑叶指纹图谱有17个共有峰,4个特征峰,采用ESI-TOF/MS对4个特征峰进行了指认,结合相似度分析可以用于不同产区桑叶药材的鉴别。桑叶HILIC指纹图谱有望成为桑叶药材真伪鉴别及质量控制的有力工具。     

葛根药材指纹图谱分析方法研究

以安徽产葛根药材为分析对象,选择Agilent ZORBAX SB-C18柱(4.6 mm×250 mm,5μm),甲醇-水梯度洗脱,流量为0.9 mL.min-1,检测波长为250 nm,柱温25℃,建立了葛根药材HPLC指纹图谱。结果表明,10批供试品的保留时间在60 min之内,共有18个典型的共有色谱峰。采用HPLC法获得的葛根药材指纹图谱稳定、可靠、重复性好,能较全面地反映葛根药材的内在质量,可用于葛根药材的质量控制。     

A carbanion induced synthesis of highly congested pyrazole and imidazole containing heterocycles

An efficient approach to the synthesis of highly congested di, penta and hexacyclic pyrazoles as well as imidazole fragment containing novel heterocyclic molecule has been developed through a carbanion induced transformation of suitably functionalized 2H-pyran-2-ones, benzo[h]chromene and thiochromeno[4,3-b]pyrans. Due to the presence of fluorescence, we report their prime application metal sensor as off/on switching in ferric ions.     

α-Amino acid derived enaminones and their application in the synthesis of N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates and other heterocycles

A new and simple synthesis of novel N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates, which exist in equilibrium with their 4-oxo tautomers, has been developed in two steps starting from N-protected α-amino acids. The key intermediates are enaminones, which can also be isolated, characterized, and used for the construction of other functionalized heterocycles, before they spontaneously decompose to pyrrole products. 4-Hydroxypyrroles are prone to partial aerial oxidation but can be efficiently alkylated or reduced to stable polysubstituted pyrrolidine derivatives.     

Specific intramolecular aromatic CH insertion of diazosulfonamides

The chemoselectivity in the intramolecular CH insertion of various diazosulfonamides has been experimentally studied. The results reveal that the aliphatic 1,4-, 1,5-, or 1,6-C(sp³)?H insertions of diazosulfonamides are not accessible, while the aromatic 1,5-C(sp²)?H insertion can be realized specifically by adjusting the diazo-adjacent group. In addition, the general chemoselectivities in the intramolecular CH insertions of diazosulfonyl compounds are summarized. Generally, diazosulfones undergo both aromatic 1,5-C(sp²)?H and aliphatic 1,5- and 1,6-C(sp³)?H insertions, while diazosulfonates undergo aliphatic 1,5- and 1,6-C(sp³)?H insertions. However, diazosulfonamides only undergo aromatic 1,5-C(sp²)?H insertion.     

N-Heterocyclic carbene-palladacyclic complexes: synthesis,characterization and their applications in the C-N coupling and α-arylation of ketones using aryl chlorides

N-Heterocyclic carbene-palladacyclic complexes 3 were successfully achieved in a one-pot procedure under mild conditions. The structure of 3a was unambiguously confirmed by X-ray single crystal diffraction and it was an active catalyst in the Buchwald-Hartwig amination and α-arylation of ketones even at very low catalyst loadings (0.01?mol%).     

Selective synthesis of 4,5-dihydroimidazo- and imidazo[1,5-a]quinoxalines via modified Pictet–Spengler reaction

An efficient tandem approach for the selective synthesis of 4,5-dihydroimidazo[1,5-a]quinoxalines 6a–g and imidazo[1,5-a]quinoxalines 7a–h by the reaction of 2-imidazolyl anilines 4a–c with aryl aldehydes 5a–k under mild reaction conditions is described. Introduction of electron releasing alkyl groups in substrates 4a–b was found to be instrumental for the success of the reaction.     

Understanding the Diels-Alder reactivity of 1,2-azaborine analogues

The Diels-Alder reactivity of 1,2-heteroborines (H₄C₄B(H)X, X?=?NH, PH, AsH; O, S, Se) has been computationally explored by means of Density Functional Theory (DFT) calculations. The influence of the HB?=?X fragment on the reactivity of the system has been quantitatively analyzed in detail by means of the so-called Activation Strain Model (ASM) of reactivity. It is found that the interaction between these species and the dienophile is significantly stronger than that computed for their all-carbon isoelectronic counterpart, benzene. In addition, the strain energy plays a key role in the observed reactivity trends. The role of the aromaticity strength of these heteroarenes on the reactivity is also assessed.     

Synthesis of N-substituted carbazolones from α-iodo enaminones via Pd(0)-catalyzed intramolecular coupling under microwave irradiation

A variety of N-aryl and N-alkyl carbazolones were conveniently achieved in good to high yields via Pd₂(dba)₃-mediated intramolecular coupling of N-substituted α-iodo enaminones under microwave irradiation. The Pd(0)-catalyzed cyclization was found to proceed favorably with the more electron-deficient phenyl ring during the reactions involving unsymmetrical N,N-diaryl α-iodo enaminones. This unique property enables the construction of carbazolone skeleton containing nitro substituted benzenoid ring.     

Iodine-mediated oxidative Pictet-Spengler reaction using terminal alkyne as the 2-oxoaldehyde surrogate for the synthesis of 1-aroyl-β-carbolines and fused-nitrogen heterocycles

An efficient iodine-mediated oxidative Pictet-Spengler reaction in dimethyl sulphoxide (DMSO) using terminal alkynes as the 2-oxoaldehyde surrogate for the synthesis of aryl (9H-pyrido[3,4-b]indol-1-yl)methanones is described. The scope of the protocol includes the total synthesis of Fascaplysin, Eudistomins Y₁ and Y₂. The methodology is extended for preparing pyrrolo[1,2-a]-quinoxaline and indolo[1,5-a]quinoxaline derivatives. The utility of 1-aroyl-β-carbolines was demonstrated by performing palladium-catalyzed β-carboline directed ortho-C(sp2)-H functionalization of the phenyl ring with thiomethyl (SMe) group using DMSO as source and for accessing 4-aryl-canthin-6-ones.     

Facile synthesis of bicyclic 1-arylpyrazol-5-ones

In this Letter, we described a facile method for constructing fused bicyclic 1-arylpyrazol-5-one ring system. We employed various methylene-containing carboxylic acids as the substrates and proved that the pyrazolone ring closure requires activated methylene group in intermediate II. Accordingly, a series of structurally diversified, fused bicyclic 1-arylpyrazol-5-ones was prepared in moderate to high yields using the requisite substrates.     

Synthesis of substituted 2,4,5,6-tetrahydrocyclopenta[c]pyrazoles and 2,4,5,6-tetrahydropyrrolo[3,4-c]pyrazoles by intramolecular nitrilimine cycloaddition

Both substituted 2,4,5,6-tetrahydrocyclopenta[c]pyrazoles and 2,4,5,6-tetrahydropyrrolo[3,4-c]pyrazoles have been synthesized by the 3+2 intramolecular dipolar cycloaddition of nitrilimines to alkynes. This cyclization has been extended to more versatile 3-bromo derivatives by the use of alkynylbromides as dipolarophiles.