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Anchau Wegermann C, Santana Bezerra E, Gomes de Macedo Sant'Anna I, Ortega De Oliveira PC, da Costa Silva R, Rocco Machado T, Wanderley Tinoco L, Vieira de Souza MCB, Pascutti P, Santos Boechat FDC, de Moraes MC. Insights into nucleoside hydrolase from Leishmania donovani inhibition: A new bioaffinity chromatography-based screening assay and docking studies. Bioorg Chem 2024; 146:107302. [PMID: 38521010 DOI: 10.1016/j.bioorg.2024.107302] [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: 02/06/2024] [Accepted: 03/19/2024] [Indexed: 03/25/2024]
Abstract
Leishmaniasis, a group of neglected infectious diseases, encompasses a serious health concern, particularly with visceral leishmaniasis exhibiting potentially fatal outcomes. Nucleoside hydrolase (NH) has a fundamental role in the purine salvage pathway, crucial for Leishmania donovani survival, and presents a promising target for developing new drugs for visceral leishmaniasis treatment. In this study, LdNH was immobilized into fused silica capillaries, resulting in immobilized enzyme reactors (IMERs). The LdNH-IMER activity was monitored on-flow in a multidimensional liquid chromatography system, with the IMER in the first dimension. A C18 analytical column in the second dimension furnished the rapid separation of the substrate (inosine) and product (hypoxanthine), enabling direct enzyme activity monitoring through product quantification. LdNH-IMER exhibited high stability and was characterized by determining the Michaelis-Menten constant. A known inhibitor (1-(β-d-Ribofuranosyl)-4-quinolone derivative) was used as a model to validate the established method in inhibitor recognition. Screening of three additional derivatives of 1-(β-d-Ribofuranosyl)-4-quinolone led to the discovery of novel inhibitors, with compound 2a exhibiting superior inhibitory activity (Ki = 23.37 ± 3.64 µmol/L) compared to the employed model inhibitor. Docking and Molecular Dynamics studies provided crucial insights into inhibitor interactions at the enzyme active site, offering valuable information for developing new LdNH inhibitors. Therefore, this study presents a novel screening assay and contributes to the development of potent LdNH inhibitors.
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Affiliation(s)
- Camila Anchau Wegermann
- BioCrom, Laboratório de Cromatografia de Bioafinidade e Química Ambiental, Departamento de Química Orgânica, Instituto de Química, Universidade Federal Fluminense (UFF), Niterói, Brazil; Laboratório GQCBio, Grupo de Química de Coordenação Biológica, Departamento de Química Geral e Inorgânica, Instituto de Química, Universidade do Estado do Rio de Janeiro (UERJ), Rio de Janeiro, Brazil
| | - Evelyn Santana Bezerra
- BioCrom, Laboratório de Cromatografia de Bioafinidade e Química Ambiental, Departamento de Química Orgânica, Instituto de Química, Universidade Federal Fluminense (UFF), Niterói, Brazil
| | - Isabella Gomes de Macedo Sant'Anna
- BioCrom, Laboratório de Cromatografia de Bioafinidade e Química Ambiental, Departamento de Química Orgânica, Instituto de Química, Universidade Federal Fluminense (UFF), Niterói, Brazil
| | - Pamella Christina Ortega De Oliveira
- BioCrom, Laboratório de Cromatografia de Bioafinidade e Química Ambiental, Departamento de Química Orgânica, Instituto de Química, Universidade Federal Fluminense (UFF), Niterói, Brazil
| | - Rodrigo da Costa Silva
- Laboratório LNHC, Instituto de Química, Departamento de Química Orgânica, Universidade Federal Fluminense (UFF), Niterói, RJ, Brazil
| | - Thamires Rocco Machado
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Luzineide Wanderley Tinoco
- Núcleo de Pesquisas de Produtos Naturais, Universidade Federal do Rio de Janeiro (UFRJ), Cidade Universitária, 21941-902 Rio de Janeiro, RJ, Brazil
| | | | - Pedro Pascutti
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Fernanda da Costa Santos Boechat
- Laboratório LNHC, Instituto de Química, Departamento de Química Orgânica, Universidade Federal Fluminense (UFF), Niterói, RJ, Brazil
| | - Marcela Cristina de Moraes
- BioCrom, Laboratório de Cromatografia de Bioafinidade e Química Ambiental, Departamento de Química Orgânica, Instituto de Química, Universidade Federal Fluminense (UFF), Niterói, Brazil.
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Ten Years Milestones in Xanthine Oxidase Inhibitors Discovery: Febuxostat-Based Inhibitors Trends, Bifunctional Derivatives, and Automatized Screening Assays. ORGANICS 2022. [DOI: 10.3390/org3040026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
Xanthine oxidase (XO) is an enzyme involved in the oxidative process of hypoxanthine and xanthine to uric acid (UA). This process also produces reactive oxygen species (ROS) as byproducts. Both UA and ROS are dangerous for human health, and some health conditions trigger upregulation of XO activity, which results in many diseases (cancer, atherosclerosis, hepatitis, gout, and others) given the worsened scenario of ROS and UA overproduction. So, XO became an attractive target to produce and discover novel selective drugs based on febuxostat, the most recent XO inhibitor out of only two approved by FDA. Under this context, high-performance liquid chromatography (HPLC) and capillary electrophoresis (CE) have been successfully applied to rapidly and easily screen for bioactive compounds, isolated or in complex natural matrixes, that act as enzyme inhibitors through the use of an immobilized enzyme reactor (IMER). This article’s goal is to present advances comprising febuxostat-based XO inhibitors as a new trend, bifunctional moieties capable of inhibiting XO and modulating ROS activity, and in-flow techniques employing an IMER in HPLC and CE to screen for synthetic and natural compounds that act as XO inhibitors.
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Travassos IO, Mello-Andrade F, Caldeira RP, Pires WC, da Silva PFF, Correa RS, Teixeira T, Martins-Oliveira A, Batista AA, de Silveira-Lacerda EP. Ruthenium (II)/allopurinol complex inhibits breast cancer progression via multiple targets. J Biol Inorg Chem 2021; 26:385-401. [PMID: 33837856 DOI: 10.1007/s00775-021-01862-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2020] [Accepted: 03/08/2021] [Indexed: 12/27/2022]
Abstract
Metal complexes based on ruthenium have established excellent activity with less toxicity and great selectivity for tumor cells. This study aims to assess the anticancer potential of ruthenium(II)/allopurinol complexes called [RuCl2(allo)2(PPh3)2] (1) and [RuCl2(allo)2(dppb)] (2), where allo means allopurinol, PPh3 is triphenylphosphine and dppb, 1,4-bis(diphenylphosphino)butane. The complexes were synthesized and characterized by elemental analysis, IR, UV-Vis and NMR spectroscopies, cyclic voltammetry, molar conductance measurements, as well as the X-ray crystallographic analysis of complex 2. The antitumor effects of compounds were determined by cytotoxic activity and cellular and molecular responses to cell death mechanisms. Complex 2 showed good antitumor profile prospects because in addition to its cytotoxicity, it causes cell cycle arrest, induction of DNA damage, morphological and biochemical alterations in the cells. Moreover, complex 2 induces cell death by p53-mediated apoptosis, caspase activation, increased Beclin-1 levels and decreased ROS levels. Therefore, complex 2 can be considered a suitable compound in antitumor treatment due to its cytotoxic mechanism.
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Affiliation(s)
- Ingrid O Travassos
- Laboratório de Genética Molecular E Citogenética Humana, sala 213, Departamento de Genética, Instituto de Ciências Biológicas I, Campus Samambaia, Universidade Federal de Goiás, Avenida Esperança, s/n, Cx Postal: 131, Goiânia, Goiás, CEP 74690-900, Brazil
| | - Francyelli Mello-Andrade
- Laboratório de Genética Molecular E Citogenética Humana, sala 213, Departamento de Genética, Instituto de Ciências Biológicas I, Campus Samambaia, Universidade Federal de Goiás, Avenida Esperança, s/n, Cx Postal: 131, Goiânia, Goiás, CEP 74690-900, Brazil.,Department of Chemistry, Federal Institute of Education, Science and Technology of Goiás, Goiânia, Goiás, 74055-110, Brazil
| | - Raíssa P Caldeira
- Laboratório de Genética Molecular E Citogenética Humana, sala 213, Departamento de Genética, Instituto de Ciências Biológicas I, Campus Samambaia, Universidade Federal de Goiás, Avenida Esperança, s/n, Cx Postal: 131, Goiânia, Goiás, CEP 74690-900, Brazil
| | - Wanessa C Pires
- Laboratório de Genética Molecular E Citogenética Humana, sala 213, Departamento de Genética, Instituto de Ciências Biológicas I, Campus Samambaia, Universidade Federal de Goiás, Avenida Esperança, s/n, Cx Postal: 131, Goiânia, Goiás, CEP 74690-900, Brazil
| | - Paula F F da Silva
- Laboratório de Genética Molecular E Citogenética Humana, sala 213, Departamento de Genética, Instituto de Ciências Biológicas I, Campus Samambaia, Universidade Federal de Goiás, Avenida Esperança, s/n, Cx Postal: 131, Goiânia, Goiás, CEP 74690-900, Brazil
| | - Rodrigo S Correa
- Department of Chemistry, Federal University of Ouro Preto-UFOP, Ouro Preto, MG, 35400-000, Brazil
| | - Tamara Teixeira
- Department of Chemistry, Federal University of Ouro Preto-UFOP, Ouro Preto, MG, 35400-000, Brazil
| | | | - Alzir A Batista
- Department of Chemistry, Federal University of Sao Carlos-UFSCar, Sao Carlos, SP, 13565-905, Brazil
| | - Elisângela P de Silveira-Lacerda
- Laboratório de Genética Molecular E Citogenética Humana, sala 213, Departamento de Genética, Instituto de Ciências Biológicas I, Campus Samambaia, Universidade Federal de Goiás, Avenida Esperança, s/n, Cx Postal: 131, Goiânia, Goiás, CEP 74690-900, Brazil.
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Rodrigues MVN, Rodrigues-Silva C, Boaventura S, Oliveira ASS, Rath S, Cass QB. On-Flow LC-MS/MS method for screening of xanthine oxidase inhibitors. J Pharm Biomed Anal 2020; 181:113097. [PMID: 31931446 DOI: 10.1016/j.jpba.2020.113097] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2019] [Revised: 12/16/2019] [Accepted: 01/05/2020] [Indexed: 11/15/2022]
Abstract
The screening of compounds is the initial step in research for the development of new drugs. For this reason, the availability of fast and reliable tools for the screening of a large number of compounds becomes essential. Among the therapeutic targets, the enzyme xanthine oxidase (XO) is of great interest for its importance as a biological source of superoxide radicals, which contribute to the oxidative stress on organisms and are involved in many pathological processes. In the present study, we validated a new method using an immobilized capillary enzyme reactor in an LC system directly coupled to triple quadrupole mass spectrometry to screen for XO ligands. The use of mass spectrometry provided selectivity and speed to the system, eliminating the analytical separation step. The Michaelis-Menten constant (KM) value determined for the immobilized enzyme was 14.5 ± 0.4 μmol L-1, which is consistent with the value previously reported for the XO-ICER with UV detection in a 2D LC method. The on-line approach was successfully applied to assay the XO inhibitory activities of thirty isolated compounds from different classes of natural products and provided greater productivity (288 analysis/day) than 2D LC method (84 analysis/day) of screened samples.
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Affiliation(s)
- Marili V N Rodrigues
- Divisão de Química Orgânica e Farmacêutica, Centro Pluridisciplinar de Pesquisas Químicas, Biológicas e Agrícolas -CPQBA, Universidade Estadual de Campinas-UNICAMP, Paulinia, 13148-218, São Paulo, Brazil.
| | - Caio Rodrigues-Silva
- Instituto de Química, Universidade Estadual de Campinas, Campinas, São Paulo, Brazil
| | - Sinésio Boaventura
- Divisão de Química Orgânica e Farmacêutica, Centro Pluridisciplinar de Pesquisas Químicas, Biológicas e Agrícolas -CPQBA, Universidade Estadual de Campinas-UNICAMP, Paulinia, 13148-218, São Paulo, Brazil
| | - Adriana S S Oliveira
- Divisão de Química Orgânica e Farmacêutica, Centro Pluridisciplinar de Pesquisas Químicas, Biológicas e Agrícolas -CPQBA, Universidade Estadual de Campinas-UNICAMP, Paulinia, 13148-218, São Paulo, Brazil
| | - Susanne Rath
- Instituto de Química, Universidade Estadual de Campinas, Campinas, São Paulo, Brazil
| | - Quezia B Cass
- Departamento de Química, Universidade Federal de São Carlos, Cx. Postal 676, São Carlos, 13565-905, São Paulo, Brazil
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New thiopyridine complexes: design, electrochemical preparation and biological assessment. POLISH JOURNAL OF CHEMICAL TECHNOLOGY 2019. [DOI: 10.2478/pjct-2019-0034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Abstract
Novel complexes of Ru (III), Cu (II) and Au (III) (2–4) were prepared using 6-phenyl-2-thioxo-4-(trifluoromethyl)-1,2-dihydropyridine-3-carbonitrile (HL, 1) adopting either electrochemical or traditional chemical methods. The electrochemical method is preferred in the synthesis of the complexes than the chemical one because it affords pure products with higher yields in shorter reaction time. The novel thiopyridine complexes were characterized by elemental analyses, IR, 1H, 19F-NMR, TGA and DTA measurements. The antimicrobial activity evaluation revealed that the complex bearing copper metal 3 has nearly the same activity as the reference drug ciprofloxacin. Anti-inflammatory activity evaluation showed that complex 4 containing gold displayed anti-inflammatory activity higher than the reference drug celecoxib upon using carrageenan rat hind paw edema method.
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de Moraes MC, Cardoso CL, Cass QB. Solid-Supported Proteins in the Liquid Chromatography Domain to Probe Ligand-Target Interactions. Front Chem 2019; 7:752. [PMID: 31803714 PMCID: PMC6873629 DOI: 10.3389/fchem.2019.00752] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2019] [Accepted: 10/21/2019] [Indexed: 12/11/2022] Open
Abstract
Ligand-target interactions play a central role in drug discovery processes because these interactions are crucial in biological systems. Small molecules-proteins interactions can regulate and modulate protein function and activity through conformational changes. Therefore, bioanalytical tools to screen new ligands have focused mainly on probing ligand-target interactions. These interactions have been evaluated by using solid-supported proteins, which provide advantages like increased protein stability and easier protein extraction from the reaction medium, which enables protein reuse. In some specific approaches, precisely in the ligand fishing assay, the bioanalytical method allows the ligands to be directly isolated from complex mixtures, including combinatorial libraries and natural products extracts without prior purification or fractionation steps. Most of these screening assays are based on liquid chromatography separation, and the binding events can be monitored through on-line or off-line methods. In the on-line approaches, solid supports containing the immobilized biological target are used as chromatographic columns most of the time. Several terms have been used to refer to such approaches, such as weak affinity chromatography, high-performance affinity chromatography, on-flow activity assays, and high-performance liquid affinity chromatography. On the other hand, in the off-line approaches, the binding event occurs outside the liquid chromatography system and may encompass affinity and activity-based assays in which the biological target is immobilized on magnetic particles or monolithic silica, among others. After the incubation step, the supernatant or the eluate from the binding assay is analyzed by liquid chromatography coupled to various detectors. Regardless of the selected bioanalytical approach, the use of solid supported proteins has significantly contributed to the development of automated and reliable screening methods that enable ligands to be isolated and characterized in complex matrixes without purification, thereby reducing costs and avoiding time-laborious steps. This review provides a critical overview of recently developed assays.
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Affiliation(s)
- Marcela Cristina de Moraes
- Laboratório SINCROMA, Instituto de Química, Departamento de Química Orgânica, Universidade Federal Fluminense, Niterói, Brazil
| | - Carmen Lucia Cardoso
- Grupo de Cromatografia de Bioafinidade e Produtos Naturais, Departamento de Química, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil
| | - Quezia Bezerra Cass
- Separare, Departamento de Química, Universidade Federal de São Carlos, São Carlos, Brazil
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Cathepsin D immobilized capillary reactors for on-flow screening assays. J Pharm Biomed Anal 2018; 151:252-259. [DOI: 10.1016/j.jpba.2018.01.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2017] [Revised: 12/29/2017] [Accepted: 01/01/2018] [Indexed: 11/16/2022]
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Correa RS, Freire V, Barbosa MIF, Bezerra DP, Bomfim LM, Moreira DRM, Soares MBP, Ellena J, Batista AA. Ru(ii)–thyminate complexes: new metallodrug candidates against tumor cells. NEW J CHEM 2018. [DOI: 10.1039/c7nj04368f] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Herein, we used thymine (HThy) as a ligand to form two new ruthenium(ii) complexes with formula [Ru(PPh3)2(Thy)(bipy)]PF6 (1) and [Ru(Thy)(bipy)(dppb)]PF6 (2).
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Affiliation(s)
- Rodrigo S. Correa
- Departamento de Química
- Universidade Federal de São Carlos – UFSCar
- Rodovia Washington Luís KM 235
- CP 676
- São Carlos
| | - Vitória Freire
- Departamento de Química
- Universidade Federal de São Carlos – UFSCar
- Rodovia Washington Luís KM 235
- CP 676
- São Carlos
| | | | - Daniel P. Bezerra
- Centro de Pesquisas Gonçalo Moniz
- Fundação Oswaldo Cruz (CPqGM-FIOCRUZ-BA)
- Salvador
- Brazil
| | - Larissa M. Bomfim
- Centro de Pesquisas Gonçalo Moniz
- Fundação Oswaldo Cruz (CPqGM-FIOCRUZ-BA)
- Salvador
- Brazil
| | - Diogo R. M. Moreira
- Centro de Pesquisas Gonçalo Moniz
- Fundação Oswaldo Cruz (CPqGM-FIOCRUZ-BA)
- Salvador
- Brazil
| | - Milena B. P. Soares
- Centro de Pesquisas Gonçalo Moniz
- Fundação Oswaldo Cruz (CPqGM-FIOCRUZ-BA)
- Salvador
- Brazil
- Centro de Biotecnologia e Terapia Celular
| | - Javier Ellena
- Departamento de Física e Informática
- Instituto de Física de São Carlos
- Universidade de São Paulo
- CP 369
- São Carlos
| | - Alzir A. Batista
- Departamento de Química
- Universidade Federal de São Carlos – UFSCar
- Rodovia Washington Luís KM 235
- CP 676
- São Carlos
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Dos Santos ER, Corrêa RS, Ribeiro JU, Graminha AE, Ellena J, Selistre-de-Araujo HS, Batista AA. Ru(II)/bisphosphine/diimine/amino acid complexes: diastereoisomerism, cytotoxicity, and inhibition of tumor cell adhesion to collagen type I. J COORD CHEM 2016. [DOI: 10.1080/00958972.2016.1244334] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Affiliation(s)
| | - Rodrigo S. Corrêa
- Departamento de Química, ICEB, Universidade Federal de Ouro Preto, Ouro Preto, Brazil
| | - Juliana U. Ribeiro
- Departamento de Química, Universidade Federal de São Carlos, São Carlos, Brazil
| | | | - Javier Ellena
- Departamento de Física e Informática, Instituto de Física de São Carlos, Universidade de São Paulo, São Carlos, Brazil
| | | | - Alzir A. Batista
- Departamento de Química, Universidade Federal de São Carlos, São Carlos, Brazil
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Rodrigues MVN, Barbosa AF, da Silva JF, dos Santos DA, Vanzolini KL, de Moraes MC, Corrêa AG, Cass QB. 9-Benzoyl 9-deazaguanines as potent xanthine oxidase inhibitors. Bioorg Med Chem 2015; 24:226-31. [PMID: 26712096 DOI: 10.1016/j.bmc.2015.12.006] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2015] [Revised: 11/23/2015] [Accepted: 12/05/2015] [Indexed: 11/28/2022]
Abstract
A novel potent xanthine oxidase inhibitor, 3-nitrobenzoyl 9-deazaguanine (LSPN451), was selected from a series of 10 synthetic derivatives. The enzymatic assays were carried out using an on-flow bidimensional liquid chromatography (2D LC) system, which allowed the screening¸ the measurement of the kinetic inhibition constant and the characterization of the inhibition mode. This compound showed a non-competitive inhibition mechanism with more affinity for the enzyme-substrate complex than for the free enzyme, and inhibition constant of 55.1±9.80 nM, about thirty times more potent than allopurinol. Further details of synthesis and enzymatic studies are presented herein.
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Affiliation(s)
- Marili V N Rodrigues
- Centro Pluridisciplinar de Pesquisas Químicas, Biológicas e Agrícolas, Universidade Estadual de Campinas, 13148-218 Paulínia, SP, Brazil; Separare-Nucleo de Pesquisa em Cromatografia, Departamento de Química, Universidade Federal de São Carlos, 13565-905 São Carlos, SP, Brazil
| | - Alexandre F Barbosa
- Laboratório de Síntese de Produtos Naturais-LSPN, Departamento de Química, Universidade Federal de São Carlos, 13565-905 São Carlos, SP, Brazil
| | - Júlia F da Silva
- Laboratório de Síntese de Produtos Naturais-LSPN, Departamento de Química, Universidade Federal de São Carlos, 13565-905 São Carlos, SP, Brazil
| | - Deborah A dos Santos
- Laboratório de Síntese de Produtos Naturais-LSPN, Departamento de Química, Universidade Federal de São Carlos, 13565-905 São Carlos, SP, Brazil
| | - Kenia L Vanzolini
- Separare-Nucleo de Pesquisa em Cromatografia, Departamento de Química, Universidade Federal de São Carlos, 13565-905 São Carlos, SP, Brazil
| | - Marcela C de Moraes
- Separare-Nucleo de Pesquisa em Cromatografia, Departamento de Química, Universidade Federal de São Carlos, 13565-905 São Carlos, SP, Brazil; Departamento de Química Orgânica, Instituto de Química, Universidade Federal Fluminense, 24020-141 Niterói, RJ, Brazil
| | - Arlene G Corrêa
- Laboratório de Síntese de Produtos Naturais-LSPN, Departamento de Química, Universidade Federal de São Carlos, 13565-905 São Carlos, SP, Brazil.
| | - Quezia B Cass
- Separare-Nucleo de Pesquisa em Cromatografia, Departamento de Química, Universidade Federal de São Carlos, 13565-905 São Carlos, SP, Brazil.
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