Gas-phase reactivity of 2-hydroxy-1,4-naphthoquinones: a computational and mass spectrometry study of lapachol congeners

Autor(es)

Vessecchi, Ricardo ^[1] ; Emery, Flavio S. ^[2] ; Galembeck, Sergio E. ^[3] ; Lopes, Norberto P. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Fac Ciencias Farmaceut Ribeirao Preto, Dept Fis & Quim, Nucleo Pesquisa Prod Nat & Sintet, BR-14040903 Ribeirao Preto, SP - Brazil

^[2] Univ Sao Paulo, Fac Ciencias Farmaceut Ribeirao Preto, Dept Ciencias Farmaceut, BR-14040903 Ribeirao Preto, SP - Brazil

^[3] Univ Sao Paulo, Fac Filosofia Ciencias & Letras Ribeirao Preto, Dept Quim, BR-14040903 Ribeirao Preto, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Journal of Mass Spectrometry; v. 47, n. 12, p. 1648-1659, DEC 2012.
• Citações Web of Science: 14

Resumo

In order to understand the influence of alkyl side chains on the gas-phase reactivity of 1,4-naphthoquinone derivatives, some 2-hydroxy-1,4-naphthoquinone derivatives have been prepared and studied by electrospray ionization tandem mass spectrometry in combination with computational quantum chemistry calculations. Protonation and deprotonation sites were suggested on the basis of gas-phase basicity, proton affinity, gas-phase acidity (?Gacid), atomic charges and frontier orbital analyses. The nature of the intramolecular interaction as well as of the hydrogen bond in the systems was investigated by the atoms-in-molecules theory and the natural bond orbital analysis. The results were compared with data published for lapachol (2-hydroxy-3-(3-methyl-2-butenyl)-1,4-naphthoquinone). For the protonated molecules, water elimination was verified to occur at lower proportion when compared with side chain elimination, as evidenced in earlier studies on lapachol. The side chain at position C(3) was found to play important roles in the fragmentation mechanisms of these compounds. Copyright (c) 2012 John Wiley \& Sons, Ltd. (AU)

• Processo FAPESP: 09/08281-3 - Reatividade em fase gasosa do lapachol e derivados quinonóides ionizados por electrospray: Sinergismo entre termoquímica computacional e métodos experimentais
• Beneficiário: Ricardo Vessecchi Lourenço
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado