Drug Metabolism in Drug Design and Development Basic Concepts and Practice

14.1.5 Notes

(1) Investigators may use a mixture of GSH and its stable labeled analog

(L-g-glutamyl-L-cysteinyl-glycine-^13 C 2 ^15 N) at a ratio of 1:1 (Yan and

Caldwell, 2004).

(2) Control experiments are conducted to evaluate the NADPH dependency

for adduct formations.

TABLE 14.1 Quantitative analysis of dGSH adducts of model compounds.a
(Gan et al, 2005)

Compound

Retention

time (min)

Mass

(Da)

Postulated

adduct

composition

Adduct

concentration

(mM)

%of

substrate

concentration

Troglitazone

19.5 0.16

22.5 0.05

23.0 0.04

29.3 979 M+dGSH-2H 5.98

Total 6.23 12.5

Acetaminophen 11.9 689 M+dGSH-2H 0.26 0.5
Bromobenzene 18.5 726 M+dGSH

• 2O-2H

0.10 0.2

Clozapine

15.1 864 M+dGSH-2H 4.39

16.2 880 M+dGSH

+ O-2H

0.44

19.5 0.09

Total 4.92 9.8

Diclofenac

22.7 815 M+dGSH

+ O-HCl

0.64

23.8 849 M+dGSH

+ O-2H

0.11

Total 0.75 1.5

Precocene I

14.7 0.16

15.1 732 M+dGSH

+ O-CH 2

0.95

16.4 732 M+dGSH

+ O-CH 2

1.44

17.7 762 M+dGSH

+2O

0.29

22.4 746 M+dGSH+O 0.38

Total 3.22 6.4

R-(+)-Pulegone 28.9 688 M+dGSH-4H 4.90 9.8

aAdduct concentrations are taken as average of two determinations. Adduct masses were
determined by full scan mass spectrometry in the negative ion mode.

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