Novel calcium antagonists with both calcium overload inhibition and antioxidant activity. 1. 2-(3,5-Di-tert-butyl-4-hydroxyphenyl)-3- (aminopropyl)thiazolidinones

Article abstract of DOI:10.1021/jm980335f

A series of 2-(3,5-di-tert-butyl-4-hydroxyphenyl)-3- (aminopropyl)thiazolidinones was synthesized in order to explore novel calcium antagonists with potent antiischemic activity. These compounds were designed to have, in addition to Ca²⁺ antago

Full text of DOI:10.1021/jm980335f

J . Med. Chem. 1998, 41, 4309-4316
4309
Novel Ca lciu m An ta gon ists w ith Both Ca lciu m Over loa d In h ibition a n d
An tioxid a n t Activity. 1.
2-(3,5-Di-ter t-bu tyl-4-h yd r oxyp h en yl)-3-(a m in op r op yl)th ia zolid in on es
Tatsuya Kato,* Tomokazu Ozaki, Kazuhiko Tamura, Yoshiyuki Suzuki, Michitaka Akima, and Nobuhiro Ohi
Fuji Gotemba Research Laboratories, Chugai Pharmaceutical Company, Ltd., 135, 1-Chome Komakado, Gotemba City,
Shizuoka 412-8513, J apan
Received J une 1, 1998
A series of 2-(3,5-di-tert-butyl-4-hydroxyphenyl)-3-(aminopropyl)thiazolidinones was synthesized
in order to explore novel calcium antagonists with potent antiischemic activity. These
compounds were designed to have, in addition to Ca2+ antagonistic activity, both Ca2+ overload
prevention and antioxidant activity in one molecule. These three kinds of activity were
evaluated by using a K+-depolarized rat aorta, a veratridine-induced Ca2+ overload model of
rat cardiomyocytes, and a soybean lipoxygenase-induced lipid peroxidation model of rabbit low-
density lipoprotein, respectively. In particular, 2-(3,5-di-tert-butyl-4-hydroxyphenyl)-3-[3-[N-
methyl-N-[2-[3,4-(methylenedioxy)phenoxy]ethyl]amino]propyl]-1,3-thiazolidin-4-one (7o) was
found to be highly potent and possessed a well-balanced combination of these actions in vitro.
In tr od u ction
structural features of diltiazem (3) and related com-
pounds (e.g., SA2572 (4) and semotiadil (5)),12 a sulfur-
and nitrogen-containing heterocycle linked to a phenyl
ring and an amine group were identified as probable
important elements for the activity of Ca2+ antagonism.
A profound imbalance between supply and demand
for oxygen in the myocardium plays a critical role in
ischemic heart diseases (IHD) such as angina pectoris
and myocardial infarction.1 Ca2+ antagonists, which
increase oxygen supply and decrease oxygen consump-
tion in myocardium, have been widely used in the
treatment of IHD.2 They have been advocated as
cardioprotective agents against ischemia on the basis
of animal experiments.3 However, it has not yet been
demonstrated that Ca2+ antagonists significantly impact
mortality in long-term clinical studies after infarction.4
On reperfusion of the ischemic heart tissue, a marked
increase in the generation of oxygen free radicals
(oxidative stress) and an extraordinary accumulation of
intracellular calcium ions (Ca2+ overload) have been
observed.5 Recent studies suggest that both the oxida-
tive stress and the Ca2+ overload are causally related
to the resultant structural damage of cardiomyocytes
and functional failure of the heart that occur under such
pathological conditions.6 Existing Ca2+ antagonists,
however, have little or no inhibitory effect against Ca2+
overload or oxidative stress.7
Therefore, we formed the hypothesis that if in 1 we
carried out a replacement of the phenyl group with the
3,5-di-tert-butyl-4-hydroxyphenyl group and an incor-
poration of the heterocyclic structure into the methylene
spacer, this might lead to compounds that would exhibit
all of the three desired pharmacological effects, as
mentioned above (Chart 1).
On the basis of this hypothesis, we designed and
synthesized derivatives of 1, bearing various kinds of
heterocycles. At the beginning of this study, it was
found that a thiazolidinone derivative (6) had the three
desired activities. We paid particular attention to the
thiazolidinone structure and extensively synthesized the
2-(3,5-di-tert-butyl-4-hydroxyphenyl)-3-(aminopropyl)-
1,3-thiazolidin-4-one derivatives shown in the general
formula 7. In this paper, we describe the synthesis and
pharmacological evaluation of the thiazolidinone deriva-
tives 6 and 7.
These considerations have led us to design and
synthesize novel Ca2+ antagonists with both Ca2+
overload inhibition and antioxidant activity, in order to
discover a more effective drug than existing Ca2+
antagonists in the treatment of IHD.
A Ca2+ overload inhibitor, R56865 (1), reportedly has
not only a potent veratridine-induced Ca2+ overload
inhibitory activity in vitro but also myocardial protective
activity in various experimental models.8 From a
structural consideration of 1, its Ca2+ overload inhibi-
tory effect was thought to be in correlation with the
distance between the benzothiazolylaminopiperidine
moiety and the phenyl group. As for the antioxidant
activity, a 3,5-di-tert-butyl-4-hydroxyphenyl group is
known to be an important moiety of the antioxidant 3,5-
di-tert-butyl-4-hydroxytoluene (BHT) (2).9 At present
there is a substantial number of Ca2+ antagonists in
use in the clinic;10 in particular, diltiazem (3) is widely
used for the treatment of IHD.11 From a study of the
10.1021/jm980335f CCC: $15.00 © 1998 American Chemical Society
Published on Web 10/07/1998

4310 J ournal of Medicinal Chemistry, 1998, Vol. 41, No. 22
Ch a r t 1. Drug Design
Kato et al.
Sch em e 1a
a
Reagents and reaction conditions: (a) reflux in benzene with a Dean-Stark trap; (b) for X ) Cl, SOCl2, CH2Cl2, reflux; (c) for X ) Br,
PBr3, Et2O, rt; (d) for X ) Cl, Na2CO3, NaI, DMF, 80 °C (method A); (e) for X ) Br, K2CO3, acetone, reflux (method B).
Ch em istr y
in Scheme 2.14 As shown in Scheme 3, reactions of 7b
with epoxides produced 7r ,s, bearing the 3-phenoxy-2-
hydroxypropylamine structure (method C).
The syntheses of the aminopropylthiazolidinone de-
rivatives 6 and 7b-q are presented in Scheme 1.
Initially, the aldehyde 8 was condensed with 3-amino-
propanol (9) to give imine 10. A further condensation
of imine 10 with R-mercaptoacetic acid 11 afforded the
key intermediate 12.13 Compound 12 was then treated
with thionyl chloride or phosphorus tribromide to give
the corresponding chloride 13a or bromide 13b. Finally,
aminations of 13a or 13b with amines 14 produced 6
or 7b-q, respectively (method A or B).
Resu lts a n d Discu ssion
The compounds prepared in this study were tested
for Ca2+ antagonistic activity by means of a K+-depo-
larized isolated rat aorta.15 For Ca2+ overload inhibitory
activity, we tested the protective effect in a veratridine-
induced Ca2+ overload model of rat cardiac myocytes.7b,16
The antioxidant activity of representative thiazolidinone
derivatives was evaluated through a determination of
their in vitro inhibitory activity on soybean lipoxyge-
Exceptionally, the primary amine 7a was indirectly
prepared from 12 by the Mitsunobu reaction as shown

Novel Calcium Antagonists
J ournal of Medicinal Chemistry, 1998, Vol. 41, No. 22 4311
Sch em e 2
Sch em e 3
nase-induced lipid peroxidations of rabbit low-density
lipoprotein (LDL).17
compound 7o (CP-060) has three types of action, and
these are well-balanced. We believe that a novel drug
with such a profile could turn out to be of great benefit
for patients with IHD.18 Further studies shall be
needed to determine whether this hypothesis shall be
borne out in the clinic.
At the beginning of this study; we found that the 4-(N-
methyl-N-benzothiazolylamino)piperidinyl compound 6,
having the same amino group as R56865 (1), exhibited
a protective effect against Ca2+ overload with an IC>80
of 1 µM, a slightly less potent Ca2+ antagonistic activity
than diltiazem (Table 1), and an inhibition of lipid
peroxidation similar to that of BHT (Table 2). These
data encouraged us to perform derivatizations of 6,
aimed at a potentiation of each of its pharmacological
effects.
In our extensive program to develop novel cardiopro-
tective drugs, we have focused on the 2-(3,5-di-tert-butyl-
4-hydroxyphenyl)-3-(aminopropyl)thiazolidinone struc-
ture, considering it to be essential, and hence synthesized
several amino-substituted derivatives (7a -s). In terms
of results, all compounds exhibited Ca2+ antagonistic
activity to various extents, as shown in Table 1. Of
particular note was the finding that 7k ,o were more
potent than diltiazem and 8 and 12 times more potent
than the parent R56865, respectively. Interestingly, the
terminal amino moieties of 7k ,o were the same as those
of the existing Ca2+ antagonists, verapamil and semo-
tiadil. A comparison of the terminal amine moieties
(-NR1R2) showed the potency order to be 7c (tertiary
amine) > 7b (secondary amine) > 7a (primary amine).
In addition, the Ca2+ antagonistic activity of the phe-
nylalkylamine derivatives (7h -k ) was higher than that
of the alkylamine derivatives (7c-g). These results
suggest that the terminal substituent at the amine may
either hydrophobically or aromatically interact with a
target receptor.
Exp er im en ta l Section
Gen er a l. The melting points were determined on
a
Yanagimoto micro melting point apparatus and are uncor-
rected. 1H NMR spectra were measured with a Hitachi R-24B
spectrometer (60 MHz), a J EOL J NM-FX200 spectrometer
(200 MHz), or a J EOL J NM-EX270 spectrometer (270 MHz),
with tetramethylsilane as the internal standard. Infrared
spectra were recorded on a Hitachi model 270-3 infrared
spectrometer. EI mass spectra were recorded on a Shimadzu
GCMS-QP1000 instrument. HPLC analyses were performed
on a Shimadzu SPD-10A (UV detector) with a Shimadzu LC-
6AD (pump); a YMC-Pack A-312 S-5 120A ODS column was
used and was eluted with CH3CN-H2O-TFA (50:50:0.1) at a
flow rate of 1.0 mL/min. TLC was routinely performed on
Merck Kieselgel 60 F254
. Organic extracts were dried over
anhydrous sodium sulfate and concentrated by a rotary
evaporator.
2-(3,5-Di-ter t-bu tyl-4-h yd r oxyp h en yl)-3-(3-h yd r oxyp r o-
p yl)-1,3-th ia zolid in -4-on e (12). To a suspension of 3,5-di-
tert-butyl-4-hydroxybenzaldehyde (8) (23.4 g, 0.10 mol) in dry
benzene (150 mL) was added 3-aminopropanol (9) (7.51 g, 0.10
mol), and the mixture was refluxed for 1.5 h in a flask equipped
with a Dean-Stark trap under nitrogen atmosphere. After
cooling to room temperature, R-mercaptoacetic acid (11) (9.21
g, 0.10 mol) was added dropwise to the solution, and the
resulting mixture was refluxed for 2 h. It was then cooled and
concentrated under reduced pressure. The obtained residue
was poured into H2O (100 mL) and extracted with CHCl3. The
extract was dried and concentrated under reduced pressure.
The residue was purified by chromatography on silica gel with
CHCl3-MeOH (99:1) and recrystallized from CHCl3-hexane
to give 20.2 g (55%) of 12 as colorless crystals: mp 100-101
Certain of these compounds were evaluated as Ca2+
overload inhibitors. Importantly, the most effective
Ca2+ antagonist, 7o, also exhibited the most effective
Ca2+ overload inhibition as well.
Antioxidative assay of 6 and 7k ,o was performed, and
their activities were evidently suggested to be compa-
rable to that of BHT, most likely because the common
structural component, the 3,5-di-tert-butyl-4-hydroxy-
phenyl group, possesses essential antioxidant activity.
It is important to note that the novel cardioprotective
1
°C; H NMR (CDCl3, 200 MHz) δ 1.42 (18H, s), 1.2-1.6 (2H,
m), 3.0-3.2 (1H, m), 3.3-3.6 (4H, m), 3.70 and 3.83 (2H, ABq,
J ) 16 Hz), 5.39 (lH, s), 5.54 (1H, s), 7.11 (2H, s); IR (KBr)
3750, 2950, 1660 (CdO), 1424, 1120 cm-1; MS m/ z 365 (M+),
332, 290. Anal. (C20H31NO3S) C, H, N.
2-(3,5-Di-ter t-b u t yl-4-h yd r oxyp h en yl)-3-(3-ch lor op r o-
p yl)-1,3-th ia zolid in -4-on e (13a ). To a solution of 12 (5.09
g, 13.9 mmol) in CH2Cl2 (50 mL) was added thionyl chloride

4312 J ournal of Medicinal Chemistry, 1998, Vol. 41, No. 22
Kato et al.
Ta ble 1. Ca2+ Antagonistic and Ca2+ Overload Inhibitory Activities of Novel Thiazolidinone Derivatives

Novel Calcium Antagonists
J ournal of Medicinal Chemistry, 1998, Vol. 41, No. 22 4313
Ta ble 1 (Continued)
a
Molar concentration required to inhibit 30 mM K+ contraction of rat aorta by 50%. Diltiazem was used as a standard compound.
b
Each value indicates a mean ( standard error from 2-6 experiments. Molar concentration required to inhibit veratridine-induced rat
myocardiac cell death by >80%. The results were determined from 2-8 experiments, and more than 50 rod-shaped myocytes were used
in each experiment. c Cl, chloroform; Hex, n-hexane; Ac, acetone; iPr, diisopropyl ether. C4H4O4, fumaric acid. e All compounds gave
d
satisfactory elemental analyses ((0.4%) for C, H, and N, unless otherwise noted. f The parent compound is an oil, and the corresponding
salt was prepared as an amorphous solid after trituration with diethyl ether, diisopropyl ether, or n-hexane. Compound failed to give
g
crystal. Anal. C, N; H: calcd, 9.37; found, 8.77.
Ta ble 2. Antioxidant Activities of Thiazolidinone Derivatives
(18H, s), 1.6-2.2 (2H, m), 2.6-3.6 (2H, m), 3.28 (2H, t, J )
6.5 Hz), 3.70 (2H, brs), 5.28 (1H, s), 5.53 (1H, s), 7.05 (2H, s);
IR (KBr) 3540, 2950, 1652 (CdO), 1408, 1100 cm-1; MS m/ z
429 (M+ + 2), 427 (M+), 354, 352. Anal. (C20H30NO2SBr) C,
H, N.
LDL oxidation (% of control)a
compd
0.5 µM
5 µM
6
7k
7o
25.8
8.7
12.9
19.7
60.2
109
4.9
0.6
3.0
0.9
13.2
111
2-(3,5-Di-ter t-bu tyl-4-h yd r oxyp h en yl)-3-[3-[N-m eth yl-
N-[2-(3,4-d im eth oxyp h en yl)eth yl]a m in o]p r op yl]-1,3-th ia -
zolid in -4-on e Hyd r ogen F u m a r a te (7k ) (Meth od A). To
a solution of 13a (384 mg, 1.00 mmol) and 2-(3,4-dimethoxy-
phenyl)-N-methylethylamine (196 mg, 1.00 mmol) in DMF (5
mL) were added Na2CO3 (211 mg, 2.00 mmol) and NaI (15 mg,
0.10 mmol) under nitrogen atmosphere, and the mixture was
stirred overnight at 80 °C. After cooling, the reaction mixture
was poured into water (50 mL) and extracted with CHCl3. The
extract was washed with brine, dried, and concentrated under
reduced pressure. The residue was purified by chromatogra-
phy on silica gel with CHCl3-MeOH (99:1) to give 355 mg
(65%) of the free form of 7k as a colorless oil: 1H NMR (CDCl3,
200 MHz) δ 1.41 (18H, s), 1.3-1.8 (2H, m), 2.53 (3H, s), 2.2-
2.9 (7H, m), 3.4-3.7 (1H, m), 3.66 and 3.81 (2H, ABq, J ) 16
Hz), 3.83 (3H, s), 3.84 (3H, s), 5.31 (1H, s), 5.60 (1H, s), 6.6-
6.9 (3H, m), 7.10 (2H, s).
A solution of the free form of 7k in EtOH was treated with
an equimolar amount of fumaric acid and concentrated under
reduced pressure. The residue was triturated with AcOEt-
hexane, and the precipitated solid was collected by filtration.
The obtained solid was dried in vacuo to give 7k as a colorless
powder: IR (KBr) 3500, 2980, 1684 (CdO), 1530, 1276, 1250,
1040 cm-1; MS m/ z 543 (M+ + 1), 542 (M+), 391; HPLC
analysis (CH3CN-H2O-TFA (50:50:0.1)) tR ) 2.9 min (11.1%,
fumaric acid) and tR ) 11.8 min (86.6%, free form of 7k ), 97.7%
pure.
BHT
R-tocopherol
diltiazem
a
Inhibition of rabbit LDL oxidation induced by soybean lipoxy-
genase. All results are shown as percent of control.
(2.5 g, 21.0 mmol) at room temperature under nitrogen
atmosphere, and the mixture was refluxed for 1 h. After
cooling, the reaction mixture was poured into brine and
extracted with CHCl3. The extract was dried and concentrated
under reduced pressure. The residue was purified by chro-
matography on silica gel with CH2Cl2 and recrystallized from
CHCl3-hexane to give 3.75 g (70%) of 13a as pale-yellow
1
crystals: mp 133-134 °C; H NMR (CDCl3, 60 MHz) δ 1.40
(18H, s), 1.5-2.0 (2H, m), 2.6-3.6 (2H, m), 3.40 (2H, t, J )
6.5 Hz), 3.68 (2H, brs), 5.27 (1H, s), 5.50 (1H, s), 7.02 (2H, s);
IR (KBr) 3560, 2980, 1664 (CdO), 1410, 1298, 1110 cm-1; MS
m/ z 383 (M+), 368, 308. Anal. (C20H30NO2SCl) C,H, N.
2-(3,5-Di-ter t-bu t yl-4-h yd r oxyp h en yl)-3-(3-br om op r o-
p yl)-1,3-th ia zolid in -4-on e (13b). To a solution of 12 (2.0 g,
5.47 mmol) in Et2O (20 mL) was added phosphorus tribromide
(0.74 g, 2.73 mmol) at room temperature under nitrogen
atmosphere, and the mixture was stirred for 6 h. The reaction
mixture was poured into ice-water (10 mL) and extracted with
Et2O. The extract was washed with brine, dried, and concen-
trated under reduced pressure. The residue was purified by
chromatography on silica gel with CHCl3 and recrystallized
from CHCl3-hexane to give 1.31 g (56%) of 13b as pale-yellow
2-(3,5-Di-ter t-bu tyl-4-h yd r oxyp h en yl)-3-[3-[N-m eth yl-
N-[2-[3,4-(m eth ylen edioxy)ph en oxy]eth yl]am in o]pr opyl]-
1,3-th ia zolid in -4-on e (7o) (Meth od B). To a solution of 13b
(89.3 mg, 0.21 mmol) and N-methyl-N-[2-[3,4-(methylenedi-
1
crystals: mp 130-131 °C; H NMR (CDCl3, 60 MHz) δ 1.43

4314 J ournal of Medicinal Chemistry, 1998, Vol. 41, No. 22
Kato et al.
oxy)phenoxy]ethyl]amine (48.8 mg, 0.25 mmol) in acetone (5
mL) was added K2CO3 (34.6 mg, 0.25 mmol) under nitrogen
atmosphere, and the mixture was refluxed for 10 h. After
cooling, the reaction mixture was filtered and washed with
acetone, and the resulting filtrate was concentrated under
reduced pressure. The residue was purified by chromatogra-
phy on silica gel with CHCl3-MeOH (97:3) and recrystallized
from AcOEt-hexane to give 67.4 mg (60%) of 7o as colorless
crystals: mp 70-71 °C; 1H NMR (CDCl3, 200 MHz) δ 1.42
(18H, s), 1.4-1.7 (2H, m), 2.20 (3H, s), 2.3-2.5 (2H, m), 2.68
(2H, t, J ) 5.9 Hz), 2.7-2.9 (1H, m), 3.5-3.6 (1H, m), 3.66
and 3.80 (2H, ABq, J ) 16 Hz), 3.92 (2H, t, J ) 5.9 Hz), 5.32
(1H, s), 5.66 (1H, s), 5.90 (2H, s), 6.2-7.1 (5H, m); IR (KBr)
(1H, s), 5.58 (1H, s), 7.06 (2H, s); IR (KBr) 3450, 2970, 2660,
1674 (CdO), 1442 cm-1; MS m/ z 449 (M+), 391; HPLC analysis
(CH3CN-H2O-TFA (50:50:0.1)) tR ) 3.6 min (97.7%).
2-(3,5-Di-ter t-bu tyl-4-h yd r oxyp h en yl)-3-[3-(N-m eth yl-
N-ben zyla m in o)p r op yl]-1,3-th ia zolid in -4-on e h yd r ogen
fu m a r a te (7h ): method B (50%); 1H NMR (CDCl3, free form,
60 MHz) δ 1.43 (18H, s), 1.2-2.0 (2H, m), 2.05 (3H, s), 2.0-
3.3 (4H, m), 3.40 (2H, s), 3.70 (2H, brs), 5.30 (1H, s), 5.57 (1H,
s), 7.07 (2H, s), 7.20 (5H, s); IR (KBr) 3470, 2980, 1680 (Cd
O), 1444, 1252, 1000 cm-1; MS m/ z 468 (M+), 377; HPLC
analysis (CH3CN-H2O-TFA (50:50:0.1)) tR ) 2.9 min (14.0%,
fumaric acid) and tR ) 13.0 min (84.5%, free form of 7h ), 98.5%
pure.
3570, 2920, 1660 (CdO), 1490, 1240, 1190, 1102, 1042 cm-1
;
2-(3,5-Di-ter t-bu tyl-4-h yd r oxyp h en yl)-3-[3-[N-m eth yl-
N-[3,4-(m et h ylen ed ioxy)p h en yl]m et h yla m in o]p r op yl]-
1,3-th ia zolid in -4-on e h yd r ogen fu m a r a te (7i): method B
MS m/ z 542 (M+), 391, 348; HPLC analysis (CH3CN-H2O-
TFA (50:50:0.1)) tR ) 13.6 min (99.3%). The following com-
pounds were prepared from 13a (method A) or 13b (method
B) via an amination reaction with the corresponding amine.
1
(75%); H NMR (CDCl3, free form, 200 MHz) δ 1.41 (18H, s),
1.5-1.8 (2H, m), 2.00 (3H, s), 2.1-2.4 (2H, m), 2.6-3.0 (1H,
m), 3.27 (2H, s), 3.4-3.7 (1H, m), 3.63 and 3.77 (2H, ABq, J )
16.0 Hz), 5.31 (1H, s), 5.56 (1H, s), 5.90 (2H, s), 6.5-6.8 (3H,
m), 7.09 (2H, s); IR (KBr) 3470, 2980, 1680 (CdO), 1460, 1264,
1050, 662 cm-1; MS m/ z 512 (M+), 164; HPLC analysis (CH3-
CN-H2O-TFA (50:50:0.1)) tR ) 2.9 min (9.0%, fumaric acid)
and tR ) 12.8 min (90.0%, free form of 7i), 99.0% pure.
2-(3,5-Di-ter t-bu tyl-4-h yd r oxyp h en yl)-3-[3-[N-m eth yl-
N-(3,4-d im eth oxyp h en yl)m eth yla m in o]p r op yl]-1,3-th ia -
zolid in -4-on e h yd r ogen fu m a r a te (7j): method A (90%);
1H NMR (CDCl3, free form, 200 MHz) δ 1.43 (18H, s), 1.2-1.9
(2H, m), 2.06 (3H, s), 2.1-2.4 (2H, m), 2.6-3.0 (1H, m), 3.34
(2H, s), 3.4-3.7 (1H, m), 3.64 and 3.78 (2H, ABq, J ) 16.0
Hz), 3.84 (3H, s), 3.86 (3H, s), 5.31 (1H, s), 5.56 (1H, s), 6.6-
6.9 (3H, m), 7.06 (2H, s); IR (KBr) 3450, 2950, 1670 (CdO),
1518, 1432, 1260, 1022 cm-1; MS m/ z 528 (M+), 180, 151;
HPLC analysis (CH3CN-H2O-TFA (50:50:0.1)) tR ) 2.9 min
(9.0%, fumaric acid) and tR ) 11.1 min (88.2%, free form of
7j), 97.2% pure.
2-(3,5-Di-ter t-bu tyl-4-h yd r oxyp h en yl)-3-[3-[N-m eth yl-
N-[2-(4-m et h oxyp h en oxy)et h yl]a m in o]p r op yl]-1,3-t h ia -
zolid in -4-on e h yd r ogen fu m a r a te (7l): method A (25%);
1H NMR (CDCl3, free form, 200 MHz) δ 1.43 (18H, s), 1.1-1.8
(2H, m), 2.21 (3H, s), 2.3-2.5 (2H, m), 2.70 (2H, t, J ) 5.7
Hz), 2.6-3.0 (1H, m), 3.4-3.9 (3H, m), 3.76 (3H, s), 3.96 (2H,
t, J ) 5.7 Hz), 5.30 (1H, s), 5.64 (1H, s), 6.79 (4H, s), 7.09 (2H,
s); IR (KBr) 3450, 2960, 1674 (CdO), 1504, 1234 cm-1; MS m/ z
528 (M+), 391; HPLC analysis (CH3CN-H2O-TFA (50:50:0.1))
tR ) 2.9 min (12.1%, fumaric acid) and tR ) 15.9 min (85.8%,
free form of 7l), 97.9% pure.
2-(3,5-Di-ter t-bu tyl-4-h yd r oxyp h en yl)-3-[3-[4-(N-m eth -
yl-N-ben zoth ia zol-2-yla m in o)p ip er id in o]p r op yl]-1,3-th i-
a zolid in -4-on e h yd r och lor id e (6): method A (50%); 1H
NMR (CDCl3, free form, 60 MHz) δ 1.43 (18H, s), 1.0-3.2 (15H,
m), 3.00 (3H, s), 3.67 (2H, brs), 5.27 (1H, s), 5.56 (1H, s), 6.7-
8.0 (6H, m); IR (KBr) 3450, 2950, 1664 (CdO), 1614, 1432,
762 cm-1; MS m/ z 594 (M+), 446, 429; HPLC analysis (CH3-
CN-H2O-TFA (50:50:0.1)) tR ) 8.0 min (99.0%).
2-(3,5-Di-ter t-bu tyl-4-h yd r oxyp h en yl)-3-[3-(N,N-d im e-
th yla m in o)p r op yl]-1,3-th ia zolid in -4-on e (7c): method B
(66%); 1H NMR (CDCl3, 270 MHz) δ 1.43 (18H, s), 1.7-1.9 (2H,
m), 2.40 (6H, s), 2.3-2.7 (2H, m), 2.8-3.0 (1H, m), 3.5-3.7
(1H, m), 3.68 and 3.79 (2H, ABq, J ) 15.8 Hz), 5.34 (1H, s),
5.65 (1H, s), 7.12 (2H, s); IR (KBr) 3420, 2950, 1684 (CdO),
1430, 1410, 1232, 1218 cm-1; MS m/ z 392 (M+), 306; HPLC
analysis (CH3CN-H2O-TFA (50:50:0.1)) tR ) 6.4 min (99.7%).
2-(3,5-Di-ter t-bu tyl-4-h yd r oxyp h en yl)-3-[3-[N-m eth yl-
N-(2-h yd r oxyeth yl)a m in o]p r op yl]-1,3-th ia zolid in -4-on e
h yd r ogen fu m a r a te (7d ): method B (49%); 1H NMR (CDCl3,
free form, 270 MHz) δ 1.43 (18H, s), 1.4-1.8 (2H, m), 1.6-2.2
(1H, m), 2.12 (3H, s), 2.32 (2H, t, J ) 6.9 Hz), 2.43 (2H, t, J )
5.3 Hz), 2.7-3.0 (1H, m), 3.53 (2H, t, J ) 5.3 Hz), 3.5-3.7
(1H, m), 3.68 and 3.79 (2H, ABq, J ) 15.5 Hz), 5.33 (1H, s),
5.57 (1H, s), 7.09 (2H, s); IR (KBr) 3420, 2960, 1664 (CdO),
1434, 982, 648 cm-1; MS m/ z 422 (M+), 391; HPLC analysis
(CH3CN-H2O-TFA (50:50:0.1)) tR ) 2.9 min (14.1%, fumaric
acid) and tR ) 5.6 min (82.6%, free form of 7d ), 96.7% pure.
2-(3,5-Di-ter t-bu tyl-4-h yd r oxyp h en yl)-3-[3-[N-m eth yl-
N-(2-eth oxyeth yl)am in o]pr opyl]-1,3-th iazolidin -4-on e h y-
d r ogen fu m a r a te (7e): method B (57%); 1H NMR (CDCl3,
free form, 270 MHz) δ 1.17 (3H, t, J ) 6.9 Hz), 1.43 (18H, s),
1.4-1.8 (2H, m), 2.16 (3H, s), 2.2-2.4 (2H, m), 2.49 (2H, t, J
) 5.9 Hz), 2.7-2.9 (IH, m), 3.4-3.5 (2H, m), 3.5-3.7 (1H, m),
3.67 and 3.79 (2H, ABq, J ) 15.5 Hz), 5.31 (1H, s), 5.61 (1H,
s), 7.09 (2H, s); IR (KBr) 3480, 2980, 1688 (CdO), 1450, 1138,
1000, 662 cm-1; MS m/ z 450 (M+), 391; HPLC analysis (CH3-
CN-H2O-TFA (50:50:0.1)) tR ) 2.9 min (13.6%, fumaric acid)
and tR ) 9.5 min (84.1%, free form of 7e), 97.7% pure.
2-(3,5-Di-ter t-bu tyl-4-h yd r oxyp h en yl)-3-[3-[N-m eth yl-
N-(cyclop r op ylm et h yl)a m in o]p r op yl]-1,3-t h ia zolid in -4-
on e h yd r ogen fu m a r a te (7f): method B (51%); 1H NMR
(CDCl3, free form, 270 MHz) δ 0.0-0.1 (2H, m), 0.4-0.6 (2H,
m), 0.7-0.9 (lH, m), 1.43 (18H, s), 1.4-1.8 (2H, m), 2.14 (2H,
d, J ) 6.6 Hz), 2.18 (3H, s), 2.2-2.4 (2H, m), 2.7-2.9 (1H, m),
3.5-3.7 (1H, m), 3.67 and 3.79 (2H, ABq, J ) 15.5 Hz), 5.31
(1H, s), 5.62 (1H, s), 7.09 (2H, s); IR (KBr) 3590, 2950, 1658
(CdO), 1432, 1240, 980 cm-1; MS m/ z 432 (M+); HPLC
analysis (CH3CN-H2O-TFA (50:50:0.1)) tR ) 2.9 min (14.2%,
fumaric acid) and tR ) 9.0 min (84.5%, free form of 7f), 98.7%
pure.
2-(3,5-Di-ter t-bu tyl-4-h yd r oxyp h en yl)-3-[3-[N-m eth yl-
N-(N′,N′-d im eth yla m in oeth yl)a m in o]p r op yl]-1,3-th ia zo-
lid in -4-on e h yd r och lor id e (7g): method B (66%); 1H NMR
(CDCl3, free form, 200 MHz) δ 1.42 (18H, s), 1.4-1.8 (2H, m),
2.11 (3H, s), 2.20 (6H, s), 2.2-2.5 (6H, m), 2.7-2.9 (1H, m),
3.4-3.7 (1H, m), 3.65 and 3.78 (2H, ABq, J ) 16 Hz), 5.31
2-(3,5-Di-ter t-bu tyl-4-h yd r oxyp h en yl)-3-[3-[N-m eth yl-
N-[2-(3,4-d im et h oxyp h en oxy)et h yl]a m in o]p r op yl]-1,3-
th ia zolid in -4-on e h yd r ogen fu m a r a te (7m ): method A
1
(28%); H NMR (CDCl3, free form, 60 MHz) δ 1.38 (18H, s),
1.2-1.9 (2H, m), 2.18 (3H, s), 2.3-2.5 (2H, m), 2.6-3.2 (3H,
m), 3.2-4.2 (3H, m), 3.67 (2H, brs), 3.76 (6H, s), 5.22 (1H, s),
5.57 (1H, s), 6.2-6.9 (3H, m), 7.00 (2H, s); IR (KBr) 3460, 2970,
1678 (CdO), 1520, 1234, 1202 cm-1; MS m/ z 558 (M+), 391;
HPLC analysis (CH3CN-H2O-TFA (50:50:0.1)) tR ) 2.9 min
(12.0%, fumaric acid) and tR ) 11.9 min (85.9%, free form of
7m ), 97.9% pure.
2-(3,5-Di-ter t-bu tyl-4-h yd r oxyp h en yl)-3-[3-[N-m eth yl-
N-[2-(3,4,5-tr im eth oxyp h en oxy)eth yl]a m in o]p r op yl]-1,3-
th ia zolid in -4-on e h yd r ogen fu m a r a te (7n ): method A
1
(45%); H NMR (CDCl3, free form, 200 MHz) δ 1.43 (18H, s),
1.3-1.9 (2H, m), 2.23 (3H, s), 2.3-2.5 (2H, m), 2.71 (2H, t, J
) 5.7 Hz), 2.6-3.0 (1H, m), 3.4-3.9 (3H, m), 3.77 (3H, s), 3.83
(6H, s), 3.97 (2H, t, J ) 5.7 Hz), 5.30 (1H, s), 5.63 (1H, s), 6.12
(2H, s), 7.08 (2H, s); IR (KBr) 3480, 2980, 1682 (CdO), 1610,
1250, 1142 cm-1; MS m/ z 588 (M+), 391, 348; HPLC analysis
(CH3CN-H2O-TFA (50:50:0.1)) tR ) 2.9 min (10.5%, fumaric
acid) and tR ) 12.5 min (89.0%, free form of 7n ), 99.5% pure.
2-(3,5-D i -t er t -b u t y l-4-h y d r o x y p h e n y l)-3-[3-(6,7-
d im et h oxy-1,2,3,4-t et r a h yd r oisoq u in olin -2-yl)p r op yl]-
1,3-th ia zolid in -4-on e h yd r ogen fu m a r a te (7p ): method A
1
(69%); H NMR (CDCl3, free form, 60 MHz) δ 1.37 (18H, s),
1.5-2.0 (2H, m), 2.1-3.1 (8H, m), 3.42 (2H, s), 3.65 (2H, brs),

Novel Calcium Antagonists
J ournal of Medicinal Chemistry, 1998, Vol. 41, No. 22 4315
3.75 (6H, s), 5.39 (1H, s), 5.57 (1H, s), 6.42 (1H, s), 6.50 (1H,
s), 7.02 (2H, s); IR (KBr) 3460, 2980, 1680 (CdO), 1526, 1272,
1132 cm-1; MS m/ z 540 (M+), 192; HPLC analysis (CH3CN-
H2O-TFA (50:50:0.1)) tR ) 2.9 min (10.6%, fumaric acid) and
tR ) 10.5 min (86.9%, free form of 7p ), 97.5% pure.
mmol) in CH3CN (10 mL) was added 2,3-(epoxypropyl)-3,4-
(methylenedioxy)phenyl ether (260 mg, 1.32 mmol), and the
mixture was refluxed for 8 h. After cooling, the reaction
mixture was poured into ice-water and extracted with AcOEt.
The extract was washed with brine, dried, and concentrated
under reduced pressure. The residue was purified by chro-
matography on silica gel with CHCl3-MeOH (98:2) to give 0.72
g (95%) of the free form of 7s as a colorless oil: 1H NMR
(CDCl3, 270 MHz) δ 1.43 (18H, s), 1.4-1.8 (2H, m), 2.17 (3H,
s), 2.2-2.6 (4H, m), 2.7-3.0 (1H, m), 3.4-3.7 (1H, m), 3.67
and 3.80 (2H, ABq, J ) 16 Hz), 3.8-4.1 (4H, m), 5.33 (1H, s),
5.57 (1H, s), 5.91 (2H, s), 6.2-6.8 (3H, m), 7.09 (2H, s).
2-(3,5-Di-ter t-bu tyl-4-h yd r oxyp h en yl)-3-[3-(4-ben zylp i-
p er id in o)p r op yl]-1,3-th ia zolid in -4-on e h yd r ogen fu m a -
1
r a te (7q): method A (60%); H NMR (CDCl3, free form, 200
MHz) δ 1.36 (18H, s), 1.1-1.9 (9H, m), 2.1-2.3 (2H, m), 2.50
(2H, d, J ) 6.6 Hz), 2.7-2.9 (3H, m), 3.4-3.6 (1H, m), 3.66
and 3.79 (2H, ABq, J ) 16 Hz), 5.32 (1H, s), 5.62 (1H, s), 7.0-
7.3 (7H, m); IR (KBr) 3470, 2980, 1678 (CdO), 1442, 1248 cm-1
;
MS m/ z 522 (M+), 188; HPLC analysis (CH3CN-H2O-TFA
(50:50:0.1)) tR ) 2.9 min (12.2%, fumaric acid) and tR ) 23.9
min (87.3%, free form of 7q), 99.5% pure.
A solution of the free form of 7s in EtOH was treated with
an equimolar amount of fumaric acid and concentrated under
reduced pressure. The residue was triturated with AcOEt-
hexane, and the precipitated solid was collected by filtration.
The obtained solid was dried in vacuo to give 7s as a colorless
powder: IR (KBr) 3440, 2960, 1674 (CdO), 1488, 1188, 1040
cm-1; MS m/ z 572 (M+), 391; HPLC analysis (CH3CN-H2O-
2-(3,5-Di-ter t-b u t yl-4-h yd r oxyp h en yl)-3-[3-(1,3-d iox-
oisoin d olin -2-yl)p r op yl]-1,3-th ia zolid in -4-on e (15). To a
solution of 12 (3.00 g, 8.20 mmol), phthalimide (1.81 g, 12.3
mmol), and triphenylphosphine (3.23 g, 12.3 mmol) in dry THF
(100 mL) was added diethyl azodicarboxylate (2.14 g, 12.3
mmol) at 0 °C under nitrogen atmosphere. The mixture was
stirred for 3 h at room temperature, and the reaction mixture
was concentrated under reduced pressure. The obtained
residue was poured into water and extracted with AcOEt. The
extract was washed with brine, dried, and concentrated under
reduced pressure. The residue was purified by chromatogra-
phy on silica gel with AcOEt-hexane (3:7) and recrystallized
from CHCl3-hexane to give 3.04 g (75%) of 15 as pale-purple
TFA (50:50:0.1)) tR ) 2.9 min (12.1%, fumaric acid) and tR
12.9 min (86.7%, free form of 7s), 98.8% pure.
)
2-(3,5-Di-ter t-bu tyl-4-h yd r oxyp h en yl)-3-[3-[N-m eth yl-
N-(2-h yd r oxy-3-p h en oxyp r op yl)a m in o]p r op yl]-1,3-th ia -
zolid in -4-on e h yd r ogen fu m a r a te (7r ): method C (57%);
1H NMR (CDCl3, free form, 200 MHz) δ 1.43 (18H, s), 1.4-1.8
(2H, m), 2.19 (3H, s), 2.2-3.0 (6H, m), 3.3-3.7 (1H, m), 3.66
and 3.79 (2H, ABq, J ) 16 Hz), 3.8-4.2 (3H, m), 5.31 (1H, s),
5.54 (1H, s), 6.7-7.0 (3H, m), 7.06 (2H, m), 7.1-7.5 (2H, m);
IR (KBr) 3450, 2980, 1678 (CdO), 1252, 766 cm-1; MS m/ z
528 (M+), 391; HPLC analysis (CH3CN-H2O-TFA (50:50:0.1))
tR ) 2.9 min (11.5%, fumaric acid) and tR ) 14.0 min (87.3%,
free form of 7r ), 98.8% pure.
Ca lciu m An ta gon istic Activity. Thoracic aortas were
removed from male Sprague-Dawley rats (350-550 g; Charles
River J apan Inc.), dissected free from surrounding connective
tissue, and cut into ring segments each about 2-3 mm long.
Each strip of smooth muscle was mounted for isometric tension
recording in an organ bath filled with 10 mL of Krebs-
Henseleit (K-H) solution (pH 7.4). This bathing solution was
maintained at 37 °C and bubbled with 95% O2/5% CO2. The
strips were given a stretched tension of 2 g and allowed to
equilibrate for more than 30 min. Isometric tension changes
were monitored using an isometric transducer (Nihon Kohden
Co., Ltd.; TB-611T) and recorded on a self-balancing poten-
tiometric recorder (Yokogawa Co., Ltd.; 3066). After the
equilibration period, a precontraction was produced by chang-
ing the solution in the bath to one containing 30 mM K+. After
the contraction was maintained for 20 min, the preparation
was washed with K-H solution. Sixty minutes thereafter (the
K-H solution was exchanged for a fresh one every 20 min),
contraction was again induced in the same manner as de-
scribed above. After the contraction stabilized, a test com-
pound or diltiazem was added to the system in a cumulative
manner in half-log unit increments to obtain a concentration-
response curve. Taking the contraction at 30 mM K+ as 100%,
the concentration of the drug at which the contraction was
1
crystals: mp 146-147 °C; H NMR (CDCl3, 270 MHz) δ 1.40
(18H, s), 1.6-2.0 (2H, m), 2.7-2.9 (1H, m), 3.5-3.8 (3H, m),
3.68 and 3.76 (2H, ABq, J ) 15.2 Hz), 5.29 (1H, s), 5.65 (1H,
s), 7.08 (2H, s), 7.6-7.9 (4H, m); IR (KBr) 3570, 2950, 1712
(CdO), 1664 (CdO), 1400, 1116, 720 cm-1; MS m/ z 494 (M+),
306.
2-(3,5-Di-ter t-bu tyl-4-h ydr oxyph en yl)-3-(3-am in opr opyl)-
1,3-th ia zolid in -4-on e Hyd r ogen F u m a r a te (7a ). To a
suspension of 15 (1.00 g, 2.02 mmol) in MeOH (5 mL) was
added 40% MeNH2 in MeOH (4 mL, 41 mmol), and the mixture
was stirred overnight at room temperature. The reaction
mixture was concentrated under reduced pressure. The
residue was purified by chromatography on silica gel with
CHCl3-MeOH (80:20) to give 0.67 g (91%) of the free form of
7a as a colorless oil: 1H NMR (CDCl3, 270 MHz) δ 1.43 (18H,
s), 1.48 (2H, brs), 1.2-1.8 (2H, m), 2.5-2.7 (2H, m), 2.7-3.0
(1H, m), 3.6-3.8 (1H, m), 3.69 and 3.80 (2H, ABq, J ) 15.2
Hz), 5.33 (1H, s), 5.57 (1H, s), 7.09 (2H, s).
A solution of the free form of 7a in EtOH was treated with
an equimolar amount of fumaric acid and concentrated under
reduced pressure. The residue was triturated with AcOEt-
hexane, and the precipitated solid was collected by filtration.
The obtained solid was dried in vacuo to give 7a as a colorless
powder: IR (KBr) 3480, 2980, 1670 (CdO), 1444 cm-1; MS m/ z
364 (M+), 306; HPLC analysis (CH3CN-H2O-TFA (50:50:0.1))
tR ) 2.9 min (14.7%, fumaric acid) and tR ) 5.6 min (84.4%,
free form of 7a ), 99.1% pure.
2-(3,5-Di-ter t-bu tyl-4-h yd r oxyp h en yl)-3-[3-(N-m eth yl-
a m in o)p r op yl]-1,3-th ia zolid in -4-on e Hyd r obr om id e (7b).
A mixture of 13b (1.10 g, 2.57 mmol) and 40% MeNH2 in
MeOH (20 mL, 232 mmol) in CH3CN (15 mL) was stirred for
15 h at room temperature under nitrogen atmosphere. The
reaction mixture was concentrated under reduced pressure,
and the residue was purified by chromatography on silica gel
with CHCl3-MeOH (95:5) to give 0.90 g (76%) of 7b as pale-
orange crystals which were characterized as hydrobromide:
mp 195-196 °C (CHCl3-hexane); 1H NMR (CDCl3, free form,
60 MHz) δ 1.37 (1H, s), 1.42 (18H, s), 1.6-2.2 (2H, m), 2.67
(3H, s), 2.6-3.6 (4H, m), 3.77 (2H, brs), 5.33 (1H, s), 5.63 (1H,
s), 7.08 (2H, s); IR (KBr) 3450, 2950, 2720, 1660 (CdO), 1436
cm-1; MS m/ z 378 (M+), 306; HPLC analysis (CH3CN-H2O-
TFA (50:50:0.1)) tR ) 6.0 min (98.6%).
relaxed to 50% was deemed the IC50
are shown in Table 1.
. The results obtained
P r otective Effects in th e Ver a tr id in e-In d u ced Ca l-
ciu m Over loa d Mod el. Isolated ventricular myocytes were
prepared from the heart of male Sprague-Dawley rats (300-
500 g; Charles River J apan Inc.), using an enzyme-perfusion
method.16 The thus obtained rod-shaped normal myocytes
were treated with a test compound or diltiazem for 30 min,
and 50 µg/mL veratridine was added. Five minutes later, the
shape of the cells was observed to obtain a survival rate
thereby to evaluate the efficacy of the compound. The results
obtained are shown in Table 1.
In h ibitor y Action on Lip id P er oxid a tion . A test com-
pound was added to rabbit LDL prepared according to the
method of Havel et al.,17a and then a soybean lipoxygenase
type-IS (SLO) was added to a final concentration of 40 µg/mL.
Oxidation of LDL was carried out by incubation at 37 °C in a
CO2 incubator for 24 h. The oxidized LDL solution was
2-(3,5-Di-ter t-bu tyl-4-h yd r oxyp h en yl)-3-[3-[N-m eth yl-
N-[2-h yd r oxy-3-[3,4-(m eth ylen ed ioxy)p h en oxy]p r op yl]-
a m in o]p r op yl]-1,3-t h ia zolid in -4-on e Hyd r ogen F u m a -
r a te (7s) (Meth od C). To a solution of 7b (500 mg, 1.32

4316 J ournal of Medicinal Chemistry, 1998, Vol. 41, No. 22
Kato et al.
(9) Yoshioka, T.; Fujita, T.; Kanai, T.; Aizawa, Y.; Kurumada, T.;
Hasegawa, K.; Horikoshi, H. Studies on Hindered Phenols and
Analogues. 1. Hypolipidemic and Hypoglycemic Agents with
Ability to Inhibit Lipid Peroxidation. J . Med. Chem. 1989, 32,
421-428.
(10) (a) Fleckenstein, A. History of Calcium Antagonists. Circ. Res.
1983, 52 (Suppl. I), 3-16. (b) Millard, R. W.; Lathrop, D. A.;
Grupp, G.; Ashraf, M.; Grupp, I. L.; Schwartz, A. Differential
Cardiovascular Effects of Calcium Channel Blocking Agents:
Potential Mechanisms. Am. J . Cardiol. 1982, 49, 499-506.
(11) Chaffman, M.; Brogden, R. N. Diltiazem: A Review of its
Pharmacological Properties and Therapeutic Efficacy. Drugs
1985, 29, 387-454.
(12) (a) Inoue, H.; Konda, M.; Hashiyama, T.; Otsuka, H.; Takahashi,
K.; Gaino, M.; Date, T.; Aoe, K.; Takeda, M.; Murata, S.; Narita,
H.; Nagao, T. Synthesis of Halogen-Substituted 1,5-Benzothi-
azepine Derivatives and Their Vasodilating and Hypotensive
Activities. J . Med. Chem. 1991, 34, 675-687. (b) Yamamoto, K.;
Fujita, M.; Tabashi, K.; Kawashima, Y.; Kato, E.; Oya, M.; Iso,
T.; Iwao, J . Novel Calcium Antagonists. Synthesis and Structure-
Activity Relationship Studies of Benzothiazoline Derivatives. J .
Med. Chem. 1988, 31, 919-930. (c) Fujita, M.; Ito, S.; Ota, A.;
Kato, N.; Yamamoto, K.; Kawashima, Y.; Yamauchi, H.; Iwao,
J. Synthesis and Ca2+ Antagonistic Activity of 2-[2-[(Aminoalkyl)-
oxy]-5-methoyphenyl]-3,4-dihydro-4-methyl-3-oxo-2H-1,4-benzothiazines.
J . Med. Chem. 1990, 33, 1898-1905. (d) Corelli, F.; Manetti,
F.; Tafi, A.; Campiani, G.; Nacci, V.; Botta, M. Diltiazem-like
Calcium Entry Blockers: A Hypothesis of the Receptor-Binding
Site Based on a Comparative Molecular Field Analysis Model.
J . Med. Chem. 1997, 40, 125-131.
(13) (a) Surrey, A. R. 4-Thiazolidones. IV. The Preparation of Some
3-Alkylaminoalkyl-2-aryl Derivatives. J . Am. Chem. Soc. 1949,
71, 3354-3356. (b) Diurno, M. V.; Mazzoni, O.; Piscopo, E.;
Calignano, A.; Giordano, F.; Bolognese, A. Synthesis and Anti-
histamic Activity of Some Thiazolidin-4-ones. J . Med. Chem.
1992, 35, 2910-2912.
(14) Mitsunobu, O. The Use of Diethyl Azodicarboxylate and Triph-
enylphosphine in Synthesis and Transformation of Natural
Products. Synthesis 1981, 1-28.
(15) Godfraind, T.; Kaba, A. Blockade or Reversal of the Contraction
Induced by Calcium and Adrenaline in Depolarized Arterial
Smooth Muscle. Br. J . Pharmacol. 1969, 36, 549-560.
(16) Powell, T.; Twist, V. W. A Rapid Technique for the Isolation and
Purification of Adult Cardiac Muscle Cells Having Respirato-
ryControl and a Tolerance to Calcium. Biochem. Biophys. Res.
Commun. 1976, 72, 327-333.
(17) (a) Havel, R. J .; Eder, H. A.; Bragdon, J . H. The Distribution
and Chemical Composition of Ultracentrifugally Separated
Lipoproteins in Human Serum. J . Clin. Invest. 1955, 34, 1345-
1353. (b) Kawabe, Y.; Cynshi, O.; Takashima, Y.; Suzuki, T.;
Ohba, Y.; Kodama, T. Oxidation-Induced Aggregation of Rabbit
Low-Density Lipoprotein by Azo Inhibitor. Arch. Biochem.
Biophys. 1994, 310, 489-496.
analyzed by gel-permeation chromatography, and the fluores-
cence intensity of the LDL fraction was measured at an
excitation wavelength of 360 nm and an emission wavelength
of 430 nm. The results of measurements, expressed as a
percentage of control, are shown in Table 2.
Ack n ow led gm en t. We gratefully acknowledge Prof.
H. Kuriyama for his valuable suggestions; O. Cynshi
and Y. Takashima for the antioxidant test; K. Tsuzuki
and Dr. H. Matsuoka for their helpful advice in the
preparation of this paper; and Dr. K. Boru and Dr. V.
A. Khlebnikov for language editing.
Refer en ces
(1) Ross, R. S. Pathophysiology of Coronary Circulation. Br. Heart
J . 1971, 33, 173-184.
(2) (a) Theroux, P.; Taeymans, Y.; Waters, D. D. Calcium Antago-
nists: Clinical Use in the Treatment of Angina. Drugs 1983,
25, 178-195. (b) Scheidt, S. The Role of Calcium Blockers in
the Treatment of Chronic Stable Angina. In Calcium Blockers:
Mechanisms of Action and Clinical Applications; Flaim, S. F.,
Zelis, R., Eds.; Urban and Schwarzenberg: Baltimore, 1982, pp
231-244. (c) Braunwald, E. Mechanism of Action of Calcium-
Channel-Blocking Agents. N. Engl. J . Med. 1982, 307, 1618-
1627.
(3) (a) Bush, L. R.; Romson, J . L.; Ash, J . L.; Lucchesi, B. R. Effects
of Diltiazem on Extent of Ultimate Myocardial Injury resulting
from Temporary Coronary Artery Occlusion in Dogs. J . Cardio-
vasc. Pharmacol. 1982, 4, 285-296. (b) Reimer, K. A.; J ennings,
R. B. Verapamil in Two Reperfusion Models of Myocardial
Infarction. Temporary Protection of Severely Ischemic Myocar-
dium without Limitation of Ultimate Infarction Size. Lab. Invest.
1984, 51, 655-666.
(4) (a) Persson, S. Calcium Antagonists in Secondary Prevention
after Myocardial Infarction. Drugs 1991, 42 (Suppl. 2), 54-60.
(b) Sleight, P. Calcium Antagonists During and After Myocardial
Infarction. Drugs 1996, 51, 216-225.
(5) (a) Zweier, J . L.; Flaherty, J . T.; Weisfeldt, M. L. Direct
Measurement of Free Radical Generation following Reperfusion
of Ischemic Myocardium. Proc. Natl. Acad. Sci. U.S.A. 1987, 84,
1404-1407. (b) Shen, A. C.; J ennings, R. B. Kinetics of Calcium
Accumulation in Acute Myocardial Ischemic Injury. Am. J .
Pathol. 1972, 67, 441-452.
(6) (a) Farber, J . L. Biology of Disease: Membrane Injury and
Calcium Homeostasis in the Pathogenesis of Coagulative Ne-
crosis. Lab. Invest. 1982, 47, 114-123. (b) Bolli, R. Oxygen-
Derived Free Radicals and Myocardial Reperfusion Injury: An
Overview. Cardiovasc. Drugs Ther. 1991, 5, 249-268. (c) J o-
sephson, R. A.; Silverman, H. S.; Lakatta, E. G.; Stern, M. D.;
Zweier, J . L. Study of the Mechanisms of Hydrogen Peroxide
and Hydroxyl Free Radical-induced Cellular Injury and Calcium
Overload in Cardiac Myocytes. J . Biol. Chem. 1991, 266, 2354-
2361.
(7) (a) Borgers, M.; Ver Donck, L.; Vandeplassche, G. Pathophysi-
ology of Cardiomyocytes. Ann. N. Y. Acad. Sci. 1988, 522, 433-
453. (b) Ver Donck, L.; Pauwels, P. J .; Vandeplassche, G.;
Borgers, M. Isolated Rat Cardiac Myocytes as an Experimental
Model to Study Calcium Overload: The Effect of Calcium-Entry
Blockers. Life Sci. 1986, 38, 765-772.
(8) (a) Koch, P.; Wilffert, B.; Peters, T. R56865: A New Anti-
Ischemic Principle. Cardiovasc. Drug Rev. 1990, 8, 238-254. (b)
Ver Donck, L.; Borgers, M. Myocardial Protection by R56865:
A New Principle Based on Prevention of Ion Channel Pathology.
Am. J . Physiol. 1991, 261, H1828-1835. (c) Wilhelm, D.;
Himmel, H.; Ravens, U.; Peters, T. Characterization of the
Interaction of R56865 with Cardiac Na- and L-type Ca Channels.
Br. J . Pharmacol. 1991, 104, 483-489. (d) Lu, H. R.; De Clerck,
F. R56865, A Na+/Ca2+-Overload Inhibitor, Protects Against
Aconitine-Induced Cardiac Arrhythmias In Vivo. J . Cardiovasc.
Pharmacol. 1993, 22, 120-125.
(18) (a) Tamura, K.; Suzuki, Y.; Koga, T.; Akima, M.; Kato, T.;
Nabata, H. Actions of CP-060S on Veratridine-Induced Ca2+
Overload in Cardiomyocytes and Mechanical Activities in Vas-
cular Strips. Eur. J . Pharmacol. 1996, 312, 195-202. (b) Koga,
T.; Fukazawa, M.; Suzuki, Y.; Akima, M.; Adachi, Y.; Tamura,
K.; Kato, T.; Kuromaru, O. The Protective Effects of CP-060S
on Ischaemia- and Reperfusion-Induced Arrhythmias in Anaes-
thetized Rats. Br. J . Pharmacol. 1998, 123, 1409-1417. (c)
Suzuki, Y.; Tamura, K.; Adachi, Y.; Fukazawa, M.; Kato, T. CP-
060S Interacts with Three Principal Binding Sites on The L-Type
Ca2+ Channel. Eur. J . Pharmacol. 1998, 342, 347-351. (d)
Suzuki, Y.; Tamura, K.; Akima, M.; Adachi, Y.; Fukazawa, M.;
Kato, T. CP-060S,
A Novel Cardioprotective Drug, Limits
Myocardial Infarct Size in Anesthetized Dogs. J . Cardiovasc.
Pharmacol. 1998, 31, 400-407.
J M980335F