Determination of the pKa values of some biologically active and inactive hydroxyquinones

Detalhes bibliográficos
Autor(a) principal: Ossowski,Tadeusz
Data de Publicação: 2008
Outros Autores: Goulart,Marília O. F., Abreu,Fabiane C. de, Sant’Ana,Antônio Euzébio G., Miranda,Paulo Rogério B., Costa,Cicero de Oliveira, Liwo,Adam, Falkowski,Piotr, Zarzeczanska,Dorota
Tipo de documento: Artigo
Idioma: eng
Título da fonte: Journal of the Brazilian Chemical Society (Online)
Texto Completo: http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0103-50532008000100025
Resumo: The apparent dissociation constants (pKa) of four 2-hydroxynaphthoquinones, differently substituted at C-3, were determined in water:ethanol (1:1, v/v) solutions by pH-metric and hybrid pH-metric/UV titration methods. Isolapachol (pKa < 6) was more acidic than lapachol (pKa > 6). Two pKa values were determined for each of the methylamino-derivatives investigated, the first relating to the enol function and the second to the ammonium salt. It was determined that under physiological pH, these derivatives would be to a large extension, zwitterionic. The possible effects of the measured parameters on the biological activities of the studied compounds are discussed.
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spelling Determination of the pKa values of some biologically active and inactive hydroxyquinonesacid dissociation constantshydroxyquinonespH-metric titrationhybrid pH-metric/UV titrationmolluscicidal activityThe apparent dissociation constants (pKa) of four 2-hydroxynaphthoquinones, differently substituted at C-3, were determined in water:ethanol (1:1, v/v) solutions by pH-metric and hybrid pH-metric/UV titration methods. Isolapachol (pKa < 6) was more acidic than lapachol (pKa > 6). Two pKa values were determined for each of the methylamino-derivatives investigated, the first relating to the enol function and the second to the ammonium salt. It was determined that under physiological pH, these derivatives would be to a large extension, zwitterionic. The possible effects of the measured parameters on the biological activities of the studied compounds are discussed.Sociedade Brasileira de Química2008-01-01info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersiontext/htmlhttp://old.scielo.br/scielo.php?script=sci_arttext&pid=S0103-50532008000100025Journal of the Brazilian Chemical Society v.19 n.1 2008reponame:Journal of the Brazilian Chemical Society (Online)instname:Sociedade Brasileira de Química (SBQ)instacron:SBQ10.1590/S0103-50532008000100025info:eu-repo/semantics/openAccessOssowski,TadeuszGoulart,Marília O. F.Abreu,Fabiane C. deSant’Ana,Antônio Euzébio G.Miranda,Paulo Rogério B.Costa,Cicero de OliveiraLiwo,AdamFalkowski,PiotrZarzeczanska,Dorotaeng2008-03-10T00:00:00Zoai:scielo:S0103-50532008000100025Revistahttp://jbcs.sbq.org.brONGhttps://old.scielo.br/oai/scielo-oai.php||office@jbcs.sbq.org.br1678-47900103-5053opendoar:2008-03-10T00:00Journal of the Brazilian Chemical Society (Online) - Sociedade Brasileira de Química (SBQ)false
dc.title.none.fl_str_mv Determination of the pKa values of some biologically active and inactive hydroxyquinones
title Determination of the pKa values of some biologically active and inactive hydroxyquinones
spellingShingle Determination of the pKa values of some biologically active and inactive hydroxyquinones
Ossowski,Tadeusz
acid dissociation constants
hydroxyquinones
pH-metric titration
hybrid pH-metric/UV titration
molluscicidal activity
title_short Determination of the pKa values of some biologically active and inactive hydroxyquinones
title_full Determination of the pKa values of some biologically active and inactive hydroxyquinones
title_fullStr Determination of the pKa values of some biologically active and inactive hydroxyquinones
title_full_unstemmed Determination of the pKa values of some biologically active and inactive hydroxyquinones
title_sort Determination of the pKa values of some biologically active and inactive hydroxyquinones
author Ossowski,Tadeusz
author_facet Ossowski,Tadeusz
Goulart,Marília O. F.
Abreu,Fabiane C. de
Sant’Ana,Antônio Euzébio G.
Miranda,Paulo Rogério B.
Costa,Cicero de Oliveira
Liwo,Adam
Falkowski,Piotr
Zarzeczanska,Dorota
author_role author
author2 Goulart,Marília O. F.
Abreu,Fabiane C. de
Sant’Ana,Antônio Euzébio G.
Miranda,Paulo Rogério B.
Costa,Cicero de Oliveira
Liwo,Adam
Falkowski,Piotr
Zarzeczanska,Dorota
author2_role author
author
author
author
author
author
author
author
dc.contributor.author.fl_str_mv Ossowski,Tadeusz
Goulart,Marília O. F.
Abreu,Fabiane C. de
Sant’Ana,Antônio Euzébio G.
Miranda,Paulo Rogério B.
Costa,Cicero de Oliveira
Liwo,Adam
Falkowski,Piotr
Zarzeczanska,Dorota
dc.subject.por.fl_str_mv acid dissociation constants
hydroxyquinones
pH-metric titration
hybrid pH-metric/UV titration
molluscicidal activity
topic acid dissociation constants
hydroxyquinones
pH-metric titration
hybrid pH-metric/UV titration
molluscicidal activity
description The apparent dissociation constants (pKa) of four 2-hydroxynaphthoquinones, differently substituted at C-3, were determined in water:ethanol (1:1, v/v) solutions by pH-metric and hybrid pH-metric/UV titration methods. Isolapachol (pKa < 6) was more acidic than lapachol (pKa > 6). Two pKa values were determined for each of the methylamino-derivatives investigated, the first relating to the enol function and the second to the ammonium salt. It was determined that under physiological pH, these derivatives would be to a large extension, zwitterionic. The possible effects of the measured parameters on the biological activities of the studied compounds are discussed.
publishDate 2008
dc.date.none.fl_str_mv 2008-01-01
dc.type.driver.fl_str_mv info:eu-repo/semantics/article
dc.type.status.fl_str_mv info:eu-repo/semantics/publishedVersion
format article
status_str publishedVersion
dc.identifier.uri.fl_str_mv http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0103-50532008000100025
url http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0103-50532008000100025
dc.language.iso.fl_str_mv eng
language eng
dc.relation.none.fl_str_mv 10.1590/S0103-50532008000100025
dc.rights.driver.fl_str_mv info:eu-repo/semantics/openAccess
eu_rights_str_mv openAccess
dc.format.none.fl_str_mv text/html
dc.publisher.none.fl_str_mv Sociedade Brasileira de Química
publisher.none.fl_str_mv Sociedade Brasileira de Química
dc.source.none.fl_str_mv Journal of the Brazilian Chemical Society v.19 n.1 2008
reponame:Journal of the Brazilian Chemical Society (Online)
instname:Sociedade Brasileira de Química (SBQ)
instacron:SBQ
instname_str Sociedade Brasileira de Química (SBQ)
instacron_str SBQ
institution SBQ
reponame_str Journal of the Brazilian Chemical Society (Online)
collection Journal of the Brazilian Chemical Society (Online)
repository.name.fl_str_mv Journal of the Brazilian Chemical Society (Online) - Sociedade Brasileira de Química (SBQ)
repository.mail.fl_str_mv ||office@jbcs.sbq.org.br
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