Synthesis of novel organohalogen chalcone derivatives and screening of their molecular docking study and some enzymes inhibition effects

Article abstract of DOI:10.1016/j.molstruc.2020.127868

Chalcones and their derivatives are increasing attention due to numerous biochemical and pharmacological applications. In this study, a series of novel organohalogen chalcone derivatives (5–12) were tested towards α-glycosidase (α-Gly), acetylcholinestera

Full text of DOI:10.1016/j.molstruc.2020.127868

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Synthesis of novel organohalogen chalcone derivatives and screening of their
molecular docking study and some enzymes inhibition effects
Serdar Burmaoglu, Elif Akin Kazancioglu, Ruya Kaya, Mustafa Kazancioglu,
Muhammet Karaman, Oztekin Algul, Ilhami Gulcin
PII:
S0022-2860(20)30192-7
DOI:
https://doi.org/10.1016/j.molstruc.2020.127868
MOLSTR 127868
Reference:
To appear in: Journal of Molecular Structure
Received Date: 13 December 2019
Revised Date: 2 February 2020
Accepted Date: 6 February 2020
Please cite this article as: S. Burmaoglu, E.A. Kazancioglu, R. Kaya, M. Kazancioglu, M. Karaman, O.
Algul, I. Gulcin, Synthesis of novel organohalogen chalcone derivatives and screening of their molecular
docking study and some enzymes inhibition effects, Journal of Molecular Structure (2020), doi: https://
doi.org/10.1016/j.molstruc.2020.127868.
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CRediT Author Statement
Serdar Burmaoglu
Elif Akin Kazancioglu
Ruya Kaya
: Writing-Original draft preparation, Supervision
: Methodology, Investigation
: Methodology, Investigation
Mustafa Kazancioglu
Muhammet Karaman
Oztekin Algul
: Methodology, Investigation
: Formal analysis, Software, Investigation
: Writing-Original draft preparation, Supervision, Data Curation
: Writing-Reviewing and Editing, Supervision, Data Curation
Ilhami Gulcin

Synthesis of Novel Organohalogen Chalcone Derivatives and Screening of Their
Molecular Docking Study and Some Enzymes Inhibition Effects
Serdar Burmaoglu1, Elif Akin Kazancioglu2, Ruya Kaya1,3, Mustafa Kazancioglu4,
Muhammet Karaman5, Oztekin Algul6, Ilhami Gulcin1,*
1Department of Chemistry, Faculty of Science, Atatürk University, 25240, Erzurum, Turkey
2Vocational High School of Health Services, Kilis 7 Aralık University, 79000, Kilis, Turkey
3Central Research and Application Laboratory, Ağri Ibrahim Cecen University, 04100, Agri,
Turkey
4Yusuf Serefoglu Faculty of Health Sciences, Kilis 7 Aralık University, 79000, Kilis, Turkey
5Molecular Biology and Genetics Department, Faculty of Art and Science, Kilis 7 Aralik
University, Kilis, Turkey
6Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Mersin University, 33169,
Mersin, Turkey
*Corresponding author
Prof. Dr. İlhami Gülçin
Tel: +90 442 2314375
Fax: +90 442 2314109
E-mails: igulcin@atauni.edu.tr
igulcin@yahoo.com
1

ABSTRACT
Chalcones and their derivatives are increasing attention due to numerous biochemical and
pharmacological applications. In this study, a series of novel organohalogen chalcone
derivatives (5-12) were tested towards α-glycosidase (α-Gly), acetylcholinesterase (AChE)
human carbonic anhydrase I (hCA I), and carbonic anhydrase II (hCA II) enzymes. These
compounds (5-12) showed Kis in ranging of 16.24-40.96 nM on hCA I, 29.61-67.15 nM on
hCA II, 1.21-4.39 nM on AChE and 12.54-35.22 nM on α-glycosidase. The novel
organohalogen chalcone derivatives (5-12) had effective inhibition profiles against all tested
metabolic enzymes. Also, because of the enzyme inhibitory effects of the compounds (5-12),
they have the potential of drug candidates to treat of some diseases including epilepsy,
glaucoma, type-2 diabetes mellitus (T2DM), Alzheimer’s disease (AD), and leukemia. Also,
the chalcone derivatives with best inhibition score docked into the active site of indicated
metabolic enzymes receptors. Bromobenzyle and chlorophenyl moieties of chalcone
derivatives contribute to their inhibitor properties on the enzymes.
Keywords: Chalcone; enzyme inhibition; carbonic anhydrase; acetylcholinesterase; α-
glycosidase
2

1. INTRODUCTION
Chalcones are a prominent class of compounds, which are frequently encountered in the
literature. The main reason is that they can be synthesized easily and show a wide range of
biological activities including antidiabetic, anticancer, antifungal, antitoxic etc [1-3]. Most of
chalcones have already been used as a drug in traditional medicine, and is also well known in
the industry by their fluorescence properties and ability to react with metal ions [4]. Recently,
it was reported that many organohalogen contains chlorine, bromine and fluorine have been
recorded to have potential anticancer, anti-inflammatory, cytotoxicity, antioxidant and
antimicrobial activity also protein tyrosine phosphatase, aldose reductase and hCA inhibitory
actions [5].
Metabolic enzymes have a key and crucial role for regulation and persistence of the
metabolism in living organisms [6,7]. Carbonic anhydrase enzymes (CAs) are an important
metabolic enzyme family and catalyze reversibly transform of carbon dioxide (CO2) and
water (H2O) to bicarbonate ion (HCO3 ) and proton (H+) [8-10]. They encoded by seven
-
distinct gene families (α-θ CAs) [11-13]. Until today, sixteen distinctive α-CA isoenzymes
have been discovered and characterized [14-16]. Furthermore, because of these crucial
physiological and inhibition properties, many researchers have done research on CAs. Among
them CA I, and II isoenzymes are the most studied and examined CA isoenzymes [17,18]. CA
inhibitors (CAIs) are mainly used as therapeutic agents in treatment of antiglaucoma,
diuretics, antitumor, anticonvulsant and antiobesity [19,20]. When viewed from this point,
improving of novel CAIs had a great importance. CAIs have various therapeutic applications
including glaucoma [21]. Chalcone derivatives are one of the best-studied CA inhibitor
classes and their inhibition profiles were well established [2,3,22,23].
Alzheimer’s disease (AD) is a one of the significant problems for elderly people
worldwide and being characterized as a multifactorial disease [24-26]. AD is the most
common progressive neurodegenerative disorder that always related to a decline of memory
and cognitive functions [27-29]. So far, AChE inhibition is one of the most common and
successful methods to treat AD [30-32]. For this reason, drug therapies have been developed
focusing on AChE inhibitors, which increase cholinergic transmission through the inhibition
of AChE responsible for breaking down the neurotransmitter acetylcholine. In addition, the
effectiveness of these therapies has been investigated by several randomized tests [33,34].
Also, it is well known that the chalcone-based derivatives could modulate different pathways
involved in disease progression, due to the peculiar trans-α, β-unsaturated ketone in the
3

chalcone framework. The simpler and more flexible framework of the new chalcone-based
derivatives is known to allow less restricted molecules to be obtained. This could interact
better with the narrow passage of cholinesterases [35]. In a recent study, a series of chalcone-
O-carbamate derivatives was designed, synthesized and evaluated based on the multitarget-
directed ligands strategy. Another suitable strategy for achieving better therapeutic efficacy
for AD is proposed by the development of multitarget-directed ligands, which can
simultaneously modulate different targets or mechanisms included in the neurodegenerative
AD cascade [36]. At the same time, ethyl acetohydroxamate and chalcone epoxide
incorporated chalcones were recently used as a novel class of chalcones for multitarget
inhibitors against AD [37,38]. They are considered a powerful organic scaffold with extensive
applications in the drug discovery and medicinal chemistry. In this perspective, chalcones
were designed for the management of central nervous system disorders, which include
acetylcholinesterase and butyrylcholinesterase inhibitions [39].
Glycosidases are the specific glycosidic bond hydrolases directly involved in the
glycosylation on cell surface. They release from small intestines and hydrolyze
oligosaccharides and polysaccharides to monosaccharides including fructose and glucose
[40,41]. The occurrence and development of many diseases including diabetes, cancers,
autoimmune diseases and viral infections are closely related to the abnormal expression of the
glycosidases [42-44]. α-Glycosidase inhibitors (α-GIs) had a quite important to control
hyperglycemia and T2DM in human [45]. They can reduce the dietary carbohydrates uptake,
suppression of postprandial diabetes and hyperglycemia [46].
Within the scope of this information, in the present study, we searched the influence of
novel chalcone derivatives (5-12) on hCA isoenzymes, AChE, and α-glycosidase enzymes.
Furthermore, the metabolic enzyme inhibition profiles of novel chalcone derivatives (5-12)
were compared to acetazolamide (AZA) and tacrine (TAC) as standard inhibitors for hCA
isoenzymes and AChE, respectively.
2. RESULTS AND DISCUSSION
2.1. Chemistry
The main goal of the present study is to synthesize and investigate the metabolic enzyme
inhibition effect of some novel organohalogen chalcone derivatives. The synthesis of the
target and intermediate compounds was done accordance with the reactions presented in
Scheme 1. The intermediate 14 was synthesized from compound 13. For this, 13 was
4

brominated to the 3-bromo-2,4,6-trimethoxyacetophenone (14) in 95% yield through the
employing of general bromination protocol (Scheme 1) [47,48]. The base-catalyzed reaction
of compound 14 with related benzaldehydes (15-22) afforded chalcone derivatives (5-12) in
good yields (Scheme 1) [10]. The formation of the chalcone skeleton was determined by
measuring the interaction constants of α,β-unsaturated protons as approximately 16 Hz.
Moreover, singlet 1 proton at about 6.38 ppm indicates that there is mono bromine in the A
ring.
Scheme 1. Synthetic pathway of chalcone derivatives. Reagents: (i) ammonium cerium (IV)
nitrate (CAN), LiBr, CH3CN, 2 h, rt; (ii) 50% KOH, MeOH, rt.
2.2. Biochemical Studies
CAIs are chemicals or pharmaceuticals, which suppressed the CA activity o as competitive or
noncompetitive. The CAIs has been clinically assigned as antiepileptics, anti-glaucoma, and
diuretic agents, to manage gastric and duodenal ulcers, mountain sickness, hypertension,
idiopathic intracranial, osteoporosis and neurological disorders. The inhibition of CAs has
been the subject of research since the finding out the biological effectiveness of CA in living
organisms and has directed researchers to these issues [49]. Recently, a large spectrum of
novel organic and derivative compounds has been raised and discovered as CAIs [50,51]. In
this context, novel chalcone derivatives (5-12) are found as effective and potent CA
inhibitors, we synthesized some novel chalcone derivatives (5-12) to explore their possible
hCA I, and hCA II, α-glycosidase and AChE inhibition effects, which summarized in Table 1
and the following results have been displayed.
The hCA I exist in erythrocytes at the high level [52]. Novel chalcone derivatives (5-
12) showed low nanomolar Kis. Lower Ki value indicates strong inhibitor affinity of inhibitor
to enzyme [53]. For determination of both inhibition types and Ki constants of novel chalcone
5

derivatives (5-12), Lineweaver-Burk graphs were obtained [54] as described in previous
studies [55,56]. Novel chalcone derivatives (5-12) showed low nanomolar inhibition levels
against hCA I with Ki values between 16.24±5.10-40.96±8.95 nM (Table 1). Also, compound
6 had the best inhibition effect toward hCA I (Ki: 16.24±5.10 nM). On the other hand,
acetazolamide (AZA), as a sulfonamide-based reference inhibitor, had Ki value of
141.02±50.84 for same isoenzyme (Ki-AZA/Ki-hCA-I:8.683). AZA provides good
pharmacokinetic exhibits and minimal toxicity properties. However, It exhibits several
undesired side effects including increase urine volume [57-60]. All undesirable side effects
form a result of its nonspecific CAs inhibition [61-63]. The results clearly exhibited that novel
chalcone derivatives (5-12) had strong inhibition effect than that of AZA toward hCA I (Table
1). Also, selectivity indexes of novel chalcone derivatives (5-12) were given in Table 2. It is
known that chalcone derivatives are well-studied CAIs and their CA inhibition effects well
established [64,65]. Recently it was approved that tetrabromo chalcone derivatives showed
excellent inhibition effects in the low nanomolar range of 11.30-21.22 nM against hCA I [2].
In a recent study, some novel chalcone-imide derivatives exhibited strong inhibition effects
with Kis of 426.47-699.58 nM against hCA I, nM [3]. In our study, novel tris-chalcones
derivatives were found potent cytosolic hCA I inhibitor with Ki values between 19.58-78.73
nM [23].
Also, CA II includes the primary Na-carrying mechanism into the eyes. As a result of
this transportation, it is responsible to regulate the intraocular pressure [66,67]. The high IOP
is harmful for the optic nerve in eye. Thus, CA II inhibition reduces a high intraocular
pressure normally accompanying glaucoma. A close look at the inhibitors of CA II is very
important for glaucoma treatment [68,69]. Another pharmaceutical application of CA II
inhibitors is their use in the treatment of bone resorption most commonly found during
postmenopausal osteoporosis [70-72]. Sulfamates as putative CA II inhibitors are directly
bound to the metal in the center of active site of hCA II [73]. As seen in Table 1, the
inhibition effects of novel chalcones (5-12) on hCA II isoenzyme is quite similar CA I. They
showed Kis between 29.61±5.65-67.15±16.21 nM. However, AZA that used to treat glaucoma
and some other diseases [74] had a Ki of 22.17±0.65 nM on hCA II. As can seen in Table 2,
compound 8 had greatest selectivity against hCA II isoenzyme. It is promising compound 8
had a drug candidate potential and can be used for the treatment of glaucoma (Ki-AZA/Ki-hCA-II
:
0.748) (Tables 1 and 2). In our recent studies, it was found that tetrabromo chalcone
derivatives inhibited hCA II with Kis between 8.21 and 12.86 nM. Recently, it was proven
that some novel chalcone-imide derivatives had powerful inhibition effects with Kis of
6

214.92-532.21 nM for hCA II [3]. Also, in our recent study, novel Tris-chalcones derivatives
were found potent cytosolic dominant hCA II inhibitor with Ki values between 12.23-41.70
nM [23].
AChE and BChE inhibition kinetics novel chalcones (5-12) were determined
according to the Ellman’s procedure [75] as previously described [76-78]. Novel chalcones
(5-12) had Kis in ranging from 1.21±0.20 to 4.39±0.25 nM for AChE (Table 1), whereas,
TAC had Ki of 5.99±1.79 against AChE. All studied novel chalcones (5-12) demonstrated
powerful inhibition against both enzymes, but compound 9 showed perfect inhibition effect
against AChE (Ki: 1.21±0.20 nM; Ki-TAC/Ki-AChE: 4.950) (Tables 1 and 2). On the other hand,
in a recent study it was found that novel chalcones had efficient inhibition impact with Ki
values of 1.09-6.84 nM against AChE [24]. Our results are similar to the results obtained from
this study.
Finally, for the α-glycosidase, novel chalcone derivatives (5-12) exhibited Ki values
are between 12.54±4.16-35.22±2.10 nM (Table 1). The results showed that all novel chalcone
derivatives (5-12) had effective α-glycosidase inhibition effects than acarbose (IC50: 22.800
mM) as standard α-glycosidase inhibitor [79]. Also, highly effective Kis were calculated for
compound 9 (Ki: 14.02±3.73 nM). In our previous study, novel Tris-chalcones were found as
potent α-GIs with Kis between 0.93±0.20-18.53±5.06 nM [23,80].
2.3. In Silico Studies
In silico studies carried out for clarifying binding affinity and interaction mode of chalcone
derivatives with best inhibition score against hCA I, hCA II, AChE, and α-glycosidase
enzymes. Before performing docking studies, we checked drug-likeness of the chalcone
derivatives. After Qikprob calculation, we considered number of reactive functional groups,
molecular weight, hydrogen bond donor and acceptor, octanol/water partition coefficient, IC50
value for blockage of HERG K+ channels, Caco-2 cell permeability, MDCK cell permeability,
brain/blood partition coefficient, and human oral absorption rate of the chalcone derivatives
(Supplementary Table 1). All parameters of the chalcone derivatives were suitable for rules of
Lipinski and co-workers [81] and Schrodinger software. For this reason, the chalcone
derivatives are non-toxic compound due to 1 reactive functional groups and they have good
membrane permeability, partition and oral absorption value. The pharmacokinetic properties
of the compounds clearly demonstrated that they may exhibit excellent drug properties.
7

In order to identify and clarify affinity and interactions between compounds which
have good drug properties and receptors, binding site of the receptors has been identified with
SiteMap module. Identified receptor’s binding sites have been evaluated on the basis of
SiteScore and Dscore. hCA I, hCA II, AChE, and α-glycosidase receptors have 1.063, 0.971,
1.090, and 1.016 SiteScore and 1.061, 0.945, 1.113, and 0.961 Dscore, respectively.
According to the SiteScores and Dscores, the binding site of each receptor was strongly
acceptable as catalytic active site and druggable site. Predicted catalytic active sites have been
used evaluating of induced fit docking poses as seen Figure 2.
Induced-fit docking technic has been validated by re-docking of co-crystallized
ligands into the predicted catalytic active site of the receptors. Fallowing re-docking process,
RMSD value calculated between re-docked ligands and co-crystallized. The RMSD values
have been determined as 1.134, 2.858, 0.330, and 1.184 for hCA I, hCA II, AChE, and α-
glycosidase receptors, respectively. The RMSD values have been shown that induced-fit
docking technique was a reliable docking technique. The best-pose of co-crystallized and re-
docked ligands have been shown in Figure 3.
After determining the accuracy of the docking method, the chalcone derivatives have
been docked into the predicted active site of the receptors with the same docking technique.
Their binding affinity calculated as docking score and docking result have been analyzed in
the perspective of docking score. Pose with highest docking score in the negative direction
has been selected as best-posed ligand. Docking score of best-posed ligands has been
presented in Table 3. According to the Docking scores, the chalcone derivatives posses well
binding affinity against their receptors. The docking scores of the chalcone derivatives were
similar to the docking scores of reference inhibitors. In order to explain the inhibition
mechanism of the chalcone derivatives, 2D and 3D binding modes of best-posed ligands have
been analysed. Interacted residues with ligands into active site of receptors was shown in
Table 4 and 3D interaction diagram have been shown in Figure 3.
According to Table 4, the chalcone derivatives formed important interactions with
active site residues of receptors. 4-Methoxy group of bromobenzyle moiety of compound 6
only formed methal coordination with Zn301 in the catalytic active site of the hCA I (Sup.
Figures 1a and 4a). The interaction diagrams shown that Zn atom of hCA I plays an crucial
role their activity. 4,6-Methoxy groups of bromobenzyle moiety of compound 8 formed
hydrogen bond with Try7 and Asn67 residue of hCA II receptor. Furthermore, bromobenzyle
moiety of compound 8 formed halogen bond with Trp5 residue in active site of the hCA II
(Sup. Figures 1b and 4b). Moreover, aromatic ring of Trp5 residue formed aromatic hydrogen
8

bond with 4-methoxy group of bromobenzyle moiety of compound 8 as seen in Figure 4b. 4-
Methoxy groups of bromobenzyle moiety and ketone group of compound 9 formed H-bond
with Ser293 and Tyr124 residues, respectively. Aromatic hydrogen bond also existed between
bromobenzyle moiety and Ser203 residues of AChE receptor as seen in Figure 4c.
Furthermore, bromobenzyle moiety of compound 9 formed halogen bond with Phe295 residue
in active site of the AChE (Sup. Figures 1c and 6c). Compound 9 only formed a H-bond with
Gol3002 (glycerole which is solvent in protein structure) in active site of the α-glycosidase
receptor, through 2-methoxy groups of bromobenzyle moiety. Compound 9 not only formed a
H-bond but also aromatic H-bond with Asp327 and Asp542 residues of the receptor as seen in
Figure 4d. Furthermore, bromobenzyle moiety of compound 9 formed halogen bond with
Thr205 residue of the receptor (Sup. Figures 1d and 6d). All compounds closely interacted
with hydrophobic residues. However, compounds 6, 8, and 9 exhibited quite close
hydrophobic interaction with hCA I, hCA II, and α-glycosidase receptors as seen in Figure 2,
respectively. Chlorophenyl moiety of compounds responsible for the hydrophobic
interactions. Also, it was observed the correlations between inhibition mechanisms of the
most active compounds and the positive controls with regard to surrounding and interacting
residues [49].
3. CONCLUSIONS
In conclusion, we designed and synthesized novel organohalogen chalcone derivatives (5-12).
The inhibition effects of all compounds on hCA I, and hCA II isoenzymes and AChE and α-
glycosidase enzymes were evaluated together. The novel chalcones demonstrated inhibition
effects against hCA I, and hCA II isoenzymes and AChE and α-glycosidase enzymes
activities at low concentrations. Especially compound 9 for hCA I and hCA II, 8 for AChE,
and 5 for α-glycosidase. Methoxy groups of bromobenzyle moiety of the compounds are
crucial importance for inhibition for indicated enzyme receptors. In other respects,
chlorophenyl moiety of compounds contributes to inhibition of the receptors. We also think
that if the compounds have hydrogen donor groups for hydrogen bond, their inhibitory
activity against the receptors could be increased. Chalcone-based derivatives could modulate
different pathways involved in disease progression, due to the peculiar trans-α,β-unsaturated
ketone in the chalcone framework. The simpler and more flexible framework of the new
chalcone-based derivatives is known to allow less restricted molecules to be obtained. The
results may be useful for designing and synthesing of new metabolic enzyme inhibitors and in
9

the improvement of drugs to treat some diseases including epilepsy, glaucoma, leukemia, AD
and T2DM in the future.
4. EXPERIMENTALS
4.1.Organic Synthesis
4.1.1.General. All reagents used in this study were commercially available unless otherwise
specified and all solvents were distilled before use. Melting points were measured with Stuart
SMP20 melting point apparatus. IR Spectra: PerkinElmer Spectrum One FT-IR spectrometer.
13
1H- and C-NMR Spectra: Bruker 400 spectrometers. Elemental analysis results were taken
in a Leco CHNS-932 instrument.
4.1.2.Synthesis of 3-bromo-2,4,6-trimethoxyacetophenone (14):
To a solution of ammonium cerium (IV) nitrate (1 eq.) and LiBr (1 eq.) in CH3CN (2.5 mL/1
mmol of substrate) was added 2,4,6-trimethoxyacetophenone (13) (1 eq.) under N2. The
mixture was stirred for 2 h at rt. After 2 h, reaction was monitored by TLC and the solvent
was removed under reduced pressure. The crude product was dissolved in EtOAc (50 mL),
washed with H2O (2 × 25 mL) and a solution of saturated aqueous NaHCO3 (50 mL), and the
organic layer was dried over Na2SO4. The solvent was removed under reduced pressure to
1
afford 3-bromo-2,4,6-trimethoxyacetophenone (14) as a light brown solid (80%). The H
NMR and 13C NMR spectra are in agreement with reported data [47].
4.1.3.General procedure for preparation of Compounds 5-12:
To a solution of 3-bromo-2,4,6-trimethoxyacetophenone (14) (1 eq.) in MeOH (2.5 mL/mmol
of substrate) was added benzaldehyde derivatives (15-22) (1.6 eq.) and 50% KOH solution
(1.5 mL/mmol of substrate) sequentially and stirred for 15 h at 25oC. After 15 h solvent was
evaporated. Crude material washed with 2 M HCl solution (2 mL/mmol of substrate) and
extracted with DCM (2 mL/mmol of substrate x 3). The combined extracts were dried over
Na2SO4. The solvent was removed in vacuo and the remaining residue purified via column
chromatography over silica gel using gradient elution with EtOAc and hexanes to yield
compounds 5-12.
4.1.4. (E)-1-(3-bromo-2,4,6-trimethoxyphenyl)-3-phenylprop-2-en-1-one (5):
10

The above procedure was followed with benzaldehyde (15) to yield 5 as a light yellow solid
(95% yield). Rf (EtOAc/Hexanes 40:60) = 0.53; mp = 165-166 °C; IR (KBr, cm-1) Vmax
1
2941, 1606, 1457, 1269, 1206, 1129; H NMR (400 MHz, CDCl3) δ 7.56 – 7.54 (m, 2H),
7.40 – 7.36 (m, 4H), 7.01 (d, 1H, A part of AB system, J = 16.1 Hz), 6.38 (s, 1H), 3.98 (s,
13
3H), 3.83 (s, 6H); C NMR (100 MHz, CDCl3) δ 193.2, 158.4, 157.6, 156.2, 145.4, 134.6,
130.6, 128.9, 128.5, 128.4, 117.9, 98.3, 92.6, 62.5, 56.6, 56.2; Anal. calcd for C18H17BrO4: C,
57.31; H, 4.54; Found: C, 57.80; H, 4.47.
4.1.5. (E)-1-(3-bromo-2,4,6-trimethoxyphenyl)-3-(2-chlorophenyl)prop-2-en-1-one (6):
The above procedure was followed with 2-chlorobenzaldehyde (16) to yield 6 as a white solid
(96% yield). Rf (EtOAc/Hexanes 40:60) = 0.56; mp = 144-145 °C; IR (KBr, cm-1) Vmax
1
2941, 1606, 1457, 1269, 1206, 1129; H NMR (400 MHz, CDCl3) δ 7.81 (d, 1H, B part of
AB system, J = 16.1 Hz), 7.70 (dd, 1H, J = 7.1, 2.1 Hz), 7.44 – 7.38 (m, 1H), 7.35 – 7.28 (m,
2H), 6.97 (d, 1H, A part of AB system, J = 16.1 Hz), 6.39 (s, 1H), 3.99 (s, 3H), 3.85 (s, 6H);
13C NMR (100 MHz, CDCl3) δ 192.8, 158.6, 157.7, 156.4, 140.9, 135.3, 133.0, 131.2, 130.5,
130.2, 127.9, 127.1, 117.7, 98.4, 92.5, 62.6, 56.6, 56.2; Anal. calcd for C18H16BrClO4: C,
52.52; H, 3.92; Found: C, 52.84; H, 3.94.
4.1.6. (E)-1-(3-bromo-2,4,6-trimethoxyphenyl)-3-(3-chlorophenyl)prop-2-en-1-one (7):
The above procedure was followed with 3-chlorobenzaldehyde (17) to yield 7 as a light
yellow solid (91% yield). Rf (EtOAc/Hexanes 40:60) = 0.50; mp = 156-158 °C; IR (KBr, cm-
1
1) Vmax 2941, 1606, 1457, 1269, 1206, 1129; H NMR (400 MHz, CDCl3) δ 7.51-7.49 (m,
1H), 7.43 – 7.38 (m, 1H), 7.35 – 7.30 (m, 2H), 7.27 (d, 1H, J = 5.3 Hz), 6.97 (d, 1H, A part of
AB system, J = 16.1 Hz), 6.36 (s, 1H), 3.96 (s, 3H), 3.82 (s, 3H), 3.81 (s, 3H); 13C NMR (100
MHz, CDCl3) δ 192.7, 158.6, 157.6, 156.3, 143.3, 136.5, 134.9, 130.3, 130.1, 129.5, 128.2,
126.6, 117.8, 98.4, 92.6, 62.6, 56.6, 56.2; Anal. calcd for C18H16BrClO4: C, 52.52; H, 3.92;
Found: C, 52.49; H, 3.99.
4.1.7. (E)-1-(3-bromo-2,4,6-trimethoxyphenyl)-3-(4-chlorophenyl)prop-2-en-1-one (8):
The above procedure was followed with 4-chlorobenzaldehyde (18) to yield 8 as a light
yellow solid (95% yield). Rf (EtOAc/Hexanes 40:60) = 0.53; mp = 189-190 °C; IR (KBr, cm-
1) Vmax 2941, 1606, 1457, 1269, 1206, 1129; 1H NMR (400 MHz, CDCl3) δ 7.48 (d, 2H, J =
8.5 Hz), 7.36 (d, 2H, J = 8.7 Hz), 7.30 (d, 1H, J = 9.4 Hz), 6.97 (d, 1H, A part of AB system,
J = 16.0 Hz), 6.38 (s, 1H), 3.98 (s, 3H), 3.83 (s, 3H), 3.82 (s, 2H); 13C NMR (100 MHz,
CDCl3) δ 192.8, 158.5, 157.6, 156.2, 143.6, 136.4, 133.2, 129.7, 129.2, 128.7, 117.8, 98.3,
11

92.6, 62.6, 56.6, 56.2; Anal. calcd for C18H16BrClO4: C, 52.52; H, 3.92; Found: C, 52.36; H,
3.84.
4.1.8. (E)-1-(3-bromo-2,4,6-trimethoxyphenyl)-3-(2-fluorophenyl)prop-2-en-1-one (9):
The above procedure was followed with 2-fluorobenzaldehyde (19) to yield 9 as a white solid
(92% yield). Rf (EtOAc/Hexanes 40:60) = 0.50; mp = 188-189 °C; IR (KBr, cm-1) Vmax
1
2941, 1606, 1457, 1269, 1206, 1129; H NMR (400 MHz, CDCl3) δ 7.61 – 7.52 (m, 2H),
7.38 – 7.37 (m, 1H), 7.19-7.16 (m, 1H), 7.12-7.06 (m, 2H), 6.38 (s, 1H), 3.98 (s, 3H), 3.84 (s,
13
6H); C NMR (100 MHz, CDCl3) δ 193.0, 162.7, 160.2, 158.5, 157.6, 156.3, 137.4, 132.0,
131.9, 130.5, 130.4, 129.0, 124.4, 122.73, 117.8, 116.3, 116.0, 98.4, 92.6, 62.5, 56.6, 56.2;
Anal. calcd for C18H16BrFO4: C, 54.70; H, 4.08; Found: C, 54.65; H, 3.95.
4.1.9. (E)-1-(3-bromo-2,4,6-trimethoxyphenyl)-3-(3-fluorophenyl)prop-2-en-1-one (10):
The above procedure was followed with 3-fluorobenzaldehyde (20) to yield 10 as a light
yellow solid (98% yield). Rf (EtOAc/Hexanes 40:60) = 0.53; mp = 171-172 °C; IR (KBr, cm-
1) Vmax 2941, 1606, 1457, 1269, 1206, 1129; 1H NMR (400 MHz, CDCl3) δ 7.39 – 7.27 (m,
3H), 7.24-7.21 (m, 1H), 7.11 – 7.03 (m, 1H), 6.96 (d, 1H, A part of AB system, J = 16.1 Hz),
13
6.36 (s, 1H), 3.96 (s, 3H), 3.82 (s, 3H), 3.81 (s, 3H); C NMR (100 MHz, CDCl3) δ 192.7,
164.2, 161.8, 158.6, 157.6, 156.3, 143.5, 137.0, 130.4, 130.3, 129.4, 124.5, 117.8, 117.4,
117.2, 114.8, 114.5, 98.4, 92.6, 62.6, 56.6, 56.2; Anal. calcd for C18H16BrFO4: C, 54.70; H,
4.08; Found: C, 54.76; H, 3.94.
4.1.10. (E)-1-(3-bromo-2,4,6-trimethoxyphenyl)-3-(4-fluorophenyl)prop-2-en-1-one (11):
The above procedure was followed with 4-fluorobenzaldehyde (21) to yield 11 as a light
yellow solid (90% yield). Rf (EtOAc/Hexanes 40:60) = 0.52; mp = 188-190 °C; IR (KBr, cm-
1
1) Vmax 2941, 1606, 1457, 1269, 1206, 1129; H NMR (400 MHz, CDCl3) δ 7.58 – 7.50 (m,
2H), 7.38 – 7.27 (m, 1H), 7.08 (t, 2H, J = 8.6 Hz), 6.93 (d, 1H, A part of AB system, J = 16.1
13
Hz), 6.38 (s, 1H), 3.98 (s, 3H), 3.84 (s, 3H), 3.83 (s, 3H); C NMR (100 MHz, CDCl3) δ
192.9, 158.5, 157.5, 156.2, 144.0, 130.9, 130.5, 130.4, 128.2, 117.9, 116.2, 115.93, 98.3, 92.6,
62.5, 56.6, 56.2; Anal. calcd for C18H16BrFO4: C, 54.70; H, 4.08; Found: C, 54.40; H, 4.00.
4.1.11.(E)-1-(3-bromo-2,4,6-trimethoxyphenyl)-3-(2,5-difluorophenyl)prop-2-en-1-one (12):
The above procedure was followed with 2,5-difluorobenzaldehyde (22) to yield 12 as a light
yellow solid (97% yield). Rf (EtOAc/Hexanes 20:80) = 0.33; mp = 171-173 °C; IR (KBr, cm-
1
1) Vmax 2941, 1606, 1457, 1269, 1206, 1129; H NMR (400 MHz, CDCl3) δ 7.48 (d, 1H, B
12

part of AB system, J = 16.2 Hz), 7.32 – 7.23 (m, 1H), 7.09-7.01 (m, 3H), 6.38 (s, 1H), 3.98 (s,
13
3H), 3.84 (s, 3H), 3.83 (s, 3H); C NMR (100 MHz, CDCl3) δ 192.5, 159.9, 158.7, 157.7,
157.4, 156.4, 156.2, 135.7, 131.2, 131.2, 124.2, 124.1, 124.0, 123.9, 118.5, 118.5, 118.3,
118.2, 117.5, 117.5, 117.4, 117.2, 117.2, 114.7, 114.7, 114.5, 114.4, 98.4, 92.5, 62.6, 56.6,
56.2; Anal. calcd for C18H15BrF2O4: C, 52.32; H, 3.66; Found: C, 52.10; H, 3.18.
4.2. Enzymes Inhibition Studies
In this work, hCA I, and II isoenzymes were purified by Sepharose-4B-L-Tyrosine-
sulfanilamide affinity chromatography [82,83], CA activity was spectrophotometrically
determined according to the method of Verpoorte et al. [84] as described in our previous
study in details [85]. p-Nitrophenylacetate was used as substrate for this enzymatic reaction
[86]. One CA enzyme unit is adopted the amount of CA, which had absorbance difference at
348 nm over a 3 min at 25°C [87].
For determination of inhibition kinetics of novel chalcones (5-12), an activity (%) and
[Novel chalcone] graph was drowned. From these graphs, half maximal inhibitor
concentrations (IC50) for novel chalcones (5-12) were determined [88]. Also, for Kis, three
different concentrations novel chalcones (5-12) were used. Then, Lineweaver-Burk graphs
were drawn according to these measurements. Kis of novel chalcone derivatives (5-12) were
determined from Lineweaver-Burk graphs [54] as previously described [89].
Quantity of protein during the purification processing, Bradford’s technique was
utilized [90], which bovine serum albumin used as the standard protein [91]. Sodium dodecyl
sulphate-polyacrylamide gel electrophoresis was employed for visualsing of image of
isoenzymes [92].
The inhibitory effect of novel chalcone derivatives (5-12) on AChE activity was
performed according to Ellman’s method [75] as described previously [93]. α-Glycosidase
inhibition effect of novel chalcone derivatives (5-12) was evaluated according to the method
of Tao et al. [79]. The absorbance o samples were recorded at 405 nm [94].
4.3. In silico Studies
Drug-likeness properties and inhibition mechanism of compounds, which have the best
inhibition score against hCA I, hCA II, AChE and α-glycosidase receptors were calculated
and specified with in silico methods. The Small Drug Discovery Suites package [95] was used
performing in silico studies.
13

4.3.1. Ligand preparation and pharmacokinetic properties prediction
In order to use in the Qikprob and IFD studies, 2D structure of the sulfamate derivatives with
best inhibition score were sketched and then their 3D structure was produced with LigPrep
module of Schrodinger Maestro 12.0. Correct molecular geometries and protonation state at
pH 7.0±2.0 of ligand were prepared using Epik module and OPLS-2005 force field. The
pharmacokinetic properties of prepared ligands were calculated with QikProp module of
Schrodinger Maestro 12.0. Briefly, prepared ligands were opened and the calculation was
performed using the default parameter by selecting identify the 5 most similar drug molecule
option on QikProp module [96,97].
4.3.2. Protein preparation and binding site prediction
X-ray crystal structures of hCA I, hCA II, AChE and α-glycosidase receptors (PDB code:
4WR7, 5AML, 4M0E, and 3L4Y, respectively) have been acquired from RCSB Protein Data
Bank. They have been selected because of their best resolution and good percentile ranks.
They have been chosen due to their better resolution and stronger percentile ranks than others.
Moreover, the structures have a ligand, which can be used for docking validation test in the
catalytic active site. The typical crystal structure in the PDB format is not suitable for
immediate use in molecular modeling calculations. Hence, the crystal structures were repaired
and prepared with Protein preparation wizard module of Schrodinger Maestro 12.0, before use
binding site prediction and induced-fit docking studies. The workflow that includes a detailed
description in previous studies [49,98] was described in overview. After protein preparation,
the active site of the receptors has been predicted with SiteMap module of Schrodinger
Maestro 12.0 for target selection and docking hits evaluation. The prepared receptor was
imported into Maestro12.0 and binding site has been calculated using the default parameter of
top-ranked potential protein binding sites. Whether the binding site has catalytic active site
characteristics has been determined by analyzing SiteScore and Dscore [55,99].
4.3.3. Induced-fit docking
In order to determine binding affinities and inhibition mechanisms of the chalcone derivatives
with best inhibition score was carried out molecular docking studies. Induced-fit docking
technique is one of the best ways to calculate binding affinity between ligand and receptor
because both ligand and receptor are completely flexible in this docking technique. The
technique has been performed with the induced-fit docking module of Schrodinger Maestro
12.0 according to proposed previous studies [100]. Before calculating banding affinity
14

between ligands and the receptors, docking validation test has been carried out for
understanding accuracy of induced-fit docking technique. The test has been performed with
re-docking procedure by evicting inhibitor complexed in the crystal structure of the receptor.
RMSD value between co-crystallized ligand and re-docked ligand have been calculated with
Atom pair method in Superposition panel of Schrodinger Maestro 12.0. Following the
docking process, it has been determined best-scored sulfamate derivatives by analyzing
docking scores.
Conflicts of Interests
The authors declare that no conflicts of interests.
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as possible anticancer agents and carbonic anhydrase inhibitors. Bioorg. Chem. 90 (2019)
103095.
59. M. Tuğrak, H.İ. Gül, H. Sakagami, I. Gulcin, C.T. Supuran, New azafluorenones with
cytotoxic and carbonic anhydrase inhibitory properties: 2-Aryl-4-(4-hydroxyphenyl)-5H-
indeno[1,2-b]pyridin-5-ones. Bioorg. Chem. 81 (2019) 433-439.
60. B. Arabaci, I. Gulcin, S. Alwasel, Capsaicin: A potent inhibitor of carbonic anhydrase
isoenzymes. Molecules, 19 (2014) 10103-10114.
61. M. Topal, I. Gulcin, Rosmarinic acid: A potent carbonic anhydrase isoenzymes inhibitor.
Turk. J. Chem. 38(5), (2014) 894-902.
62. S. Göksu, A. Naderi, Y. Akbaba, P. Kalın, A. Akıncıoğlu, I. Gulcin, S. Durdaği, R.E.
Salmas, Carbonic anhydrase inhibitory properties of novel benzylsulfamides using
molecular modeling and experimental studies. Bioorg. Chem. 56 (2014) 75-82.
21

63. H. Göçer, A. Akıncıoğlu, S. Göksu, I. Gulcin, C.T. Supuran, Carbonic anhydrase and
acetylcholine esterase inhibitory effects of carbamates and sulfamoylcarbamates. J.
Enzyme Inhib. Med. Chem. 30(2), (2015) 316-320.
64. K. Aksu, F. Topal, I. Gulcin, F. Tümer, S. Göksu, Acetylcholinesterase inhibitory and
antioxidant activities of novel symmetric sulfamides derived from phenethylamines.
Arch. Pharm. 348(6), (2015) 446-455.
65. B. Ozgeriş, S. Göksu, L. Köse Polat, I. Gulcin, R.E. Salmas, S. Durdagi, F. Tümer, C.T.
Supuran, Acetylcholinesterase and carbonic anhydrase inhibitory properties of novel urea
and sulfamide derivatives incorporating dopaminergic 2-aminotetralin scaffolds. Bioorg.
Med. Chem. 24(10), (2016) 2318-2329.
66. F. Topal, I. Gulcin, A. Dastan, M. Guney, Novel eugenol derivatives: potent
acetylcholinesterase and carbonic anhydrase inhibitors. Int. J. Biol. Macromol. 94, (2017)
845-851.
67. S. Schwarz S. Sommerwerk S.D. Lucas, L. Heller, R. Csuk, Sulfamates of methyl
triterpenoates are effective and competitive inhibitors of carbonic anhydrase II. Eur. J.
Med. Chem. 86, (2014) 95-102.
68. H. Göcer, A. Akıncıoğlu, S. Göksu, I. Gulcin, Carbonic anhydrase inhibitory properties
of phenolic sulfonamides derived from dopamine related compounds. Arab. J. Chem.
10(3), (2017) 398-402.
69. A.D. Kenny, Role of carbonic anhydrase in bone. SAAS Bull. Biochem. Biotechnol. 4
(1991) 6-12.
70. C. Bayrak, P. Taslimi, I. Gulcin, A. Menzek, The first synthesis of 4-phenylbutenone
derivative bromophenols including natural products and their inhibition profiles for
carbonic anhydrase, acetylcholinesterase and butyrylcholinesterase enzymes. Bioorg.
Chem. 72 (2017) 359-366.
71. M. Zengin, H. Genç, P. Taslimi, A. Kestane, E. Güçlü, A. Ögütlü, O. Karabay, I. Gulcin,
Novel thymol bearing oxypropanolamine derivatives as potent some metabolic enzyme
inhibitors-their antidiabetic, anticholinergic and antibacterial potentials. Bioorg. Chem.
81 (2017) 119-126.
22

72. K. Oktay, L. Polat Kose, K. Sendil, M.S. Gultekin, I. Gulcin, Synthesis of 3-chloro-1-
substituted aryl pyrrolidine-2,5-dione derivatives: discovery of potent human carbonic
anhydrase inhibitors. Med. Chem. Res. 26(8), (2017) 1619–1627.
73. B. Yiğit, M. Yiğit, D. Barut Celepci, Y. Gök, A. Aktaş, M. Aygün, P. Taslimi, I. Gulcin,
Novel
benzylic
substituted
imidazolinium,
tetrahydropyrimidinium
and
tetrahydrodiazepinium salts-potent carbonic anhydrase and acetylcholinesterase
inhibitors. ChemistrySelect, 3(27), (2018) 7976-7982.
74. L. Polat Köse, I. Gulcin, Inhibition effects of some lignans on carbonic anhydrase,
acetylcholinesterase and butyrylcholinesterase enzymes. Rec. Nat. Prod. 11(6), (2017)
558-561.
75. G.L. Ellman, K.D. Courtney, V. Andres Jr, R.M. Featherstone, A new and rapid
colorimetric determination of acetylcholinesterase activity. Biochem. Pharmacol. 7
(1961) 88-95.
76. L. Polat Köse, I. Gulcin, A.C. Gören, J. Namiesnik, A.L. Martinez-Ayala, S. Gorinstein,
LC-MS/MS analysis, antioxidant and anticholinergic properties of galanga (Alpinia
officinarum Hance) rhizomes. Ind. Crop Prod. 74, (2015) 712-721.
77. M., Rezai, Ç. Bayrak, P. Taslimi, I. Gulcin, A. Menzek, The first synthesis, antioxidant
and anticholinergic activities of 1-(4,5-dihydroxybenzyl)pyrrolidin-2-one derivative
bromophenols including natural products. Turk. J. Chem. 42(3), (2018) 808-825.
78. A. Behcet, T. Çağlılar, D. Barut Celepci, A. Aktaş, P. Taslimi, Y. Gök, M. Aygün, R.
Kaya, I. Gulcin, Synthesis, characterization and crystal structure of 2-(4-
hydroxyphenyl)ethyl and 2-(4-nitrophenyl)ethyl substituted benzimidazolium bromide
salts: their inhibitory properties against carbonic anhydrase and acetylcholinesterase. J.
Mol. Struct. 1170 (2018) 160-169.
79. Y. Tao, Y.F. Zhang, Y.Y. Cheng, Y. Wang, Rapid screening and identification of alpha-
glucosidase inhibitors from mulberry leaves using enzyme-immobilized magnetic beads
coupled with HPLC/MS and NMR. Biomed. Chromatogr. 27(2), (2013) 148-155.
80. P. Taslimi, H.E. Aslan, Y. Demir, N. Oztaskın, A. Maras, I. Gulcin, Ş. Beydemir, Ş.
Göksu, Diarilmethanon, bromophenols and diarilmetan compounds: discovery of potent
aldose reductase, α-amylase and α-glycosidase inhibitors as new therapeutic approach in
diabetes and functional hyperglycemia. Int. J. Biol. Macromol. 119 (2018) 857-863.
23

81. C.A. Lipinski, F. Lombardo, B.W. Dominy, P.J. Feeney, Experimental and computational
approaches to estimate solubility and permeability in drug discovery and development
settings. Adv. Drug Deliv. Rev. 23 (1997) 3-25.
82. F. Erdemir, D. Barut Celepci, A. Aktaş, Y. Gök, R. Kaya, P. Taslimi, Y. Demir, I.
Gulcin, Novel 2-aminopyridine liganded Pd(II) N-heterocyclic carbene complexes:
synthesis, characterization, crystal structure and bioactivity properties. Bioorg. Chem. 91
(2019) 103134.
83. T.A. Coban, S. Beydemir, I. Gulcin, D. Ekinci, A. Innocenti, D. Vullo, C.T. Supuran,
Sildenafil is a strong activator of mammalian carbonic anhydrase isoforms I-XIV.
Bioorg. Med. Chem. 17(16), (2009) 5791-5795.
84. J.A. Verpoorte, S. Mehta, J.T. Edsall, Esterase activities of human carbonic anhydrases B
and C. J. Biol. Chem. 242 (1967) 4221-4229.
85. S.B. Ozturk Sarikaya, I. Gulcin, C.T. Supuran, Carbonic anhydrase inhibitors. Inhibition
of human erythrocyte isozymes I and II with a series of phenolic acids. Chem. Biol.
Drugs Des. 75(5), (2010) 515-520.
86. A. Innocenti, S.B. Öztürk Sarıkaya, I. Gulcin, C.T. Supuran, Carbonic anhydrase
inhibitors. Inhibition of mammalian isoforms I-XIV with a series of natural product
polyphenols and phenolic acids. Bioorg. Med. Chem. 18(6), (2010) 2159-2164.
87. A. Innocenti, I. Gulcin, A. Scozzafava, C.T. Supuran, Carbonic anhydrase inhibitors.
Antioxidant polyphenol natural products effectively inhibit mammalian isoforms I-XV.
Bioorg. Med. Chem. Lett. 20(18), (2010) 5050-5053.
88. C. Caglayan, I. Gulcin, The toxicological effects of some avermectins on goat liver
carbonic anhydrase enzyme. J. Biochem. Mol. Toxicol. 32(1), (2018) e22010.
89. G. Mamedova, A. Mahmudova, S. Mamedov, Y. Erden, P. Taslimi, B. Tüzün, R. Tas, V.
Farzaliyev,
A.
Sujayev,
S.H.
Alwasel,
I.
Gulcin,
Novel
tribenzylaminobenzolsulphonylimine based on their pyrazine and pyridazines: synthesis,
characterization, antidiabetic, anticancer, anticholinergics, and molecular docking studies.
Bioorg. Chem. 93 (2019) 103313.
90. M.M. Bradford, A rapid and sensitive method for the quantitation of microgram
quantities of protein utilizing the principle of protein-dye binding. Anal. Biochem. 72
(1976) 248-254.
24

91. N. Oztaskin, R. Kaya, A. Maraş, E. Sahin, I. Gulcin, S. Göksu, Synthesis and
characterization of novel bromophenols: Determination of their anticholinergic,
antidiabetic and antioxidant activities. Bioorg. Chem. 87 (2019) 91-102.
92. M. Huseynova, P. Taslimi, A. Medjidov, V. Farzaliyev, M. Aliyeva, G. Gondolova, O.
Sahin, B. Yalçın, A. Sujayev, E.B. Orman, A.R. Ozkaya, I. Gulcin, Synthesis,
characterization, crystal structure, electrochemical studies and biological evaluation of
metal complexes with thiosemicarbazone of glyoxylic acid. Polyhedron, 155 (2018) 25-
33.
93. A. Aktas, D. Barut Celepci, R. Kaya, P. Taslimi, Y. Gök, M. Aygün, I. Gulcin, Novel
morpholine liganded Pd-based N-heterocyclic carbene complexes: Synthesis,
characterization, crystal structure, antidiabetic and anticholinergic. Polyhedron, 159
(2019) 345–354.
94. I. Gulcin, A.Z. Tel, A.C. Gören, P. Taslimi, S. Alwasel, Sage (Salvia pilifera):
Determination its polyphenol contents, anticholinergic, antidiabetic and antioxidant
activities. J. Food Measure. 13(3), (2019) 2062-2074.
95. L. Schrödinger, Induced Fit Docking protocol; Glide version 5.5; Prime version 2.1. New
York, NY, (2009).
96. L. Schrödinger, Drug Discovery Suite. New York, NY, (2017).
97. F. Türkan, Z. Huyut, P. Taslimi, I. Gulcin, The effects of some antibiotics from
cephalosporin groups on the acetylcholinesterase and butyrylcholinesterase enzymes
activities in different tissues of rats. Arch. Physiol. Biochem. 125(1), (2019) 12-18.
98. P. Taslimi, F. Türkan, A. Cetin, H. Burhan, M. Karaman, I. Bildirici, I. Gulcin, F. Sen,
Pyrazole[3,4-ka]pyridazine derivatives: Molecular docking and explore of
acetylcholinesterase and carbonic anhydrase enzymes inhibitors as anticholinergics
potentials. Bioorg. Chem. 92, (2019) 103213.
99. L. Schrödinger, SiteMap, version 2.3. New York, NY, (2009).
100.S. Bal, R. Kaya, P. Taslimi, A. Aktaş, M. Karaman, I. Gulcin, Novel 2-
methylimidazolium salts: synthesis, characterization, molecular docking, and carbonic
anhydrase and acetylcholinesterase inhibitory properties. Bioorg. Chem. 94 (2020)
103468.
25

Table 1. Inhibition parameters including IC50 and Kis for novel chalcone derivatives (5-12) of metabolic enzymes hCA I, and II isoenzymes, α-
glycosidase and AChE (α-Gly: α-Glycosidase, AChE: acetylcholinesterase, CA I: carbonic anhydrase I isoenzyme, CA II: carbonic anhydrase II
isoenzyme, *Acetazolamide (AZA) was used as a positive standard for CA isoenzymes, ** Tacrine (TAC) was used as a positive standard for
cholinergic enzymes)
IC50 (nM)
Ki (nM)
AChE
Compou
nds
hCA I
35.0
r2
hCA II
37.66
r2
AChE
r2
α-Gly
18.28
22.28
r2
hCA I
26.58±8.77
16.24±5.10
hCA II
52.00±13.44
40.36±13.50
α-Gly
5
6
0.9453
0.9473
0.9528
0.9456
5.63
4.36
0.9908
0.9893
0.9697
0.9697
4.39±0.25
1.46±0.26
16.76±4.42
35.22±2.10
28.06
29.74
7
8
30.94
32.08
2.07
0.9596
0.9885
0.9487
0.9777
0.9754
31.22
34.48
28.17
38.08
33.81
0.9736
0.9979
0.9504
0.9554
0.9475
4.65
2.97
5.72
3.73
3.82
3.38
0.9705
0.9428
0.9887
0.9546
0.9895
0.9776
20.69
26.76
20.56
23.26
23.02
18.48
0.9408
0.9957
0.9805
0.9674
0.9825
0.9528
16.66±4.91
31.79±9.24
21.80±9.69
26.59±1.86
24.40±6.92
45.89±12.21
29.61±5.65
49.11±10.67
51.65±2.30
42.35±10.03
2.95±1.21
1.72±0.72
1.21±0.20
3.10±0.89
3.06±1.40
18.85±7.84
14.60±1.24
12.54±4.16
23.35±1.15
14.78±1.62
10.37±1.55
9
10
11
12
28.17
20.69
31.94
0.9685
0.9932
37.26
31.79
0.9763
0.9816
40.96±8.95
67.15±16.21
22.17±0.65
2.83±0.76
113.79
-
-
-
141.02±50.84
AZA*
TAC**
-
-
-
-
5.97
0.9706
-
-
-
5.99±1.79
26

Table 2. Selectivity indexes of novel chalcone derivatives (5-12)
Ki-hCA II / Ki-hCA I Ki-AZA / Ki-hCA I Ki-AZA / Ki-hCA II Ki-TAC / Ki-AChE
Compounds
1.956
2.485
2.754
0.931
2.252
1.942
1.735
1.639
5.305
8.683
8.464
4.435
6.468
5.303
5.779
3.442
0.426
0.549
0.483
0.748
0.451
0.429
0.523
0.330
1.364
4.102
2.030
3.482
4.950
1.932
1.957
2.116
5
6
7
8
9
10
11
12
27

Table 3. Docking scores (kcal/mol) of the chalcone derivatives in the sites of hCA I, and II,
AChE, and α-glycosidase.
IFD Glide Score
Compounds
α-Glycosidase
hCA I
hCA II
AChE
-6.227
-
-
-
6
-
-7.250
-
-
8
-
-
-8.571
-6.432
9
-9.016
-9.560
-
-9.579
-
-
AZA*
TAC**
ACR***
-
-
-
-
-
-16.933
*Acetazolamide (AZA) was used as positive control for hCA I, and II.
** Tacrine (TAC) was used as was used as positive control for AChE.
*** Acarbose (ACR) was used as was used as positive control for α-glycosidase [70]
28