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Jaffrezic-Renault NJ, Giuffrè O, Gallardo E, Bala C, Cass QB. Editorial: Women in Analytical Chemistry. Front Chem 2022; 10:949793. [PMID: 36034667 PMCID: PMC9403982 DOI: 10.3389/fchem.2022.949793] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2022] [Accepted: 06/03/2022] [Indexed: 11/24/2022] Open
Affiliation(s)
- N. J. Jaffrezic-Renault
- Université Claude Bernard Lyon 1, Villeurbanne, France
- *Correspondence: N. J. Jaffrezic-Renault, ; O. Giuffrè, ; E. Gallardo, ; C. Bala, ; Q. B. Cass,
| | - O. Giuffrè
- Dipartimento di Scienze Chimiche, Biologiche, Farmaceutiche ed Ambientali, Università di Messina, Messina, Italy
- *Correspondence: N. J. Jaffrezic-Renault, ; O. Giuffrè, ; E. Gallardo, ; C. Bala, ; Q. B. Cass,
| | - E. Gallardo
- Centro de Investigação em Ciências da Saúde (CICS-UBI), Faculdade de Ciências da Saúde, Universidade da Beira Interior, Covilhã, Portugal
- *Correspondence: N. J. Jaffrezic-Renault, ; O. Giuffrè, ; E. Gallardo, ; C. Bala, ; Q. B. Cass,
| | - C. Bala
- Department of Analytical Chemistry, University of Bucharest, Bucharest, Romania
- *Correspondence: N. J. Jaffrezic-Renault, ; O. Giuffrè, ; E. Gallardo, ; C. Bala, ; Q. B. Cass,
| | - Q. B. Cass
- Departamento de Química, Universidade Federal de São Carlos, São Carlos, Brazil
- *Correspondence: N. J. Jaffrezic-Renault, ; O. Giuffrè, ; E. Gallardo, ; C. Bala, ; Q. B. Cass,
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Ximenes IAT, Albino M, Sangregorio C, Cass QB, de Moraes MC. On-flow magnetic particle activity assay for the screening of human purine nucleoside phosphorylase inhibitors. J Chromatogr A 2021; 1663:462740. [PMID: 34942489 DOI: 10.1016/j.chroma.2021.462740] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Revised: 12/02/2021] [Accepted: 12/05/2021] [Indexed: 12/13/2022]
Abstract
Human purine nucleoside phosphorylase (HsPNP) catalyzes reversible phosphorolysis of nucleosides and deoxynucleosides in the purine cascade. HsPNP has been a target on behalf of the development of new leads for the treatment of a variety of T-cell mediated disorders. Several studies on the HsPNP are focused on the identification of effective, safe, and selective inhibitors. Therefore, this study describes the development of direct, simple, reliable, and inexpensive enzymatic assays to screen HsPNP inhibitors. Initially, HsPNP was covalently immobilized on the surface of magnetic particles (MPs). Due to the versatility of the MPs as solid support for enzyme immobilization, two different methods to monitor the enzyme activity are presented. Firstly, the activity of HsPNP-MPs was assessed offline by HPLC-DAD quantifying the formed hypoxanthine. Then, HsPNP-MPs were trapped in a peek tube, furnishing a microreactor which was inserted on-flow in an HPLC-DAD system to monitor the enzyme activity by the hypoxanthine quantification. Kinetic assays provided KMapp values for the inosine substrate of 488.2 ± 49.1 and 1084 ± 111 µM for the offline and on-flow assays, respectively. For the first time, kinetic studies for Pi as substrate using the HsPNP-MPs exhibits a Michaelis-Menten kinetic, yielding KMapp values for offline and on-flow of 521.2 ± 62.9 µM and 601 ± 66.5 µM, respectively. Inhibition studies conducted with a fourth generation immucillin derivative (DI4G) were employed as proof of concept to validate the use of the HsPNP-MPs assays for screening purposes. Additionally, a small library containing 11 compounds was used to assess the selectivity of the developed assays. The results showed that both presented assays can be applied to selectively recognizing and characterizing HsPNP inhibitors. Particularly, the on-flow method exhibited a high throughput and performance because of its automation and represents an easy and practical approach to reuse the HsPNP-MPs. Besides, this novel enzyme activity assay model can be further applied to other biological targets.
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Affiliation(s)
- I A T Ximenes
- Instituto de Química, Universidade Federal Fluminense. Niterói, Rio de Janeiro, 24020-141, Brazil
| | - M Albino
- INSTM and Dept. of Chemistry "Ugo Schiff", University of Florence, via della Lastruccia 3, 50019 Sesto Fiorentino, Italy
| | - C Sangregorio
- INSTM and Dept. of Chemistry "Ugo Schiff", University of Florence, via della Lastruccia 3, 50019 Sesto Fiorentino, Italy; ICCOM-CNR, via Madonna del Piano 10, 50019 Sesto Fiorentino, Italy
| | - Q B Cass
- SEPARARE - Núcleo de Pesquisa em Cromatografia, Department of Chemistry, Federal University of São Carlos, Rod. Washington Luiz, Km 235, São Carlos, SP, Brazil
| | - M C de Moraes
- Instituto de Química, Universidade Federal Fluminense. Niterói, Rio de Janeiro, 24020-141, Brazil.
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Sprenger RF, Thomasi SS, Ferreira AG, Cass QB, Batista Junior JM. Solution-state conformations of natural products from chiroptical spectroscopy: the case of isocorilagin. Org Biomol Chem 2016; 14:3369-75. [PMID: 26946940 DOI: 10.1039/c6ob00049e] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Isocorilagin, the α-anomer of the ellagitannin corilagin, has been frequently reported in the literature as a constituent of various plant species. Its identification is based mainly on the smaller value for the coupling constant of its anomeric proton when compared to that of corilagin. A careful investigation of the corilagin structure in both methanol and DMSO solutions using NMR, electronic and vibrational CD, and DFT and MD calculations confirmed that isocorilagin is the result of a solvent-induced conformational transition of corilagin, rather than its diastereoisomer. Corilagin changes from B1,4 and (o)S5 conformations of the β-glucose core in DMSO-d6 to an inverted (1)C4 conformation in methanol-d4, which accounts for NMR observables attributed to the alleged α-anomer. This misassignment reinforces the risks of relying upon a single technique for structural elucidation and stereochemical analysis of complex natural products, especially those containing saccharide moieties.
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Affiliation(s)
- R F Sprenger
- Department of Chemistry, Federal University of São Carlos, UFSCar. Rod. Washington Luís km 235, São Carlos, SP 13565-305, Brazil.
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Rodrigues MVN, Corrêa RS, Vanzolini KL, Santos DS, Batista AA, Cass QB. Characterization and screening of tight binding inhibitors of xanthine oxidase: an on-flow assay. RSC Adv 2015. [DOI: 10.1039/c5ra01741f] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
On-flow characterization of tight binders of xanthine oxidase.
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Affiliation(s)
- M. V. N. Rodrigues
- Centro Pluridisciplinar de Pesquisas Químicas
- Biológicas e Agrícolas
- Universidade Estadual de Campinas
- Paulínia 13140-000
- Brazil
| | - R. S. Corrêa
- Departamento de Química
- Universidade Federal de São Carlos
- São Carlos
- Brazil
| | - K. L. Vanzolini
- Departamento de Química
- Universidade Federal de São Carlos
- São Carlos
- Brazil
| | - D. S. Santos
- Instituto Nacional de Ciência e Tecnologia em Tuberculose
- Centro de Pesquisas em Biologia Molecular e Funcional
- Pontifícia Universidade Católica do Rio Grande do Sul
- Porto Alegre
- Brazil
| | - A. A. Batista
- Departamento de Química
- Universidade Federal de São Carlos
- São Carlos
- Brazil
| | - Q. B. Cass
- Departamento de Química
- Universidade Federal de São Carlos
- São Carlos
- Brazil
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Pistolozzi M, Royo V, Pereira AC, Silva MLA, Silva R, Cunha WR, Vaconcelos K, Cass QB, Martins CHG, Bastos JK, Varchi G, Guerrini A, Bertucci C. Enantiomeric HPLC resolution and absolute stereochemistry assignment of a new poligamain derivative. J Pharm Biomed Anal 2013; 75:118-22. [PMID: 23312389 DOI: 10.1016/j.jpba.2012.11.012] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2012] [Accepted: 11/07/2012] [Indexed: 11/28/2022]
Abstract
A new aryltetralin lignan derivative, 1, was obtained by reacting dimethyl succinate and piperonal, furnishing the lactone 4-(3',4'-methylenedioxybenzyl)-4,5-dihydro-2(3H)-furanone, which was reacted once again with piperonal and LDA to give the dibenzylbutirolactone 7-hydroxyhinokinin. The cyclization of 7-hydroxyhinokinin into polygamain occurred in the presence of trifluoroacetic acid. The reduction of the furanic ring of polygamain was done by its reaction with DIBAL in THF, furnishing the diol functionalized lignin derivative 1 as single diastereomer. The enantiomeric fractions of 1 were obtained by preparative enantioselective HPLC. The absolute stereochemistry was assigned by electronic circular dichroism (ECD) and nuclear magnetic resonance (NMR) spectroscopy. An all-trans relative configuration was determined by NMR on the bases of ¹H coupling constants and nuclear Overhauser effect (n.O.e.) experiments. The absolute configuration at C1 was assigned on the basis of the ECD sign at 296 nm by comparison to the ECD spectra of structural analogues with defined stereochemistry. The assignment of the absolute configuration was confirmed by applying the exciton chirality method to the well-defined ECD couplets at 285 and 200 nm allied to the two electronic transitions L(b) and B(b) of the aromatic moieties, respectively. Rac-1 and its enantiomeric isomers were evaluated against important bacteria responsible for dental caries. The best results obtained for the (1R,2S,3S) isomer were against Streptococcus mutans (250 μM), Streptococcus salivarius (250 μM), Streptococcus sobrinus (280 μM) and Streptococcus mitis (280 μM). The (1S,2R,3R) isomer was active only against Streptococcus sanguinis (280 μM). The enantiomeric mixture was less active than the (1R,2S,3S) isomer.
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Affiliation(s)
- M Pistolozzi
- Dipartimento di Scienze Farmaceutiche, Università di Bologna, Via Belmeloro 6, 40126 Bologna, Italy
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Madureira TV, Rocha MJ, Cass QB, Tiritan ME. Development and Optimization of a HPLC-DAD Method for the Determination of Diverse Pharmaceuticals in Estuarine Surface Waters. J Chromatogr Sci 2010; 48:176-82. [DOI: 10.1093/chromsci/48.3.176] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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de Paula FCCR, de Pietro AC, Cass QB. Simultaneous quantification of sulfamethoxazole and trimethoprim in whole egg samples by column-switching high-performance liquid chromatography using restricted access media column for on-line sample clean-up. J Chromatogr A 2008; 1189:221-6. [PMID: 17850809 DOI: 10.1016/j.chroma.2007.08.046] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2007] [Revised: 08/09/2007] [Accepted: 08/23/2007] [Indexed: 11/16/2022]
Abstract
This work reports the application of restricted access media (RAM) column, in a multidimensional configuration, for simultaneous analysis of sulfamethoxazole (SMX) and trimethoprim (TMP) in whole eggs with ultraviolet detection. The proteins were partially precipitated by adding 0.5 mL of acetonitrile into 1.0 mL of blended egg followed by centrifugation. The supernatant was injected (250 microL) directly into the multidimensional system. At the first dimension, a restricted access medium (RAM) bovine serum albumin (BSA) octadecyl column (100 mm x 46 mm I.D., Luna silica, 10 microm particle size and 100 A pore size), was used for extraction and concentration of the analytes and at second dimension, an octadecyl column (150 mm x 46 mm I.D., Luna silica, 10 microm particle size and 100 A pore size), for analysis. The developed method showed good selectivity, accuracy and precision for quantification of these different compounds in eggs, and the limits of quantification were 80 ng/mL, for both compounds. The validated method is reliable and sensitive for monitoring residues in whole eggs samples and thus, to determine withdraw period for laying hens using veterinary medicine having SMX-TMP combination.
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Affiliation(s)
- F C C R de Paula
- Departamento de Química, Universidade Federal de São Carlos, Cx. Postal 676, São Carlos 13565-905, SP, Brazil
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Carvalho PO, Cass QB, Calafatti SA, Contesini FJ, Bizaco R. Review- Alternatives for the separation of drug enantiomers: ibuprofen as a model compound. Braz J Chem Eng 2006. [DOI: 10.1590/s0104-66322006000300003] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
| | - Q. B. Cass
- Universidade Federal de São Carlos, Brazil
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Montanari MLC, Montanari CA, Piló-Veloso D, Cass QB. Estimation of the RP-HPLC Lipophilicity Parameters Log K', and Log KW, A Comparison with the Hydrophobicity Index ϕ0. J LIQ CHROMATOGR R T 2006. [DOI: 10.1080/10826079708006327] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
- M. L. C. Montanari
- a Departamento de Química/ICEx , Universidade Federal de Minas Gerai , Belo Horizonte , 31270-901 , MG , Brazil
- b Departamento de Química , Universidade Federal de São , Carlos Caixa Postal 676, São Carlos , 13565-905 , SP , Brazil
| | - C. A. Montanari
- a Departamento de Química/ICEx , Universidade Federal de Minas Gerai , Belo Horizonte , 31270-901 , MG , Brazil
- b Departamento de Química , Universidade Federal de São , Carlos Caixa Postal 676, São Carlos , 13565-905 , SP , Brazil
| | - D. Piló-Veloso
- a Departamento de Química/ICEx , Universidade Federal de Minas Gerai , Belo Horizonte , 31270-901 , MG , Brazil
- b Departamento de Química , Universidade Federal de São , Carlos Caixa Postal 676, São Carlos , 13565-905 , SP , Brazil
| | - Q. B. Cass
- a Departamento de Química/ICEx , Universidade Federal de Minas Gerai , Belo Horizonte , 31270-901 , MG , Brazil
- b Departamento de Química , Universidade Federal de São , Carlos Caixa Postal 676, São Carlos , 13565-905 , SP , Brazil
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Cassiano NM, Lima VV, Oliveira RV, de Pietro AC, Cass QB. Development of restricted-access media supports and their application to the direct analysis of biological fluid samples via high-performance liquid chromatography. Anal Bioanal Chem 2006. [DOI: 10.1007/s00216-006-0598-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Montanari MLC, Cass QB, Leitão A, Andricopulo AD, Montanari CA. The role of molecular interaction fields on enantioselective and nonselective separation of chiral sulfoxides. J Chromatogr A 2006; 1121:64-75. [PMID: 16716332 DOI: 10.1016/j.chroma.2006.04.072] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2005] [Revised: 03/30/2006] [Accepted: 04/05/2006] [Indexed: 11/30/2022]
Abstract
The separation of a series of 23 asymmetric sulfoxides, including the three proton pump inhibitors (PPI) omeprazole, lansoprazole and pantoprazole was investigated by HPLC, under reversed-phase elution with amylose tris(3,5-dimethylphenylcarbamate), amylose tris[(S)-1-phenylethylcarbamate] and amylose tris(3,5-dimethoxyphenylcarbamate) chiral stationary phases, CSP1-3, respectively. The whole set of sulfoxides showed better enantioselectivity and enantioresolution on CSP1. However, the three PPI were enantioseparated only when using CSP1 and CSP3. It was observed an improved enantioselectivity and enantioresolution on CSP3. The mechanisms of retention were evaluated by molecular interaction fields (MIF) generated via GRID force field, which yielded the geometric reasons leading to the scenario outlined. The enantioselective and nonselective interactions are discussed in terms of the reported selectivity. The steric structural outline of the CSP nonselective interaction sites is of major importance to deliver the sulfoxides to the chiral selective sites where the enantioselective interactions take place.
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Affiliation(s)
- M L C Montanari
- Departamento de Química, Universidade Federal de São Carlos, P.O. Box 676, 13565-905 São Carlos/SP, Brazil
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Cassiano NM, Lima VV, Oliveira RV, de Pietro AC, Cass QB. Development of restricted-access media supports and their application to the direct analysis of biological fluid samples via high-performance liquid chromatography. Anal Bioanal Chem 2006; 384:1462-9. [PMID: 16800052 DOI: 10.1007/s00216-005-0253-9] [Citation(s) in RCA: 95] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A quick overview of published methods for analyzing compounds in complex biological samples reveals that the most difficult step is the clean-up or extraction of a required compound from the matrix. The strategy required to analyze exogenous compounds in biological fluids depends greatly upon the nature of the compound and upon the biomatrix. Coupled-column separation using restricted-access media as the first dimension in order to exclude macromolecules and retain micromolecules has been successfully used for a number of biological fluids. This paper presents the history of the development of restricted-access media supports and of their application to the direct injection of biological fluid samples in high-performance liquid chromatography.
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Affiliation(s)
- N M Cassiano
- Departamento de Química, Universidade Federal de São Carlos, Cx. Postal 676, São Carlos, SP, 13565-905, Brazil
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Urban VM, Cass QB, Oliveira RV, Giampaolo ET, Machado AL. Development and application of methods for determination of residual monomer in dental acrylic resins using high performance liquid chromatography. Biomed Chromatogr 2006; 20:369-76. [PMID: 16177959 DOI: 10.1002/bmc.575] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Two high-performance liquid chromatographic methods for determination of residual monomer in dental acrylic resins are described. Monomers were detected by their UV absorbance at 230 nm, on a Nucleosil C18 (5 microm particle size, 100 A pore size, 15 x 0.46 cm i.d.) column. The separation was performed using acetonitrile-water (55:45 v/v) containing 0.01% triethylamine (TEA) for methyl methacrylate and butyl methacrylate, and acetonitrile-water (60:40 v/v) containing 0.01% TEA for isobutyl methacrylate and 1,6-hexanediol dimethacrylate as mobile phases, at a flow rate of 0.8 mL/min. Good linear relationships were obtained in the concentration range 5.0-80.0 microg/mL for methyl methacrylate, 10.0-160.0 microg/mL for butyl methacrylate, 50.0-500.0 microg/mL for isobutyl methacrylate and 2.5-180.0 microg/mL for 1,6-hexanediol dimethacrylate. Adequate assay for intra- and inter-day precision and accuracy was observed during the validation process. An extraction procedure to remove residual monomer from the acrylic resins was also established. Residual monomer was obtained from broken specimens of acrylic disks using methanol as extraction solvent for 2 h in an ice-bath. The developed methods and the extraction procedure were applied to dental acrylic resins, tested with or without post-polymerization treatments, and proved to be accurate and precise for the determination of residual monomer content of the materials evaluated.
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Affiliation(s)
- V M Urban
- Department of Dental Materials and Prosthodontics, São Paulo State University, UNESP, Araraquara, São Paulo, Brazil
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Pereira AV, Cass QB. High-performance liquid chromatography method for the simultaneous determination of sulfamethoxazole and trimethoprim in bovine milk using an on-line clean-up column. J Chromatogr B Analyt Technol Biomed Life Sci 2005; 826:139-46. [PMID: 16169294 DOI: 10.1016/j.jchromb.2005.08.006] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2004] [Revised: 07/22/2005] [Accepted: 08/16/2005] [Indexed: 11/21/2022]
Abstract
A bidimensional HPLC method for the simultaneous determination of sulfamethoxazole (SMX) and trimethoprim (TMP) in bovine milk has been developed and validated. After centrifugation, aliquots (150 microl) of milk samples were directly injected to a column-switching HPLC system. At the first step a RAM octyl-BSA column was employed to automatically remove proteins that otherwise would interfere with milk analysis. The mobile phase 0.01 M phosphate buffer pH 6.0:acetonitrile (95:5, v/v) was used in the first 5 min for the elution of milk proteins and then 0.01 M phosphate buffer pH 6.0:acetonitrile (83:17, v/v) for transfer SMX and TMP to the analytical column. The separation of SMX and TMP from one another and from other remaining milk components was performed on an octyl column using the mobile phase 0.01 M phosphate buffer pH 5.0:acetonitrile (82:18, v/v), which were detected by UV at 265 nm. The calibration graphs were linear in the concentration ranges of 25-800 ng/ml and 50-400 ng/ml for SMX and TMP, respectively. The intra- and inter-assay coefficients of variation were less than 15% for both drugs. The validated method was applied to the analysis of milk samples of twelve (two groups of six) cows after administration (intramuscular or subcutaneous) of a single recommended therapeutic dose of the SMX-TMP combination.
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Affiliation(s)
- A V Pereira
- Departamento de Ciências Farmacêuticas, Universidade Estadual de Ponta Grossa, 84030-900, Ponta Grossa, PR, Brazil
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Cass QB, Lima VV, Oliveira RV, Cassiano NM, Degani ALG, Pedrazzoli J. Enantiomeric determination of the plasma levels of omeprazole by direct plasma injection using high-performance liquid chromatography with achiral-chiral column-switching. J Chromatogr B Analyt Technol Biomed Life Sci 2004; 798:275-81. [PMID: 14643507 DOI: 10.1016/j.jchromb.2003.09.053] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
A direct injection high-performance liquid chromatographic (HPLC) method, with column-switching, for the determination of omeprazole enantiomers in human plasma is described. A restricted access media (RAM) of bovine serum albumin (BSA) octyl column has been used in the first dimension for separation of the analyte from the biological matrix. The omeprazole enantiomers were eluted from the RAM column onto an amylose tris(3,5-dimethylphenylcarbamate) chiral column by the use of a column-switching valve and the enantioseparation was performed using acetonitrile-water (60:40 v/v) as eluent. The analytes were detected by their UV absorbance at 302 nm. The validated method was applied to the analysis of the plasma samples obtained from 10 Brazilian volunteers who received a 40 mg oral dose of racemic omeprazole and was able to quantify the enantiomers of omeprazole in the clinical samples analyzed. The assay was able to determine the cytochrome P450 2C19 phenotype of the subjects participating in this study.
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Affiliation(s)
- Q B Cass
- Departamento de Química, Universidade Federal de São Carlos, São Carlos13565-905, SP, Brazil.
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Sousa EP, Tiritan ME, Oliveira RV, Afonso CMM, Cass QB, Pinto MMM. Enantiomeric resolution of kielcorin derivatives by HPLC on polysaccharide stationary phases using multimodal elution. Chirality 2004; 16:279-85. [PMID: 15069657 DOI: 10.1002/chir.20031] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Analytical HPLC methods using carbamate chiral stationary phases of polysaccharide derivatives were developed for the enantiomeric resolution of five racemic mixtures of xanthonolignoids: rac-trans-kielcorin C, rac-cis-kielcorin C, rac-trans-kielcorin D, rac-trans-isokielcorin D, and rac-trans-kielcorin E. The separations were evaluated with the stationary phases cellulose tris-3,5-dimethylphenylcarbamate, amylose tris-3,5-dimethylphenylcarbamate, amylose tris-(S)-1-phenylethylcarbamate, and amylose tris-3,5-dimethoxyphenylcarbamate under normal, reversed-phase, and polar organic elution conditions. Chiral recognition of those chiral stationary phases, the influence of mobile phases on the enantiomers separation, and the effects of structural features of the solutes on the chiral discrimination observed are discussed. The best performance was achieved on an amylose tris-3,5-dimethylphenylcarbamate phase. Polar organic conditions gave shorter retention factors and better resolutions and were a valuable alternative to the alcohol-hexane or reversed-phase conditions.
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Affiliation(s)
- Emília P Sousa
- Centro de Estudos de Química Orgânica, Fitoquímica e Farmacologia-Universidade do Porto, Faculdade de Farmácia, Porto, Portugal
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Cass QB, Gomes RF, Calafatti SA, Pedrazolli Júnior J. Determination of amoxycillin in human plasma by direct injection and coupled-column high-performance liquid chromatography. J Chromatogr A 2003; 987:235-41. [PMID: 12613817 DOI: 10.1016/s0021-9673(02)01660-6] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
This work reports the use of multidimensional HPLC by coupling a restricted access medium (RAM) bovine serum albumin (BSA) octadecyl column (100 x 4.6 mm I.D., 10 microm particle size and 120 A pore size) to an octadecyl Hypersil column (150 x 4.6 mm I.D., 5 microm particle size and 120 A pore size) to the analysis of amoxycillin in human plasma by direct injection. Ion pairing was necessary to extract amoxycillin with good recovery from the plasma proteins. To prepare the spiked samples, aliquots (60 microl) of the appropriated standard solutions were added to each culture tube containing an 180 microl of plasma and a solution of 0.30 mM tetrabuthylammonium phosphate (60 microl). They were vortexed for 15 s and then 290 microl were transferred to autosampler vials. Aliquots (250 microl) of the spiked plasma samples were injected to a column-switching HPLC system. An analysis time of 25 min with no time spent on sample preparation was achieved. The developed method showed good selectivity, sensitivity, accuracy and precision for direct analysis of this polar low wavelength ultraviolet absorption antibiotic using only 180 microl of human plasma. The validated method proved to be reliable and sensitive for the determination of amoxycillin in plasma samples of five healthy volunteers to whom test and reference formulations were administered as an oral dose (500 mg).
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Affiliation(s)
- Q B Cass
- Departamento de Química, Universidade Federal de São Carlos, Cx Postal 676, São Carlos, SP, Brazil.
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Cass QB, Batigalhia F. Enantiomeric resolution of a series of chiral sulfoxides by high-performance liquid chromatography on polysaccharide-based columns with multimodal elution. J Chromatogr A 2003; 987:445-52. [PMID: 12613840 DOI: 10.1016/s0021-9673(02)01451-6] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The enantiomeric resolution of a series of 20 asymmetric sulfoxides was systematically investigated by HPLC using multimodal elution with amylose trisR(S)-1-phenylethylcarbamate], amylose tris(3,5-dimethoxyphenylcarbamate) and amylose and cellulose tris(3,5-dimethylphenylcarbamate) phases. The sulfoxide series was composed of aromatic, olefinic and ketosulfoxides, sulfinyl acids and esters. This work has shown that enantioselectivity and enantioresolution of the polysaccharide-based columns can be achieved by changing the type and composition of the mobile phase, widening the applicability of these chiral phases.
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Affiliation(s)
- Q B Cass
- Universidade Federal de São Carlos, Departamento de Química, Caixa Postal 676, 13.565-970 Sio Carlos, SP, Brazil.
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Cass QB, Degani ALG, Cassiano NM, Pedrazolli J. Enantiomeric determination of pantoprazole in human plasma by multidimensional high-performance liquid chromatography. J Chromatogr B Analyt Technol Biomed Life Sci 2002; 766:153-60. [PMID: 11824393 DOI: 10.1016/s0378-4347(01)00472-8] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Multidimensional HPLC is a powerful tool for the analysis of samples of a high degree of complexity. This work reports the use of multidimensional HPLC by coupling a RAM column with a chiral polysaccharide column to the analysis of Pantoprazole in human plasma by direct injection. The enantiomers from the plasma samples were separated with high resolution on a tris(3,5-dimethoxyphenylcarbamate) of amylose phase after clean-up by a RAM BSA octyl column. Water was used as solvent for the first 5 min in a flow-rate of 1.0 ml/min for the elution of the plasmatic proteins and then acetonitrile-water (35:65 v/v) for the transfer and analysis of pantoprazole enantiomers, which were detected by UV at 285 nm. Analysis time was 28 min with no time spent on sample preparation. A good linear relationship was obtained in the concentration range of 0.20 to 1.5 microg/ml for each enantiomer. Inter and intra-day precision and accuracy were determined by one low (0.24 microg/ml), one medium (0.70 microg/ml) and one high (1.3 microg/ml) plasma concentration and gave a C.V. varying from 1.80 to 8.43% and accuracy from 86 to 92%. Recoveries of pantoprazole enantiomers were in the range of 93.7-101.2%. The validated method was applied to the analysis of the plasma samples obtained from ten Brazilian volunteers who received an 80 mg oral dose of racemic pantoprazole and was able to quantify the enantiomers of pantoprazole in all clinical samples analyzed.
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Affiliation(s)
- Q B Cass
- Universidade Federal de São Carlos, Departamento de Química, SP, Brazil.
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Sensato FR, Cass QB, Longo E, Zukerman-Schpector J, Custodio R, Andrés J, Hernandes MZ, Longo RL. Molecular structure of the molybdenum oxo-diperoxo compound MoO(O(2))(2)(OPy)(H(2)O): a computational and X-ray study. Inorg Chem 2001; 40:6022-5. [PMID: 11681920 DOI: 10.1021/ic010020h] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We have carried out a combined experimental and theoretical study of the molecular structure of the MoO(O(2))(2)(OPy)(H(2)O) coordination compound using X-ray crystallography and DFT-B3LYP computational method, respectively. The MoO(O(2))(2)(OPy)(H(2)O) complex crystallizes in the orthorhombic space group Pmna with Z = 4, a = 6.9001(9) A, b = 8.0471(1) A, c = 16.227(2) A, V = 901.0(2) A(3), and the X-ray data analysis yields a bipyramidal-pentagonal coordination polyhedron for the Mo atom. The pyridine N-oxide (OPy) ligand occupies the equatorial position, with the oxygen atom of this ligand being located in the same plane as the four peroxo oxygen atoms. The H(2)O ligand is situated trans to the oxo group, forming intermolecular hydrogen bonds with peroxo groups belonging to two adjacent complexes. In our theoretical approach these intermolecular interactions were taken into account by including two methanol molecules which form hydrogen bonds with the water ligand leading to a good agreement between the calculated and the experimental geometry. Our results suggest that it is necessary to take into account the presence of these interactions in order to reconcile the theoretical results to the experimental data, in particular the distance between Mo and the oxygen of water ligand. These results seem to be a general feature for analogous bis-peroxo complexes that have been reported in the literature.
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Affiliation(s)
- F R Sensato
- Departamento de Química, Universidade Federal de São Carlos, CP 676, 13565-905, São Carlos, SP, Brazil
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Abstract
Enantiomers of modafinil, (diphenylmethyl)sulphinyl-2-acetamide, were separated by an amylose tris[(S)-1-phenylethylcarbamate] chiral stationary phase, using acetonitrile: water (25:75 v/v) as mobile phase, with excellent selectivity (alpha=1.4) and resolution factors (R(s)=1.5). The assay involved a solid-phase extraction of the enantiomers of modafinil from plasma using a C(18) Cartridge. A good linear relationship was obtained in the concentration of 0.15-3 microg ml(-1) for each enantiomer. The method developed is sufficiently accurate and precise to be used for clinical samples and has a good selectivity with the two main circulating metabolites: the (diphenylmethyl)sulphinyl-2-acetic acid and (diphenylmethyl)sulphonyl-2-acetamide. The use of a polysaccharide-based column on multimodal elution was explored in developing the method.
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Affiliation(s)
- Q B Cass
- Departamento de Química, Universidade Federal de S. Carlos, Cx. Postal 676, São Carlos, SP, Brazil.
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Cortez DAG, Fernandes JB, Vieira PC, da Silva MGF, Ferreira AG, Cass QB. SEPARATION AND PURIFICATION OF MELIACIN BUTENOLIDES FROM TRICHILIA ESTIPULATA BY NORMAL-PHASE HPLC. J LIQ CHROMATOGR R T 2001. [DOI: 10.1081/jlc-100001344] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
- D. A. G. Cortez
- a Departamento de Química , Universidade Federal de São Carlos , Rod. Washington Luís, Km 235, CP 676, São Carlos, SP, CEP 13565-905, Brazil
| | - J. B. Fernandes
- b Departamento de Farmácia e Farmacologia , Universidade Estadual de Maringá , Avenida Colombo n° 5790, CP 331, Maringá, PR, CEP 87020-900, U.S.A
| | - P. C. Vieira
- b Departamento de Farmácia e Farmacologia , Universidade Estadual de Maringá , Avenida Colombo n° 5790, CP 331, Maringá, PR, CEP 87020-900, U.S.A
| | - M. G. Fernandes da Silva
- b Departamento de Farmácia e Farmacologia , Universidade Estadual de Maringá , Avenida Colombo n° 5790, CP 331, Maringá, PR, CEP 87020-900, U.S.A
| | - A. G. Ferreira
- b Departamento de Farmácia e Farmacologia , Universidade Estadual de Maringá , Avenida Colombo n° 5790, CP 331, Maringá, PR, CEP 87020-900, U.S.A
| | - Q. B. Cass
- b Departamento de Farmácia e Farmacologia , Universidade Estadual de Maringá , Avenida Colombo n° 5790, CP 331, Maringá, PR, CEP 87020-900, U.S.A
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Britto MM, Cass QB, Jardim ICSF, Montanari CA, Aboul-Enein HY. The role of ion pairing in the chromatographic study of propranolol analogues. Chromatographia 2001. [DOI: 10.1007/bf02492420] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Abstract
Investigation of the leaves of Raulinoa echinata Cowan (Rutaceae) has led to the isolation of several furofuran (2,6-diaryl-3,7-dioxabicyclo[3.3.0]-octane) lignan derivatives, namely (+)-sesamin, (+)-eudesmin, (+)-methylpiperitol (= kobusin), (+)-piperitol-gamma,gamma-dimethylallylether and the corresponding epi compounds: (+)-asarinin, (+)-epieudesmin, (+)-methylxanthoxylol, (+)-methylpluviatilol, (+)-xanthoxylol-gamma,gamma-dimethylallylether and (+)-pluviatilol-gamma,gamma-dimethylallylether. This is the first report of the chromatographic separation of the epimers (+)-methylxanthoxylol/(+)-methylpluviatilol and (+)-xanthoxylol-gamma,gamma-dimethylallylether/(+)-pluviatilol-gamma,gamma- dimethylallylether and of their NMR nOe difference studies.
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Affiliation(s)
- M W Biavatti
- Departamento de Química, Universidade Federal de São Carlos, CP 676, 13565-905, São Carlos, SP, Brazil
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Montanari MLC, Cass QB, Montanari CA. Quantitative structure-retention relationships of antimicrobial hydrazides evaluated by reverse-phase liquid chromatography. Chromatographia 2000. [DOI: 10.1007/bf02505411] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Abstract
The enantiomeric resolution of a series of N-arylamides was examined on amylose tris[(S)-1-phenylethylcarbamate] coated onto aminopropylated 7 microns silica with 500 A diameter pores and on naked silica 5 microns particle size with 500 A diameter pores. The enantiomeric resolution obtained for this series was excellent on both columns. The enantioselectivity of cellulose and amylose tris(3,5-dimethylphenylcarbamate) coated onto APS-Hypersil (120 A pore size, 5 microns particle size) was also investigated for this series of compounds.
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Affiliation(s)
- Q B Cass
- Departamento de Química, Universidade Federal de São Carlos, Brazil
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Matlin SA, Chan L, Prazeres MA, Mehani S, Cass QB. Long-acting androgens: Analytical and preparative HPLC of testosterone esters. ACTA ACUST UNITED AC 1987. [DOI: 10.1002/jhrc.1240100406] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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