Wu Wang1, Ivan Kourtchev1, Bim Graham2, Jan Cafmeyer3, Willy Maenhaut3, M. Claeys1
1Department of Pharmaceutical Sciences, University of Antwerp (Campus Drie Eiken), Universiteitsplein 1, B–2610 Antwerp, Belgium
2Biogeochemistry, Max Planck Institute for Chemistry, Max Planck Society
3Department of Analytical Chemistry, Institute for Nuclear Sciences, Ghent University, Proeftuinstraat 86, B–9000 Gent, Belgium
Tóm tắt
AbstractIn the present study, we have tentatively identified the structures of three oxygenated derivatives of isoprene in Amazonian rain forest aerosols as the C5 alkene triols, 2‐methyl‐1,3,4‐trihydroxy‐1‐butene (cis and trans) and 3‐methyl‐2,3,4‐trihydroxy‐1‐butene. The formation of these oxygenated derivatives of isoprene can be explained by acid‐catalyzed ring opening of epoxydiol derivatives of isoprene, namely, 1,2‐epoxy‐2‐methyl‐3,4‐dihydroxybutane and 1,2‐dihydroxy‐2‐methyl‐3,4‐epoxybutane. The structural proposals of the C5 alkene triols were based on chemical derivatization reactions and detailed interpretation of electron and chemical ionization mass spectral data, including data obtained from first‐order mass spectra, deuterium labeling of the trimethylsilyl methyl groups, and MS2 ion trap experiments. The characterization of 2‐methyl‐1,3,4‐trihydroxy‐1‐butene (cis and trans) and 3‐methyl‐2,3,4‐trihydroxy‐1‐butene in forest aerosols is important from an atmospheric chemistry viewpoint in that these compounds hint at the formation of intermediate isomeric epoxydiol derivatives of isoprene and as such provide mechanistic insights into the formation of the previously reported 2‐methyltetrols through photooxidation of isoprene. Copyright © 2005 John Wiley & Sons, Ltd.
