An extended π-system and enhanced electronic delocalization on symmetric [Ru3O(CH3COO)6(L)3]n complexes combined with azanaphthalene ligands

FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOWe report on the investigation of a new series of symmetric trinuclear ruthenium complexes combined with azanaphthalene ligands: [Ru3O(CH3COO)6(L)3]PF6where L = (1) quinazoline (qui), (2) 5-nitroisoquinoline (5-nitroiq), (3) 5-bromoisoquinoline (5-briq),462479267938FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOFAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO2015/20302-72013/22127-2305415/2015-

Precursor Ion Scan Mode-Based Strategy for Fast Screening of Polyether Ionophores by Copper-Induced Gas-Phase Radical Fragmentation Reactions

The potential of copper­(II) to induce gas-phase fragmentation reactions in macrotetrolides, a class of polyether ionophores produced by Streptomyces species, was investigated by accurate-mass electrospray tandem mass spectrometry (ESI-MS/MS). Copper­(II)/copper­(I) transition directly induced production of diagnostic acylium ions with <i>m</i>/<i>z</i> 199, 185, 181, and 167 from α-cleavages of [macrotetrolides + Cu]²⁺. A UPLC-ESI-MS/MS methodology based on the precursor ion scan of these acylium ions was developed and successfully used to identify isodinactin (<b>1</b>), trinactin (<b>2</b>), and tetranactin (<b>3</b>) in a crude extract of Streptomyces sp. AMC 23 in the precursor ion scan mode. In addition, copper­(II) was also used to induce radical fragmentation reactions in the carboxylic acid polyether ionophore nigericin. The resulting product ions with <i>m</i>/<i>z</i> 755 and 585 helped to identify nigericin in a crude extract of Streptomyces sp. Eucal-26 by means of precursor ion scan experiments, demonstrating that copper-induced fragmentation reactions can potentially identify different classes of polyether ionophores rapidly and selectively