Structure determination of a diuretic-glutathione conjugate by mass and n.m.r. spectrometry

Abstract

1. A glutathione (GSH) conjugate of the uricosuric diuretic DBCA 6,7-dichloro-5(N,N-dimethylsulphamoyl)-2,3-dihydrobenzofuran-2-carboxylic acid, formed enzymically in rat liver 10000g supernatant fortified with GSH, was purified by t.l.c. and h.p.l.c.

2. According to mass spectrometry the composition of the GSH-conjugate corresponded to C₂₁H₂₉N₄O₁₁S₂Cl₂. ¹H- and ¹³C-n.m.r. studies gave the structure of the conjugate as 2-glutathionyl-3-[3,4-dichloro-5-(N,N-dimethyl sulphamoyl)2-hydroxy phenyl]-propionic acid, which indicates that GSH was bound to the chiral centre carbon and caused scission of the C-O bond in the dihydrofuran ring.