高效液相色谱法测定麻黄及其制剂中的麻黄类生物碱和川芎嗪

 用RP HPLC分离测定了麻黄及其制剂中的麻黄类生物碱及川芎嗪。采用色谱柱Nova Pak C18(15 0mm×3.9mmi.d .) ,二极管阵列检测器 (DAD)。测定麻黄类生物碱时 ,以甲醇 0 .0 2mol/LKH2 PO4 乙酸 三乙胺 (体积比为 4∶96∶0 .2∶0 .0 1)为流动相 ,在 2 10nm波长下检测 ;测定川芎嗪时 ,以甲醇 水 乙酸 (体积比为 35∶6 5∶0 .5 )为流动相 ,在 2 90nm波长下检测。分别测定了麻黄原药材、中成药 (小儿清肺丸、鹭鸶咳丸 )中麻黄碱、伪麻黄碱、去甲基麻黄碱、去甲基伪麻黄碱和川芎嗪的含量。     

Identification and Quantification of Hydrocarbon Functional Groups in Gasoline Using 1H-NMR Spectroscopy for Property Prediction

Gasoline is one of the most important distillate fuels obtained from crude refining; it is mainly used as an automotive fuel to propel spark-ignited (SI) engines. It is a complex hydrocarbon fuel that is known to possess several hundred individual molecules of varying sizes and chemical classes. These large numbers of individual molecules can be assembled into a finite set of molecular moieties or functional groups that can independently represent the chemical composition. Identification and quantification of groups enables the prediction of many fuel properties that otherwise may be difficult and expensive to measure experimentally. In the present work, high resolution ¹H nuclear magnetic resonance (NMR) spectroscopy, an advanced structure elucidation technique, was employed for the molecular characterization of a gasoline sample in order to analyze the functional groups. The chemical composition of the gasoline sample was then expressed using six hydrocarbon functional groups, as follows: paraffinic groups (CH, CH₂ and CH₃), naphthenic CH-CH₂ groups and aromatic C-CH groups. The obtained functional groups were then used to predict a number of fuel properties, including research octane number (RON), motor octane number (MON), derived cetane number (DCN), threshold sooting index (TSI) and yield sooting index (YSI).     

1H-NMR spectra of some ditriazolyls and ditriazolyalkanes

Summary The proton magnetic resonance spectra of 12 azoles were measured in neutral and acidic solvents. The protonation shifts observed by comparison of the spectra inDMSO-d ₆ andTFA were attributed to an amidinium type resonance of the resulting cations. The synthesis and characterization of the azoles are also discussed.

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¹H-NMR-Spektren einiger Ditriazolyle und Ditriazolylalkane

Zusammenfassung Es wurden die¹H-NMR-Spektren von 12 Azol-Verbindungen in neutralem (DMSO-d ₆) und azidischem (TFA) Lösungsmittel gemessen und die chemischen Verschiebungswerte verglichen. Der Unterschied beider Werte beruht höchstwahrscheinlich auf einer Amidinium-Typ Resonanz der im azidischen Bereich entstandenen Kationen. Im Rahmen dieser Arbeit wurden 12 Azol-Verbindungen synthetisiert und beschrieben.

     

毛细管电泳/发光二极管诱导荧光法测定麻黄中麻黄碱与伪麻黄碱含量

基于麻黄碱及伪麻黄碱衍生物的光谱及化学性质,设计并构建了毛细管电泳/发光二极管诱导荧光检测系统.对关键光学元件进行组合选择,以蓝光发光二极管为光源,BP 470和BP 530分别为光源滤光片和荧光滤光片,光电倍增管检测信号,并对电泳分离系统的缓冲溶液、分离电压等参数进行优化;以FITC为衍生试剂,10 mmol/L Na2B4O7+ 16 mmol/L SDS为缓冲溶液,12 kV电压下可实现麻黄中麻黄碱和伪麻黄碱的基线分离.在0.25～10 mg/L范围内,麻黄碱和伪麻黄碱标准溶液的质量浓度与荧光响应的峰高之间呈较好的线性关系,相关系数(r)均大于0.99,其检出限分别为0.38 μg/L和0.29 μg/L,峰高的日内重复性(RSD)分别为2.0％和2.2％,日间重复性(RSD)分别为5.4％和5.1％.将该方法用于中药麻黄中麻黄碱和伪麻黄碱的测定,加标回收率分别为94％和107％.     

1H-NMR Metabolomics as a Tool for Winemaking Monitoring

The chemical composition of wine is known to be influenced by multiple factors including some viticulture practices and winemaking processes. ¹H-NMR metabolomics has been successfully applied to the study of wine authenticity. In the present study, ¹H-NMR metabolomics in combination with multivariate analysis was applied to investigate the effects of grape maturity and enzyme and fining treatments on Cabernet Sauvignon wines. A total of forty wine metabolites were quantified. Three different stages of maturity were studied (under-maturity, maturity and over-maturity). Enzyme treatments were carried out using two pectolytic enzymes (E1 and E2). Finally, two proteinaceous fining treatments were compared (vegetable protein, fining F1; pea protein and PVPP, fining F2). The results show a clear difference between the three stages of maturity, with an impact on different classes of metabolites including amino acids, organic acids, sugars, phenolic compounds, alcohols and esters. A clear separation between enzymes E1 and E2 was observed. Both fining agents had a significant effect on metabolite concentrations. The results demonstrate that ¹H-NMR metabolomics provides a fast and robust approach to study the effect of winemaking processes on wine metabolites. These results support the interest to pursue the development of ¹H-NMR metabolomics to investigate the effects of winemaking on wine quality.     

Determination of the stereochemistry of rotenoids by1H-NMR spectroscopy in C6D6

The application of¹H-NMR spectroscopy in C₆D₆ for the determination of configurations at C_12a and C_6a in rotenoids is discussed.

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Bestimmung der Stereochemie von Rotenoiden mittels¹H-NMR-Spektroskopie in C₆D₆

Zusammenfassung Es wird die Anwendung der¹H-NMR-Spektroskopie in C₆D₆ zur Bestimmung der Konfigurationen an C_12a und C_6a in Rotenoiden diskutiert.

     

Metabolite Fingerprinting Using 1H-NMR Spectroscopy and Chemometrics for Classification of Three Curcuma Species from Different Origins

Curcuma longa, Curcuma xanthorrhiza, and Curcuma manga have been widely used for herbal or traditional medicine purposes. It was reported that turmeric plants provided several biological activities such as antioxidant, anti-inflammatory, hepatoprotector, cardioprotector, and anticancer activities. Authentication of the Curcuma species is important to ensure its authenticity and to avoid adulteration practices. Plants from different origins will have different metabolite compositions because metabolites are affected by soil nutrition, climate, temperature, and humidity. ¹H-NMR spectroscopy, principal component analysis (PCA), and orthogonal projections to latent structures-discriminant analysis (OPLS-DA) were used for authentication of C. longa, C. xanthorrhiza, and C. manga from seven different origins in Indonesia. From the ¹H-NMR analysis it was obtained that 14 metabolites were responsible for generating classification model such as curcumin, demethoxycurcumin, alanine, methionine, threonine, lysine, alpha-glucose, beta-glucose, sucrose, alpha-fructose, beta-fructose, fumaric acid, tyrosine, and formate. Both PCA and OPLS-DA model demonstrated goodness of fit (R² value more than 0.8) and good predictivity (Q² value more than 0.45). All OPLS-DA models were validated by assessing the permutation test results with high value of original R² and Q². It can be concluded that metabolite fingerprinting using ¹H-NMR spectroscopy and chemometrics provide a powerful tool for authentication of herbal and medicinal plants.     

1H-NMR Profiling Shows as Specific Constituents Strongly Affect the International EVOO Blends Characteristics: The Case of the Italian Oil

Considering the growing number of extra virgin olive oil (EVOO) producers in the world, knowing the influence of olive oils with different geographical origins on the characteristics of the final blend becomes an interesting goal. The present work is focused on commercial organic EVOO blends obtained by mixing multiple oils from different geographical origins. These blends have been studied by ¹H-NMR spectroscopy supported by multivariate statistical analysis. Specific characteristics of commercial organic EVOO blends originated by mixing oils from Italy, Tunisia, Portugal, Spain, and Greece were found to be associated with the increasing content of the Italian component. A linear progression of the metabolic profile defined characteristics for the analysed samples—up to a plateau level—was found in relation to the content of the main constituent of the Italian oil, the monocultivar Coratina. The Italian constituent percentage appears to be correlated with the fatty acids (oleic) and the polyphenols (tyrosol, hydroxytyrosol, and derivatives) content as major and minor components respectively. These results, which highlight important economic aspects, also show the utility of ¹H-NMR associated with chemometric analysis as a powerful tool in this field. Mixing oils of different national origins, to obtain blends with specific characteristics, could be profitably controlled by this methodology.     

Conversion factors for carbohydrate analysis by hydrolysis and <Superscript>1</Superscript>H-NMR spectroscopy

Conversion factor to calibrate the lower xylan content in carbohydrate compositional analysis in wood by ¹H-NMR spectroscopy was investigated. During acid hydrolysis, xylan monomer was dehydrated as furfural, and that furfural was further degraded or condensed in acidic reaction condition. Anomeric hydrogen peaks integration in ¹H-NMR spectroscopic method excluded xylose reacted products (such as furfural and their condensed or degraded products). Only 52% of xylose was counted in anomeric hydrogen integration and 62% of xylose was counted in integration of furfural peak and anomeric hydrogen. For accurate carbohydrate compositional analysis by NMR spectroscopic method, furfural and their reacted products should be counted as xylose. Conversion factor for xylose content analysis was introduced from the acid hydrolysis of several different combinations of standard cellulose and xylan. In this study xylan conversion factor 0.66 was obtained based on compared NMR data from the prepared cellulose and xylan mixtures acid hydrolyzed with the same condition for woodmeal and pulps. With corrected xylan content calculation, NMR spectroscopic method gave rather closer carbohydrate composition compared to the other analytical methods.     

Volume phase transition and structure of poly(N-isopropylacrylamide) microgels studied with 1H-NMR spectroscopy in D2O

Thermoresponsive colloidal microgels were prepared by polymerisation of N-isopropylacrylamide (NIPAM) with varying concentration of a cross-linking monomer, N,N-methylenebisacrylamide (MBA), in water with either 0.4 or 6.7 mM concentration of an anionic surfactant, sodium dodecylsulphate (SDS). Volume phase transitions of the prepared microgels were studied in D₂O by ¹H-NMR spectroscopy including the measurements of spin–lattice (T1) and spin–spin (T2) relaxation times for the protons of poly(N-isopropylacrylamide) (PNIPAM) at temperature range 22–50 °C. In addition, microcalorimetry, turbidometry, dynamic light scattering and electrophoretic mobility measurements were used to characterise the aqueous microgels. The results from the different characterisation methods indicated that PNIPAM microgels prepared in 6.7 mM SDS concentration are structurally different compared to their correspondences prepared in 0.4 mM concentration. Increasing MBA concentration in the microgel synthesis appears to increase the structural heterogeneity in both cases of SDS concentration. PNIPAM structures with significantly higher molecular mobilities at temperatures above 35 °C were observed in the microgels prepared in 0.4 mM SDS concentration, as indicated by the ¹H NMR relaxation times of different PNIPAM protons. We conclude that the high mobilities measured with NMR at elevated temperatures and also the clearly negative values of zeta potential are in connection to a fairly mobile surface layer with polyelectrolyte nature and a consequent high local lower critical solution temperature.     

A Stability Indicating Proton NMR Spectroscopic Assay Method for Succinylcholine Chloride Injections

Abstract

A simple, accurate, and specific -¹H-NMR spectroscopic method is presented for the assay of succinylcholine chloride injections. After freeze-drying the sample solution, a mixture of the residue with acetamide, serving as the internal standard, is dissolved in deuterium oxide, and the spectrum of the solution is recorded. The quantity of drug in the dosage form is calculated from the integral values for the resonance signals at ca. 2.01 ppm (acetamide) and ca. 3.27 ppm (succinylcholine chloride). The mean ± SD recovery value from synthetic formulations was 99.93 ± 0.60% (n = 10), with a corresponding CV of 0.60%. Assay values for a group of 10 commercial samples ranged from 86.1 to 100.7 (mean = 98.01)% of declared. Injection additives such as methyl paraben and benzyl alcohol did not interfere with the assays. The proposed method will also permit the simultaneous monitoring of the hydrolytic degradation of succinylcholine to its ester components.     

Synthesis and characterisation of Pd(II) complexes with a derivative of aminoazobenzene: Dynamic H-NMR study of cyclopalladation reactions in DMF

Three new Pd(II) complexes, i.e. [PdCl₂L]₂ (A), PdCl₂L₂ (B) and [Pd(μ-Cl)(L-H)]₂ (C), each with two diethyl [α-(4-benzenazoanilino)-2-hydroxybenzyl]phosphonates (L) bound to either one or two palladium atoms, are synthesized and characterized by elemental analysis, by IR, UV-vis and solid-state ¹³C-NMR spectra. Complexes B and C are additionally characterized by ¹H-, ¹³C- and ³¹P-NMR and electrospray mass spectrometry (ESMS) studies using dimethylformamide (DMF) as a solvent. In DMF solution adducts A and B undergo spontaneous rearrangement into the cyclopalladated complex C. Dynamic ¹H-NMR study of this rearrangement as well as of the reactions of L with PdCl₂ and Na₂PdCl₄ revealed a complex equilibrium in DMF solutions and enabled the formation mechanism of all involved species to be resolved. The complex A is immediately solvolyzed producing two molecules of intermediate M [PdCl₂(L)(DMF)]. Complex M was also the first intermediate in the reaction of L with PdCl₂. Once present in concentration above 10⁻⁵ mol dm⁻³M dimerizes very fast into chloro-bridged dimer [PdCl(μ-Cl)(L)]₂ (D) which undergoes cyclopalladation and converts into the complex C. The formation of C from the intermediate D is clearly demonstrated by the concentration dependence of the cyclopalladation reaction which has order greater than one. Chloride ions, released by cyclopalladation, react with D by splitting chloro-bridge and binding to metal atoms to produce byproduct [PdCl₃(L)]⁻ (T). The same species T are formed in the reaction of L with Na₂PdCl₄ whereby a chloride ion is replaced by the ligand L. The complex B undergoes similar, but slower, solvolytic reaction producing M and L while further reaction steps are identical as in the solvolysis of A.     

Zur Struktur der Produkte der Reaktion vonE/Z-1-Benzolsulfonyl-3-(1-pentenyl)-indol mit N-Phenylmaleinimid: Ein erster Beitrag zur Konfigurations- und Konformationsanalyse in der Vinylindol-Cycloadditionsreihe

The products2,3 of the reaction ofE/Z-1-benzenesulfonyl-3-(1-pentenyl)-indole (1) and N-phenylmaleimide were analysed by¹H-NMR spectroscopy. Exemplarily, the structure elucidation of theendo-cyclo-adduct2 b was achieved by using several NMR techniques (diff. NOE-, INDOR-measurements, decoupling experiments, spectra simulation). The¹H-NMR-spectroscopically gained prediction of relative configuration and conformation of2 b was supported on X-ray analysis. The cyclohexene ring of the new cycloadducts adopts in the liquid phase and in the crystal a slightly twisted boat conformation.

     

Metabolomic Approach for Rapid Identification of Antioxidants in Clinacanthus nutans Leaves with Liver Protective Potential

Antioxidants are currently utilized to prevent the occurrence of liver cancer in non-alcoholic fatty liver disease (NAFLD) patients. Clinacanthus nutans possesses anti-oxidative and anti-inflammatory properties that could be an ideal therapy for liver problems. The objective of this study is to determine the potential antioxidative compounds from the C. nutans leaves (CNL) and stems (CNS). Chemical- and cell-based antioxidative assays were utilized to evaluate the bioactivities of CNS and CNL. The NMR metabolomics approach assisted in the identification of contributing phytocompounds. Based on DPPH and ABTS radical scavenging activities, CNL demonstrated stronger radical scavenging potential as compared to CNS. The leaf extract also recorded slightly higher reducing power properties. A HepG2 cell model system was used to investigate the ROS reduction potential of these extracts. It was shown that cells treated with CNL and CNS reduced innate ROS levels as compared to untreated controls. Interestingly, cells pre-treated with both extracts were also able to decrease ROS levels in cells induced with oxidative stress. CNL was again the better antioxidant. According to multivariate data analysis of the ¹H NMR results, the main metabolites postulated to contribute to the antioxidant and hepatoprotective abilities of leaves were clinacoside B, clinacoside C and isoschaftoside, which warrants further investigation.     

D1-Differential Potentiometric and 1H-NMR Spectrometric Determinations of Ketoconazole and its Formulations

Abstract

Two rapid and direct quantitative assays have been investigated for ketoconazole alone and in tablet form. the first one is a non-aqueous potentiometric titration in which the equivalence point has been located graphically using its distinct and sharp D₁differential (peak-shape) potentiograph. the second is based on ₁H-NMR spectrometry and involves the integration of the methyl protons-signal of ketoconazole (at 2.07 δ) relative to that of benzocaine (at 1.30 δ) which is used as internal standard. the obtained results were in good agreement with regard to accuracy, precision as well as sensitivity and reproducibility. However, by comparison with the official USP procedure, the two methods were significantly more accurate and more sensitive. the validity of the two methods were confirmed using the authentic addition technique.     

Inclusion complexation of diclofenac with natural and modified cyclodextrins explored through phase solubility, 1H-NMR and molecular modeling studies

Guest–host interactions were examined for neutral diclofenac (Diclo) and Diclofenac sodium (Diclo sodium) with each of the cyclodextrin (CD) derivatives: α-CD, β-CD, γ-CD and 2-hydroxypropyl-β-cyclodextrin (HP-β-CD), all in 0.05 M aqueous phosphate buffer solution adjusted to 0.2 M ionic strength with NaCl at 20 °C, and with β-CD at different pHs and temperatures. The pH solubility profiles were measured to obtain the acid–base ionization constants (pK _as) for Diclo in the presence and absence of β-CD. Phase solubility diagrams (PSDs) were also measured and analyzed through rigorous procedures to obtain estimates of the complex formation constants for Diclo/CD and Diclo sodium/CD complexation in aqueous solutions. The results indicate that both Diclo and Diclo sodium form soluble 1:1 complexes with α-, β-, and HP-β-CD. In contrast, Diclo forms soluble 1:1 Diclo/γ-CD complexes, while Diclo sodium forms 1:1 and 2:1 Diclo/γ-CD, but the 1:1 complex saturates at 5.8 mM γ-CD with a solubility product constant (pK _sp = 5.5). Therefore, though overall complex stabilities were found to follow the decreasing order: γ-CD > HP-β-CD > β-CD > α-CD, some complex precipitation problems may be faced with aqueous formulations of Diclo sodium with γ-CD, where the overall concentration of the latter exceeds 5.8 mM γ-CD. Both ¹H-NMR spectroscopic and molecular mechanical modeling (MM⁺) studies of Diclo/β-CD indicate the possible formation of soluble isomeric 1:1 complexes in water.     

Polymerization of Bis(Pyridine)bis-(2,4,6-tribromophenoxo)copper(II) Complex (Py2Cu(TBrP)2) by Electrooxidation and Structural Characterization by 1H-NMR, 13C-NMR,and FTIR Spectroscopies

Abstract

Electroinitiated polymerization of bis(2,4,6-tribromophenoxo)- bis(pyridine)copper(II) complex was achieved in dimethylformamide-tetrabutylammonium tetrafluoroborate solvent-electrolyte couple under air or nitrogen at room temperature by constant potential electrolysis. Polymerization conditions were based on the peak potentials measured by cyclic voltammetry. The structural analyses of the polymers were done by ¹H-NMR, ¹³C-NMR, and FTIR spectral analyses along with molecular weight measurements by cryoscopy. The poly(dibromo phenylene oxide)s obtained only at oxidation potentials in either atmosphere were found to be highly linear, indicating mainly 1,4-catenation was taking place.     

The modes of complexation of benzimidazole with aqueous β-cyclodextrin explored by phase solubility, potentiometric titration, 1H-NMR and molecular modeling studies

The results of rigorous modeling of phase solubility diagrams, pH solubility profiles and potentiometric titrations revealed the following for benzimidazole (BZ) and BZ/β-CD complexation in aqueous solution: (a) the pK _a value of BZ estimated at 5.66 ± 0.08 was reduced to 5.33 ± 0.06 in the presence of 15 mM β-CD at 25 °C, thus indicating inclusion complex formation; (b) BZ forms soluble 1:1 and 2:1 BZ/β-CD complexes with complex formation constants K ₁₁ = 104 ± 8 M⁻¹ and K ₂₁ = 16 ± 6 M⁻¹; (c) protonated BZ forms only 1:1 complex with K ₁₁ = 42 ± 12 M⁻¹; (d) ¹H-NMR studies in D₂O showed significant upfield chemical shift displacements for inner cavity β-CD protons indicating inclusion complex formation, while (e) Molecular modeling of BZ-β-CD interactions in water clearly indicated complete inclusion of one BZ molecule into the β-CD cavity.     

Synthesis, characterization and crystal structures of the tetrachlorocuprate and tetrabromocadmate salts of the antimalarial mefloquine

Two new compounds, bis (DL-erythro-α-2-piperydylium-2,8-bis(trifluoromethyl)-4-quinolinemethanol) tetrachlorocuprate(II) tetrahydrate [LH⁺]₂[CuCl₄]^2??4H₂O 1 [L = mefloquine] and bis(DL-erythro-α-2-piperydylium-2,8-bis(trifluoromethyl)-4-quinolinemethanol) tetrabromocadmate (II) bis(methanol) [LH⁺]₂[CdBr₄]^2?·2CH₃OH 2, have been synthesized and characterized by elemental analysis, ¹H-NMR and IR spectroscopy. Single-crystal X-ray diffraction analysis of 1 showed the structure to be ionic with formula unit comprising two protonated monocationic mefloquine molecules of opposite chirality, a tetrachlorocuprate (II) anion and a complement of four water molecules, disordered over several sites. The crystals are orthorhombic, space group Pnma, a = 9.6975(1) Å, b = 29.5385(3) Å, c = 15.9423(1) Å, V = 4566.67(7) ų, Z = 4. The formula unit of compound 2 comprises two protonated monocationic mefloquine molecules, a tetrabromocadmate(II) anion and two molecules of methanol. The crystals are orthorhombic, space group Fdd2, a = 17.2185(5) Å, b = 55.456(2) Å, c = 9.5140(3) Å, V = 9084.6(5) ų, Z = 8. The mefloquine molecule is protonated at the piperidinyl N atom and extensive hydrogen bonding occurs in both crystal structures. The conformation of the mefloquine cation in 1 and 2 is very similar to that recently observed in other salts of the drug, confirming its relevance in the context of antimalarial action.