4948 J ournal of Medicinal Chemistry, 2002, Vol. 45, No. 23
Letters
Sch em e 1a
Ta ble 1. Antiapoptotic Effect of Various Benzylindazole
Compounds on the Sodium Nitroprusside-Mediated Apoptosis
of VSMCsa
cell survival
compd
R
R′
R′′
(% of control)
SNP
22
23
24
25
26
27
29
30
31
17
41.3 ( 3.7
-H
-H
-H
-H
-H
-CH2OH
94.7 ( 7.6**
93.9 ( 10.4**
83.3 ( 1.5**
84.5 ( 10.3**
75.8 ( 1.5**
93.2 ( 9.1**
57.2 ( 7.6
-H
-F
-CH2OH
-CH2OH
-OCH3 -CH2OH
-CH2OH
-H
-H
-H
-H
-H
-OCH2O-
-H
-CH2OCH3
-CH2NHCH3
-H
-H
-CH2N(CH2CH3)2 39.7 ( 8.3
-H
-CH3
-COOCH3
31.1 ( 7.6
78.0 ( 10.6*
-H
a
Effects of SNP and benzylindazole derivatives on the survival
of rat aortic smooth muscle cells. Cells were pretreated with
benzylindazole derivatives (30 µM) for 30 min. Then, vehicle or
SNP (1 mM) was added for another 24 h. After the incubation
period, cell viability was assayed by the MTT assay and TUNEL
techniques. Data are expressed as mean ( SEM of 5-7 determi-
nations (each in triplicate). * p < 0.01 and ** p < 0.001 as
compared with SNP alone.
a
Reagents: (a) FeCl3, CH2Cl2, reflux. (b) HOAc, MeOH, reflux.
(c) Pb(OAc)4, CH2Cl2, 30 °C. (d) BF3‚Et2O, reflux. (e) Ca(BH4)2,
THF, reflux. (f) Compound 22 reacts with NaH and MeI in THF
in a ice bath to afford 27; 22 reacts with BCl3 in CH2Cl2 to afford
28; 28 reacts with MeNH2 or Et2NH to afford 29 or 30; 28 reacts
with H2/Pd-C in THF to afford 31.
group of compound 22 into -COOCH3 (17) slightly
reduced its activity to the level of compound 26.
ketones (6-9) were treated with appropriate hydrazines
(10 and 11) to yield the corresponding hydrazones (12-
16) as mixtures of E- and Z-isomers. These hydrazones
(12-16) were then treated with Pb(OAc)4 in CH2Cl2 at
low temperature. Subsequently, BF3‚Et2O was added,
and the mixture was heated to yield the desired inda-
zoles (17-21) via cyclization. The indazoles (17-21)
were then reduced with Ca(BH4)2 to afford the corre-
sponding carbinol derivatives (22-26).
The -CH2OH group of compound 22 was modified to
give its corresponding methoxy methyl derivative (27).
Meanwhile, intermediate 28, obtained by treating 22
with BCl3, was either treated with alkylamine to give
its alkylaminomethyl derivatives (29 and 30) or hydro-
genated to yield the 5′-methyl derivative (31).
After screening the above derivatives for their inhibi-
tory effect on SNP-induced apoptosis, we concluded that
compound 22 together with compounds 27 and 23 were
the most effective inhibitors of SNP-induced apoptosis.
In a preliminary in vivo study, the intraperitoneal
application of LPS (60 mg/kg) caused death in all mice
within 24 h (n ) 9). However, oral administration of
compound 22 (10 mg/kg) at 6 h after LPS application
markedly decreased the septic death rate (66.7%) in
mice. A complete report of our in vivo study will be
published elsewhere. The present work demonstrated
remarkable therapeutic potential for compound 22
derivatives in the treatment of sepsis and suggested
that these drugs may be developed for clinical use soon.
An tia p op totic Effect. As shown in Table 1, at a
concentration of 30 µM, compound 22 almost completely
reversed the SNP-induced apoptosis of VSMCs. Replace-
ment of the 1-benzyl group with a phenyl group resulted
in compound 23 with similar activity as compound 22.
Introduction of F (24) or OCH3 (25) groups into the
6-position of compound 22 resulted in slightly reduced
potency. Replacement of the 5- and 6-substituents of
compound 22 with a bridging -OCH2O- group provided
compound 26 with even lower activity. On the other
hand, converting the -CH2OH group of compound 22
into -CH2OCH3 (27) retained the activity of compound
22. Subsequent conversion of compound 27 to -CH2-
NHCH3 (29) resulted in significantly reduced activity,
and conversion to -CH2N(CH2CH3)2 (30) impaired its
activity further. Conversion of the -CH2OH group of
compound 22 into -CH3 (31) produced a cytotoxic effect
in VSMC and caused considerable reduction in anti-
apoptotic activity. Finally, conversion of the -CH2OH
Su p p or tin g In for m a tion Ava ila ble: Synthetic methods,
yields, and complete physical and spectral data for compounds
6-31. Experimental details for cell culture, cytotoxicity assay,
and statistical analysis. This material is available free of
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