Novel propanolamine derivatives attached to 2-metoxifenol moiety: Synthesis, characterization, biological properties, and molecular docking studies

Article abstract of DOI:10.1016/j.bioorg.2020.103969

The synthesis of seven new ?-amino alcohols was designed and performed by starting from eugenol, a natural phenolic compound known to be biologically active. The synthesized compounds were obtained in yields ranging from 54 to 81%. Molecule structures were determined with FT-IR, ¹H NMR and ¹³C NMR spectroscopies. In addition, the inhibitory effects of these substances on acetylcholinesterase (AChE), α-glycosidase (α-Gly), human carbonic anhydrase I (hCA I), and human carbonic anhydrase II (hCA II) enzymes have been investigated. It has been seen that all compounds have a better ability to inhibit compared to existing tried inhibitors. Among these, the best inhibitor against AChE enzyme is 2b (Ki 62.08 ± 11.67 μM and IC₅₀ 90.33), and against α-Gly, 2c showed the highest effect (Ki 0.33 ± 0.08 μM and IC₅₀ 0.28). The best inhibitor against hCA I, and hCA II enzymes is compound 2f. For hCA I and hCA II, Ki value was measured as 9.68 ± 1.32 and 11.46 ± 2.64 μM and IC₅₀ values as 7.37 and 8.26 μM respectively. The interactions of the studied new propanolamine derivatives with the enzymes were done by molecular docking calculations and their biological activities were compared to the experimental tests. Studied enzymes in molecular docking calculations are acetylcholinesterase (AChE) is PDB ID: 4M0E, α-glycosidase (α-Gly) is PDB ID: 1R47, human carbonic anhydrase isoenzyme I (hCA I) PDB ID: 3LXE is human carbonic anhydrase isoenzyme II (hCA II) is PDB ID: 5 AML.

Full text of DOI:10.1016/j.bioorg.2020.103969

Journal Pre-proofs
Novel Propanolamine Derivatives Attached to 2-Metoxifenol Moiety: Synthe-
sis, Characterization, Biological Properties, and Molecular Docking Studies
Hayriye Genç Bilgiçli, Derya Ergön, Parham Taslimi, Burak Tüzün, İnci
Akyazı Kuru, Mustafa Zengin, İlhami Gülçin
PII:
S0045-2068(20)31031-2
DOI:
https://doi.org/10.1016/j.bioorg.2020.103969
YBIOO 103969
Reference:
To appear in:
Bioorganic Chemistry
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Revised Date:
Accepted Date:
1 May 2020
13 May 2020
22 May 2020
Please cite this article as: H.G. Bilgiçli, D. Ergön, P. Taslimi, B. Tüzün, I.A. Kuru, M. Zengin, I. Gülçin, Novel
Propanolamine Derivatives Attached to 2-Metoxifenol Moiety: Synthesis, Characterization, Biological
Properties, and Molecular Docking Studies, Bioorganic Chemistry (2020), doi: https://doi.org/10.1016/j.bioorg.
2020.103969
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Novel Propanolamine Derivatives Attached to 2-Metoxifenol
Moiety: Synthesis, Characterization, Biological Properties, and
Molecular Docking Studies
Hayriye Genç Bilgiçli1,*, Derya Ergön1, Parham Taslimi2, Burak Tüzün3, İnci Akyazı
Kuru1, Mustafa Zengin1, İlhami Gülçin4
1Department of Chemistry, Faculty of Arts and Sciences, Sakarya University, 54050-Serdivan,
Sakarya, Turkey
2Department of Biotechnology, Faculty of Science, Bartin University, 74100-Bartin, Turkey
3Department of Chemistry, Faculty of Sciences, Cumhuriyet University, 58140-Sivas, Turkey
4Department of Chemistry, Faculty of Science, Ataturk University, 25240-Erzurum, Turkey

ABSTRACT
The synthesis of seven new ß-amino alcohols was designed and performed by starting from
eugenol, a natural phenolic compound known to be biologically active. The synthesized
compounds were obtained in yields ranging from 54 to 81%. Molecule structures were
1
determined with FT-IR, H NMR and 13C NMR spectroscopies. In addition, the inhibitory
effects of these substances on acetylcholinesterase (AChE), α-glycosidase (α-Gly), human
carbonic anhydrase I (hCA I), and human carbonic anhydrase II (hCA II) enzymes have been
investigated. It has been seen that all compounds have a better ability to inhibit compared to
existing tried inhibitors. Among these, the best inhibitor against AChE enzyme is 2b (Ki 62.08
± 11.67 µM and IC50 90.33), and against α-Gly, 2c showed the highest effect (Ki 0.33 ± 0.08
µM and IC50 0.28). The best inhibitor against hCA I, and hCA II enzymes is compound 2f. For
hCA I and hCA II, Ki value was measured as 9.68 ± 1.32 and 11.46 ± 2.64 µM and IC50 values
as 7.37 and 8.26 µM respectively. The interactions of the studied new propanolamine
derivatives with the enzymes were done by molecular docking calculations and their biological
activities were compared to the experimental tests. Studied enzymes in molecular docking
calculations are acetylcholinesterase (AChE) is PDB ID: 4M0E, α-glycosidase (α-Gly) is PDB
ID: 1R47, human carbonic anhydrase isoenzyme I (hCA I) PDB ID: 3LXE is human carbonic
anhydrase isoenzyme II (hCA II) is PDB ID: 5 AML.
Keywords: Eugenol; propanol amine; β-amino alcohols; enzyme inhibition; molecular docking

1. INTRODUCTION
It is well known that when drugs enter the body, they are converted into metabolites by various
enzymes and excreted from the organism [1]. Thus, when designing the synthesis of compounds
having high potential to be a drug active substance, referencing to the molecule structures found
in existing drugs or natural products [2] are favorably supports the process. Because the
metabolites of such compounds have already been tested and their positive or negative aspects
have been investigated in detail [3,4].
The β-amino alcohol structures also known as β-hydroxylamin or 1,2-amino alcohol are
considered as significant pharmacofores [5] due to be present in the structure of many
pharmacologically active natural or synthetic compounds [6,7]. These compounds have an
undeniable importance especially in the synthesis of substances such as synthetic amino acids,
β-blockers and insecticidal agents [8]. Currently, there are 82 aminoalcohol-derived compounds
in the FDA approved drug list, while 119 drug candidates are pending the approval. There are
also 23 amino alcohols used as a nutritional supplement in the food industry [9]. Eugenol is an
essential oil and widely used in industries such as medicine, food and cosmetics [10]. This
natural phenolic compound, which has been used an antibacterial since ancient times, has
important effects on human health [11].
Based on this, the synthesis of new β-amino alcohol derivatives carrying the 2-
methoxyphenol group, which is also found in the eugenol compound, was designed and carried
1
13
out (Scheme 1). Their structures were determined by H NMR and C NMR spectroscopies.
The inhibitory effects of these substances on acetylcholinesterase (AChE), α-glycosidase (α-
Gly), human carbonic anhydrase I (hCA I), and human carbonic anhydrase II (hCA II) enzymes
were investigated.
Scheme 1
The role of carbonic anhydrase (CA) in human physiological is vital such as electrolytes
secretion, intracellular pH regulation, lipogenesis, gluconeogenesis, and bone resorption and
consequently interests the medicinal chemists for drug discovery of anticancer, antiglaucoma,
antineuropathic pain, antiepileptic and antiobesity agents [12,13]. α-Glycosidase is a primary
target of type-2 diabetes mellitus (T2DM) therapy and drug discovery. The three main clinically
practiced drugs (Acarbose, Miglitol, and Voglibose) for T2DM are α-glycosidase and work by
reduction of post-prandial hyperglycemia. The unfortunate side effects including hepatotoxicity
limit their use and impact, calling to design better inhibitors for α-glycosidase [14,15]. AD is

the single most complex neurodegradation challenge of 21st century. Presently, 40 million are
suffering from dementia worldwide mainly caused by AD, the number is expected to increase
two-fold after every two decades. Multitarget drug discovery strategies have been studied for
last twenty years to yield potential candidates for Alzheimer’s disease (AD), citing
cholinesterase enzymes including acetylcholinesterase and butyrylcholinesterase to be the
major targets of Cholinergic pathway associated to dementia in AD and Parkinson’s diseases
(PD) [16,17].
Many of the theoretical studies conducted today have started to guide experimental
studies [18–21]. Theoretical studies reduce the duration and cost of experimental studies. This
provides great convenience to researchers. These theoretical studies allow us to find the
optimized structures of molecules, the atom or groups of atoms to interact with the enzyme, and
find the active regions of the enzymes. Today, molecular docking is the most common among
the theoretical methods. With this method, the comparison of the biological activities of the
molecules with the enzymes is calculated by finding the numerical values [18]. Using this
method, the conditions for the methoxyphenol derivatives studied to become drugs in the future
will be examined. Many parameters are obtained for this study by molecular docking
calculations [22]. Numerical values of these parameters will be checked to see if they are within
the limits of being a drug. These analyzes are called ADME analysis [23–25]. In this analysis,
the conditions of molecules to be drugs are examined.
In the present study, we determined the synthesis and characterization of novel
propanolamine derivatives attached to 2-metoxifenol moiety (2a-g) and effects of these
derivatives on CA isoenzymes (hCA I and II), cholinergic enzyme (AChE), and digestive
enzyme (α-glycosidase). Furthermore, the metabolic enzyme inhibition profiles of novel
propanolamine derivatives attached to 2-metoxifenol moiety (2a-g) were compared to
acetazolamide, tacrine, and acarbose as standard inhibitors for metabolic enzymes. Also, with
molecular docking studies, the conditions of molecules to be drugs are examined.
2. MATERIALS AND METHODS
2.1.Synthesis of 2-methoxy-4-(oxiran-2-ylmethyl)phenol (1)
To the stirred solution of eugenol (1) (0,5 g, 3 mmol) in CHCl3, was added dropwise the solution
of m-CPBA (meth-achloroperbenzoic acid) (1.29 g, 7.5 mmol) of CHCl3 (20 mL). The reaction
mixture was stirred at 80 °C for 24 hours and then cooled to room temperature and filtered. The

filtrate was transferred to the separatory funnel and extracted with NaHCO3(aq) (2x10 mL) and
then water (2x10 mL) respectively. The organic phase was dried with MgSO4 and concentrated
in a rotary evaporator. The crude product was analyzed with 1H and 13C NMR spectra and was
used in the subsequent reactions without any additional purification (Scheme 2).
2-methoxy-4-(oxiran-2-ylmethyl)phenol (1): Colorless oily; yield 0.52g, 95%; 1H NMR (300
MHz, Chloroform-d) δ 6.81 (dd, J = 8.0, 1.5 Hz, 1H), 6.73 (d, J = 1.7 Hz, 1H), 6.69 (dd, J =
8.0, 1.7 Hz, 1H), 3.80 (d, J = 1.5 Hz, 3H), 3.10 (ddtd, J = 5.4, 4.2, 2.7, 1.4 Hz, 1H), 2.83 – 2.68
(m, 3H), 2.52 (tt, J = 4.6, 3.1, 2.7, 1.5 Hz, 1H); 13C NMR (75 MHz, CDCl3) δ 146.94, 144.66,
129.20, 121.77, 114.81, 112.02, 56.06, 53.16, 47.15, 38.50.
Scheme 2
2.2.Synthesis of propyl amine derivatives (2a-g)
To the mixture of 2-methoxy-4-(oxyran-2-ylmethyl) phenol (1) (0.18 g, 1 mmol) and amine
derivative (1.40 mmol), Na2CO3 (0.18 g, 1.40 mmol) was added and it was stirred at room
temperature for 24 hours. At the end of the reaction, after removed excess amine in vacuum,
the residue was dissolved with dichloromethane (30 mL) and washed with brine (20 mL) and
water (2x20 mL), respectively. The organic phase was dried with MgSO4 and concentrated in
a rotary evaporator. Purification methods for each compound are described in the experimental
1
section. The structures were characterized by H NMR, 13C NMR and FT-IR spectrums.
General reaction equation and structures of synthesized compounds are given in Scheme 3.
Scheme 3
4-(3-(Diethylamino)-2-hydroxypropyl)-2-methoxyphenol (2a): Hexane was added to the
crude product and the viscose substance (2a) was separated from the mixture by centrifugation.
Brown viscose liquid; yield 0.18g, 72%; FT-IR ν (cm-1) = 1035 (CO stretching), 1121 (CN
stretching), 1268 (CO stretching), 2969 (CH stretching), 3374 (OH stretching); 1H NMR (300
MHz, Chloroform-d) δ 6.83 (d, J = 8.0 Hz, 1H), 6.78 (s, 1H), 6.71 (d, J = 8.0 Hz, 1H), 3.87 (s,
3H), 3.83 – 3.71 (m, 1H), 2.84 – 2.07 (m, 10H), 1.00 (td, J = 7.1, 0.9 Hz, 6H); 13C NMR (75
MHz, CDCl3) δ 146.63, 144.29, 130.68, 122.01, 114.48, 112.10, 68.27, 59.23, 56.08, 47.29
(2C), 41.32, 12.20 (2C).
4-(3-(Tert-butylamino)-2-hydroxypropyl)-2-methoxyphenol (2b): Hexane and ether (1: 1)
solvents were added to the crude product. Separation of the insoluble particles by filtration,

pure 2b was obtained. Brown solid; yield 0.16g, 63%; mp: 116-118 ºC; FT-IR ν (cm-1) = 1032
(CO stretching), 1085 (CN stretching), 1268 (CO stretching), 2961 (CH stretching), 3294 (OH
1
stretching); H NMR (300 MHz, DMSO-d6) δ 6.74 (d, J = 1.8 Hz, 1H), 6.63 (d, J = 8.0 Hz,
1H), 6.55 (dd, J = 8.0, 1.8 Hz, 1H), 3.71 (s, 3H), 3.61 – 3.50 (m, 1H), 2.74 – 2.13 (m, 6H), 0.97
(s, 9H); 13C NMR (75 MHz, CDCl3) δ 146.73, 144.38, 130.42, 122.08, 114.61, 112.04, 71.57,
56.07, 50.85, 47.73, 41.61, 29.20 (3C).
4-(3-(Allylamino)-2-hydroxypropyl)-2-methoxyphenol (2c): To the obtained crude product,
DCM was added and insoluble beige solid (2c) was filtered off. Beige solid; yield 0.19g, 81%;
mp: 114-116 ºC; FT-IR ν (cm-1) = 1034 (CO stretching), 1082 (CN stretching), 1269 (CO
stretching), 2923 (CH stretching), 3307 (OH stretching); 1H NMR (300 MHz, Chloroform-d) δ
6.83 (d, J = 8.0 Hz, 1H), 6.78 – 6.56 (m, 2H), 5.99 – 5.74 (m, 1H), 5.24 – 5.00 (m, 2H), 3.87
(s, 3H), 3.95 – 3.76 (m, 1H), 3.48 – 2.97 (m, 4H), 2.75 (dd, J = 12.1, 3.1 Hz, 1H), 2.68 (d, J =
13
5.8 Hz, 2H), 2.54 (dd, J = 12.1, 9.1 Hz, 1H); C NMR (75 MHz, CDCl3) δ 146.81, 144.50,
135.22, 129.93, 122.08, 117.86, 114.70, 112.09, 70.66, 56.07, 53.83, 51.99, 41.50.
4-(3-(Butylamino)-2-hydroxypropyl)-2-methoxyphenol (2d): After dissolving the crude
product in a mixture of ether: DCM (50:50) by heating, the solution was left in the freezer
overnight. Pure 2d was obtained by filtration of the settled solid. Pale brown solid; yield 0.15g,
61%; mp: 111-113 ºC; FT-IR ν (cm-1) = 1035 (CO stretching), 1076 (CN stretching), 1250 (CO
stretching), 2928 (CH stretching), 3173 (OH stretching); 1H NMR (300 MHz, Chloroform-d) δ
6.81 (d, J = 7.9 Hz, 1H), 6.73 (d, J = 1.9 Hz, 1H), 6.67 (dd, J = 8.0, 1.9 Hz, 1H), 3.98 – 3.68
(m, 4H), 2.85 – 2.41 (m, 9H), 1.46 (p, J = 6.9 Hz, 2H), 1.32 (ddd, J = 16.0, 12.9, 7.0 Hz, 2H),
0.89 (t, J = 7.3 Hz, 4H); 13C NMR (75 MHz, CDCl3) δ 146.85, 144.56, 130.11, 122.08, 114.73,
112.11, 70.77, 56.05, 54.83, 49.53, 41.59, 32.11, 20.61, 14.22.
4-(2-Hydroxy-3-(isopropylamino)propyl)-2-methoxyphenol (2e): The light yellow viscous
material obtained after extraction was loaded onto a pad of 5cm silica gel prepared in a glass
micropipette and eluted with hexane, ether, DCM and MeOH solvents respectively. The MeOH
fraction gave pure 2e. Light brown solid; yield 0.14, 58%; mp: 133-135 ºC; FT-IR ν (cm-1) =
1034 (CO stretching), 1082 (CN stretching), 1268 (CO stretching), 2923 (CH stretching), 3307
(OH stretching); 1H NMR (300 MHz, Chloroform-d) δ 6.82 (d, J = 8.0 Hz, 1H), 6.73 (d, J = 1.7
Hz, 1H), 6.67 (dd, J = 8.0, 1.7 Hz, 1H), 3.85 (s, 3H), 3.88 – 3.75 (m, 1H), 2.78 (dt, J = 4.1, 1.1
Hz, 1H), 2.74 (dd, J = 3.2, 0.9 Hz, 1H), 2.67 (dd, J = 6.3, 2.5 Hz, 2H), 2.48 (ddd, J = 12.0, 9.1,

1.0 Hz, 1H), 1.05 (d, J = 6.3 Hz, 6H); 13C NMR (75 MHz, CDCl3) δ 146.91, 146.86, 130.39,
122.06, 114.79, 112.22, 69.75, 56.05, 56.00, 52.19, 49.21, 41.27, 22.55.
4-(2-Hydroxy-3-(phenylamino)propyl)-2-methoxyphenol (2f): The obtained crude product
was purified over silica gel column eluting with a mixture of DCM / MeOH (30:70). The
collected fractions gave the pure 2f product. Brown solid; yield 0.19g, 70%; mp: 91-93 ºC; FT-
IR ν (cm-1) = 1032 (CO stretching), 1266 (CO stretching), 2919 (CH stretching), 3389 (OH
stretching); 1H NMR (300 MHz, Chloroform-d) δ 7.19 (td, J = 7.8, 3.6 Hz, 1H), 6.94 – 6.53 (m,
2H), 4.03 (tdd, J = 8.2, 5.1, 3.2 Hz, 0H), 3.83 (d, J = 5.0 Hz, 1H), 3.29 (dd, J = 12.8, 3.5 Hz,
0H), 3.07 (dd, J = 12.8, 7.9 Hz, 0H), 2.78 (qt, J = 13.5, 6.3 Hz, 1H); 13C NMR (75 MHz, CDCl3)
δ148.43, 146.88, 144.57, 129.76, 129.56 (2C), 122.20, 118.13, 114.83, 113.58 (2C), 112.10,
71.49, 56.13, 49.54, 41.44.
4-(3-((3-(dimethylamino)propyl)amino)-2-hydroxypropyl)-2-methoxyphenol (2g): The
crude product was washed with hexane (3x5mL) and pure 2g was obtained by separating the
viscous layer. Light brown viscous; yield 0.17g, 61%; FT-IR ν (cm-1) = 1035 (CO stretching),
1
1080 (CN stretching), 1270 (CO stretching), 2938 (CH stretching), 3307 (OH stretching); H
NMR (300 MHz, Chloroform-d) δ 6.75 (d, J = 8.0 Hz, 1H), 6.69 (d, J = 1.9 Hz, 1H), 6.62 (dd,
J = 8.0, 1.9 Hz, 1H), 4.55 (bs, 1H), 3.84 – 3.74 (m, 1H), 3.80 (s, 3H), 2.64 (tdd, J = 12.3, 9.6,
13
5.1 Hz, 5H), 2.45 – 2.25 (m, 4H), 2.20 (s, 6H), 1.63 (p, J = 8.5, 7.8 Hz, 2H); C NMR (75
MHz) δ 148.43, 146.88, 144.57, 129.75, 129.55 (2C), 122.20, 118.13, 114.83, 113.58 (2C),
112.10, 71.49, 56.13, 49.54, 41.44.
2.3. Biochemical Studies
The inhibitory effects of novel propanolamine derivatives attached to 2-metoxifenol moiety
(2a-g) on both hCA isozymes have been described in Verpoorte et al. [26] and according to an
esterase assay using p-nitrophenylacetate (PNA) substrate was recorded spectrophotometrically
at 348 nm [27]. On the other hand, the inhibitory effects of AChE and BChE compounds were
determined according to the method of Ellman et al. [28]. They were recorded
spectrophotometrically at 412 nm using acetylcholine iodide and butyrylcholine iodide and
recorded as enzymatic reaction substrates according to previous studies. 5,5-Dithio-bis (2-nitro-
benzoic acid) was used to measure AChE and BChE activity [29,30]. In addition, the inhibitory
effect of these compounds on the activity of α-glycosidase enzyme was assessed using the p-
nitrophenyl-D-glycopyranoside substrate (p-NPG) according to the analysis of Tao et al. [31].
First, 200 liters of phosphate buffer was mixed with 40 liters of homogenate in phosphate buffer

(0.15 U / mL, pH 4.7). In addition, after preincubation, 50 μL of p-NPG was added to phosphate
buffer (5 mM, pH 7.4) and incubated again at 30 °C. The absorbance was
spectrophotometrically measured at 405 nm [32,33].
In silico studies
There are theoretically many methods and procedures to determine the activity of the
methoxyphenol derivatives studied against enzymes. Molecular docking is the most common
of these. Molecular docking calculations of methoxyphenol derivatives were done using
Maestro Molecular Modeling platform (version 12.0) by Schrödinger, LLC [34]. Protein
structures of enzymes were obtained from the Protein Data Bank site. Enzymes used for
calculations are acetylcholinesterase (AChE) is PDB ID: 4M0E, α-glycosidase (α-Gly) is PDB
ID: 1R47, human carbonic anhydrase isoenzyme (hCA I) is PDB ID: 3LXE is human Carbonic
anhydrase isoenzyme II (hCA II) is PDB ID: 5 AML. In molecular docking calculations of
methoxyphenol derivatives with enzymes, all calculations were made in the pH 7.0 ± 2.0 range.
In order to interact with these enzymes with methoxyphenol derivatives, preparation was done
with enzyme protein preparation module [35,36]. Using this module, all the water molecules in
the crystal structure of the enzyme were removed. Again, using this module, the binding
methods and loads of proteins in the structure of the enzyme were optimized. The active site of
proteins was determined. The proteins in the active region were given mobility during
interaction. After this process, the molecular structures of the studied methoxyphenol
derivatives were drawn using the Gaussian software program [37]. After the molecules drawn,
the LigPrep module [38,39] was used for molecular docking calculations. In this module, 3D
structures of methoxyphenol derivatives, correct protonation state in physiological pH and
molecular geometries of the methoxyphenol derivatives were obtained. After the
methoxyphenol derivatives were prepared, calculations were made using the Glide ligand-
docking module [40] for molecular docking calculations of enzymes with the studied
methoxyphenol derivatives. After calculating the biological activities of molecules against
enzymes, the drug properties of methoxyphenol derivatives will be examined. ADME
(Absorption, distribution, metabolism, excretion, and toxicity) analysis is performed to examine
the drug properties of the methoxyphenol derivatives studied. To make this analysis, the Qik-
prop module [41] of Schrödinger software is used. This module provides a lot of information
about the conditions of a molecule to become a drug. Many parameters are calculated with the
Qik-prop module. A few of these parameters are molecular weight, QP log p
accptHB, rule of five, and rule of three, etc. [42,43].
donorHB,
o/w

3. RESULTS AND DISCUSSION
3.1.Chemistry
In our previous studies oxypropanol amine derivatives starting with natural phenolic
compounds such as eugenol [16], thymol [44] and carvacrol [22] were synthesized and a
number of their biological properties were investigated. As a result, it has demonstrated that
they show superior some antibacterial and inhibitor properties when compared to existing
drugs. In this study, unlike the previous ones, 7 new propanol amine derivatives were
investigated by advancing the reaction through the double bond of eugenol. At the end of the
literature studies for the synthesis of target compounds, the synthesis of propanol amines with
a nucleophilic attack of amines on epoxide was found appropriate. Among the methods used to
convert the double bond in the eugenol to the oxirane ring, the method with m-CPBA was
preferred [45]. This is because it provides high yield (95%), and besides, the resulting benzoic
acid by-product is easily separated from the medium by filtration and no additional purification
is required to clean the target product 1. In the second step, it is aimed to open the oxirane ring
with different amine compounds. In order to perform the synthesis of α-propanol amine
compounds, a reaction method to be performed in basic environment has been determined
considering the reaction mechanism [16]. In order to determine the scope of the study, the amine
derivatives were selected from existing in different drug structures and having different
properties. It was selected from amine groups consisting of primary (n-butyl amine, isopropyl
amine), secondary (diethylamine), straight chain (n-butyl amine), branched (isopropyl amine,
tert-butylamine), including an unsaturation bond (ally amine), having steric hindrance (tert-
butyl amine, diethylamine), aromatic cycle (aniline) and different functional group (3-
dimethylaminopropylamine).
Different methods such as column chromatography, crystallization, precipitation and
washing with solvents have been tried to purify the target products from the crude products.
When DCM is added to the substance obtained from the reaction with allyl amine, the product
(2e) collapses and easily separated by filtration. Unfortunately, purification with such a simple
process for other products has not been possible. For this reason, compound 2e (81%) was
obtained with the highest yield among other products. The product of 2f obtained in the
synthesis with aniline was successfully purified by column chromatography (70%). However,

column chromatography could not be applied for other substances. This is because these
compounds degrade in column conditions in a short time. The reason for not occurring of
degrading of 2f is that delocalization of unpaired electrons in the nitrogen with the ring increases
the stability and makes the compound more stable in acidic or basic conditions. Synthesis of
the product made with isopropyl amine (2e) was purified (58%) by rapid passing of hexane,
ether, DKM and MeOH solvents respectively, over very little silica gel pad prepared in a 150
mm glass micropipette. Among the methods tested to purify of other compounds precipitation
with different solvents was successful. Thus, the synthesis of target compounds was carried out
in 54-81% yields. The structures of the compounds are clarified with 1H NMR, 13C NMR and
FT-IR. Inhibition effects of the synthesized compounds on acetylcholinesterase (AChE), α-
glycosidase (α-Gly), human carbonic anhydrase I (hCA I), and human carbonic anhydrase II
(hCA II) enzymes were investigated.
3.2.Biochemistry results
3.2.1. hCA I and II isoenzymes inhibition results
The strong CA inhibitors acetazolamide (AZA) and methazolamide have been used clinically
as weak diuretic factors, in the prevention of altitude sickness and therapy of glaucoma [46–
48]. The results presented in Table 1 and indicate that novel propanolamine derivatives attached
to 2-metoxifenol moiety (2a-g) had effective inhibition profile against hCA I isoform. The hCA
I isoform was inhibited by these novel propanolamine derivatives attached to 2-metoxifenol
moiety (2a-g) in low micromolar levels, the Ki of which differed between 9.68±1.32 and
33.78±6.08 µM. Indeed, acetazolamide (AZA) as a broad-specificity CA inhibitor showed Ki
value of 57.64±5.41 µM against hCA I. Among the inhibitors, the 2f and 2g were obtained to
be the excellent hCA I inhibitor with Ki of 9.68±1.32 and 16.06±3.77 µM, respectively. The
hCA I inhibition effects of novel propanolamine derivatives attached to 2-metoxifenol moiety
(2a-g) were found to be the greater than that of acetazolamide. For hCA I, IC50 values of AZA
as positive control and some novel propanolamine derivatives attached to 2-metoxifenol moiety
(2a-g); the following order: 2f (7.37 µM, r2: 0.9562) < 2g (12.37 µM, r2: 0.9611) < 2a (13.65
µM, r2: 0.9384) < 2b (17.26 µM, r2: 0.9889) < AZA (45.46 µM, r2: 0.9585). CA Inhibitor (CAI)
compounds of several human isozymes have found clinical applications for the management of
diseases like ocular hypertension in epilepsy; obesity, glaucoma, hypoxic cancers and recently
they were proved beneficial in neuropathic pain too. The major hurdle in CAI development and
design is related to the isozyme selectivity issue, which thrived to novel chemotypes [44,49–

51]. Against the physiologically dominant isoform hCA II, the novel propanolamine derivatives
attached to 2-metoxifenol moiety (2a-g) demonstrated Kis varying from 11.46±2.64 to
26.86±5.08 µM (Table 1). These novel propanolamine derivatives attached to 2-metoxifenol
moiety (2a-g) were observed to have high inhibition effects toward hCA II. Also, control AZA
showed Ki of 79.75±8.34 µM against hCA II. The 2f and 2a had shown the most inhibition
effect with Ki values of 11.46±2.64 and 14.74±4.11 µM, respectively. For hCA II, IC50 values
of AZA as control and other compounds synthesized in this study; the following order: 2f (8.26
µM, r2: 0.9361) < 2a (10.25 µM, r2: 0.9838) < 2g (10.53 µM, r2: 0.9836) < 2b (14.38 µM, r2:
0.9683) < AZA (60.33 µM, r2: 0.9364).
3.2.2. AChE inhibition results
To date, many AChE inhibitor compounds have been approved for the therapy of AD, like
rivastigmine, donepezil, huperzine-A, physostigmine, galantamine, tacrine, and these drugs are
capable to prevent the degradation of ACh and also increase its level in the cholinergic
synapses, which can improve cognitive deficits [52–55]. Thus, the adverse effects like
vomiting, bradycardia, nausea, and weight loss have limited their clinical efficacy. In this case,
it is necessary to develop new AChE inhibitor compounds with a better therapeutic effect and
less toxic side effects. Recently, there is a major interest in the extension of selective AChE
inhibitors [56–58]. All of novel propanolamine derivatives attached to 2-metoxifenol moiety
(2a-g) had significantly higher AChE inhibitory activity than that of standard AChE inhibitors
such as Tacrine. Furthermore, the Ki values of novel propanolamine derivatives attached to 2-
metoxifenol moiety (2a-g) and tacrine are summarized in Table 1. As can be seen from the
results obtained in Table 1, these novel propanolamine derivatives attached to 2-metoxifenol
moiety (2a-g) effectively inhibited AChE, with Ki values in the range of 62.08±11.67 to
123.76±22.06 µM. However, all of these novel molecules (2a-g) had almost similar inhibition
profiles. The most active 2b showed Ki values of 62.08±11.67 µM. For AChE, IC50 values of
TAC as TAC and other compounds were studied in this study the following order: 2b (90.33
µM, r2: 0.9208) < 2f (103.25 µM, r2: 0.9627) < 2e (111.84 µM, r2: 0.9370) < 2c (113.47 µM,
r2: 0.9835) < TAC (198.24 µM, r2: 0.9077). Recently, the development of new AChE inhibitors
has become the focus of research.
3.2.3. α-Glycosidase inhibition results

α-Glycosidase inhibition helps to slowly release monosaccharide molecules after food. In
T2DM, postprandial blood sugar is caused by insulin resistance [59,60]. α-Glycosidase
inhibitors are used as therapeutic drugs to control post-meal blood sugar conditions. Many
organisms naturally produce α-glycosidase inhibitors, and several inhibitors have been reported
so far, some of which have previously been used for therapeutic purposes [61]. For enzyme
glycosidase, novel propanolamine derivatives attached to 2-metoxifenol moiety (2a-g) have
IC50 values in the range of 0.28-2.34 µM and Ki in the range of 0.33±0.08-2.55±0.28 µM (Table
1). The results have clearly documented that all of these novel propanolamine derivatives
attached to 2-metoxifenol moiety (2a-g) have shown the inhibitory effects of α-glycosidase
efficient acarbose (IC50: 5.44 µM) as a standard glycosidase inhibitor. In fact, the most effective
Ki values of 2c and 2f were with Ki values of 0.33±0.08 and 1.03±0.10 µM, respectively. For
α-glycosidase, IC50 values of ACR as positive control and some novel propanolamine
derivatives attached to 2-metoxifenol moiety (2a-g) the following order: 2c (0.28 µM, r2:
0.9034) < 2f (0.84 µM, r2: 0.9731) < 2a (0.95 µM, r2: 0.9343) < ACR (5.44 nM).
Table 1
Molecular Docking results
In this study, the interaction of the methoxyphenol derivatives with the proteins of the enzymes
was examined and the biological activity values of the molecules were compared [22]. As a
result of the calculations, using the numerical values of the obtained parameters have been made
a comparison. Many parameters are obtained, among which the most important parameter is
the docking score [23–25]. The numerical value of this parameter is the highest, the biological
activity value of the negative molecule. Therefore, biological activity can be ordered according
to the numerical value of this parameter. Many parameters other than this parameter are
obtained from docking calculations, but these parameters are used to explain the interactions of
molecules with enzymes. The interactions of methoxyphenol derivatives with enzymes in this
study are given in Figure 1, 2, 3, and 4. Some parameters obtained from these interactions of
methoxyphenol derivatives with enzymes are given in Table 2.
Table 2 and Figure 1, 2, 3, and 4
Many parameters are obtained from interactions of studied methoxyphenol derivatives
with enzymes. Among these, the most important parameter for molecular docking calculations
is Docking Score. Molecules with the highest biological activity value according to the

numerical value of this parameter; It is the 2b molecule for AChE and α-Gly enzymes, the
compound 2f for hCA I and hCA II isoenzymes in Figure 5.
Figure 5
The interactions of molecules with enzymes are very important because, as the
interaction of molecules with enzymes increases, the biological activities of molecules increase
[62–64]. After molecular docking calculations of the biological activities of the molecules, the
ability of these molecules to be advanced drugs was investigated. As a result of the calculations
in the Qik-prop module for this study, many parameters were obtained. These parameters give
information about the possibility of molecules to be drugs [23].
ADME properties of molecules were examined with the parameters obtained as a result
of calculations. Many parameters of the molecules are examined and these parameters are given
in the supplementary file Table S1. The parameter given in the Table S1 gives a lot of
information about molecules. The parameter range for the parameters given in Table S1. It is
believed that if the parameters obtained were in this range, these molecules met the condition
of being a drug. These parameters include a parameter known as the 5 rules of Pfizer, but also
used as the 5 rules of Lipinski in molecular docking [24]. In this rule, the number of hydrogen
bonding atoms in the molecule will not be more than 5 (nitrogen and oxygen atoms for one or
more hydrogen atoms attached to it). However, the number of atoms accepting hydrogen bonds
in the molecule will not exceed 10 (number of nitrogen and oxygen atoms). In addition, its
molecular weight should be below 500 Da and the lipophilicity coefficient (log p) should be
below 5. Small molecules that follow these rules are thought to have potential to become drugs.
Another parameter is Solute as Donor-Hydrogen Bonds, which is estimated number of
hydrogen bonds that would be donated by the solute to water molecules in an aqueous solution
[25]. Another parameter is Solute as Acceptor-Hyrogen Bonds, which is estimated number of
hydrogen bonds that would be accepted by the solute from water molecules in an aqueous
solution [23]. The properties of a parameter molecule such as drug molecule are examined.
Given the parameters in Table 2, the biological activity of the compound 2f for hCA I, and hCA
II isoenzymes was high, but the numerical values of Apparent Caco-2 Permeability (nm / sec)
and Apparent MDCK Permeability (nm / sec) were above normal.
4. CONCLUSIONS

In conclusion, synthesis of novel propanolamine derivatives attached to 2-metoxifenol moiety
(2a-g) were reported, which designed to target inhibitor against hCA I, and hCA II isoenzymes
and AChE, and α-glycosidase enzymes. All of the compounds have showed significant sub-
micromolar inhibition towards all metabolic enzymes. Especially compound 2f for cytosolic
hCA I, and II isoenzymes, compound 2b for AChE cholinergic enzyme and 2c for α-glycosidase
enzyme. Theoretical study results obtained from molecular docking studies have support
experimental study results. The results may useful for designing and synthesizing of novel
metabolic enzyme inhibitors, which had further potential lead candidates for the design of novel
drugs to treat some diseases including glaucoma, epilepsy, AD, leukemia, and T2DM in the
future.
References
[1] Pharmacologically Active Drug Metabolites: Impact on Drug Discovery and
Pharmacotherapy
|
Pharmacological
Reviews,
(n.d.).
http://pharmrev.aspetjournals.org/content/65/2/578.short (accessed March 4, 2020).
[2] M. Lahlou, The Success of Natural Products in Drug Discovery, Pharmacology &amp;
Pharmacy. 4 (2013) 17–31. https://doi.org/10.4236/pp.2013.43A003.
[3] J.S. Lazo, L.S. Brady, R. Dingledine, Building a Pharmacological Lexicon: Small
Molecule Discovery in Academia, Mol Pharmacol. 72 (2007) 1–7.
https://doi.org/10.1124/mol.107.035113.
[4] G.D.J. Davis, A.H.R. Vasanthi, Seaweed metabolite database (SWMD): A database of
natural compounds from marine algae, Bioinformation. 5 (2011) 361–364.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3053594/ (accessed March 4, 2020).
[5] P. O’Brien, Sharpless Asymmetric Aminohydroxylation: Scope, Limitations, and Use in
Synthesis, Angewandte Chemie International Edition. 38 (1999) 326–329.
https://doi.org/10.1002/(SICI)1521-3773(19990201)38:3<326::AID-
ANIE326>3.0.CO;2-T.
[6] G. Li, H.-T. Chang, K.B. Sharpless, Catalytic Asymmetric Aminohydroxylation (AA) of
Olefins, Angewandte Chemie International Edition in English. 35 (1996) 451–454.
https://doi.org/10.1002/anie.199604511.
[7] P. Gupta, A. Rouf, B.A. Shah, D. Mukherjee, S.C. Taneja, Efficient Preparation of
Biologically Important 1,2-Amino Alcohols, Synthetic Communications. 43 (2013) 505–
519. https://doi.org/10.1080/00397911.2011.603876.
[8] Efficient Synthesis of β‐Amino Alcohols Catalyzed by Niobium Pentachloride:
Regioselective Ring Opening of Epoxides with Aromatic Amines: Synthetic
Communications:
Vol
36,
No
21,
(n.d.).
https://www.tandfonline.com/doi/full/10.1080/00397910600908884 (accessed March 9,
2020).
[9] T. Sehl, Z. Maugeri, D. Rother, Multi-step synthesis strategies towards 1,2-amino alcohols
with special emphasis on phenylpropanolamines, Journal of Molecular Catalysis B:
Enzymatic. 114 (2015) 65–71. https://doi.org/10.1016/j.molcatb.2014.12.005.

[10] A. Marchese, R. Barbieri, E. Coppo, I.E. Orhan, M. Daglia, S.F. Nabavi, M. Izadi, M.
Abdollahi, S.M. Nabavi, M. Ajami, Antimicrobial activity of eugenol and essential oils
containing eugenol: A mechanistic viewpoint, Critical Reviews in Microbiology. 43
(2017) 668–689. https://doi.org/10.1080/1040841X.2017.1295225.
[11] H.A. Bartels, The effect of eugenol and oil of cloves on the growth of microorganisms,
American Journal of Orthodontics and Oral Surgery. 33 (1947) B458–B465.
https://doi.org/10.1016/S0096-6347(47)90017-3.
[12] F. Erdemir, D.B. Celepci, A. Aktaş, Y. Gök, R. Kaya, P. Taslimi, Y. Demir, İ. Gulçin,
Novel 2-aminopyridine liganded Pd(II) N-heterocyclic carbene complexes: Synthesis,
characterization, crystal structure and bioactivity properties, Bioorganic Chemistry. 91
(2019) 103134. https://doi.org/10.1016/j.bioorg.2019.103134.
[13] P. Taslimi, F.M. Kandemir, Y. Demir, M. İleritürk, Y. Temel, C. Caglayan, İ. Gulçin, The
antidiabetic and anticholinergic effects of chrysin on cyclophosphamide-induced multiple
organ toxicity in rats: Pharmacological evaluation of some metabolic enzyme activities,
Journal of Biochemical and Molecular Toxicology. 33 (2019) e22313.
https://doi.org/10.1002/jbt.22313.
[14] M. Boztas, P. Taslimi, M.A. Yavari, I. Gulcin, E. Sahin, A. Menzek, Synthesis and
biological evaluation of bromophenol derivatives with cyclopropyl moiety: Ring opening
of cyclopropane with monoester, Bioorganic Chemistry. 89 (2019) 103017.
https://doi.org/10.1016/j.bioorg.2019.103017.
[15] F. Turkan, A. Cetin, P. Taslimi, H.S. Karaman, İ. Gulçin, Synthesis, characterization,
molecular docking and biological activities of novel pyrazoline derivatives, Arch. Pharm.
(Weinheim). 352 (2019) e1800359. https://doi.org/10.1002/ardp.201800359.
[16] H. Genç Bilgiçli, A. Kestane, P. Taslimi, O. Karabay, A. Bytyqi-Damoni, M. Zengin, İ.
Gulçin, Novel eugenol bearing oxypropanolamines: Synthesis, characterization,
antibacterial, antidiabetic, and anticholinergic potentials, Bioorganic Chemistry. 88
(2019) 102931. https://doi.org/10.1016/j.bioorg.2019.102931.
[17] R. Kaya, P. Taslimi*, M.E.N. and İ. Gulçin, The Impacts of Some Sedative Drugs on α -
Glycosidase, Acetylcholinesterase and Butyrylcholinesterase Enzymes-potential Drugs
for Some Metabolic Diseases, Letters in Drug Design & Discovery. 16 (2019) 592–596.
http://www.eurekaselect.com/165585/article (accessed April 21, 2020).
[18] B. Tüzün, E. Saripinar, Molecular docking and 4D-QSAR model of methanone derivatives
by electron conformational-genetic algorithm method, Journal of the Iranian Chemical
Society. (2019). https://doi.org/10.1007/s13738-019-01835-8.
[19] S. Kaya, B. Tüzün, C. Kaya, I.B. Obot, Determination of corrosion inhibition effects of
amino acids: Quantum chemical and molecular dynamic simulation study, Journal of the
Taiwan
Institute
of
Chemical
Engineers.
58
(2016)
528–535.
https://doi.org/10.1016/j.jtice.2015.06.009.
[20] B. Tüzün, K. Sayin, Investigations over optical properties of boron complexes of
benzothiazolines, Spectrochimica Acta Part A: Molecular and Biomolecular
Spectroscopy. 208 (2019) 48–56. https://doi.org/10.1016/j.saa.2018.09.060.
[21] E. Güzel, A. Günsel, B. Tüzün, G.Y. Atmaca, A.T. Bilgiçli, A. Erdoğmuş, M.N. Yarasir,
Synthesis of tetra-substituted metallophthalocyanines: Spectral, structural, computational
studies and investigation of their photophysical and photochemical properties,
Polyhedron. 158 (2019) 316–324. https://doi.org/10.1016/j.poly.2018.10.072.
[22] A. Bytyqi-Damoni, A. Kestane, P. Taslimi, B. Tuzun, M. Zengin, H.G. Bilgicli, İ. Gulcin,
Novel carvacrol based new oxypropanolamine derivatives: Design, synthesis,
characterization, biological evaluation, and molecular docking studies, Journal of
Molecular Structure. (2019) 127297. https://doi.org/10.1016/j.molstruc.2019.127297.

[23] B.N. Sağlık, B. Kaya Çavuşoğlu, D. Osmaniye, S. Levent, U. Acar Çevik, S. Ilgın, Y.
Özkay, Z.A. Kaplancıklı, Y. Öztürk, In vitro and in silico evaluation of new thiazole
compounds as monoamine oxidase inhibitors, Bioorganic Chemistry. 85 (2019) 97–108.
https://doi.org/10.1016/j.bioorg.2018.12.019.
[24] A. Mermer, N. Demirbas, H. Uslu, A. Demirbas, S. Ceylan, Y. Sirin, Synthesis of novel
Schiff bases using green chemistry techniques; antimicrobial, antioxidant, antiurease
activity screening and molecular docking studies, Journal of Molecular Structure. 1181
(2019) 412–422. https://doi.org/10.1016/j.molstruc.2018.12.114.
[25] P. Singh, F. Bast, In silico molecular docking study of natural compounds on wild and
mutated epidermal growth factor receptor, Med Chem Res. 23 (2014) 5074–5085.
https://doi.org/10.1007/s00044-014-1090-1.
[26] J.A. Verpoorte, S. Mehta, J.T. Edsall, Esterase activities of human carbonic anhydrases B
and C, J. Biol. Chem. 242 (1967) 4221–4229.
[27] F. Turkan, A. Cetin, P. Taslimi, M. Karaman, İ. Gulçin, Synthesis, biological evaluation
and molecular docking of novel pyrazole derivatives as potent carbonic anhydrase and
acetylcholinesterase inhibitors, Bioorganic Chemistry. 86 (2019) 420–427.
https://doi.org/10.1016/j.bioorg.2019.02.013.
[28] G.L. Ellman, K.D. Courtney, V. Andres, R.M. Feather-Stone, A new and rapid
colorimetric determination of acetylcholinesterase activity, Biochem. Pharmacol. 7 (1961)
88–95. https://doi.org/10.1016/0006-2952(61)90145-9.
[29] K. Kucukoglu, H.I. Gul, P. Taslimi, I. Gulcin, C.T. Supuran, Investigation of inhibitory
properties of some hydrazone compounds on hCA I, hCA II and AChE enzymes, Bioorg.
Chem. 86 (2019) 316–321. https://doi.org/10.1016/j.bioorg.2019.02.008.
[30] B. Kuzu, M. Tan, P. Taslimi, İ. Gülçin, M. Taşpınar, N. Menges, Mono- or di-substituted
imidazole derivatives for inhibition of acetylcholine and butyrylcholine esterases, Bioorg.
Chem. 86 (2019) 187–196. https://doi.org/10.1016/j.bioorg.2019.01.044.
[31] Y. Tao, Y. Zhang, Y. Cheng, Y. Wang, Rapid screening and identification of α-
glucosidase inhibitors from mulberry leaves using enzyme-immobilized magnetic beads
coupled with HPLC/MS and NMR, Biomed. Chromatogr. 27 (2013) 148–155.
https://doi.org/10.1002/bmc.2761.
[32] Y. Demir, P. Taslimi, M.S. Ozaslan, N. Oztaskin, Y. Çetinkaya, İ. Gulçin, Ş. Beydemir,
S. Goksu, Antidiabetic potential: In vitro inhibition effects of bromophenol and
diarylmethanones derivatives on metabolic enzymes, Arch. Pharm. (Weinheim). 351
(2018) e1800263. https://doi.org/10.1002/ardp.201800263.
[33] M. Huseynova, P. Taslimi, A. Medjidov, V. Farzaliyev, M. Aliyeva, G. Gondolova, O.
Şahin, B. Yalçın, A. Sujayev, E.B. Orman, A.R. Özkaya, İ. Gulçin, Synthesis,
characterization, crystal structure, electrochemical studies and biological evaluation of
metal complexes with thiosemicarbazone of glyoxylic acid, Polyhedron. 155 (2018) 25–
33. https://doi.org/10.1016/j.poly.2018.08.026.
[34] Schrodinger, L., Small Molecule Drug Discovery Suite, 2017.
[35] R.A. Friesner, R.B. Murphy, M.P. Repasky, L.L. Frye, J.R. Greenwood, T.A. Halgren,
P.C. Sanschagrin, D.T. Mainz, Extra Precision Glide:ꢀ Docking and Scoring Incorporating
a Model of Hydrophobic Enclosure for Protein−Ligand Complexes, J. Med. Chem. 49
(2006) 6177–6196. https://doi.org/10.1021/jm051256o.
[36] Schrödinger Release 2019-4: Protein Preparation Wizard; Epik, Schrödinger, LLC, New
York, NY, 2016; Impact, Schrödinger, LLC, New York, NY, 2016; Prime, Schrödinger,
LLC, New York, NY, 2019., n.d.
[37] Frisch M.J., Trucks G.W., Schlegel H.B., Scuseria G.E., Robb M.A., Cheeseman J.R.,
Scalmani G., Barone V., Mennucci B., Petersson G.A., Nakatsuji H., Caricato M., Li X.,
Hratchian H.P., Izmaylov A.F., Bloino J., Zheng G., Sonnenberg J.L., Hada M., Ehara M.,

Toyota K., Fukuda R., Hasegawa J., Ishida M., Nakajima T., Honda Y., Kitao O., Nakai
H., Vreven T., Montgomery J.A., Peralta J.E., Ogliaro F., Bearpark M., Heyd J.J., Brothers
E., Kudin K.N., Staroverov V.N., Kobayashi R., Normand J., Raghavachari K., Rendell
A., Burant J.C., Iyengar S.S., Tomasi J., Cossi M., Rega N., Millam J.M., Klene M., Knox
J.E., Cross J.B., Bakken V., Adamo C., Jaramillo J., Gomperts R., Stratmann R.E., Yazyev
O., Austin A.J., Cammi R., Pomelli C., Ochterski J.W., Martin R.L., Morokuma K.,
Zakrzewski V.G., Voth G.A., Salvador P., Dannenberg J.J., Dapprich S., Daniels A.D.,
Farkas O., Foresman J.B., Ortiz J.V., Cioslowski J., Fox D.J. (2009) Gaussian, Inc.,
Wallingford, CT (2009), n.d.
[38] G.M. Sastry, M. Adzhigirey, T. Day, R. Annabhimoju, W. Sherman, Protein and ligand
preparation: parameters, protocols, and influence on virtual screening enrichments, J.
Comput. Aided Mol. Des. 27 (2013) 221–234. https://doi.org/10.1007/s10822-013-9644-
8.
[39] Schrödinger Release 2019-4: LigPrep, Schrödinger, LLC, New York, NY, 2019., n.d.
[40] Q. Du, Y. Qian, X. Yao, W. Xue, Elucidating the tight-binding mechanism of two oral
anticoagulants to factor Xa by using induced-fit docking and molecular dynamics
simulation, Journal of Biomolecular Structure and Dynamics. 38 (2020) 625–633.
https://doi.org/10.1080/07391102.2019.1583605.
[41] Schrödinger Release 2020-1: QikProp, Schrödinger, LLC, New York, NY, 2020, n.d.
[42] W.L. Jorgensen, E.M. Duffy, Prediction of drug solubility from structure, Adv. Drug
Deliv. Rev. 54 (2002) 355–366. https://doi.org/10.1016/s0169-409x(02)00008-x.
[43] K. Sayin, A. Üngördü, Investigations of structural, spectral and electronic properties of
enrofloxacin and boron complexes via quantum chemical calculation and molecular
docking, Spectrochim Acta A Mol Biomol Spectrosc. 220 (2019) 117102.
https://doi.org/10.1016/j.saa.2019.05.007.
[44] M. Zengin, H. Genc, P. Taslimi, A. Kestane, E. Guclu, A. Ogutlu, O. Karabay, İ. Gulçin,
Novel thymol bearing oxypropanolamine derivatives as potent some metabolic enzyme
inhibitors – Their antidiabetic, anticholinergic and antibacterial potentials, Bioorganic
Chemistry. 81 (2018) 119–126. https://doi.org/10.1016/j.bioorg.2018.08.003.
[45] E.M. Elgendy, S.A. Khayyat, Oxidation reactions of some natural volatile aromatic
compounds: anethole and eugenol, Russ J Org Chem. 44 (2008) 823–829.
https://doi.org/10.1134/S1070428008060079.
[46] C. Bayrak, P. Taslimi, H.S. Karaman, I. Gulcin, A. Menzek, The first synthesis, carbonic
anhydrase inhibition and anticholinergic activities of some bromophenol derivatives with
S
including natural products, Bioorganic Chemistry. 85 (2019) 128–139.
https://doi.org/10.1016/j.bioorg.2018.12.012.
[47] B. Yiğit, R. Kaya, P. Taslimi, Y. Işık, M. Karaman, M. Yiğit, İ. Özdemir, İ. Gulçin,
Imidazolinium chloride salts bearing wingtip groups: Synthesis, molecular docking and
metabolic enzymes inhibition, Journal of Molecular Structure. 1179 (2019) 709–718.
https://doi.org/10.1016/j.molstruc.2018.11.038.
[48] A. Biçer, P. Taslimi, G. Yakalı, I. Gülçin, M. Serdar Gültekin, G. Turgut Cin, Synthesis,
characterization, crystal structure of novel bis-thiomethylcyclohexanone derivatives and
their inhibitory properties against some metabolic enzymes, Bioorganic Chemistry. 82
(2019) 393–404. https://doi.org/10.1016/j.bioorg.2018.11.001.
[49] M. Huseynova, A. Medjidov, P. Taslimi, M. Aliyeva, Synthesis, characterization, crystal
structure of the coordination polymer Zn(II) with thiosemicarbazone of glyoxalic acid and
their inhibitory properties against some metabolic enzymes, Bioorganic Chemistry. 83
(2019) 55–62. https://doi.org/10.1016/j.bioorg.2018.10.012.
[50] S. Ökten, M. Ekiz, Ü.M. Koçyiğit, A. Tutar, İ. Çelik, M. Akkurt, F. Gökalp, P. Taslimi, İ.
Gülçin, Synthesis, characterization, crystal structures, theoretical calculations and

biological evaluations of novel substituted tacrine derivatives as cholinesterase and
carbonic anhydrase enzymes inhibitors, Journal of Molecular Structure. 1175 (2019) 906–
915. https://doi.org/10.1016/j.molstruc.2018.08.063.
[51] İ. Gulçin, P. Taslimi, Sulfonamide inhibitors: a patent review 2013-present, Expert Opin
Ther Pat. 28 (2018) 541–549. https://doi.org/10.1080/13543776.2018.1487400.
[52] P. Taslimi, İ. Gulçin, Antioxidant and anticholinergic properties of olivetol, Journal of
Food Biochemistry. 42 (2018) e12516. https://doi.org/10.1111/jfbc.12516.
[53] A. Akıncıoğlu, E. Kocaman, H. Akıncıoğlu, R.E. Salmas, S. Durdagi, İ. Gülçin, C.T.
Supuran, S. Göksu, The synthesis of novel sulfamides derived from β-
benzylphenethylamines as acetylcholinesterase, butyrylcholinesterase and carbonic
anhydrase
enzymes
inhibitors,
Bioorg.
Chem.
74
(2017)
238–250.
https://doi.org/10.1016/j.bioorg.2017.08.012.
[54] U. Atmaca, A. Yıldırım, P. Taslimi, S.T. Çelik, İ. Gülçin, C.T. Supuran, M. Çelik,
Intermolecular amination of allylic and benzylic alcohols leads to effective inhibitions of
acetylcholinesterase enzyme and carbonic anhydrase I and II isoenzymes, Journal of
Biochemical
and
Molecular
Toxicology.
32
(2018)
e22173.
https://doi.org/10.1002/jbt.22173.
[55] M. Tugrak, H. Inci Gul, 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
(2018)
433–439.
https://doi.org/10.1016/j.bioorg.2018.09.013.
[56] D. Ozmen Ozgun, H.I. Gul, C. Yamali, H. Sakagami, I. Gulcin, M. Sukuroglu, C.T.
Supuran, Synthesis and bioactivities of pyrazoline benzensulfonamides as carbonic
anhydrase and acetylcholinesterase inhibitors with low cytotoxicity, Bioorg. Chem. 84
(2019) 511–517. https://doi.org/10.1016/j.bioorg.2018.12.028.
[57] N. Öztaşkın, R. Kaya, A. Maraş, E. Şahin, İ. Gülcin, S. Göksu, Synthesis and
characterization of novel bromophenols: Determination of their anticholinergic,
antidiabetic and antioxidant activities, Bioorganic Chemistry. 87 (2019) 91–102.
https://doi.org/10.1016/j.bioorg.2019.03.010.
[58] M. Tugrak, H.I. Gul, K. Bandow, H. Sakagami, I. Gulcin, Y. Ozkay, C.T. Supuran,
Synthesis and biological evaluation of some new mono Mannich bases with piperazines
as possible anticancer agents and carbonic anhydrase inhibitors, Bioorganic Chemistry.
90 (2019) 103095. https://doi.org/10.1016/j.bioorg.2019.103095.
[59] P. Taslimi, H.E. Aslan, Y. Demir, N. Oztaskin, A. Maraş, İ. Gulçin, S. Beydemir, S.
Goksu, Diarylmethanon, bromophenol and diarylmethane compounds: Discovery of
potent aldose reductase, α-amylase and α-glycosidase inhibitors as new therapeutic
approach in diabetes and functional hyperglycemia, International Journal of Biological
Macromolecules. 119 (2018) 857–863. https://doi.org/10.1016/j.ijbiomac.2018.08.004.
[60] İ. Gulçin, P. Taslimi, A. Aygün, N. Sadeghian, E. Bastem, O.I. Kufrevioglu, F. Turkan, F.
Şen, Antidiabetic and antiparasitic potentials: Inhibition effects of some natural
antioxidant compounds on α-glycosidase, α-amylase and human glutathione S-transferase
enzymes,
Int.
J.
Biol.
Macromol.
119
(2018)
741–746.
https://doi.org/10.1016/j.ijbiomac.2018.08.001.
[61] P. Taslimi, İ. Gulçin, Antidiabetic potential: in vitro inhibition effects of some natural
phenolic compounds on α-glycosidase and α-amylase enzymes, J. Biochem. Mol. Toxicol.
31 (2017). https://doi.org/10.1002/jbt.21956.
[62] K. Sayin, D. Karakaş, Determination of structural, spectral, electronic and biological
properties of tosufloxacin boron complexes and investigation of substituent effect, Journal
of
Molecular
Structure.
1146
(2017)
191–197.
https://doi.org/10.1016/j.molstruc.2017.05.130.

[63] R. Jayarajan, R. Satheeshkumar, T. Kottha, S. Subbaramanian, K. Sayin, G. Vasuki, Water
mediated synthesis of 6-amino-5-cyano-2-oxo-N-(pyridin-2-yl)-4-(p-tolyl)-2H-[1,2’-
bipyridine]-3-carboxamide and 6-amino-5-cyano-4-(4-fluorophenyl)-2-oxo-N-(pyridin-
2-yl)-2H-[1,2’-bipyridine]-3-carboxamide - An experimental and computational studies
with non-linear optical (NLO) and molecular docking analyses, Spectrochim Acta A Mol
Biomol Spectrosc. 229 (2020) 117861. https://doi.org/10.1016/j.saa.2019.117861.
[64] A. Üngördü, K. Sayin, Quantum chemical calculations on sparfloxacin and boron
complexes,
Chemical
Physics
Letters.
733
(2019)
136677.
https://doi.org/10.1016/j.cplett.2019.136677.

Table 1. The enzyme inhibition results of novel compounds (2a-g) against human carbonic anhydrase isoenzymes I and II (hCA I and II),
acetylcholinesterase (AChE) and α-glycosidase (α-Gly) enzymes
IC50 (µM)
Ki (µM)
hCA II
Compounds
hCA I
r2
hCA II
r2
AChE
r2
α-Gly
r2
hCA I
AChE
α-Gly
2a
2b
13.65
17.26
20.34
19.26
28.51
7.37
12.37
45.46
-
0.9384
0.9889
0.9682
0.9581
0.9964
0.9562
0.9611
0.9422
-
10.25
14.38
16.06
14.88
22.35
8.26
10.53
60.33
-
0.9838
0.9683
0.9770
0.9604
0.9739
0.9361
0.9836
0.9364
-
125.04
90.33
113.47
155.38
111.84
103.05
134.87
-
0.9488
0.9208
0.9835
0.9598
0.9370
0.9627
0.9205
-
0.95
1.37
0.28
1.93
2.34
0.84
1.14
-
0.9343
0.9375
0.9034
0.9950
0.9623
0.9731
0.9698
-
16.34±4.74
21.45±2.06
26.44±6.57
22.67±5.71
33.78±6.08
9.68±1.32
16.06±3.77
57.64±5.41
-
14.74±4.11
17.08±3.66
20.36±1.87
18.45±7.28
26.86±5.08
11.46±2.64
15.82±4.88
79.75±8.34
-
111.45±23.45
62.08±11.67
74.34±16.94
123.76±22.06
87.46±10.77
78.08±15.83
103.37±9.63
-
1.14±0.13
1.83±0.23
0.33±0.08
2.34±0.40
2.55±0.28
1.03±0.10
1.47±0.22
-
2c
2d
2e
2f
2g
AZA*
TAC**
ACR***
198.24
-
0.9077
-
-
-
167.05±23.64
-
-
-
-
-
-
5.44
0.9642
-
-
7.45±1.04
*Acetazolamide (AZA) was used as a control for hCA I, and II isoenzymes.
**Tacrine (TAC) was used as a control for AChE enzyme.
***Acarbose (ACR) was used as a control for α-glycosidase enzyme.

Table 2. Numerical values of the parameters obtained from interaction of enzymes studied with
enzymes
2a
2b
2c
2d
2e
2f
2g
Docking Score
Glide hbond
-7.52
-0.14
-8.13
-0.31
-8.12
-0.43
-6.78
-0.46
-7.74
-0.37
-6.91
-0.41
-8.04
-0.53
AChE
α-Gly
Glide emodel
-62.97 -59.03 -71.13 -69.81 -68.81 -52.95 -89.52
Glide ligand efficiency
Docking Score
Glide hbond
-0.41
-4.94
-0.36
-0.45
-6.26
-0.65
-0.47
-5.62
-0.63
-0.37
-3.95
-0.33
-0.45
-5.89
-0.71
-0.34
-4.87
-0.57
-0.44
-4.10
-0.38
Glide emodel
-51.34 -51.30 -55.17 -50.64 -48.84 -38.69 -65.81
Glide ligand efficiency
Docking Score
Glide hbond
-0.27
-4.79
-0.50
-0.34
-4.89
-0.49
-0.33
-4.35
-0.47
-0.18
-2.63
0.00
-0.34
-5.13
-0.40
-0.24
-6.11
-0.45
-0.20
-2.44
-0.32
hCA I
hCA II
Glide emodel
-40.37 -41.08 -39.02 -32.21 -41.20 -48.05 -33.70
Glide ligand efficiency
Docking Score
Glide hbond
-0.26
-4.60
-0.23
-0.27
-4.00
0.00
-0.25
-4.09
0.00
-0.14
-2.71
-0.19
-0.30
-3.98
0.00
-0.30
-4.83
-0.29
-0.12
-2.57
0.00
Glide emodel
-39.76 -38.55 -37.66 -33.10 -38.37 -41.62 -37.08
-0.25 -0.22 -0.24 -0.15 -0.23 -0.24 -0.12
Glide ligand efficiency
* Apparent Caco-2 Permeability and Apparent MDCK Permeability are <25 poor and >500 great

Figure 1. Demonstration of the interaction of α-Gly enzymes with 2b
Figure 2. Demonstration of the interaction of hCA I enzymes with 2f

Figure 3. Demonstration of the interaction of AChE enzymes with 2b
Figure 4. Demonstration of the interaction of hCA II enzymes with 2f

Figure 5. Demonstration of the interaction of 1A (AChE enzymes with 2b), 1B (α-Gly
enzymes with 2b), 1C (hCA I isoenzymes with 2f), and 1D (hCA II isoenzymes with 2f)

H
N
R2
R1
m-CPBA
CHCI3
R2
N
O
Na2CO3
OH R1
HO
80 oC
24 h
HO
HO
rt
24 h
OCH3
OCH3
OCH3
1
2a-g
Scheme 1. General synthesis of new 2-metoxifenol propanolamine derivatives

m-CPBA
CHCI3
O
HO
HO
80 oC
24 h
OCH3
OCH3
1
Scheme 2. Synthesis of 2-methoxy-4-(oxiran-2-ylmethyl)phenol

R2
R2
N
Na2CO3
O
OH R1
+
HN
HO
OH
HO
R1
24 h
rt
OCH3
OCH3
1
2a-g
N
N
N
H
N
H
OH
OCH3
OH
OCH3
H
HO
OH
HO
HO
HO
OCH3
OCH3
2a
2b
2c
2d
N
N
N
N
H
OH
OCH3
H
OH
OCH3
HO
H
OH
OCH3
2f
HO
HO
2e
2g
Scheme 3. Synthesis of hydroxypropyl amine derivatives (2a-g)

Highlights
• A series of seven new ß-amino alcohol derivatives were synthesized and characterized.
• They are effective inhibitors against α-glycosidase and AChE.
• The compounds also effectively inhibit hCA I and II isoenzymes.
• Experimental results were compared with molecular docking calculations.