Table 2

Pseudo first-order rate constants for decay of cleavable complexes stabilized by 7,10-disubstituted CPTs

Camptothecin Analog	Rate Constant τ
Camptothecin Analog	From plasmid^2-a	From nuclei^2-b
	min⁻¹
CPT	0.061 ± 0.010	0.130 ± 0.013
C1CPT	0.066 ± 0.008
C2CPT	0.034 ± 0.006
C3CPT	0.024 ± 0.009
C4CPT	0.050 ± 0.005
OHCPT	0.082 ± 0.004
OHC1CPT	0.108 ± 0.012
OHC2CPT	0.061 ± 0.013
OHC3CPT	0.064 ± 0.006
OHC4CPT	0.058 ± 0.010
OMeCPT	0.131 ± 0.017
OMeC1CPT	0.054 ± 0.012
OMeC2CPT	0.044 ± 0.006
OMeC3CPT	0.054 ± 0.014
OMeC4CPT	0.045 ± 0.024
MDCPT	0.028 ± 0.007	0.036 ± 0.011
MDC1CPT	0.049 ± 0.008
MDC2CPT	0.040 ± 0.006	0.045 ± 0.019
MDC3CPT	0.114 ± 0.012
MDC4CPT	0.045 ± 0.009
CMMD (chloromethyl)	0.277 ± 0.048	0.088 ± 0.011

↵2-a Disappearance of cleavable complexes with time after addition of 100-fold excess sheared salmon sperm DNA.
↵2-b Disappearance of PDCs in CEM nuclei after suspension of nuclei in drug-free buffer.