Synthesis and blood glucose and lipid-lowering effects of benzothiazole-substituted benzenesulfonylurea derivatives

Article abstract of DOI:10.1007/s00706-015-1471-2

Sulfonylurea drugs are widely used for the therapy of non-insulin-dependent diabetes mellitus. These drugs improve glucose and lipid levels by stimulating insulin secretion by the pancreatic β-cell comprising two generations with the second one more potent than the first. Glibenclamide is a well-known and potent second-generation sulfonylurea oral hypoglycemic drug which is most widely used in type II diabetes. In this research, five new analogs were synthesized by exchanging the lipophilic phenyl and urea moieties in the first and the end of the molecule with chlorobenzamide and hydrophilic and antidiabetic aminobenzothiazole substituents. Their glucose and lipid-lowering activities were evaluated and compared to the standard drug. Results showed that all of the new compounds exhibited better activities. In addition, in particular aminomethylbenzothiazoles derivatives could have exerted prominent hypoglycemic and a noticeable hypolipidemic effects superior to glibenclamide. Graphical abstract: [Figure not available: see fulltext.]

Full text of DOI:10.1007/s00706-015-1471-2

Monatsh Chem
DOI 10.1007/s00706-015-1471-2
ORIGINAL PAPER
Synthesis and blood glucose and lipid-lowering effects
of benzothiazole-substituted benzenesulfonylurea derivatives
Abbas Ahmadi1 Mohsen Khalili2 Parisa Ghaderi1
•
•
•
Ghazale Rastegar1 Babak Nahri-Niknafs1
•
Received: 16 January 2015 / Accepted: 22 March 2015
ꢀ Springer-Verlag Wien 2015
Abstract Sulfonylurea drugs are widely used for the ther-
apy of non-insulin-dependent diabetes mellitus. These drugs
improve glucose and lipid levels by stimulating insulin se-
cretion by the pancreatic b-cell comprising two generations
with the second one more potent than the first. Glibenclamide
is a well-known and potent second-generation sulfonylurea
oral hypoglycemic drug which is most widely used in type II
diabetes. In this research, five new analogs were synthesized
by exchanging the lipophilic phenyl and urea moieties in the
first and the end of the molecule with chlorobenzamide and
hydrophilic and antidiabetic aminobenzothiazole substituents.
Their glucose and lipid-lowering activities were evaluated and
compared to the standard drug. Results showed that all of the
new compounds exhibited better activities. In addition, in
particular aminomethylbenzothiazoles derivatives could have
exerted prominent hypoglycemic and a noticeable hypolipi-
demic effects superior to glibenclamide.
Keywords Non-insulin-dependent diabetes mellitus ꢀ
Sulfonylureas ꢀ Glibenclamide ꢀ
Hypoglycemic and hypolipidemic effects ꢀ
Aminobenzothiazoles
Introduction
Type II diabetes is a chronic metabolic disorder charac-
terized by abnormalities in carbohydrate and lipid
metabolism, which lead to postprandial and fasting hy-
perglycemia, dyslipidemia, and hyperinsulinemia. Insulin
resistance is considered to be the significant pathogenic
factor in type II diabetes and an obvious target for an-
tidiabetic medication [1].
Blood glucose levels are usually sufficiently controlled
by diet therapy and exercise in the early stage of type II
diabetes. However, when this control becomes poor, var-
ious antidiabetic drugs are used depending on the
pathophysiology of each patient, such as a-glucosidase
inhibitors for postprandial hyperglycemia, biguanides for
enhancing insulin action at the post-receptor level in pe-
ripheral tissues such as muscle, thiazolidinediones for
enhancing insulin action and promoting glucose utilization
in peripheral tissue for insulin resistance therapy, and
sulfonylureas for deficiency of insulin secretion from
pancreatic b cells [2, 3].
Graphical abstract
R1
R2
R4
R3
O
S
O
S
N
N
H
N
H
Cl
O
O
N
H
The most commonly used antidiabetic agents are sul-
fonylureas (SUs). They have been used for type II diabetes
therapy over 40 years, helping to counter the detrimental
effects of insulin deficiency and progressive loss of pan-
creatic beta cell responsiveness associated with chronic
hyperglycemia [4]. There are two generations of SU an-
tidiabetic drugs (first and second generations) where the
latter is more potent.
& Abbas Ahmadi
ahmadikiau@yahoo.com;
a-ahmadi@kiau.ac.ir
1
2
Department of Chemistry, Faculty of Science, Karaj Branch,
Islamic Azad University, Karaj, Iran
Neurophysiology Research Center, Shahed University,
Tehran, Iran
123

A. Ahmadi et al.
Glibenclamide
(5-chloro-N-(4-[N-(cyclohexylcar-
of DMF as a catalyst. Then, it was reacted with
2-phenylethylamine in the presence of potassium hydrox-
ide to obtain 2,4-dichloro-N-phenethylbenzamide (3).
Reaction of 3 with chlorosulfonic acid in chloroform and
ammonium hydroxide solution yields sulfonyl chloride 4
and sulfonamide 5 intermediates [7].
bamoyl)sulfamoyl]phenethyl)-2-methoxybenzamide, gly-
buride, 1) is a well-known and potent second-generation
drug which is widely used in oral type II antidiabetic drugs
clinically [5]. Up to now, many derivatives of 1 have been
synthesized and their anti-hyperglycemic and anti-hyper-
lipidemic activities evaluated [6–9]. According to SAR
studies, the search for novel glibenclamide derivatives is
originated to influence the in vivo behaviors by adding new
structural moieties to its structure while preserving its
binding affinity to the receptor (Scheme 1) [9, 10].
The sulfonamide compound 5 was converted to carba-
mate intermediate 6 by refluxing with ethyl chloroformate
in dry acetone containing anhydrous K2CO3 according to a
known procedure [15]. The resulting carbamate was sub-
sequently condensed with amines 7a–7e in dry toluene to
give the aminobenzothiazol-substituted benzenesulfony-
lureas 8a–8e.
In this research, because of our previous finding about
significant hypoglycemic and hypolipidemic activities of a
chloro derivative of 1 in its phenyl moiety [7], new analogs
by keeping this side were synthesized. In addition, cyclo-
hexyl moiety (D moiety in Scheme 1) of 1 was also
replaced by substituted benzothiazoles with many phar-
macological (such as antidiabetic) activities [11] in these
new analogs 8a–8e. Glucose and lipid-lowering activities
of 8a–8e were evaluated and compared to 1 and the control
groups by known procedures [12, 13].
Pharmacology
Blood serum glucose
Four days after alloxan injection, none of derivates have
significant effects on blood serum glucose (Fig. 1). How-
ever, on days 9–16 after alloxan application, a significant
reduction in glucose level was found between the treatment
and control animals. On day 9, glibenclamide, 8b, and 8c
could identically reduce blood serum glucose to: 38.40,
36.40, and 38.37 %. However, the related values on day 16
changed to 45.17, 40.61, and 41.18 %.
Results and discussion
Chemistry
Blood serum triglyceride (TG), cholesterol, LDL, HDL,
and VLDL
Sulfonylureas are derivatives with an arylsulfonyl group to
one nitrogen and another group which usually determines
the lipophilic properties of the molecule attached to ter-
minal nitrogen of urea viz., alkyl, alicyclic, heterocycles,
etc. [14].
The mean values of blood serum parameters including
triglyceride, cholesterol, LDL, HDL, and HDL/LDL ratio
are shown in Fig. 2. As indicated, 8a, 8b, and 8c could
markedly diminish TG and VLDL levels. The TG level in
the control animal (118.5) reaches 81.4, 82.6, and
82.01 mg/dm3 using 8a, 8b, and 8c. Also, related values
for VLDL yielded 16.28, 16.02, and 16.40 in comparison
with the control ones (23.7). The animals treated with 8c
and 8d showed a significant loss in serum LDL level,
The desired products 8a–8e were synthesized from
readily available materials. Moreover, a convenient syn-
thesis route was developed (Scheme 2). Initially, 2,4-
dichlorobenzoyl chloride (2) was synthesized from 2,4-
dichlorobenzoic acid and thionyl chloride in the presence
Scheme 1
O
S
O
CH3
O
NH
NH
O
O
D
NH
C
B
Cl
A
123

Synthesis and blood glucose…
Scheme 2
Cl
O
Cl
O
Cl
O
H N
N
H
SOCl2
Cl
Cl
OH
2
KOH
Cl
Cl
2
3
NH2
SO2
SO2Cl
Cl
O
Cl
O
H
ClSO3
N
H
N
H
NH
4OH
3
Cl
Cl
4
5
O
O
S
N
H
Cl
O
O
O
Anhydrous
acetone
O
N
H
5
+
Cl
O
Cl
R1
6
R2
R3
S
N
-
7a 7e
Anhydrous
toluene
H2N
R4
R1
R2
R4
R3
O
O
S
S
N
N
H
N
H
Cl
O
O
N
H
-
8a 8e
Cl
R1
R2
R
H
CH3
R1
R4
R
R
3
2
3
4
R1
R
R
H
3
4
R1
R2
R
R
H
3
=
=
=
=
=
=
=
H
=
=
=
=
=
=
=
=
4
8a: R1
R
8d:
8e:
-
=
H
8b:
8c:
4
R2 Br
=
CH3
R
Cl
45.14 and 44.9, respectively, which were control animals
(64.01). Finally, a high HDL/LDL ratio was found to be
good marker for the lipid profile in animals treated with
8b.
The principal action of the sulfonylureas is to stimulate
the release of insulin from b cells even when glucose levels
are low. They act by affecting the ATP-sensitive potassium
channels. These channels are hetero-octameric complexes
123

A. Ahmadi et al.
Fig. 1 The effects of 8a–8e and
glibenclamide (1) on blood
serum glucose on days 4, 9, and
16 after alloxan injection. Bars
the mean SEM serum
Control
Glyb.
8a
8b
8c
8d
8e
600
500
400
300
200
100
0
glucose (n = 12) in each group.
*P \ 0.05 shows the difference
*
*
*
*$ *$
$
*
*
*
with the control and P \ 0.05
shows the difference with
glibenclamide group
4th
9th
16th
Days
which are also composed of two subunits: sulfonylurea
receptors (SUR1, SUR2A, and SUR2B), and the inwardly
rectifying potassium channels KIR6.1 or KIR6.2 [16].
All compounds that block ATP channels stimulate in-
sulin secretion, but only those that interact with the SUR
subunit are used therapeutically to treat type II diabetes
[17]. They not only bind tightly to SUR1 in b cells but also
to SUR2A (as found in cardiac smooth muscle) and
SUR2B (as found in brain and smooth muscle). In the first
generation of SUs (for example: tolbutamide), it has been
reported to bind with high affinity to SUR1 but with more
than 100-fold lower affinity to SUR2A and SUR2B [4]. In
the second generation (such as glibenclamide), it has been
reported that they bind with high affinity to SUR1 (due to
lipophilic substitution on its urea group, D moiety in
Scheme 1) and with lower affinity to SUR2A and SUR2B
(due to the methoxy group as well as halogen atoms on the
phenyl ring in the other lipophilic side, the moiety in
Scheme 1) [16].
was maintained. Also, because an addition of hydrophilic
substitutions could result in lead compounds for the de-
velopment of SUR2-selective drugs with low affinity to
SUR1 [9], the cyclohexyl ring with lipophilic property (D
moiety in Scheme 1) was replaced by substituted
aminobenzothiazoles 7a–7e with hydrophilic and many
pharmacological (such as antidiabetic) activities [11, 19].
The results showed that 8a–8e exhibited higher hypo-
glycemic and hypolipidemic activities compared to the
control but only derivatives with aminomethylbenzothia-
zole substitutions (8b and 8c) could reduce blood glucose
and lipid profiles better than glibenclamide (1) too. It
seems that exchanging the lipophilic side on urea (D
moiety in Scheme 1) of Glibenclamide (which is re-
sponsible for SUR1 binding of the molecule) by
hydrophilic aminobenzothiazole could improve an-
tidiabetic and antilipidemic activities due to probably
high binding to SUR2. But this affinity is higher for
aminomethylbenzothiazole derivatives 8b and 8c as
compared to chlorine, bromine, or unsubstituted ones (8a,
8d, and 8e).
Therefore, the search for novel glibenclamide deriva-
tives originates from the idea to influence the in vivo
behavior by adding new chemical moieties to its structure
by changing the A–D moieties on the molecule (Scheme 1)
with different lipophilic or hydrophilic chemical structures
for obtaining more hypoglycemia and hypolipidemia ac-
tivities while preserving its binding affinity to SUR2 with a
higher degree compared to SUR1 or only SUR2-selective
drugs targeted to glycaemic control on one hand and to
reduction of cardiovascular complications on the other
hand [9, 18].
Also, it seems that these higher activities of methy-
laminobenzothiazole analogs 8b and 8c may influence the
hydrophilic/lipophilic balancing ratio or electron-donating
property of methyl compared to halogen groups (with
electron-withdrawing activities) in 8d and 8e. Comparing
bromine and chlorine substitutions on amino benzothiazole
derivatives, 8d and 8e also showed a higher hypoglycemic
effect for 8e which may result from the lower electron-
withdrawing property of bromine compared to chlorine
atoms on the molecules.
In this paper, because of significant results about addi-
tion of chloride instead of methoxy substitutions on the
phenyl moiety (A moiety in Scheme 1) of 1, for decreasing
the serum glucose and LDL levels [7], this side of 8a–8e
The lipid profiles of 8a–8e showed that TG and
cholesterol were decreased and the HDL/LDL ratio in-
creased compared to the control and glibenclamide groups.
123

Synthesis and blood glucose…
Fig. 2 The effects of 8a–8e and glibenclamide (1) on blood lipid profile. Bars the mean SEM serum lipid profile (n = 12) in each group.
*P \ 0.05 shows the difference with the control group
new antidiabetic drugs 8a–8e. Aminomethylbenzothiazoles
derivatives 8b and 8c exhibited higher hypoglycemic and
hypolipidemic activities compared to glibenclamide which
may result from the higher affinity of these new drugs
toward SUR2 more than SUR1.
Conclusion
It can be concluded that changing the lipophilic urea
moiety of glibenclamide by hydrophilic and antidiabetic
aminobenzothiazole substitutions 7a–7e could produce
123

A. Ahmadi et al.
d = 2.85–2.90 (2H, m), 3.43–3.49 (2H, m), 7.29–7.74
(10H, m), 8.56–8.60 (1H, m) ppm; 13C NMR: d = 34.5,
40.3, 117.8, 119.4, 125.6, 127.2, 129.1, 129.2, 130.1,
131.1, 134.3, 135.8, 142.1, 143.4, 165.2, 175.3 ppm; MS:
m/z (%) = 550 (96), 538 (14), 524 (20), 478 (40), 445 (15),
420 (30), 409 (44), 403 (40), 372 (100), 360 (80).
Experimental
2,4-Dichlorobenzoic acid, thionyl chloride, chlorosulfonic
acid, ethyl chloroformate, 2-phenylethyl amine, dimethyl
formamide (DMF), substituted benzothiazoles, and all
other chemicals were purchased from Merck (Darmstadt,
Germany) and Sigma-Aldrich chemical Co. (USA). Melt-
ing points were determined with a digital Electrothermal
melting point apparatus (model 9100, Electrothermal
Engineering Ltd., Essex, UK). The 1H and 13C NMR
spectra were recorded with a Bruker AMX 300 MHz
spectrometer (Karlsruhe, Germany; internal reference:
TMS). The IR spectra were recorded with a Thermo Ni-
colet FT-IR Nexus-870 spectrometer (Nicolet Instrument
Corp, Madison, WI, USA). Mass spectra were recorded
with an Agilent Technologies 5973, Mass Selective De-
tector (MSD) spectrometer (Wilmington, USA). Column
chromatographic separations were performed over Acros
silica gel (particle size 35–70 lm, Geel, Belgium). Ele-
mental analyses were carried out with a Perkin-Elmer,
CHN elemental analyzer model 2400; their results were
within 0.4 % of the theoretical values. The purity of the
compounds was determined by TLC using ethyl acetate/n-
hexane as the eluent. Compounds 2–5 were prepared ac-
cording to the procedure described in our previous study
[7].
2,4-Dichloro-N-[2-[4-[(4,6-dimethyl-2-benzothiazolyl-
amino)sulfamoyl]phenyl]ethyl]benzamide
(8b, C25H22Cl2N4O4S2)
Orange solid; yield 62 %; m.p.: 178–180 ꢁC; IR (KBr):
ꢀ
m = 3302, 3257, 2924, 2853, 1645, 1585, 1543, 1457,
1302, 1156, 1095, 835, 697 cm-1; 1H NMR: d = 2.38 (3H,
s), 2.58 (3H, s), 2.81–2.86 (2H, m), 3.46–3.51 (2H, m),
7.25–8.02 (8H, m), 8.43–8.50 (1H, m) ppm; 13C NMR:
d = 16.4, 20.9, 35.0, 42.0, 118.0, 124.3, 126.5, 127.0,
127.9, 128.3, 128.8, 129.1, 129.2, 130.3, 134.1, 135.3,
143.6, 143.8, 165.2, 176.3 ppm; MS: m/z (%) = 576 (70),
507 (45), 455 (27), 430 (49), 403 (31), 387 (100), 359 (49),
343 (31), 333 (30).
2,4-Dichloro-N-[2-[4-[(4-methyl-2-benzothiazolylamino)-
sulfamoyl]phenyl]ethyl]benzamide
(8c, C24H20Cl2N4O4S2)
White solid; yield 68 %; m.p.: 174 ꢁC; IR (KBr):
ꢀ
m = 3340, 3204, 3060, 1650, 1537, 1450, 1306, 1245,
1
1147, 1084, 883, 729, 611 cm-1; H NMR: d = 2.49 (3H,
s), 2.85–2.94 (2H, m), 3.46–3.57 (2H, m), 7.01–7.81 (9H,
m), 8.56–8.58 (1H, m) ppm; 13C NMR: d = 15.2, 36.9,
45.1, 119.9, 121.3, 125.0, 125.2, 126.0, 127.3, 128.2,
128.4, 130.1, 132.8, 134.3, 136.3, 142.3, 148.3, 165.3,
172.3 ppm; MS: m/z (%) = 562 (54), 536 (29), 479 (45),
460 (27), 435 (72), 423 (45), 398 (100).
General procedure for the preparation of new
compounds 8a–8e
A mixture of 3.73 g sulfonamide intermediate 5 (0.01 mol)
and 1.07 g anhydrous potassium carbonate in 100 cm3
anhydrous acetone was refluxed for 15 min. Then, 1.41 g
ethyl chloroformate (0.013 mol) was dropwise added and
refluxed for 8 days. After monitoring by TLC, acetone was
removed by distillation under reduced pressure; the residue
was suspended in 100 cm3 water and neutralized with
acetic acid. The product separated out was filtered, washed,
dried, and recrystallized from ethanol to obtain carbamate
intermediate 6 (yield: 51 %, m.p.: 192–196 ꢁC) which was
used in the next step without further purification.
2,4-Dichloro-N-[2-[4-[(6-chloro-2-benzothiazolylamino)-
sulfamoyl]phenyl]ethyl]benzamide
(8d, C23H17Cl3N4O4S2)
White solid; yield 71 %; m.p.: 173–176 ꢁC; IR (KBr):
ꢀ
m = 3402, 3360, 3333, 2922, 1632, 1591, 1491, 1460,
1273, 1156, 1087, 817, 764 cm-1 1H NMR:
;
d = 2.82–2.87 (2H, m), 3.45–3.53 (2H, m), 7.27–7.73
(9H, m), 8.69–8.73 (1H, m) ppm; 13C NMR: d = 35.7,
40.2, 119.6, 121.3, 125.2, 127.4, 129.0, 129.1, 130.1,
131.8, 134.3, 135.3, 142.3, 144.3, 148.2, 165.4, 175.0 ppm;
MS: m/z (%) = 582 (70), 560 (30), 547 (50), 514 (100),
487 (30).
Appropriate aminobenzothiazoles 7a–7e (0.0011 mol)
were added to a solution of carbamate intermediate 6
(0.001 mol) in 50 cm3 boiling toluene. The mixture was
subsequently refluxed for further 10 days and cooled.
Benzenesulfonylureas 8a–8e, which precipitated out on
cooling, were filtered and recrystallized from ethanol.
2,4-Dichloro-N-[2-[4-[(6-bromo-2-benzothiazolylamino)-
sulfamoyl]phenyl]ethyl]benzamide
(8e, C23H17BrCl2N4O4S2)
Light brown solid; yield 65 %; m.p.: 161 ꢁC; IR (KBr):
2,4-Dichloro-N-[2-[4-[(2-benzothiazolylamino)sul-
famoyl]phenyl]ethyl]benzamide (8a, C23H18Cl2N4O4S2)
White solid; yield 63 %; m.p.: 168 ꢁC; IR (KBr):
ꢀ
m = 3310, 3256, 2927, 2856, 1645, 1539, 1328, 1156,
1098, 826 cm-1 1H NMR: d = 2.74–2.79 (2H, m),
3.62–3.71 (2H, m), 7.1–7.9 (9H, m), 8.70–8.72 (1H, m)
;
ꢀ
m = 3448, 3285, 3067, 2936, 2736, 1645, 1537, 1410,
1310, 1276, 1070, 870, 734, 565 cm-1
;
1H NMR:
ppm; 13C NMR: d = 34.6, 42.3, 124.4, 124.5, 127.6, 128.1,
123

Synthesis and blood glucose…
128.3, 130.8, 133.2, 135.7, 138.2, 141.2, 142.3, 144.1,
151.7, 169.4, 174.2 ppm; MS: m/z (%) = 627 (68), 613
(10), 590 (8), 528 (12), 503 (10), 496 (25), 478 (15), 466
(24), 459 (100).
VLDL ¼ Triglyceride=5
LDL ¼ Total cholesterol ꢁ HDL cholesterol ꢁ VLD
Statistical analysis
Measurement data were tabulated as mean SEM. Com-
parisons were carried out using one-way analysis of
variances (ANOVA) followed by post hoc Tukey test and
P value \0.05 as the level of significance.
Animals
Initially, 84 adult male Wistar rats, weighing 190–220 g
(Razi Institute, Iran) with blood glucose under 150 mg/dm3
as non-diabetic animals were randomly selected and
housed three to four per cage in a temperature-controlled
colony room under a 12 h light/dark cycle. Animals were
given free access to water and standard laboratory rat chow
(Pars Company, Tehran, Iran). All the experiments were
conducted between 11 a.m. and 4 p.m. under the normal
room light at 25 ꢁC. This study was carried out in line with
the policies provided in the Guide for the Care and Use of
Laboratory Animals (NIH) and those in the Research
Council at Shahed University of Medical Sciences (Tehran,
Iran).
Acknowledgments This work was a research project at Karaj
Branch, Islamic Azad University, Iran and the authors would like to
express their gratitude to them. They thank Fariba Ansari for her
assistance with the pharmacological tests. They appreciate Mojtaba
Chaichi, EFL educator at Safir English Language Academy, for
proofreading the initial draft of this article.
References
1. Chakrabarti R, Vikramadithyan RK, Mullangi R, Sharma VM,
Jagadheshan H, Rao YN, Sairam P, Rajagopalan R (2002) J
Ethnopharmacol 81:343
2. Satoh J, Takahashi K, Takizawa Y, Ishihara H, Hirai M, Katagiri
H, Hinokio Y, Suzuki S, Tsuji I, Oka Y (2005) Diabetes Res Clin
Pract 70:291
3. Jawale DV, Pratap UR, Rahuja N, Srivastava AK, Mane RA
(2012) Bioorg Med Chem Lett 22:436
4. McClenaghan NH, Ball AJ, Flatt PR (2001) Biochem Pharmacol
61:527
Mortality (number of deaths), morbidity (defined as any
abnormal condition or behavior due to a disorder), irri-
tability (a condition of aggressiveness or increased
response on handling), and other related abnormal states
were observed in experimental animals. However, the
motor coordination index (measured by means of Rota-rod
apparatus, Harvard, UK) did not indicate any significant
differences between treated rats.
5. Pill J, Ku¨hnle HF (1999) Metabolism 48:34
6. Ahmadi A, Khalili M, Farsadrooh M, Ghiasi M, Nahri-Niknafs B
(2013) Drug Res 63:614
7. Ahmadi A, Khalili M, Khatami K, Farsadrooh M, Nahri-Niknafs
B (2014) Mini Rev Med Chem 14:208
Serum parameters analysis
8. Velingkar VS, Dandekar VD, Murugananthan K (2009) Inter J
Pharm Pharm Sci 1:149
9. Schneider S, Ueberberg S, Korobeynikov A, Schechinger W,
Schwanstecher C, Schwanstecher M, Klein HH, Schirrmacher E
(2007) Regul Pept 139:1
10. Zaman MK, Arayne MS, Sultana N, Farooq A (2006) Pak J
Pharm Sci 19:114
11. Mariappan G, Prabhat P, Sutharson L, Banerjee J, Patangia U,
Nath S (2012) J Korean Chem Soc 56:251
12. Patel SS, Shah RS, Goyal RK (2009) Indian J Exp Biol 47:564
13. Latha RC, Daisy P (2011) Chem Biol Interact 189:112
14. Tyagi S, Kumar S, Kumar A, Singla M (2010) Int J Pharm World
Res 1:1
15. Rathish IG, Javed K, Bano S, Ahmad S, Alam MS, Pillai KK
(2009) Eur J Med Chem 44:2673
16. Meyer M, Chudziak F, Schwanstecher C, Schwanstecher M,
Panten U (1999) Br J Pharmacol 128:27
17. Proks P, Reimann F, Green N, Gribble F, Ashcroft F (2002)
Diabetes 51:S368
For inducing diabetes, a single dose of alloxan (Sigma,
UK) in 150 mg/kg (immediately before usage dissolved in
0.9 % saline) was injected intraperitoneally to all selected
animals (with serum glucose under 150 mg/dl) and ran-
domly divided into seven groups; control, glibenclamide,
and 8a–8e [12, 13]. These drugs (each one at 0.25 mg/kg,
i.p) [20] were injected to the animals on day 3–16 after
alloxan injection. Glucose in the serum as the main pa-
rameter for efficiency of origin or synthesized antidiabetic
drugs was measured due to the alloxan injection on days 4,
9, and 16. Other serum parameters, i.e., triglyceride, total
cholesterol, LDL, HDL, and VLDL were calculated on day
16 after alloxan injection. To measure the mentioned serum
parameters, blood samples were collected. Serum glucose
concentrations, triglyceride, total cholesterol, and HDL
cholesterol levels were spectrophotometrically measured
with appropriate kits (Zistshimi, Tehran). Only the animals
with serum glucose content of higher than 250 mg/dl were
selected as diabetics for the following measurements. LDL
and a low-density lipoprotein (VLDL) cholesterol levels
were calculated using following formulae:
18. Calderone V, Rapposelli S, Martelli A, Digiacomo M, Testai L,
Torri S, Marchetti P, Breschi MC, Balsamo A (2009) Bioorg Med
Chem 17:5426
19. Meltzer-Mats E, Babai-Shani G, Pasternak L, Uritsky N, Getter
T, Viskind O, Eckel J, Cerasi E, Senderowitz H, Sasson S,
Gruzman A (2013) J Med Chem 56:5335
20. Devaki K, Beulah U, Akila G, Narmadha R, Gopalakrishnan VK
(2011) J Basic Clin Pharm 2:167
123