New benzamide derivatives and their nicotinamide/cinnamamide analogs as cholinesterase inhibitors

Article abstract of DOI:10.1007/s11030-021-10249-9

In this study, a total of 18 new benzamide/ nicotinamide/ cinnamamide derivative compounds were designed and synthesized for the first time (except B1 and B5) by conventional and microwave irradiation methods. The chemical structures of the synthesized co

Full text of DOI:10.1007/s11030-021-10249-9

Molecular Diversity
https://doi.org/10.1007/s11030-021-10249-9
ORIGINAL ARTICLE
New benzamide derivatives and their nicotinamide/cinnamamide
analogs as cholinesterase inhibitors
Mehmet Koca1 · Sinan Bilginer1
Received: 12 April 2021 / Accepted: 7 June 2021
© The Author(s), under exclusive licence to Springer Nature Switzerland AG 2021
Abstract
In this study, a total of 18 new benzamide/ nicotinamide/ cinnamamide derivative compounds were designed and synthe-
sized for the frst time (except B1 and B5) by conventional and microwave irradiation methods. The chemical structures of
the synthesized compounds were characterized by 1H NMR, 13C NMR, and HRMS spectra. In vitro acetylcholinesterase
(AChE) and butyrylcholinesterase (BuChE) inhibition efects of the compounds were evaluated to fnd out new possible drug
candidate molecule/s. According to the inhibition results, the IC50 values of the compounds synthesized were in the range of
10.66–83.03 nM towards AChE, while they were in the range of 32.74–66.68 nM towards BuChE. Tacrine was used as the
reference drug and its IC50 values were 20.85 nM and 15.66 nM towards AChE and BuChE, respectively. The most active
compounds B4 (IC50: 15.42 nM), N4 (IC50: 12.14 nM), and C4 (IC50: 10.67 nM) in each series towards AChE were docked
at the binding site of AChE enzyme to explain the inhibitory activities of each series. On the other hand, the compounds B4,
N4, and C4 showed satisfactory pharmacokinetic properties via the prediction of ADME profles.
Graphic abstract
Extended author information available on the last page of the article
Vol.:(0123456789)
1 3

Molecular Diversity
Keywords Benzamide · Nicotinamide · Cinnamamide · Cholinesterase inhibition · Molecular docking
neurodegenerative disorders have been investigated, and
it was reported that nicotinamide can cross the blood and
brain barrier [36] and thus, this may have some positive
efects against neurodegenerative diseases [37–40]. Żurek
et al. synthesized hybrid compounds in hydrazide structure
containing donepezil and nicotinamide structures and these
compounds had cholinesterase inhibitory activities with
nanomolar enzyme inhibition constants [41].
Introduction
Alzheimer’s disease (AD), which is generally observed espe-
cially in the elderly, has become an important health prob-
lem worldwide [1]. One of the most important fndings in
patients with AD is a decrease in the level of acetylcholine
in the cerebral cortex [2]. Thus, one of the most important
methods to slow down the progression of AD is by increas-
ing the level of acetylcholine in the cerebral cortex via cho-
linesterase enzymes inhibition [3]. There are two types of
cholinesterase enzymes which are known as acetylcholinest-
erase (AChE) and butyrylcholinesterase (BuChE). Both of
these enzymes play an important role in the regulation of the
level of acetylcholine [4, 5]. It was reported that inhibition
of cholinesterase enzymes reduces the progression of the
disease and improves perception in patients with AD [6, 7].
Tacrine, rivastigmine, and donepezil are the main cholinest-
erase inhibitors used in clinics for the treatment of AD [8,
9]. On the other hand, ambenonium, a diamide derivative, is
used in myasthenia gravis as an AChE inhibitor [10].
In order to reduce the hepatotoxicity of tacrine and
increase its bioavailability, Ragab et al. made some modif-
cations in the tacrine skeleton[11]. Among these modifed
compounds, chlorinated derivatives showed higher cho-
linesterase inhibitory activity and lower hepatotoxicity than
non-chlorinated derivatives. In the same study, the derivative
of tacrine with 1-benzylamino substituent was reported to
have high cholinesterase inhibitory activity. There are also
other studies in the literature reporting the cholinesterase
inhibitory activities of various derivatives in which substi-
tuted benzene/benzyl structures are bound to the nitrogen
atom [12–14].
Cinnamamide is a natural compound that has a phenyl
ring at the 3rd position of the acrylamide structure and is
found in many plants. In the literature, many biological
activities of cinnamamide derivatives have been reported,
such as antibacterial [42], anti-infammatory [43], antima-
larial [44], anticancer [45], tyrosinase inhibitory [46], antivi-
ral [47], anticonvulsant [48], antifungal [49], anti-Alzheimer
[50] activities. On the other hand, cinnamamide derivative
some compounds and tacrine-cinnamic acid hybrids were
reported with high cholinesterase inhibition efects with
low nanomolar inhibition constant [51, 52]. Besides, in our
previous study, new butendiamide and oxalamide deriva-
tive compounds were synthesized and some of them showed
strong cholinesterase inhibition efects [53, 54].
In this study, we aimed to synthesize novel benzamide/
nicotinamide/cinnamamide derivatives which have 4-chlo-
robenzyl and 4-substituted phenyl on their nitrogen atoms,
to evaluate their in vitro cholinesterase inhibitory activities
to fnd out new possible drug candidate molecule/s. Besides,
we planned to identify the binding profles of the most active
compounds (B4, N4, C4) of the series with AChE enzyme
by molecular docking studies to determine their possible
mechanism of cholinesterase inhibitory activities.
There are many studies in the literature on the antimicro-
bial [15], antioxidant [16], antiasthmatic [17], and cholinest-
erase inhibitory [18, 19] activities of benzamide derivatives.
Some compounds in the arylalkylaminoketone scafold, in
which structure of benzoyl/naphthoyl is linked to a second-
ary amine via the intermediate carbon chain, were reported
to be cholinesterase inhibitors with an ADME profle that
can pass into the central nervous system [20].
Materials and methods
Chemistry
General procedure of the synthesis of the secondary
amines
Nicotinamide is an amide derivative of nicotinic acid,
also known as vitamin B3, found in many natural foods such
as meat, milk, fsh, and grains [21]. In humans, nicotinamide
is converted to Nicotinamide Adenine Dinucleotide (NAD)
which plays an important role in cellular functions in the
body [22, 23]. Various nicotinamide derivatives have been
reported with many biological activities such as antituber-
culosis [24, 25], antifungal [26] antitumor [27–29] antidia-
betic [30–32], antioxidative [33] and neuroprotective [34,
35] activities. The efects of nicotinamide on AD and other
By conventional method para-Substituted aniline (20 mmol)
and sodium bicarbonate (6 mmol) in 15 ml water were
heated to 90–95 ºC. To this mixture, p-chlorobenzyl chlo-
ride (5 mmol) was added and stirred for 1.5–2 h, give of
PhCH2NHPh. After completion of the reaction, the reaction
mixture was extracted with CH2Cl2 (2×10 mL). The com-
bined organic layer was dried over with MgSO4, fltered,
and concentrated by rotary evaporation and the crude prod-
uct was purifed by silica gel column chromatography using
hexane:ethylacetate (2:1).
1 3

Molecular Diversity
By microwave irradiation A mixture of para-substituted
aniline (20 mmol), p-chlorobenzyl chloride (10 mmol) was
adsorbed on a mixture of potassium carbonate (12 mmol)
and tetrabutylammonium bromide (1 mmol). The result-
ing fne powder was irradiated with microwave irradia-
tion (150 W, 120 °C) for 5 min to give of PhCH2NHPh.
After completion of the reaction, the reaction mixture was
quenched with 15 mL of distilled water and the aqueous
phase was extracted with two parts of CH2Cl2 (2×10 mL).
The combined organic layers were dried over with MgSO4,
fltered, and concentrated. The crude product was purifed by
silica gel column chromatography using hexane:ethylacetate
(2:1) [55].
N-(4-chlorobenzyl)-N-(p-tolyl)benzamide (B2) Yield:
1
77% (79% by MW), mp: 85–87 °C. H-NMR (400 MHz,
CDCl3) ẟ (ppm): 2.21(s, 3H, CH3-Ar), 5.05 (s, 2H,
N-CH2), 6.75 (d, 2H, J:8.20 Hz, Ar–H), 6.92 (d, 2H,
J:8.12 Hz, Ar–H), 7.28–7.12 (m, 8H, Ar–H), 7.32–7.30
(m, 2H, Ar–H). 13C-NMR (100 MHz, CDCl3) ẟ (ppm):
20.95 (CH3-Ar), 53.29 (Ar-CH2-N), 127.49 (2xCHAr),
127.72 (2xCHAr), 128.59 (2xCHAr), 128.75 (2xCHAr),
129.65 (CHAr), 129.75 (2xCHAr), 130.00 (2xCHAr), 133.17
(CAr), 135.87 (CAr), 136.14 (CAr), 136.65 (CAr), 140.59
(CAr), 170.58 (C= O). Anal. Calcd. for C21H18ClNO (MW
335.11): C, 75.11; H, 5.4%. Found: C, 74.48; H, 5.51%.
HRMS (Q-TOF) m/z Calcd for [M + H]+ 336,1077, found.
336.1148.
General procedure of the synthesis of fnal compounds
N-(4-chlorobenzyl)-N-(4-methoxyphenyl)benzamide
1
(B3) Yield: 80% (85% by MW), mp: 93–95 °C. H-NMR
By conventional method A mixture of the para-substituted
benzaniline (1.7 mmol), triethylamine (TEA) (1.4 mmol),
and benzoyl/nicotinoyl/cinnamoyl chloride (1.4 mmol) in
dichloromethane (5 mL) were stirred at room temperature for
12 h. After completion of the reaction, the reaction mixture
was quenched with 15 mL of distilled water and the aque-
ous phase was extracted of CH2Cl2 (2×10 mL). The com-
bined organic layers were dried over with MgSO4, fltered,
and concentrated. Finally, the crude product was purifed
by silica gel column chromatography hexane:ethylacetate
(6:4) or crystallized from ethanol.
(400 MHz, CDCl3) ẟ (ppm): 3.68(s, 3H, Ar-OCH3), 5.03
(s, 2H, N-CH2), 6.65–6.63 (m, 2H, Ar–H), 6.77 (d, 2H,
J:8.72 Hz, Ar–H), 7.20–7.14 (m, 5H, Ar–H), 7.25–7.22 (m,
2H, Ar–H), 7.31–7.29 (m, 2H, Ar–H). 13C-NMR (100 MHz,
CDCl3) ẟ (ppm): 53.35 (Ar-CH2-N), 55.28 (OCH3-Ar),
114.26 (2xCHAr), 127.74 (2xCHAr), 128.60 (4xCHAr),
128.67 (2xCHAr), 128.95 (2xCHAr), 129.56 (CAr), 130.13
(CHAr), 133.21 (CAr), 135.91 (CAr), 136.09 (CAr), 158.07
(CAr), 170.58 (C=O). Anal. Calcd. for C21H18ClNO2 (MW
351.10): C, 71.69; H, 5.16%. Found: C, 74.44; H, 5.18%.
HRMS (Q-TOF) m/z Calcd for [M+H]+ 352.1026, found.
352.1099.
By microwave irradiation A mixture of para-substituted
benzaniline (1.7 mmol), benzoyl/nicotinoyl/cinnamoyl
chloride (1,7 mmol) in dioxane (0.6 mL) as solvent was
reacted under microwave irradiation at 100 ºC for 10 min.
After completion of the reaction, the reaction mixture was
concentrated by rotary evaporation. Finally, the crude
product was purifed by silica gel column chromatography
hexane:ethylacetate (6:4) or crystallized from ethanol.
1 H- and 13 C-NMR spectra were recorded with 400 (100)
MHz Bruker and Varian instruments. Interchangeable hydro-
gens or carbons were shown with the same letters. Elemental
analyses were performed with a LECO CHNS-932. HRMS
spectra were recorded with an Agilent 6530 LC–MS QTOF.
N-(4-chlorobenzyl)-N-phenylbenzamide (B1) Yield: 76%
(80% by MW), mp: 83–85 °C. 1H-NMR (400 MHz, CDCl3)
ẟ (ppm): 5.08 (s, 2H, N-CH2), 6.88 (d, 2H, J:8.5 Hz, Ar–H),
7.16 -7.09 (m, 5 H, Ar–H), 7.25 -7.20 (m, 5 H, Ar–H)
7.32–7.30 (m, 2H, Ar–H). 13C-NMR (100 MHz, CDCl3) ẟ
(ppm): 53.24 (Ar-CH2-N), 126.83 (CHAr), 127.74 (2xCHAr),
127.75 (2xCHAr), 128.64 (2xCHAr), 128.79 (2xCHAr),
129.13 (2xCHAr), 129.78 (CHAr), 129.95 (2xCHAr), 133.24
(CAr), 135.71 (CAr), 136.04 (CAr), 143.27 (CAr), 170.55
(C = O). Anal. Calcd. for C20H16ClNO (MW 321.09):
C, 74.65; H, 5.01%. Found: C, 74.32; H, 4.99%. HRMS
(Q-TOF) m/z Calcd for [M+H]+ 322.0920, found. 322.099.
N-(4-chlorobenzyl)-N-(4-fuorophenyl)benzamide (B4)
1
Yield: 72% (73% by MW), mp: 132–134 °C. H-NMR
(400 MHz, CDCl3) ẟ (ppm): 5.04 (s, 2H, N-CH2), 6.83
(d, 2H, J: 6.48 Hz, Ar–H), 7.30 -7.15 (m, 11H, Ar–H).
13C-NMR (100 MHz, CDCl3) ẟ (ppm): 53.26 (Ar-CH2-
N), 115.96–116.19 (JCF:22.7 2xCHAr), 127.88 (2xCHAr),
128.64 (2xCHAr), 128.72 (2xCHAr), 129.52 -129.43 (JCF:8.7
2xCHAr), 129.85 (CHAr), 130.04 (2xCHAr), 133.43 (CAr),
135.52 (CAr), 135.74 (CAr), 139.18 (CAr), 159.74–162.20
(JCF:247.6 CAr), 170.56 (C = O). Anal. Calcd. for
C20H15ClFNO (MW 339.08): C, 70.7; H, 4.45%. Found: C,
69.06; H, 4.29%. HRMS (Q-TOF) m/z Calcd for [M+H]+
340.0826, found. 340.0899.
N-(4-chlorobenzyl)-N-(4-chlorophenyl)benzamide
1
(B5) Yield: 75% (78% by MW), mp: 113–114 °C. H-
NMR (400 MHz, CDCl3) ẟ (ppm): 5.05 (s, 2H, CH2N),
6.82–6.80 (m, 2H, Ar–H), 7.31–7.10 (m, 11H, Ar–H)
13C-NMR (100 MHz, CDCl3) ẟ (ppm): 53.15 (Ar-CH2-
N), 127.96 (2xCHAr), 128.72 (2xCHAr), 128.75 (2xCHAr),
128.93 (2xCHAr), 129.34 (2xCHAr), 129.94 (2xCHAr),
130.03 (CHAr), 132.51 (CAr), 133.46 (CAr), 135.34 (CAr),
135.66( CAr), 141.78 (CAr), 170.46 (C=O). Anal. Calcd. for
C20H15Cl2NO (MW 355.05): C, 67.43; H, 4.24%. Found: C,
66.89; H, 4.28%. HRMS (Q-TOF) m/z Calcd for [M+H]+
356.0530, found. 356.0603.
1 3

Molecular Diversity
N-(4-bromophenyl)-N-(4-chlorobenzyl)benzamide
Anal. Calcd. for C20H17ClN2O2 (MW 352.10): C, 68.09; H,
4.86%. Found: C, 67.18; H, 4.80%. HRMS (Q-TOF) m/z
Calcd for [M+H]+ 353.0978, found. 353.1051.
1
(B6) Yield: 73% (75% by MW), mp: 91–93 °C. H-
NMR (400 MHz, CDCl3) ẟ (ppm): 5.05 (s, 2H, N-CH2),
6.76–6.74 (m, 2H, Ar–H), 7.31–7.18 (m, 11H, Ar–H) 13C-
NMR (100 MHz, CDCl3) ẟ (ppm): 53.12 (Ar-CH2-N),
120.45 (CAr), 127.99 (2×CHAr), 128.74 (2×CHAr), 128.76
(2 × CHAr), 129.24 (2 × CHAr), 129.92 (2 × CHAr), 130.07
(CHAr), 132.33 (2 × CHAr), 133.46 (CAr), 135.31 (CAr),
135.65 (CAr), 142.32 (CAr), 170.41 (C=O). Anal. Calcd. for
C20H15BrClNO (MW 399.00): C, 59.95; H, 3.77%. Found:
C, 59.82; H, 3.77%. HRMS (Q-TOF) m/z Calcd for [M+H]+
400.0025, found. 400.0097.
N-(4-chlorobenzyl)-N-(4-fluorophenyl)nicotinamide
1
(N4) Yield: 76% (79% by MW), mp: 116–118 °C. H-
NMR (400 MHz, CDCl3) ẟ (ppm): 5.05 (s, 2H, N-CH2),
6.90–6.86 (m, 4H, Ar–H), 7.14 (dd, 1H, J: 5.0 Hz, J:4.9 Hz,
Ar–H), 7.27–7.20 (m, 4H, Ar–H), 7.62 (d, 1H, J: 7.8 Hz,
Ar–H), 8.47 (d, 1H, J: 4.7 Hz, Ar–H), 8.5 (s, 1H, Ar–H)
13C-NMR (100 MHz, CDCl3) ẟ (ppm): 53.39 (Ar-CH2-N),
116.44–116.67 (JCF:22.6 2xCHAr), 122.84 (CHAr), 128.81
(2xCHAr), 129.71 -129.80 (JCF:10.7 2xCHAr), 130.20
(2xCHAr), 131.45 (CAr), 133.68 (CAr), 135.13 (CHAr),
136.15 (CHAr), 138.31 (CAr), 149.45 (CHAr), 150.53 (CHAr),
160.07–162.54 (JCF:248.6 CAr), 168.08 (C=O). Anal. Calcd.
for C19H14ClFN2O (MW 340.08): C, 66.97; H, 4.14%.
Found: C, 66.99; H, 4.22%. HRMS (Q-TOF) m/z Calcd for
[M+H]+ 340.0778, found. 341.0851.
N-(4-chlorobenzyl)-N-phenylnicotinamide (N1) Yield:
78% (83% by MW), mp: 112–114 °C. 1H-NMR (400 MHz,
CDCl3) ẟ (ppm): 5.09 (s, 2H, N-CH2), 6.9 (d, 2H, J:6.7 Hz,
Ar–H), 7.11 (dd, 1H, J: 4.9 Hz, J:5.0 Hz, Ar–H), 7.22–7.15
(m, 4H, Ar–H), 7.27–7.24 (m, 4H, Ar–H), 7.64–7.61
(m, 1H, Ar–H), 8.45–8.44 (m, 1H, Ar–H), 8.51 (d, 1H,
J:2.6 Hz, Ar–H), 13C-NMR (100 MHz, CDCl3) ẟ (ppm):
53.32 (Ar-CH2-N), 122.71 (CHAr), 127.57 (CHAr), 127.97
(2xCHAr), 128.72 (2xCHAr), 129.54 (2xCHAr), 130.12
(2xCHAr), 131.61 (CAr), 133.49 (CAr), 135.42 (CAr), 136.21
(CHAr), 142.37 (CAr), 149.65 (CHAr), 150.47 (CHAr), 168.07
(C = O). Anal. Calcd. for C19H15ClN2O (MW 322.09): C,
70.7; H, 4.68%. Found: C, 69.31; H, 4.88%. HRMS (Q-TOF)
m/z Calcd for [M+H]+ 323.0872, found. 323.0945.
N-(4-chlorobenzyl)-N-(p-tolyl)nicotinamide (N2) Yield:
80% (80% by MW), mp: 126–128 °C. 1H-NMR (400 MHz,
CDCl3) ẟ (ppm): 2.24 (s, 3H, CH3-Ar), 5.06 (s, 2H, N-CH2),
6.77 (d, 2H, J: 8.1 Hz, Ar–H), 6.9 (d, 2H, J: 7.9 Hz, Ar–H),
7.13 (dd, 1H, J: 4.8 Hz, J:4.8 Hz,, Ar–H), 7.27–7.22 (m,
4H, Ar–H), 7.65 (d, 1H, J: 7.8 Hz, Ar–H), 8.45 (d, 1H, J:
3.2 Hz, Ar–H), 8.49 (s, 1H, Ar–H). 13C-NMR (100 MHz,
CDCl3) ẟ (ppm): 21.05 (CH3-Ar), 53.32 (Ar-CH2-N),
122.73 (CHAr), 127.72 (2xCHAr), 128.68 (2xCHAr), 130.15
(4xCHAr), 131.74 (CAr), 133.43 (CAr), 135.52 (CAr), 136.24
(CHAr), 137.49 (CAr), 139.70 (CAr), 149.64 (CHAr), 150.36
(CHAr), 168.07 (C=O). Anal. Calcd. for C20H17ClN2O (MW
336.10): C, 71.32; H, 5.09%. Found: C, 70.71; H, 5.10%.
HRMS (Q-TOF) m/z Calcd for [M+H]+ 337.1029, found.
337.1102.
N-(4-chlorobenzyl)-N-(4-chlorophenyl)nicotinamide
1
(N5) Yield: 78% (80% by MW), mp: 144–146 °C. H-
NMR (400 MHz, CDCl3) ẟ (ppm): 5.05 (s, 2H, N-CH2),
6.82 (d, 2H, J: 8.3 Hz, Ar–H), 7.27–7.14 (m, 8H, Ar–H),
7.63 (d, 1H, J: 7.8 Hz, Ar–H), 8.50–8.47 (m, 1H, Ar–H).
13C-NMR (100 MHz, CDCl3) ẟ (ppm): 53.26 (Ar-CH2-
N), 122.92 (CHAr), 128.84 (2xCHAr), 129.18 (2xCHAr),
129.78 (2xCHAr), 130.12 (2xCHAr), 131.27 (CAr), 133.36
(CAr), 133.71 (CHAr), 135.05 (CAr), 136.21 (CHAr), 140.87
(CAr), 149.54 (CHAr), 150.72 (CHAr), 167.96 (C=O). Anal.
Calcd. for C19H14Cl2N2O (MW 356.05): C, 63.88; H, 3.95%.
Found: C, 62.71; H, 4.05%. HRMS (Q-TOF) m/z Calcd for
[M+H]+ 357.0483, found. 357.0555.
N-(4-bromophenyl)-N-(4-chlorobenzyl)nicotinamide
(N6) Yield: 72% (72% by MW), mp: 156–158 °C. 1H-NMR
(400 MHz, CDCl3) ẟ (ppm): 5.06 (s, 2H, N-CH2), 6.77 (d,
2H, J: 8.6 Hz, Ar–H), 7.33–7.15 (m, 8H, Ar–H), 7.65–7.62
(m, 1H, Ar–H), 8.51–8.49 (m, 1H, Ar–H). 13C-NMR
(100 MHz, CDCl3) ẟ (ppm): 53.24 (Ar-CH2-N), 121.34
(CAr), 122.92 (CHAr), 128.90 (2xCHAr), 129.48 (2xCHAr),
130.10 (2xCHAr), 131.23 (CAr), 132.77 (2xCHAr), 133.73
(CAr), 135.04 (CHAr), 136.21 (CHAr), 141.42 (CAr), 149.58
(CHAr), 150.77 (CHAr), 167.96 (C = O). Anal. Calcd. for
C19H14BrClN2O (MW 400.00): C, 56.81; H, 3.51%. Found:
C, 57.20; H, 3.43%. HRMS (Q-TOF) m/z Calcd for [M+H]+
400.9978, found. 401.0050.
N-(4-chlorobenzyl)-N-(4-methoxyphenyl)nicotinamide
1
(N3) Yield: 81%, (85% by MW), mp: 133–135 °C. H-
NMR (400 MHz, CDCl3) ẟ (ppm): 3.71 (s, 3H, Ar-OCH3),
5.03 (s, 2H, N-CH2), 6.68 (d, 2H, J: 8.7 Hz, Ar–H), 6.79
(d, 2H, J: 8.6 Hz Ar–H), 7.12 (dd, 1H, J: 5.0 Hz, J:4.9 Hz,
Ar–H), 7.27–7.14 (m, 4H, Ar–H), 7.63 (d, 1H, J: 7.8 Hz,
Ar–H), 8.44 (d, 1H, J: 4.6 Hz, Ar–H), 8.5 (s, 1H, Ar–H).
13C-NMR (100 MHz, CDCl3) ẟ (ppm): 53.39 (Ar-CH2-N),
55.32 (OCH3-Ar), 114.61 (2xCHAr), 122.75 (CHAr), 128.69
(2xCHAr), 129.18 (2xCHAr), 130.29 (2xCHAr), 131.83 (CAr),
133.47 (CAr), 134.92 (CAr), 135.49 (CAr), 136.20 (CHAr),
149.51 (CHAr), 150.22 (CHAr), 158.53 (CAr), 168.08 (C=O).
N-(4-chlorobenzyl)-N-phenylcinnamamide (C1) Yield:
80% (82% by MW), mp: 133–135 °C. 1H-NMR (400 MHz,
CDCl3) ẟ (ppm): 5.01 (s, 2H, N-CH2), 6.33 (d, H, Jtrans
:
15.5 COCH =), 7.08 (d, 2H, J: 5.0 Hz, Ar–H), 7.28–7.20
(m, 8H, Ar–H), 7.41–7.30 (m, 4H, Ar–H), 7.76 (d, H, Jtrans
:
15.5 Ar–CH =). 13C-NMR (100 MHz, CDCl3) ẟ (ppm):
52.15 (Ar-CH2-N), 118.06 (COCH =), 127.40 (2xCHAr),
127.49 (CHAr), 127.83 (2xCHAr), 128.08 (2xCHAr),
128.19 (2xCHAr), 129.11 (2xCHAr), 129.15 (CHAr), 129.64
1 3

Molecular Diversity
(2xCHAr), 132.73 (CAr), 134.57 (CAr), 135.57 (CAr), 141.33
(CAr), 142.06 (CH=CAr), 165.55 (C=O). Anal. Calcd. for
C22H18ClNO (MW 347.11): C, 75.97; H, 5.22%. Found: C,
75.71; H, 5.42%. HRMS (Q-TOF) m/z Calcd for [M+H]+
348.1076, found. 348.1149.
(m, 10H, Ar–H), 7.75 (d, H, Jtrans: 15.7 Ar–CH=). 13C-NMR
(100 MHz, CDCl3) ẟ (ppm): 52.79 (Ar-CH2-N), 118.28
(COCH =), 128.18 (2xCHAr), 128.92 (2xCHAr), 128.99
(2xCHAr), 129.86 (2xCHAr), 130.08 (4xCHAr), 130.35
(CHAr), 133.66 (CAr), 134.07 (CAr), 135.09 (CAr), 135.96
(CAr), 140.55 (CAr), 143.40 (CH = CAr), 166.11 (C = O).
Anal. Calcd. for C22H17Cl2NO (MW 381.07): C, 69.12; H,
4.48%. Found: C, 70.43; H, 4.62%. HRMS (Q-TOF) m/z
Calcd for [M+H]+ 382.0687, found. 382.0760.
N-(4-chlorobenzyl)-N-(p-tolyl)cinnamamide (C2) Yield:
78% (84% by MW), mp: 109–111 °C. 1H-NMR (400 MHz,
CDCl3) ẟ (ppm): 2.36 (s, 3H, CH3Ar), 4.95 (s, 2H, N-CH2),
6.33 (d, H, Jtrans: 15.5 COCH=), 7.38–7.13 (m, 12H, Ar–H),
7.73 (d, H, Jtrans: 15.5 Ar–CH =).13C-NMR (100 MHz,
CDCl3) ẟ (ppm): 21.15 (CH3-Ar), 52.69 (Ar-CH2-N),
118.64 (COCH =), 127.92 (2xCHAr), 128.06 (2xCHAr),
128.55 (2xCHAr), 128.68 (2xCHAr), 129.60 (CHAr), 129.19
(2xCHAr), 130.23 (2xCHAr), 133.16 (CAr), 135.15 (CAr),
136.17 (CAr), 137.91 (CAr), 139.12 (CAr), 142.43 (CH=CAr),
166.18 (C = O). Anal. Calcd. for C20H15ClFNO (MW
361.12): C, 76.34; H, 5.57%. Found: C, 74.49; H, 5.36%.
HRMS (Q-TOF) m/z Calcd for [M+H]+ 362.1233, found.
362.1306.
N-(4-bromophenyl)-N-(4-chlorobenzyl)cinnamamide
(C6) Yield: 74% (76% by MW), mp: 161–163 °C. 1H-NMR
(400 MHz, CDCl3) ẟ (ppm): 4.98 (s, 2H, N-CH2), 6.30 (d,
H, Jtrans: 15.3 COCH=), 6.95 (d, 2H, J: 8.4 Hz, Ar–H), 7.19
(d, 2H, J: 8.3 Hz, Ar–H), 7.33–7.26 (m, 6H, Ar–H), 7.52 (d,
2H, J: 8.5 Hz, Ar–H), 7.77 (d, H, Jtrans: 15.4 Hz, Ar–CH=).
13C-NMR (100 MHz, CDCl3) ẟ (ppm): 52.04 (Ar-CH2-
N), 117.52 (COCH =), 121.34 (CAr), 127.47 (2xCHAr),
128.21 (2xCHAr), 128.27 (2xCHAr), 129.38 (CHAr), 129.45
(2xCHAr), 129.61 (2xCHAr), 132.35 (2xCHAr), 132.95 (CAr),
134.35 (CAr), 135.21 (CAr), 140.35 (CAr), 142.74 (CH=CAr),
165.34 (C = O). Anal. Calcd. for C22H17BrClNO (MW
425.02): C, 61.92; H, 4.02%. Found: C, 61.86; H, 4.09%.
HRMS (Q-TOF) m/z Calcd for [M+H]+ 426.0182, found.
426.0254.
N-(4-chlorobenzyl)-N-(4-methoxyphenyl)cinnamamide
1
(C3) Yield: 85% (85% by MW), mp: 84–87 °C. H-NMR
(400 MHz, CDCl3) ẟ (ppm): 3.84 (s, 3H, Ar-OCH3), 4.96 (s,
2H, N-CH2), 6.34 (d, H, Jtrans: 15.5 COCH=), 6.88 (d, 2H,
J: 8.7 Hz, Ar–H), 6.96 (d, 2H, J: 8.6 Hz, Ar–H), 7.32–7.20
(m, 8H, Ar–H), 7.74 (d, H, Jtrans: 15.5 Hz, Ar–CH=).13C-
NMR (100 MHz, CDCl3) ẟ (ppm): 52.23 (Ar-CH2-N), 54.95
(OCH3-Ar), 114.20 (2xCHAr), 118.06 (COCH =), 127.39
(2xCHAr), 128.05 (2xCHAr), 128.18 (2xCHAr), 128.99
(2xCHAr), 129.09 (CHAr), 129.79 (2xCHAr), 132.70 (CAr),
133.90 (CAr), 134.64 (CAr), 135.65 (CAr), 141.90(CAr),
158.49 (CH = CAr), 165.78 (C = O). Anal. Calcd. for
C23H20ClNO2 (MW 377.12): C, 73.11; H, 5.34%. Found: C,
73.01; H, 5.28%. HRMS (Q-TOF) m/z Calcd for [M+H]+
378.1182, found. 378.1255.
The chemical structures of the synthesized compounds
were characterized by 1H NMR, 13C NMR, and HRMS (see
the supporting fle for details).
2.2. Pharmacological/biological assays
AChE and BuChE inhibition assay
Tertiary benzamide/ nicotinamide/ cinnamamide deriva-
tives were evaluated against AChE (E.C. 3.1.1.7, Type VI-S,
Electrophorus electricus) and BuChE (E.C. 3.1.1.8, equine
serum) spectrophotometrically by the method of Ellman with
slight modifcations using commercially available Tacrine as
the reference compound [56]. Stock solutions were dissolved
in dimethylsulfoxide and then diluted in a 50 mM Tris bufer
(pH 8.0) to provide a fnal concentration range. In a 96-well
polystyrene photometric microplates, the assay medium
in each well consisted of 50 μL of a Tris bufer, 125 μL of
3 mM 5,5-dithiobis-(2-nitrobenzoic acid) (DTNB), 25 μL
of 0.2U/mL enzyme (AChE or BuChE), and a 15 mM sub-
strate acetylthiocholine iodide (ATCI) or butyrylthiocholine
iodide (BTCI). The assay mixture containing the enzyme,
bufer, DTNB, and 25 μL of the inhibitor compound was
preincubated for 15 min at 37 °C before the substrate was
added to begin the reaction. All test compounds were pre-
pared at diferent concentrations: 4–65 ng/mL. The absorb-
ance of the reaction mixture was then measured three times
at 412 nm every 45 s using a microplate reader (Bio-Tek
N-(4-chlorobenzyl)-N-(4-fluorophenyl)cinnamamide
1
(C4) Yield: 73% (75% by MW), mp: 111–113 °C. H-
NMR (400 MHz, CDCl3) ẟ (ppm): 4.98 (s, 2H, N-CH2),
6.29 (d, H, Jtrans: 15.4 COCH=), 7.10–7.04 (m, 4H, Ar–H),
7.32–7.19 (m, 8H, Ar–H), 7.76 (d, H, Jtrans: 15.4 Ar–CH=).
13C-NMR (100 MHz, CDCl3) ẟ (ppm): 52.17 (Ar-CH2-
N), 115.98–116.20 (JCF:22.6 2xCHAr), 117.61 (COCH=),
127.41 (2xCHAr), 128.18 (2xCHAr), 128.21 (CHAr), 128.25
(2xCHAr), 129.30 (2xCHAr), 129.71 -129.61 (JCF:10.7
2xCHAr), 132.92 (CAr), 134.43 (CAr), 135.31 (CAr), 137.26
(CAr), 142.50 (CH=CAr), 160.13–162.61 (JCF:248.6 CAr),
165.78 (C = O). Anal. Calcd. for C22H17ClFNO (MW
365.10): C, 72.23; H, 4.68%. Found: C, 71.25; H, 4.61%.
HRMS (Q-TOF) m/z Calcd for [M+H]+ 366.0982, found.
366.1055.
N-(4-chlorobenzyl)-N-(4-chlorophenyl)cinnamamide
(C5) Yield: 81% (84% by MW), mp: 151–153 °C. 1H-NMR
(400 MHz, CDCl3) ẟ (ppm): 4.95 (s, 2H, N-CH2), 6.28 (d, H,
Jtrans: 15.3 COCH=), 6.99–6.97 (m, 2H, Ar–H), 7.35–7.16
1 3

Molecular Diversity
ELx800, Winooski, VT). IC50 values were obtained from
activity (%) versus compounds plots.
(simplifed molecular-input line-entry system) by using the
SwissADME. Finally, the program was run to calculate the
physicochemical and pharmacokinetic parameters of the
compounds. (http://www.swissadme.ch/index.php) [58].
Molecular docking studies
Docking simulation was carried out by using the Auto-
dock4.2 program [57]. The crystal structures of AChE
(PDB: 1EVE) and BuChE (PDB: 1P0I) enzymes in PDB
format were used for the preparation of proteins. Molecules
were drawn by using Chemdraw 19.0, and then passed to
Chemdraw 3D 19.0. The molecules were minimized in the
MM2 area and saved in PDB format.
Results
Chemistry
The compounds were synthesized and purifed for the frst
time (except B1 and B5) by conventional and microwave
irradiation methods according to Scheme 1. First, secondary
amines were synthesized by using a suitable aniline [aniline
(1), 4-methylaniline (2), 4-methoxyaniline (3), 4-foroani-
line (4), 4-chloroaniline (5), and 4-bromoaniline (6)]. Then,
amides were synthesized successfully in the second step by
using a suitable acid chloride (Scheme 1). The acid chlo-
rides used in the series are as follows: benzoyl chloride for B
series, nicotinamide chloride for N series, and cinnamamide
chloride for the C series.
Using Autodock Tools (ADT ver 1.5.6): All other hydro-
gens, water molecules, and non-standardized residues were
removed, except polar hydrogens in the structure of pro-
teins. Kollman united atom charges and solvation parameters
were assigned to the proteins and the Gasteiger charge was
assigned to the ligand. The modifed structures obtained
were converted to PDBQT format in ADT for AutoDock
calculations. The grid size for specifying the search space
was set at 60×60×60 cenrred on the macromolecule with
a default grid point spacing of 0.375 Å. The Lamarckian
Genetic Algorithm was implemented with a population size
of 10 dockings. Analysis of clustering conformations was
performed on the docked results using an RMSD tolerance
of 2.0 Å. The conformation with the lowest binding energy
was evaluated by using Pyton Molecule Viewer (PMV
ver.1.5.6) and Protein–Ligand Interaction Profler (PLIP).
AChE and BuChE inhibitory activity
In vitro cholinesterase inhibitory activities of the compounds
were reported for the frst time in this study and the inhibi-
tion results were presented in Table 1.
Molecular docking studies
Prediction of physicochemical and ADME properties
Among the benzamide, nicotinamide, and cinnamamide
series, the compounds with the highest AChE inhibition
potential (B4, N4, and C4) were docked at the binding
site of AChE to explain the binding pattern of the com-
pounds. The X-ray crystallographic structures of AChE
The free SwissADME web tool was used for in silico predic-
tion of the pharmacokinetic properties and ADME param-
eters of the synthesized compounds. The chemical structures
of the compounds were drawn and converted to SMILES
Scheme 1 Synthesis of the
target compounds
1 3

Molecular Diversity
Table 1 Inhibitory activity
(IC50) of the compounds
against ChEs
Compounds
R1
R–C=O
AChE
(nM)
r2
BuChE
(nM)
r2
B1
B2
B3
B4
B5
B6
N1
N2
N3
N4
N5
N6
C1
C2
C3
C4
C5
–H
Benzoyl
Benzoyl
Benzoyl
Benzoyl
Benzoyl
Benzoyl
Nicotinoyl
Nicotinoyl
Nicotinoyl
Nicotinoyl
Nicotinoyl
Nicotinoyl
Cinnamoyl
Cinnamoyl
Cinnamoyl
Cinnamoyl
Cinnamoyl
Cinnamoyl
83.03
79.98
45.63
15.42
43.52
34.95
51.09
64.00
26.35
12.14
32.86
28.23
48.94
57.62
24.12
10.67
21.76
26.90
20.85
0.9853
0.9675
0.9979
0.9776
0.9881
0.9957
0.9738
0.9810
0.9911
0.9676
0.9676
0.9890
0.9858
0.9984
0.9516
0.9629
0.9947
0.9946
0.9839
66.68
59.28
38.37
37.88
49.16
54.73
59.89
55.68
42.02
43.32
45.55
48.75
69.86
62.77
32.74
37.78
49.50
54.03
15.66
0.9787
0.9857
0.9864
0.9732
0.9970
0.9782
0.9897
0.9724
0.9871
0.9946
0.9558
0.9759
0.9806
0.9322
0.9854
0.9847
0.9674
0.9949
0.9874
–CH3
–OCH3
–F
–Cl
–Br
–H
–CH3
–OCH3
–F
–Cl
–Br
–H
–CH3
–OCH3
–F
–Cl
–Br
C6
Tacrine*
*Tacrine was used as a standard inhibitor towards both AChE and BuChE enzymes. r2: is a statistical meas-
ure of how close the data are to the ftted regression line. It is also known as the coefcient of determina-
tion, or the coefcient of multiple determinations for multiple regressions[59]
Table 2 Binding free energies
of B4, N4, and C4 in the AChE
binding site
most active compounds B4, N4, and C4 were presented
Compound
Binding Free
Energy (kcal/
mol)
in Table 2.
Prediction of physicochemical and ADME properties
B4
N4
C4
− 9.09
− 9.30
− 9.58
Molecular weights, the numbers of hydrogen bond donors
and acceptors, the topological surface areas (TPSA; a sum of
polar atoms’ surfaces), lipophilicities, and water solubilities
of all compounds were calculated and presented in the sup-
porting fle. ADME profles of the most active compounds in
each series were calculated and presented in Table 3.
(1EVE) were obtained from the Protein Data Bank (PDB,
https://www.rcsb.org/). The binding free energies of the
Table 3 In silico
e
Compound
MWa
HBAb
HBDc
TPSAd
CLogPo/w
logSf
Violationsg
physicochemical properties of
the compounds B4, N4, and C4
B4
N4
C4
Tacrine
339.79
340.78
365.83
198.26
2
3
2
1
0
0
0
1
20.31
33.20
20.31
38.91
4.92
4.10
5.29
2.59
− 5.42
− 4.75
− 5.75
− 3.27
1
0
1
0
aMolecular weight (<500 Da),
bNumber of hydrogen bond acceptors (<10),
cNumber of hydrogen bond donors (<5),
dTopological polar surface area (20–130 Å2),
eOctanol/water partition coefcient (recommended range:−2.0 to 6.5),
fAqueous solubility prediction (not higher than 6),
gNumber of Lipinski’s rule of 5 violations
1 3

Molecular Diversity
4th position of the phenyl ring led to an increase in AChE
inhibitory activity (about 2 times).
Discussion
The inhibition results presented in Table 1 showed that all
compounds synthesized had higher IC50 values than Tacrine
against BuChE. According to BuChE inhibition results pre-
sented in Table 1, the most active compound was 4-methoxy
substituted and cinnamamide derivative compound C3 hav-
ing IC50 value of 32,74 nM against BuChE.
Chemistry
Secondary amines were synthesized in the range of 80–90%
yields by both conventional and microwave irradiation meth-
ods. The reaction took place in a solvent-free environment
in a shorter period under the microwave irradiation method
while it took place in the aqueous medium by the conven-
tional method. In both methods, the completion of the reac-
tion was checked by TLC and all of the compounds were
purifed by column chromatography on silica gel with hex-
ane: ethyl acetate (2:1) as the mobile phase.
Molecular docking studies
According to the results in Table 2, the binding free energy
of the C4 (-9.58 kcal/mol) was higher than the free bind-
ing energy of the compounds B4 (-9.09 kcal/mol) and N4
(-9.30 kcal/mol). Also, the results showed that the binding
free energy scores of the compounds B4, N4, and C4 pre-
sented in Table 2 were in an agreement with in vitro AChE
inhibition results presented in Table 1.
Amides were also synthesized in similar yields (72–85%)
by both conventional and microwave irradiation methods
(Scheme 1). The fact that the reaction takes place in lower
solvent conditions (1 mL) and the procedure can be carried
out in 10 min makes microwave assisted synthesis prefer-
able over the conventional method. Moreover, the meth-
odologies proceeds with high atom economy which is in
harmony with the green chemistry laws. The reaction pro-
cesses includes low energy consumption process; it either
occurs at room temperature in CH2Cl2 or with a moderate
temperature by microwave irradiation in dioxane. The prod-
ucts can be isolated with high yields and selectivity in both
cases (microwave assisted and conventional). As a result,
the microwave irradiation method provided great advantages
in terms of reaction periods, especially for the synthesis of
amide derivatives.
According to the B4-1EVE complex presented in Fig. 1,
π-π charge transfer interactions were observed between the
indole ring of TRP84A and the 4-fuoro substituted phenyl
ring of the compound B4 (3.63 Å and 4.02 Å, respectively).
On the other hand, many hydrophobic interactions were
determined between B4 and the active site of the enzyme,
1EVE (Fig. 1).
According to the N4-1EVE complex presented in Fig. 2,
hydrogen bondings were observed between N atom in the
pyridine ring of the compound N4 and the amino acids
GLY118A (NH; 3.13 Å), GLY119A (NH; 3.01 Å), HIS440A
(ArNH; 3.33 Å), SER200A (OH; 1.89 Å). In addition, the
carbonyl group of the compound N4 realized a hydrogen
AChE and BuChE inhibitory activity
Tacrine was used as the reference drug and its IC50 values
were 20.85 nM and 15.66 nM against AChE and BuChE,
respectively. According to Table 1, IC50 values of the
compounds were in the range from 10.67 nM to 83.03 nM
against AChE, while they were in the range from 32.74 nM
to 66.68 nM against BuChE.
According to Table 1, compound C4 had a higher IC50
value (about 2 times) than the reference drug towards AChE.
The inhibition results in Table 1 pointed out that the syn-
thesized compounds had stronger inhibition efects towards
AChE than BuChE enzyme. The most active compound in
the series was 4-fuoro substituted compound C4 (cinnama-
mide derivative) having IC50 value of 10.67 nM in terms of
AChE inhibitory activity. On the other hand, the results in
Table 1 showed that halogen substitution at the 4th position
of the phenyl ring (series 4, 5, 6) was a useful modifcation
in terms of AChE inhibitory activity. When the inhibition
results in Table 1 were evaluated, it was seen that the substi-
tution of a methoxy group rather than a methyl group at the
Fig. 1 Schematic presentation of interactions between B4 and AChE
(1EVE). Green colour represents π-π charge transfer interactions and
grey represents pink represents hydrophobic interactions
1 3

Molecular Diversity
indole structure of TRP84A and the 4-fuoro substituted phe-
nyl ring of the compound C4 (4.43 Å and 3.93 Å, respec-
tively). Also, the benzene ring of the 4-chlorobenzyl of the
molecule realized a π-π charge-transfer interaction with the
benzene ring of PHE331A (4.70 Å) (Fig. 3).
The molecular modelling studies showed that the benzene
rings in the amide part of the molecules realized the charge-
transfer interaction with the anionic side of AChE (TRP84A,
PHE331A). Besides, the nicotinoyl structure replaced by
the benzoyl structure of the compounds led to the forma-
tion of hydrogen bonds with both the catalytic (SER200A,
HİS440A) and oxyanion side (GLY118A, GLY119A) of the
enzyme.
Prediction of physicochemical and ADME properties
Fig. 2 Schematic presentation of interactions between the compound
N4 and AChE (1EVE). Blue colour represents hydrogen bondings,
green colour represents π-π charge transfer interactions and grey rep-
resents hydrophobic interactions
The physicochemical properties of a molecule are very
important in designing drug-candidate because they deter-
mine the pharmacokinetic properties of the molecule. ‘Drug-
likeness’ is a term explained earlier in the literature that
describes the possibility for a molecule to be used as an oral
drug in terms of bioavailability [58]. In medicinal chemistry,
Lipinski’s 5 rules are used to score the drug-likeness proper-
ties of a compound [60, 61].
According to the results presented in the supporting
fle, ClogP values of the compounds were in the range of
4.59–5.21(<5) for benzamide (B) series, 3.76–4.38 (<5) for
nicotinamide (N) series, and 4.94–5.59 for cinnamamide (C)
series. The molecular weights of the compounds were in the
range of 321.80–400.70 (<500) for benzamide (B) series,
322.79–401.68 (<500) for nicotinamide (N) series, and
347.84–426.76 (<500) for cinnamamide (C) series. HBA
values of the compounds ranged 1–3 (≤10) and HBD values
of the compounds were 0 (<5) for each series. When these
results were compared with the reference drug Tacrine, it
was seen that the ADME profles of the N series had the
closest values to the physicochemical properties of Tacrine.
Besides, the most active compounds in each series towards
AChE B4, N4, and C4 had desired logP values (Table 3) in
terms of penetrating the blood–brain barrier. This means
that the compounds had CNS efects in terms of being used
as AChE inhibitors for the treatment of AD. According to
Table 3, both compounds B4 and C4 had 1 violation in terms
of Lipinski’s rule of fve because of having a MlogP value
higher than 4.15.
Fig. 3 Schematic presentation of interactions between the compound
C4 and AChE (1EVE). Green colour represents π-π charge transfer
interactions and grey represents hydrophobic interactions
bonding with the side chain of the amino acid SER122 (OH;
2.86 Å). π-π charge transfer interactions were determined
between the indole ring of TRP84A and the 4-fuoro phe-
nyl ring of the compound N4 (4.02 Å and 3.63 Å, respec-
tively). Besides, many hydrophobic interactions were iden-
tifed between N4 and the active site of the enzyme, 1EVE
(Fig. 2).
Conclusion
The newly designed (except B1 and B5) total of 18 com-
pounds, N-(4-chlorobenzyl)-N-(4-substituted phenyl)ben-
zamide/nicotinamide/cinnamamide, were synthesized and
purifed successfully for the frst time with their potential
According to the C4—1EVE complex presented in Fig. 3,
π-π charge transfer interactions were observed between the
1 3

Molecular Diversity
Nat Prod Rep 36(8):1053–1092. https://doi.org/10.1039/C9NP0
0010K
inhibitory efects on AChE and BuChE enzymes. According
to the inhibition results, the IC50 values of the compounds
synthesized were in the range of 10.66–83.03 nM towards
AChE, while they were in the range of 32.74–66.68 nM
towards BuChE. The inhibition results showed that the
newly synthesized compounds had higher inhibitory efects
towards AChE than BuChE. According to the AChE inhi-
bition results, among the synthesized benzamide/nicotina-
mide/cinnamamide derivatives, 4-foroaniline derivatives
(B4, N4, C4) showed the highest AChE inhibitory activities
in each series and had the highest selectivity to AChE. The
most active compounds B4 (IC50: 15.42 nM), N4 (IC50:
12.14 nM), and C4 (IC50: 10.67 nM) in each series had
higher in vitro AChE inhibitory activity than the reference
drug TAC (IC50: 20.85 nM). The most active compound
towards AChE in the series was the cinnamamide deriva-
tive compound C4 having a lower IC50 value (about two
times) than TAC. Besides, the inhibition results of the com-
pounds towards AChE suggested that replacing the cinnama-
mide structure with benzamide and nicotinamide structure
led to an increase in AChE inhibitory efect. On the other
hand, the most active compounds B4, N4, and C4 in each
series towards AChE were docked at the binding sites of the
enzyme to explain the inhibitory activities of each series.
ADME prediction studies of the compounds showed that
the newly designed compounds were not only potent AChE
inhibitors but also had desired physicochemical and ADME
profles for further studies as drug candidates.
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Funding
This work was supported by the Ataturk University Scien-
tifc Research Projects Coordination Unit (Project number:
THD-2020–8258).
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Zanotto C, Zdovc I, De Giuli Morghen C, Radaelli A, Valoti E
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Acknowledgements I would like to thank Prof. Dr. Hasan Seçen
for supporting this study with laboratory facilities, knowledge, and
experience.
Declaration
Conflict of interest The authors declare that there is no confict of in-
terest.
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Publisher’s Note Springer Nature remains neutral with regard to
jurisdictional claims in published maps and institutional afliations.
Authors and Afliations
Mehmet Koca1 · Sinan Bilginer1
1
* Mehmet Koca
Department of Pharmaceutical Chemistry, Faculty
kocamehmet@atauni.edu.tr
of Pharmacy, Ataturk University, TR-25240 Erzurum,
Turkey
1 3