Marcos Di Falco

Publications (2)7.91 Total impact

• Article: Multiple losses of neutral C14H14 in the tandem mass spectrometry of several perbenzyl ether intermediates in the synthesis of green tea constituents.

  Alain Lesimple, Marcos Di Falco, Yannick Richard, Souad Lesimple, Zhigang Wang, Tak Hang Chan, Orval A Mamer
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  ABSTRACT: Electrospray and matrix-assisted laser desorption/ionization (MALDI) tandem mass spectrometry (MS/MS) experiments were used to investigate an unusual fragmentation in collision-induced dissociation (CID) of sodiated and potassiated perbenzyl ether intermediates obtained in the total synthesis of gallate ester constituents of green tea. Prominent fragments correspond to multiple sequential losses of neutral C14H14 that were not observed in the protonated and ammoniated species, that instead present fragment ion series in which members are separated by C7H6. High-resolution MALDI quadrupole time-of-flight (Q-TOF) and electrospray-Fourier transform mass spectrometry (FTMS) were used to confirm elemental compositions of these and related ions.
  Rapid Communications in Mass Spectrometry 02/2005; 19(22):3253-8. · 2.79 Impact Factor
• Article: Protein carbonyl formation in the diaphragm.

  Esther Barreiro, Joaquim Gea, Marcos Di Falco, Leonid Kriazhev, Susan James, Sabah N A Hussain
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  ABSTRACT: Although protein carbonyl formation is an index of oxidative stress in skeletal muscles, the exact proteins, which undergo oxidation in these muscles, remain unknown. We used 2D electrophoresis, immunoblotting, and mass spectrometry to identify carbonylated proteins in the diaphragm in septic animals. Rats were injected with saline (control) or Escherichia coli lipopolysaccharides (LPS) and killed after various intervals. Diaphragm protein carbonylation increased significantly and peaked 12 h after LPS injection, and it was localized both inside muscle fibers and in blood vessels supplying muscle fibers. Aldolase A, glyceraldehyde 3-phosphate dehydrogenase, enolase 3beta, mitochondrial and cytosolic creatine kinases, alpha-actin, carbonic anyhdrase III, and ubiquinol-cytochrome c reductase were all carbonylated in septic rat diaphragms. In addition, we found significant negative correlations between the intensity of carbonylation and creatine kinase and aldolase activities. We conclude that glycolysis, ATP production, CO2 hydration, and contractile proteins are targeted by oxygen radicals inside the diaphragm during sepsis.
  American Journal of Respiratory Cell and Molecular Biology 02/2005; 32(1):9-17. · 5.13 Impact Factor