title: Preparation of 7-hydroxy-2-oxoindolin-3-ylacetic acid and its [13C2], [5-n-3H], and [5-n-3H]-7-O-glucosyl analogues for use in the study of indol-3-ylacetic acid catabolism.
abstract: An improved synthesis of 7-hydroxy-2-oxoindolin-3-ylacetic acid via the base-induced condensation reaction between oxalate esters and 7-benzyloxyindolin-2-one is described.  7-Benzyloxyindolin-2-one was prepared in four steps and 50% overall yield from 3-hydroxy-2-nitrotoluene.  The yield of the title compound from 7-benzyloxyindolin-2-one was 56%.  This route was used to prepare 7-hydroxy-2-oxoindolin-3-yl[13C2]acetic acid in 30% yield from [13C2]oxalic acid dihydrate.  The method could not be extended to the preparation of the corresponding [14C2]-compound.  However, an enzyme preparation from Zea mays roots catalysed the conversion of carrier-free [5-n-3H]indol-3-ylacetic acid with a specific activity of 16.7 Ci mmol-1 to a mixture of 7-hydroxy-2-oxo[5-n-3H]indolin-3-ylacetic acid and its [5-n-3H]-7-O-glucoside in ca. 3 and 40% radiochemical yield respectively.  The glucoside was converted into the 7-hydroxy compound in 80% yield by means of beta-glucosidase.
authors.affiliation: Department of Botany and Plant Pathology, Michigan State University, East Lansing 48824-1312, USA.
authors.forename: P
authors.initials: P
authors.lastname: Lewer
mesh_terms: D006897:Hydroxyindoleacetic Acid / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000378:metabolism; D007210:Indoleacetic Acids / Q000378:metabolism*; D010937:Plant Growth Regulators / Q000378:metabolism*; D018517:Plant Roots / Q000378:metabolism; D003313:Zea mays / Q000378:metabolism*
chemical_list: D007210:Indoleacetic Acids; D010937:Plant Growth Regulators; D006897:Hydroxyindoleacetic Acid; C030737:indoleacetic acid; C046777:7-hydroxy-2-oxoindole-3-acetic acid 7'-O-glucopyranoside