1
|
Ma X, Li C, Zhang J, Xin J, Mosongo I, Yang J, Hu K. Monosaccharide composition analysis by 2D quantitative gsHSQC i. Carbohydr Res 2024; 541:109168. [PMID: 38833821 DOI: 10.1016/j.carres.2024.109168] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2024] [Revised: 05/13/2024] [Accepted: 05/27/2024] [Indexed: 06/06/2024]
Abstract
The physicochemical properties and biological activities of polysaccharides depend on their structures. Monosaccharide composition analysis is indispensable for the structural characterization of polysaccharides and is helpful in the quality control of polysaccharide preparation. Here, using a model mixture and tamarind seed polysaccharide as examples, we demonstrated that a quantitative 2D NMR method, gsHSQCi (three gradient-selective Heteronuclear Single Quantum Coherence spectra acquired with incremented repetition times, i = 1, 2, 3) can directly quantify a variety of monosaccharides in solution with adequate precision and accuracy, requiring no derivatization, postprocessing steps and column separation. Both anomeric and non-anomeric signals of monosaccharides can be utilized for content determination. More accurate quantification of fructose in a mixture containing nine monosaccharides is obtained, which is difficult to achieve by quantitative 1D 1HNMR and the common PMP-HPLC method (high-performance liquid chromatography through pre-column derivatization with 1-phenyl-3-methyl-5-pyrazolone) due to the peak overlapping and the poor derivatization efficiency, respectively. The results also revealed that Na[Fe(EDTA)] can serve as a proper relaxation-enhancing agent for saccharide samples to save experimental time. We expect that this approach can be applied as an alternative to analyzing the monosaccharide composition and be helpful in interpreting the structure of polysaccharides.
Collapse
Affiliation(s)
- Xiaofang Ma
- State Key Laboratory of Southwestern Chinese Medicine Resources, Chengdu University of Traditional Chinese Medicine, Chengdu, Sichuan, 611137, China; Innovative Institute of Chinese Medicine and Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu, Sichuan, 611137, China.
| | - Caihong Li
- School of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu, Sichuan, 611137, China
| | - Junyin Zhang
- School of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu, Sichuan, 611137, China
| | - Jiang Xin
- School of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu, Sichuan, 611137, China
| | - Isidore Mosongo
- School of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu, Sichuan, 611137, China
| | - Jiahui Yang
- School of Basic Medicine, Chengdu University of Traditional Chinese Medicine, Chengdu, Sichuan, 611137, China.
| | - Kaifeng Hu
- State Key Laboratory of Southwestern Chinese Medicine Resources, Chengdu University of Traditional Chinese Medicine, Chengdu, Sichuan, 611137, China; Innovative Institute of Chinese Medicine and Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu, Sichuan, 611137, China.
| |
Collapse
|
2
|
Simultaneous Determination of the Saponification Value, Acid Value, Ester Value, and Iodine Value in Commercially Available Red Fruit Oil (Pandanus conoideus, Lam.) Using 1H qNMR Spectroscopy. FOOD ANAL METHOD 2022. [DOI: 10.1007/s12161-022-02401-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
AbstractRed fruit oil (RFO) can be extracted from fruits of Pandanus conoideus, Lam., an endogenous plant of Papua, Indonesia. It is a commonly used essential original traditional medicine. By applying a newly developed quantitative 1H NMR (qNMR) spectroscopy method for quality assessment, a simultaneous determination of the saponification value (SV), acid value (AV), ester value (EV), and iodine value (IV) in RFO was possible. Dimethyl sulfone (DMSO2) was used as an internal standard. Optimization of NMR parameters, such as NMR pulse sequence, relaxation delay time, and receiver gain, finally established the 1H NMR-based quantification approach. Diagnostic signals of the internal standard at δ = 2.98 ppm, SV at δ = 2.37–2.20 ppm, AV at δ = 2.27–2.20 ppm, EV at δ = 2.37–2.27 ppm, and IV at δ = 5.37–5.27 ppm, respectively, were used for quantitative analysis. The method was validated concerning linearity (R2 = 0.999), precision (less than 0.83%), and repeatability in the range 99.17–101.17%. Furthermore, this method was successfully applied to crude RFO, crude RFO with palmitic and oleic acid addition, and nine commercial products. The qNMR results for the respective fat values are in accordance with the results of standard methods, as can be seen from the F- and t-test (< 1.65 and < 1.66, respectively). The fundamental advantages of qNMR, such as its rapidity and simplicity, make it a feasible and existing alternative to titration for the quality control of RFO.
Collapse
|
3
|
Multinuclear NMR screening of pharmaceuticals using standardization by 2H integral of a deuterated solvent. J Pharm Biomed Anal 2021; 209:114530. [PMID: 34915326 DOI: 10.1016/j.jpba.2021.114530] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2021] [Revised: 12/05/2021] [Accepted: 12/08/2021] [Indexed: 11/21/2022]
Abstract
NMR standardization approach that uses the 2H integral of deuterated solvent for quantitative multinuclear analysis of pharmaceuticals is described. As a proof of principle, the existing NMR procedure for the analysis of heparin products according to US Pharmacopeia monograph is extended to the determination of Na+ and Cl- content in this matrix. Quantification is performed based on the ratio of a 23Na (35Cl) NMR integral and 2H NMR signal of deuterated solvent, D2O, acquired using the specific spectrometer hardware. As an alternative, the possibility of 133Cs standardization using the addition of Cs2CO3 stock solution is shown. Validation characteristics (linearity, repeatability, sensitivity) are evaluated. A holistic NMR profiling of heparin products can now also be used for the quantitative determination of inorganic compounds in a single analytical run using a single sample. In general, the new standardization methodology provides an appealing alternative for the NMR screening of inorganic and organic components in pharmaceutical products.
Collapse
|
4
|
Krishnamurthy K. Complete Reduction to Amplitude Frequency Table (CRAFT)-A perspective. MAGNETIC RESONANCE IN CHEMISTRY : MRC 2021; 59:757-791. [PMID: 33486830 DOI: 10.1002/mrc.5135] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Revised: 01/19/2021] [Accepted: 01/21/2021] [Indexed: 06/12/2023]
Abstract
The CRAFT (Complete Reduction to Amplitude Frequency Table) technique, based on Bayesian analysis approach, converts FID and/or interferogram (time domain) to a frequency-amplitude table (tabular domain) in a robust, automated, and time-efficient fashion. This mini review/perspective presents an introduction to CRAFT as a processing workflow followed by a discussion of several practical 1D and 2D examples of its applicability and associated benefit. CRAFT provides high quality quantitative results for complex systems without any need for conventional preprocessing steps, such as phase and baseline corrections. Two-dimensional time domain data are typically truncated, particularly in the evolution dimension, and conventional processing after zero-filling and t1max -matched apodization masks potentially available peak resolution. The line broadening introduced by extensive zero-filling and severe apodization functions leads to the lack of clear resolution of cross peaks. CRAFT decimation of interferograms, on the other hand, requires minimal or no apodization prior to extraction of the NMR parameters and significantly improves the spectral linewidth of the cross peaks along F1 dimension compared to conventional (FT) processing. The tabular representation of the CRAFT2d cross peaks information can be visualized in a variety of frequency domain formats for conventional spectral interpretation as well as quantitative applications. A simple workflow to generate in silico oversampled interferogram (iSOS) is presented, and its potential benefit in CRAFT decimation of highly crowded 2D NMR is demonstrated. This report is meant as a collective thesis to present a potentially new paradigm in data processing that questions the need for hitherto unchallenged preprocessing steps, such as phase and baseline correction in 1D and zero-fill/severe apodization in 2D.
Collapse
|
5
|
Zhang N, Li Y, Wen S, Sun Y, Chen J, Gao Y, Sagymbek A, Yu X. Analytical methods for determining the peroxide value of edible oils: A mini-review. Food Chem 2021; 358:129834. [PMID: 33933972 DOI: 10.1016/j.foodchem.2021.129834] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Revised: 04/12/2021] [Accepted: 04/14/2021] [Indexed: 01/06/2023]
Abstract
Edible oils are prone to oxidation during processing and storage that may negatively affect the oil quality and human health. Determining the peroxide value (PV) of edible oils is essential because PV is one of the most typically used quality parameters to monitor lipid oxidation and control oil quality. Many approaches have been developed to determine the PV of oils. Among them, iodometric titration is the commonly used method for PV determination. Considering the limitations related to titrimetric methods, such as time and environmental concerns, several instrumental techniques have been considered as reliable alternatives. The advantages and limitations of classical titration and instrumental methods are summarized in this review. The prospects and reformative aspects for the future applications of these approaches in PV determination are also discussed.
Collapse
Affiliation(s)
- Na Zhang
- College of Food Science and Engineering, Northwest A&F University, 22 Xinong Road Yangling, 712100 Shaanxi, PR China
| | - Yonglin Li
- College of Food Science and Engineering, Northwest A&F University, 22 Xinong Road Yangling, 712100 Shaanxi, PR China
| | - Shasha Wen
- College of Food Science and Engineering, Northwest A&F University, 22 Xinong Road Yangling, 712100 Shaanxi, PR China
| | - Yiwen Sun
- College of Food Science and Engineering, Northwest A&F University, 22 Xinong Road Yangling, 712100 Shaanxi, PR China
| | - Jia Chen
- College of Food Science and Engineering, Northwest A&F University, 22 Xinong Road Yangling, 712100 Shaanxi, PR China
| | - Yuan Gao
- College of Food Science and Engineering, Northwest A&F University, 22 Xinong Road Yangling, 712100 Shaanxi, PR China
| | - Altayuly Sagymbek
- S.Seifullin Kazakh Agro Technical University, 62 Zhenis Avenue, 010011, 14 Nur-Sultan, Kazakhstan
| | - Xiuzhu Yu
- College of Food Science and Engineering, Northwest A&F University, 22 Xinong Road Yangling, 712100 Shaanxi, PR China.
| |
Collapse
|
6
|
Monakhova YB, Diehl BWK. Novel approach of qNMR workflow by standardization using 2H integral: Application to any intrinsic calibration standard. Talanta 2021; 222:121504. [PMID: 33167217 DOI: 10.1016/j.talanta.2020.121504] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2020] [Revised: 07/30/2020] [Accepted: 08/03/2020] [Indexed: 12/23/2022]
Abstract
Quantitative nuclear magnetic resonance (qNMR) is routinely performed by the internal or external standardization. The manuscript describes a simple alternative to these common workflows by using NMR signal of another active nuclei of calibration compound. For example, for any arbitrary compound quantification by NMR can be based on the use of an indirect concentration referencing that relies on a solvent having both 1H and 2H signals. To perform high-quality quantification, the deuteration level of the utilized deuterated solvent has to be estimated. In this contribution the new method was applied to the determination of deuteration levels in different deuterated solvents (MeOD, ACN, CDCl3, acetone, benzene, DMSO-d6). Isopropanol-d6, which contains a defined number of deuterons and protons, was used for standardization. Validation characteristics (precision, accuracy, robustness) were calculated and the results showed that the method can be used in routine practice. Uncertainty budget was also evaluated. In general, this novel approach, using standardization by 2H integral, benefits from reduced sample preparation steps and uncertainties, and can be applied in different application areas (purity determination, forensics, pharmaceutical analysis, etc.).
Collapse
Affiliation(s)
- Yulia B Monakhova
- Spectral Service AG, Emil-Hoffmann-Straße 33, 50996, Köln, Germany; Institute of Chemistry, Saratov State University, Astrakhanskaya Street 83, 410012, Saratov, Russia
| | - Bernd W K Diehl
- Spectral Service AG, Emil-Hoffmann-Straße 33, 50996, Köln, Germany.
| |
Collapse
|
7
|
A validated 1H-NMR method for quantitative analysis of DOTAP lipid in nanoliposomes containing soluble Leishmania antigen. J Pharm Biomed Anal 2020; 194:113809. [PMID: 33293176 DOI: 10.1016/j.jpba.2020.113809] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Revised: 11/25/2020] [Accepted: 11/25/2020] [Indexed: 01/29/2023]
Abstract
Leishmaniasis is a serious health problem that needs a suitable vaccine delivery system to control the disease. Cationic lipids such as 1, 2-dioleoyl-3-trimethylammonium-propane (DOTAP) have been widely used in nanoliposomes' formulation to deliver antigen and adjuvant at the same time to induce protection against Leishmaniasis. Therefore, it is necessary to accurately quantify DOTAP concentration in the formulation and biological materials. Due to the poor UV absorbance of DOTAP, the use of the conventional HPLC-UV method was impossible. Currently, an evaporative light scattering detector (ELSD) or MS/MS detector in conjunction with HPLC is used to quantify DOTAP. These methods have several disadvantages, including time- consuming during extraction procedure and decrease or/and even remove some components of the formulation. According to the advantages of the quantitative 1H Nuclear Magnetic Resonance (1H-NMR) spectroscopic method, a free extraction approach was developed to the assay of DOTAP in nanoliposomes containing Leishmania antigens. This method was carried out based on the relative ratio of signal integration of DOTAP [CH2 (CH2-CH = CH-CH2)] in δ 2 ppm to a definite amount of an internal standard called dimethyl sulfone (DMSO2). The q1H-NMR method showed good precision (intra-day RSD = 1.8 % and inter-day RSD = 2.5 %), linearity (in the ranges of 1.3-7.8 mg. mL-1 with correlation coefficients at 1), repeatability (RSD ≤ 2.39 %), and stability (RSD ≤ 2.32 %) for the quantification of the DOTAP without any extraction method. Considering all the experiments conducted in this study, NMR can be a feasible alternative to other traditional techniques for the simultaneous quantification of lipids in liposome formulations.
Collapse
|
8
|
Garrido R, Baró B, Soubal JP, Santana D. Quantitative assessment of C-polysaccharide in capsular polysaccharides of Streptococcus pneumoniae by 31PNMR. J Pharm Biomed Anal 2020; 192:113670. [PMID: 33080557 DOI: 10.1016/j.jpba.2020.113670] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Revised: 09/29/2020] [Accepted: 09/30/2020] [Indexed: 11/25/2022]
Abstract
Capsular polysaccharides of Streptococcus pneumoniae are key components of commercially available anti-pneumococcal vaccines; meanwhile C-polysaccharide is considered an impurity. World Health Organization recommends a strict control over the presence of this biomolecule due to the possibility of introducing an undesired response. An alternative way for assessing this impurity is focused on detect the phosphocholine residues by means of quantitative 1H-NMR. This could be tricky due to the amounts of this substituent may vary generating two C-polysaccharides forms. In this work we propose an improved quantitative NMR methodology based on 31P-NMR for the quantification of C-polysaccharide on capsular polysaccharide preparations. The technique also focuses on phosphocholine but, conversely to above-mentioned methods, allows to discriminate between phosphocholine linked in different positions. The methodology was run on samples of eleven vaccine serotypes, including seven with phosphate groups. From a rational acceptance criterion of 10 wt%, the method allows to quantified from 30 μg of the impurity in 3 mg of total polysaccharide (1 wt%) with a signal/noise ratio of 16:1. Repeatability and intermediate precision evaluation showed a relative standard deviation of 3.33 % and 8.34 % respectively. Additionally, the method provides information about structural identity of phosphate contained in capsular polysaccharides and C-polysaccharide species. This constitutes a new contribution from the NMR that highlights the power of these techniques for assessing imperative parameters in carbohydrate-based vaccines.
Collapse
|
9
|
Nesměrák K, Pospíchal R. Spectrometric methods in pharmaceutical analysis of glycosaminoglycans: the state-of-the-art. MONATSHEFTE FUR CHEMIE 2020. [DOI: 10.1007/s00706-020-02632-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
|
10
|
Diehl B, Holzgrabe U, Monakhova Y, Schönberger T. Quo Vadis qNMR? J Pharm Biomed Anal 2019; 177:112847. [PMID: 31505431 DOI: 10.1016/j.jpba.2019.112847] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Revised: 08/27/2019] [Accepted: 08/28/2019] [Indexed: 01/11/2023]
Abstract
The quantification of a drug, its impurities, and e.g. components of a mixture has become routine in NMR laboratories and many applications have been described in the literature. However, besides simply using 1D 1H or 13C NMR, a number of more advanced methods has been developed and used in the past. Here, we want to describe the applicability of nuclei beyond the classical ones 1H and 13C. Mixtures can be characterized much better by applying various chemometric methods and separating the signals of mixture components can be achieved by DOSY experiments. All these methods contribute to the platform of qNMR methods and extend the possibilities of NMR for quantification and quality evaluation of drugs, excipients, polymers, and plant extracts. However, for quantification purposes, validation is always an issue and it is necessary to think about taking NMR related measures which might be different from the ones considered for chromatographic methods.
Collapse
Affiliation(s)
- Bernd Diehl
- Spectral Service AG, Emil-Hoffmann-Str. 33, 50996, Cologne, Germany
| | - Ulrike Holzgrabe
- Institute of Pharmacy, University of Wuerzburg, Am Hubland, 97074, Wuerzburg, Germany.
| | - Yulia Monakhova
- Spectral Service AG, Emil-Hoffmann-Str. 33, 50996, Cologne, Germany; Institute of Chemistry, Saratov State University, Astrakhanskaya Street 83, 410012, Saratov, Russia; Institute of Chemistry, Saint Petersburg State University, 13B Universitetskaya Emb., St Petersburg, 199034, Russia
| | - Torsten Schönberger
- Bundeskriminalamt, Forensic Science Institute, KT43 - Central Analytics II, 65173 Wiesbaden, Germany
| |
Collapse
|
11
|
A feasible and practical 1H NMR analytical method for the quality control and quantification of bioactive principles in Lycii Fructus. J Food Drug Anal 2018; 26:1105-1112. [PMID: 29976403 PMCID: PMC9303018 DOI: 10.1016/j.jfda.2018.01.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2017] [Revised: 12/26/2017] [Accepted: 01/04/2018] [Indexed: 11/20/2022] Open
Abstract
Lycii Fructus, a solanaceous drug, is widely used as functional foods and in Traditional Chinese Medicine. Samples collected from different regions of China have been found to be not identical in chemical compositions which might affect the biological activities. Although many chromatographic and spectrometric methods have been reported to determine the concentration of betaine and other bioactive amino acids, disturbance resulted from other polar substances with low UV-absorbance and expensive mass facilities reduced the applicability of these techniques. In the present study, the strong cation exchange solid phase extraction procedure incorporated with 1H NMR was successfully developed as a rapid and reliable method that can simultaneously determine betaine, citric acid, threonine, alanine, and proline in various Lycii Fructus. In addition, ERETIC 2 method based on PULCON principle was also applied and compared with conventional method. This feasible and practical method offers a very powerful tool for the quality control of commercial Lycii Fructus from different sources.
Collapse
|
12
|
Garrido R, Soubal JP, Torres L, Ramírez U, Vérez V. NMR line-fitting quantification of polysaccharide N-acylurea-based modification in glycoconjugates of Salmonella Typhi Vi polysaccharide. MAGNETIC RESONANCE IN CHEMISTRY : MRC 2017; 55:720-723. [PMID: 28087987 DOI: 10.1002/mrc.4579] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2016] [Revised: 01/10/2017] [Accepted: 01/11/2017] [Indexed: 06/06/2023]
Abstract
The polysaccharides modification via carbodiimide reaction is one of the most applied methods for obtaining conjugated vaccines against Salmonella enterica. However, N-acylurea carbodiimide adduct generated in the process is a critical impurity in carbohydrate-based vaccines. A quantitative NMR method was developed for assessing the N-acylurea carbodiimide adduct impurity. The procedure was based on line-fitting facilities for processing the NMR signals on complex spectra. The method showed good linearity, accuracy and precision under inter-operator variation (relative standard deviation <5%). Copyright © 2017 John Wiley & Sons, Ltd.
Collapse
Affiliation(s)
- Raine Garrido
- Finlay Institute of Vaccines, Ave 27, No. 19805, La Lisa 17100, Havana, Cuba
| | - Jean Pierre Soubal
- Finlay Institute of Vaccines, Ave 27, No. 19805, La Lisa 17100, Havana, Cuba
| | - Leonid Torres
- Finlay Institute of Vaccines, Ave 27, No. 19805, La Lisa 17100, Havana, Cuba
| | - Ubel Ramírez
- Finlay Institute of Vaccines, Ave 27, No. 19805, La Lisa 17100, Havana, Cuba
| | - Vicente Vérez
- Finlay Institute of Vaccines, Ave 27, No. 19805, La Lisa 17100, Havana, Cuba
| |
Collapse
|
13
|
Begnaud F, Chaintreau A. Good quantification practices of flavours and fragrances by mass spectrometry. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2016; 374:rsta.2015.0365. [PMID: 27644977 PMCID: PMC5031632 DOI: 10.1098/rsta.2015.0365] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Accepted: 07/06/2016] [Indexed: 06/06/2023]
Abstract
Over the past 15 years, chromatographic techniques with mass spectrometric detection have been increasingly used to monitor the rapidly expanded list of regulated flavour and fragrance ingredients. This trend entails a need for good quantification practices suitable for complex media, especially for multi-analytes. In this article, we present experimental precautions needed to perform the analyses and ways to process the data according to the most recent approaches. This notably includes the identification of analytes during their quantification and method validation, when applied to real matrices, based on accuracy profiles. A brief survey of application studies based on such practices is given.This article is part of the themed issue 'Quantitative mass spectrometry'.
Collapse
Affiliation(s)
- Frédéric Begnaud
- Firmenich SA, Corporate R&D Division, Route des Jeunes 1, CH-1211 Geneva 8, Switzerland
| | - Alain Chaintreau
- Firmenich SA, Corporate R&D Division, Route des Jeunes 1, CH-1211 Geneva 8, Switzerland
| |
Collapse
|
14
|
Schoenberger T, Menges S, Bernstein MA, Pérez M, Seoane F, Sýkora S, Cobas C. Improving the Performance of High-Precision qNMR Measurements by a Double Integration Procedure in Practical Cases. Anal Chem 2016; 88:3836-43. [PMID: 26927683 DOI: 10.1021/acs.analchem.5b04911] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Quantitative (1)H NMR (qNMR) is a widely applied technique for compound concentration and purity determinations. The NMR spectrum will display signals from all species in the sample, and this is generally a strength of the method. The key spectral determination is the full and accurate determination of one or more signal areas. Accurate peak integration can be an issue when unrelated peaks resonate in an important integral region. We describe a "hybrid" approach to signal integration that provides an accurate estimation of signal area, removing the component(s) that may arise from unrelated peaks. This is achieved by using the most accurate integration method for the region and removing unwanted contributions. The key to this performing well, and in almost all cases, is the use of areas from deconvolved peaks. We describe this process and show that it can be very successfully applied to cases where the highest precision is required and for more common cases of NMR-based quantitation.
Collapse
Affiliation(s)
| | - Sonja Menges
- Bundeskriminalamt-KT12 , 65173, Wiesbaden, Germany
| | - Michael A Bernstein
- Mestrelab Research , S.L Feliciano Barrera 9B-Baixo, 15706 Santiago de Compostela, Spain
| | - Manuel Pérez
- Mestrelab Research , S.L Feliciano Barrera 9B-Baixo, 15706 Santiago de Compostela, Spain
| | - Felipe Seoane
- Mestrelab Research , S.L Feliciano Barrera 9B-Baixo, 15706 Santiago de Compostela, Spain
| | - Stanislav Sýkora
- Extra Byte , Via Raffaello Sanzio 22C, Castano Primo I-20022, Italy
| | - Carlos Cobas
- Mestrelab Research , S.L Feliciano Barrera 9B-Baixo, 15706 Santiago de Compostela, Spain
| |
Collapse
|
15
|
Jia CH, Wang XY, Qi JF, Hong ST, Lee KT. Antioxidant Properties of Caffeic acid Phenethyl Ester and 4-Vinylcatechol in Stripped Soybean Oil. J Food Sci 2015; 81:C35-41. [PMID: 26641978 DOI: 10.1111/1750-3841.13160] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2015] [Accepted: 10/22/2015] [Indexed: 01/22/2023]
Abstract
Caffeic acid was used to synthesize 4-vinylcatechol (4-VC) by thermal decarboxylation and to prepare caffeic acid phenethyl ester (CAPE) by esterification reaction. The identities of synthesized products were confirmed by (1)H NMR. Antioxidative activities of 4-VC and CAPE were compared with α-tocopherol and BHT in stripped soybean oil at 60 °C under the dark. To evaluate the degrees of oxidation at different concentrations and combinations, peroxide value (PV) and (1)H NMR were performed. From the results of PV, the formation of primary oxidation products (i.e., hydroperoxides) in stripped soybean oil containing 200 ppm CAPE was the slowest. The relative oxidation degree of 200 ppm CAPE (9.5%) was lower than other samples on 9 d. Similar results were obtained by (1)H NMR analysis. After 15 d of storage, levels of conjugated diene forms and aldehydes of 200 ppm CAPE sample (57.3 and 0.9 mmol/mol oil) were also lower than other treatments. In addition, 4-VC and α-tocopherol were found to have a synergistic antioxidant effect.
Collapse
Affiliation(s)
- Cai-Hua Jia
- Dept. of Food Science and Technology, Chungnam National Univ, Daejeon 305-764, Republic of Korea
| | - Xiang-Yu Wang
- Dept. of Food Science and Technology, Chungnam National Univ, Daejeon 305-764, Republic of Korea
| | - Jin-Feng Qi
- Dept. of Food Science and Technology, Chungnam National Univ, Daejeon 305-764, Republic of Korea
| | - Soon-Taek Hong
- Dept. of Food Science and Technology, Chungnam National Univ, Daejeon 305-764, Republic of Korea
| | - Ki-Teak Lee
- Dept. of Food Science and Technology, Chungnam National Univ, Daejeon 305-764, Republic of Korea
| |
Collapse
|
16
|
Parsha S, Kumar YR, Ravichander M. LC–MS/MS and NMR Characterization of Key Impurities in Linagliptin and Pramipexole. J LIQ CHROMATOGR R T 2015. [DOI: 10.1080/10826076.2015.1087861] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
- Swetha Parsha
- Department of Analytical Research and Development, Integrated Product Development, Dr. Reddy’s Laboratories, Hyderabad, India
- Department of Chemistry, Jawaharlal Nehru Technological University, Hyderabad, India
| | - Y. Ravindra Kumar
- Department of Analytical Research and Development, Integrated Product Development, Dr. Reddy’s Laboratories, Hyderabad, India
| | - M. Ravichander
- Department of Chemistry, Mahatma Gandhi Institute of Technology, Hyderabad, India
| |
Collapse
|
17
|
Effect of Positional Distribution of Linoleic Acid on Oxidative Stability of Triacylglycerol Molecules Determined by 1H NMR. J AM OIL CHEM SOC 2015. [DOI: 10.1007/s11746-015-2590-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
|
18
|
Le Gresley A, Fardus F, Warren J. Bias and Uncertainty in Non-Ideal qNMR Analysis. Crit Rev Anal Chem 2014; 45:300-10. [DOI: 10.1080/10408347.2014.944971] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
|
19
|
Pauli GF, Chen SN, Simmler C, Lankin DC, Gödecke T, Jaki BU, Friesen JB, McAlpine JB, Napolitano JG. Importance of purity evaluation and the potential of quantitative ¹H NMR as a purity assay. J Med Chem 2014; 57:9220-31. [PMID: 25295852 PMCID: PMC4255677 DOI: 10.1021/jm500734a] [Citation(s) in RCA: 249] [Impact Index Per Article: 24.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
![]()
In any biomedical and chemical context,
a truthful description of chemical constitution requires coverage
of both structure and purity. This qualification affects all drug
molecules, regardless of development stage (early discovery to approved
drug) and source (natural product or synthetic). Purity assessment
is particularly critical in discovery programs and whenever
chemistry is linked with biological and/or therapeutic outcome. Compared
with chromatography and elemental analysis, quantitative NMR (qNMR)
uses nearly universal detection and provides a versatile and orthogonal
means of purity evaluation. Absolute qNMR with flexible calibration
captures analytes that frequently escape detection (water, sorbents).
Widely accepted structural NMR workflows require minimal or no adjustments
to become practical 1H qNMR (qHNMR) procedures with simultaneous
qualitative and (absolute) quantitative capability. This study reviews
underlying concepts, provides a framework for standard qHNMR purity
assays, and shows how adequate accuracy and precision are achieved
for the intended use of the material.
Collapse
Affiliation(s)
- Guido F Pauli
- Department of Medicinal Chemistry and Pharmacognosy and ‡Institute for Tuberculosis Research, College of Pharmacy, University of Illinois at Chicago , 833 S. Wood Street, Chicago, Illinois 60612, United States
| | | | | | | | | | | | | | | | | |
Collapse
|
20
|
Giraudeau P. Quantitative 2D liquid-state NMR. MAGNETIC RESONANCE IN CHEMISTRY : MRC 2014; 52:259-272. [PMID: 24700689 DOI: 10.1002/mrc.4068] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2014] [Revised: 03/07/2014] [Accepted: 03/07/2014] [Indexed: 06/03/2023]
Abstract
Two-dimensional (2D) liquid-state NMR has a very high potential to simultaneously determine the absolute concentration of small molecules in complex mixtures, thanks to its capacity to separate overlapping resonances. However, it suffers from two main drawbacks that probably explain its relatively late development. First, the 2D NMR signal is strongly molecule-dependent and site-dependent; second, the long duration of 2D NMR experiments prevents its general use for high-throughput quantitative applications and affects its quantitative performance. Fortunately, the last 10 years has witnessed an increasing number of contributions where quantitative approaches based on 2D NMR were developed and applied to solve real analytical issues. This review aims at presenting these recent efforts to reach a high trueness and precision in quantitative measurements by 2D NMR. After highlighting the interest of 2D NMR for quantitative analysis, the different strategies to determine the absolute concentrations from 2D NMR spectra are described and illustrated by recent applications. The last part of the manuscript concerns the recent development of fast quantitative 2D NMR approaches, aiming at reducing the experiment duration while preserving - or even increasing - the analytical performance. We hope that this comprehensive review will help readers to apprehend the current landscape of quantitative 2D NMR, as well as the perspectives that may arise from it.
Collapse
Affiliation(s)
- Patrick Giraudeau
- EBSI Team, Chimie et Interdisciplinarité: Synthèse, Analyse, Modélisation (CEISAM), Université de Nantes, CNRS, UMR 6230, LUNAM Université, 2 rue de la Houssinière, B.P. 92208, 44322, Nantes Cedex 03, France
| |
Collapse
|
21
|
Holzgrabe U, Malet-Martino M. NMR spectroscopy in pharmaceutical and biomedical analysis. J Pharm Biomed Anal 2014; 93:1-2. [DOI: 10.1016/j.jpba.2014.04.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
|
22
|
Giraudeau P, Tea I, Remaud GS, Akoka S. Reference and normalization methods: Essential tools for the intercomparison of NMR spectra. J Pharm Biomed Anal 2014; 93:3-16. [DOI: 10.1016/j.jpba.2013.07.020] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2013] [Revised: 07/12/2013] [Accepted: 07/15/2013] [Indexed: 12/17/2022]
|
23
|
Maggio RM, Calvo NL, Vignaduzzo SE, Kaufman TS. Pharmaceutical impurities and degradation products: uses and applications of NMR techniques. J Pharm Biomed Anal 2014; 101:102-22. [PMID: 24853620 DOI: 10.1016/j.jpba.2014.04.016] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2014] [Revised: 04/11/2014] [Accepted: 04/12/2014] [Indexed: 11/29/2022]
Abstract
Current standards and regulations demand the pharmaceutical industry not only to produce highly pure drug substances, but to achieve a thorough understanding of the impurities accompanying their manufactured drug substances and products. These challenges have become important goals of process chemistry and have steadily stimulated the search of impurities after accelerated or forced degradation procedures. As a result, impurity profiling is one of the most attractive, active and relevant fields of modern pharmaceutical analysis. This activity includes the identification, structural elucidation and quantitative determination of impurities and degradation products in bulk drugs and their pharmaceutical formulations. Nuclear magnetic resonance (NMR) spectroscopy has evolved into an irreplaceable approach for pharmaceutical quality assessment, currently playing a critical role in unequivocal structure identification as well as structural confirmation (qualitative detection), enabling the understanding of the underlying mechanisms of the formation of process and/or degradation impurities. NMR is able to provide qualitative information without the need of standards of the unknown compounds and multiple components can be quantified in a complex sample without previous separation. When coupled to separative techniques, the resulting hyphenated methodologies enhance the analytical power of this spectroscopy to previously unknown levels. As a result, and by enabling the implementation of rational decisions regarding the identity and level of impurities, NMR contributes to the goal of making better and safer medicines. Herein are discussed the applications of NMR spectroscopy and its hyphenated derivate techniques to the study of a wide range pharmaceutical impurities. Details on the advantages and disadvantages of the methodology and well as specific challenges with regards to the different analytical problems are also presented.
Collapse
Affiliation(s)
- Rubén M Maggio
- Instituto de Química Rosario (IQUIR, CONICET-UNR) and Área Análisis de Medicamentos, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Suipacha 531, Rosario S2002LRK, Argentina
| | - Natalia L Calvo
- Instituto de Química Rosario (IQUIR, CONICET-UNR) and Área Análisis de Medicamentos, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Suipacha 531, Rosario S2002LRK, Argentina
| | - Silvana E Vignaduzzo
- Instituto de Química Rosario (IQUIR, CONICET-UNR) and Área Análisis de Medicamentos, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Suipacha 531, Rosario S2002LRK, Argentina
| | - Teodoro S Kaufman
- Instituto de Química Rosario (IQUIR, CONICET-UNR) and Área Análisis de Medicamentos, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Suipacha 531, Rosario S2002LRK, Argentina.
| |
Collapse
|
24
|
Affiliation(s)
- Vitor H. Pomin
- Program of
Glycobiology, Institute of Medical Biochemistry,
and University Hospital Clementino Fraga Filho, Federal University of Rio de Janeiro, Rio de Janeiro, 21941-913,
Brazil
| |
Collapse
|
25
|
Skiera C, Steliopoulos P, Kuballa T, Diehl B, Holzgrabe U. Determination of free fatty acids in pharmaceutical lipids by ¹H NMR and comparison with the classical acid value. J Pharm Biomed Anal 2013; 93:43-50. [PMID: 23664852 DOI: 10.1016/j.jpba.2013.04.010] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2013] [Revised: 04/08/2013] [Accepted: 04/10/2013] [Indexed: 10/26/2022]
Abstract
Indices like acid value, peroxide value, and saponification value play an important role in quality control and identification of lipids. Requirements on these parameters are given by the monographs of the European pharmacopeia. (1)H NMR spectroscopy provides a fast and simple alternative to these classical approaches. In the present work a new (1)H NMR approach to determine the acid value is described. The method was validated using a statistical approach based on a variance components model. The performance under repeatability and in-house reproducibility conditions was assessed. We applied this (1)H NMR assay to a wide range of different fatty oils. A total of 305 oil and fat samples were examined by both the classical and the NMR method. Except for hard fat, the data obtained by the two methods were in good agreement. The (1)H NMR method was adapted to analyse waxes and oleyloleat. Furthermore, the effect of solvent and in the case of castor oil the effect of the oil matrix on line broadening and chemical shift of the carboxyl group signal are discussed.
Collapse
Affiliation(s)
- Christina Skiera
- Institute of Pharmacy and Food Chemistry, University of Würzburg, Am Hubland, 97074 Würzburg, Germany; Chemisches und Veterinäruntersuchungsamt Karlsruhe, Weißenburger Str. 3, 76187 Karlsruhe, Germany.
| | - Panagiotis Steliopoulos
- Chemisches und Veterinäruntersuchungsamt Karlsruhe, Weißenburger Str. 3, 76187 Karlsruhe, Germany
| | - Thomas Kuballa
- Chemisches und Veterinäruntersuchungsamt Karlsruhe, Weißenburger Str. 3, 76187 Karlsruhe, Germany
| | - Bernd Diehl
- Spectral Service, Emil-Hoffmann-Str. 33, 50996 Köln, Germany
| | - Ulrike Holzgrabe
- Institute of Pharmacy and Food Chemistry, University of Würzburg, Am Hubland, 97074 Würzburg, Germany
| |
Collapse
|
26
|
Volpi N, Maccari F, Suwan J, Linhardt RJ. Electrophoresis for the analysis of heparin purity and quality. Electrophoresis 2012; 33:1531-7. [PMID: 22736353 DOI: 10.1002/elps.201100479] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The adulteration of raw heparin with oversulfated chondroitin sulfate (OSCS) in 2007-2008 produced a global crisis resulting in extensive revisions to the pharmacopeia monographs and prompting the FDA to recommend the development of additional methods for the analysis of heparin purity. As a consequence, a wide variety of innovative analytical approaches have been developed for the quality assurance and purity of unfractionated and low-molecular-weight heparins. This review discusses recent developments in electrophoresis techniques available for the sensitive separation, detection, and partial structural characterization of heparin contaminants. In particular, this review summarizes recent publications on heparin quality and related impurity analysis using electrophoretic separations such as capillary electrophoresis (CE) of intact polysaccharides and hexosamines derived from their acidic hydrolysis, and polyacrylamide gel electrophoresis (PAGE) for the separation of heparin samples without and in the presence of its relatively specific depolymerization process with nitrous acid treatment.
Collapse
Affiliation(s)
- Nicola Volpi
- Department of Biology, University of Modena and Reggio Emilia, Italy.
| | | | | | | |
Collapse
|
27
|
|
28
|
Garrido Arteaga R, Cardoso San Jorge F, Rodríguez Montero MDC, Fernández Santana V, Vérez Bencomo V, Vélez Castro H. Quantitative proton magnetic resonance determination of N,N-dimethylformamide in one intermediate of the Quimi-Hib vaccine. MAGNETIC RESONANCE IN CHEMISTRY : MRC 2012; 50:525-528. [PMID: 22730256 DOI: 10.1002/mrc.3831] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2012] [Revised: 05/15/2012] [Accepted: 05/18/2012] [Indexed: 06/01/2023]
Abstract
Quimi-Hib is a conjugate vaccine against Haemophilus influenza type b (Hib) where the Hib antigen is the only one produced by chemical synthesis. NMR has become the alternative of choice for the identity of intermediates during the chemical synthesis of Hib antigen. We explore a rapid quantitative proton magnetic resonance (qHNMR) assay for the determination of N,N-dimethylformamide (DMF) as a residual in one of the critical intermediates. The proposed assay has been shown to be accurate, precise for intermediate precision conditions (relative standard deviation <3% for spectrometer-to-spectrometer variations), specific (no detected interferences), and rugged (percentage difference <3% for day-to-day and spectrometer-to-spectrometer variations). The quantitative NMR assay can replace the common chromatographic methods for monitoring the DMF contents in one crucial step of the synthetic scheme.
Collapse
Affiliation(s)
- Raine Garrido Arteaga
- Center of Biomolecular Chemistry, 200 Street and 21 Ave. Atabey, Playa, La Habana, Cuba 11600.
| | | | | | | | | | | |
Collapse
|
29
|
Quantitative proton nuclear magnetic resonance evaluation and total assignment of the capsular polysaccharide Neisseria meningitidis serogroup X. J Pharm Biomed Anal 2012; 70:295-300. [PMID: 22877873 DOI: 10.1016/j.jpba.2012.07.014] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2012] [Revised: 06/25/2012] [Accepted: 07/15/2012] [Indexed: 11/24/2022]
Abstract
Neisseria meningitidis constitutes the main cause of meningococcal disease in infants. Serogroups A, B, C, W135, Y, and X have the higher incidence in young children and teenagers. The use of polyvalent conjugate carbohydrate-based vaccines has decreased the meningococcal infection around the world. Recently, the serogroup X has been found to be responsible of different outbreaks of meningococcal diseases, mainly in "Meningitis Belt" of Africa and the structure of the repetitive unit of the capsular polysaccharide has been confirmed through a monodimensional (13)C NMR study. No further characterization studies have been carried out, especially with the use of other nuclei. In this paper a novel method for quantification of the N. meningitidis serogroup X by proton qNMR is reported. Deep characterization of the serogroup X polysaccharide was also carried out by combination of correlation experiments involving (13)C, (1)H, and (31)P nuclei.
Collapse
|
30
|
Salinero C, Feás X, Mansilla JP, Seijas JA, Vázquez-Tato MP, Vela P, Sainz MJ. ¹H-nuclear magnetic resonance analysis of the triacylglyceride composition of cold-pressed oil from Camellia japonica. Molecules 2012; 17:6716-27. [PMID: 22664463 PMCID: PMC6268380 DOI: 10.3390/molecules17066716] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2012] [Revised: 05/23/2012] [Accepted: 05/28/2012] [Indexed: 11/28/2022] Open
Abstract
Camellia japonica (CJ) has oil-rich seeds, but the study of these oils has received little attention and has mainly focused only on their health properties. In the present work the relative composition of the fatty acid (FA) components of the triglycerides in cold-pressed oil from CJ is studied by ¹H-NMR. The results obtained were: 75.75%, 6.0%, 0.17% and 18.67%, for oleic, linoleic, linolenic and saturated FA respectively. Levels of C₁₈ unsaturated FA found in CJ oil were similar to those reported for olive oils. We also checked the possibility of using ¹³C-NMR spectroscopy; however, the results confirmed the drawback of ¹³C over ¹H-NMR for the study of FA components of CJ triglycerides due to its low gyromagnetic ratio and its very low natural abundance.
Collapse
Affiliation(s)
- Carmen Salinero
- Areeiro Phytopathological Station, Pontevedra Deputation, Subida a la Robleda s/n., E36153 Pontevedra, Spain; (C.S.); (J.P.M.); (P.V.)
| | - Xesús Feás
- Department of Organic Chemistry, Faculty of Science, University of Santiago de Compostela, E27002 Lugo, Spain; (X.F.); (M.P.V.-T.)
| | - J. Pedro Mansilla
- Areeiro Phytopathological Station, Pontevedra Deputation, Subida a la Robleda s/n., E36153 Pontevedra, Spain; (C.S.); (J.P.M.); (P.V.)
| | - Julio A. Seijas
- Department of Organic Chemistry, Faculty of Science, University of Santiago de Compostela, E27002 Lugo, Spain; (X.F.); (M.P.V.-T.)
| | - M. Pilar Vázquez-Tato
- Department of Organic Chemistry, Faculty of Science, University of Santiago de Compostela, E27002 Lugo, Spain; (X.F.); (M.P.V.-T.)
| | - Pilar Vela
- Areeiro Phytopathological Station, Pontevedra Deputation, Subida a la Robleda s/n., E36153 Pontevedra, Spain; (C.S.); (J.P.M.); (P.V.)
| | - María J. Sainz
- Department of Plant Production, University of Santiago de Compostela, E27002 Lugo, Spain;
| |
Collapse
|
31
|
Fernandes JLN, de Souza ROMA, de Vasconcellos Azeredo RB. 13C NMR quantification of mono and diacylglycerols obtained through the solvent-free lipase-catalyzed esterification of saturated fatty acids. MAGNETIC RESONANCE IN CHEMISTRY : MRC 2012; 50:424-428. [PMID: 22539418 DOI: 10.1002/mrc.3814] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2011] [Revised: 02/16/2012] [Accepted: 02/25/2012] [Indexed: 05/31/2023]
Abstract
In the present investigation, we studied the enzymatic synthesis of monoacylglycerols (MAG) and diacylglycerols (DAG) via the esterification of saturated fatty acids (stearic, palmitic and an industrial residue containing 87% palmitic acid) and glycerol in a solvent-free system. Three immobilized lipases (Lipozyme RM IM, Lipozyme TL IM and Novozym 435) and different reaction conditions were evaluated. Under the optimal reaction conditions, esterifications catalyzed by Lipozyme RM IM resulted in a mixture of MAG and DAG at high conversion rates for all of the substrates. In addition, except for the reaction of industrial residue at atmospheric pressure, all of these products met the World Health Organization and European Union directives for acylglycerol mixtures for use in food applications. The products were quantified by (13)C NMR, with the aid of an external reference signal which was generated from a sealed coaxial tube filled with acetonitrile-d3. After calibrating the area of this signal using the classical external reference method, the same coaxial tube was used repeatedly to quantify the reaction products.
Collapse
Affiliation(s)
- Jane Luiza Nogueira Fernandes
- Laboratório de Aplicações da RMN, Departamento de Química Orgânica, Instituto de Química, Universidade Federal Fluminense, Rua Outeiro de São João Batista s/n°, CEP: 24020-150, Niterói, Rio de Janeiro, Brazil
| | | | | |
Collapse
|
32
|
1H-NMR Spectroscopy as a New Tool in the Assessment of the Oxidative State in Edible Oils. J AM OIL CHEM SOC 2012. [DOI: 10.1007/s11746-012-2051-9] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
33
|
Analytical challenges in drug counterfeiting and falsification—The NMR approach. J Pharm Biomed Anal 2011; 55:679-87. [DOI: 10.1016/j.jpba.2010.12.017] [Citation(s) in RCA: 72] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2010] [Revised: 12/09/2010] [Accepted: 12/11/2010] [Indexed: 11/18/2022]
|
34
|
Affiliation(s)
- R. K. Gilpin
- Department of Chemistry, Wright State University, Dayton, Ohio 45435, United States
| | - C. S. Gilpin
- Select-O-Sep, LLC, 111 West Main Street, Freeport, Ohio 43973, United States
| |
Collapse
|
35
|
NMR techniques in biomedical and pharmaceutical analysis. J Pharm Biomed Anal 2011; 55:1-15. [DOI: 10.1016/j.jpba.2010.12.023] [Citation(s) in RCA: 97] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2010] [Revised: 12/12/2010] [Accepted: 12/15/2010] [Indexed: 01/04/2023]
|