Table 2

Stereoselectivity of GST-mediated PNU-109112 sulfonamide cleavage

StereoisomerRelative Rate (Normalized to PNU-109111)
PNU-109111 (3′R,6S)1.0
PNU-109112 (3′R,6R)2.2
PNU-109113 (3′S,6S)1.1
PNU-109114 (3′S,6R)1.2
PNU-1081602-b 1.2

Each stereoisomer (50 μM) was incubated with 0.5 mM GSH, 0.02 mg (0.6 U)2-a of purified rat liver GST (Sigma)/ml for 60 min at 37°C, in 10 mM phosphate buffer, pH 7.4.

  • ↵2-a 1 U = 1 μmol CDNB/min at pH 6.5, 25 °C

  • ↵2-b Racemic mixture of all four stereoisomers.