title: Fate and kinetic modeling of reactivity of alkanesulfenic acids and thiosulfinates in model systems and onion homogenates.
abstract: The dynamic changes in thiosulfinate profiles were studied in reaction systems containing a crude onion alliinase, S-alk(en)yl-L-cysteine sulfoxide substrates (1) and preformed thiosulfinates (4). Regioisomeric excesses of one of two possible heterologous 4 species (RS(O)SR', where R does not equal R') could be manipulated under conditions where alliinase, 1, and 4 levels were varied. Regioisomeric excesses could be explained by a thiosulfinate (4)/alkanesulfenic acid (2) trapping mechanism, with the greatest control over product profile governed by the rate of 2 generation in the system. The series of reactions existing in this dynamic reaction system was kinetically modeled with reasonable fits to the experimental data. The application of the 4/2 trapping strategy to manipulate thiosulfinate and related organosulfur product profiles in diluted onion homogenates was demonstrated using exogenous MeS(O)SMe (4a), PrS(O)SPr (4c), and AllS(O)SAll (4d) as the preformed thiosulfinate.
authors.affiliation: Department of Food Science, University of Wisconsin-Madison, Babcock Hall, 1605 Linden Drive, Madison, WI 53706, USA.
authors.forename: Cunxi
authors.initials: C
authors.lastname: Shen
authors.forename: Zongxuan
authors.initials: Z
authors.lastname: Hong
authors.forename: Kirk L
authors.initials: KL
authors.lastname: Parkin
mesh_terms: D000473:Alkanes / Q000737:chemistry / Q000378:metabolism*; D000490:Allium / Q000737:chemistry*; D013437:Carbon-Sulfur Lyases / Q000378:metabolism; D007700:Kinetics; D008956:Models, Chemical; D013434:Sulfenic Acids / Q000737:chemistry / Q000378:metabolism*; D013441:Sulfinic Acids / Q000737:chemistry / Q000378:metabolism*
chemical_list: D000473:Alkanes; D013434:Sulfenic Acids; D013441:Sulfinic Acids; C100040:thiosulfinic acids; D013437:Carbon-Sulfur Lyases; C019243:alliin lyase