JJC Volume 16, Number 1, 2021

JJC

Volume 16, Number 1, 2021

Pages 1-11

*Corresponding Author: Yaseen A. Al-Soud Email: [email protected]

Jordan Journal of Chemistry https://doi.org/10.47014/16.1.1

ARTICLE

Synthesis, Molecular Docking and Evaluation of

Hetaryl Fragment Tagged 1H-1,2,4-Triazole

Derivatives As Nematicidal Agents

Haitham H. Al-Sa’donia, Hamdoon A. Mohammed

b, Belal O.

Al-Najjarc,d

, Hossam H. Al-Suoda, Ala’a H. Al-Ahmad

a, Esra’a

Y. Al-Souda, Kafa’ A. S. Alhelal

a and Yaseen A. Al-Soud

a,*

a Department of Chemistry, Faculty of Science, Al al-Bayt University, Al-Mafraq, Jordan.

bDepartment of Medicinal Chemistry and Pharmacognosy, College of Pharmacy,

Qassim University, Buraydah, 51452, Kingdom of Saudi Arabia; and Department of

Pharmacognosy, Faculty of Pharmacy, Al-Azhar University, Cairo 11371, Egypt. cDepartment of Pharmaceutical Sciences, Al-Ahliyya Amman University, School of

Pharmacy, Amman, Jordan. dPharmacological & Diagnostic Research Centre, Faculty of Pharmacy, Al-Ahliyya

Amman University, Amman, Jordan.

Received on: 13th

Feb. 2021; Accepted on: 25th

April 2021

Abstract: New hetaryl fragment tagged 1H-1,2,4-triazole derivatives 7a-l were designed

and synthesized via Suzuki coupling between the bromo derivatives 4-6, which were used

as key intermediates for the synthesis of our targets and the appropriate boronic acid. The

structures of the newly synthesized compounds were unambiguously confirmed through

physico-chemical analysis (1H,

13C NMR and mass spectra). Six synthesized 1,2,4-triazole

derivatives were selected to evaluate the potential nematocidal effect and to analyze their

structure-activity relationships. Nematocidal activity of the compounds at (50, 100, 200,

300, 400 and 500 µM) was tested against Bursaphelenchus xylophilus nematode wherein

the best activity was recorded for compound 7e (52.1% ± 1.8 mortality at 100 µM). The

highest mortality rates of 88% and 55% were observed for 7e and 7h, respectively at 500

μM after exposure for 6 h. The molecular docking of compounds 7e, 7h and 7g has been

studied and its results revealed that the newly designed hetaryl fragment tagged 1H-1,2,4-

triazole derivatives bind to the hydrophobic pocket and polar contact with high affinity.

Keywords: Synthesis, 1,2,4-triazoles, Nematocidal effects, Molecular docking study.

Introduction

A large number of heterocyclic compounds

containing the 1,2,4-triazole ring are associated

with diverse pharmacological properties, such as

anticonvulsant, antifungal, antimicrobial, anti-

hypertensive, anti-cancer, analgesic, anti-HIV,

antiviral, anti-inflammatory and antioxidant

activities[1–15]

. Some compounds containing a

1,2,4-triazole ring are known as drugs; For

example, Ribavirin (antiviral)[16]

, Rizatriptan

(antimigraine)[17]

, Alprazolam (anxiolytic)[18]

,

Anastrozole (antitumoral), Vorozole and

Letrozole[19]

(Scheme 1).

Over the last ten years, our laboratory

prepared different compounds containing a

1,2,4-triazole skeleton and screened them for

their antitumor, antibacterial and anti-HIV

activities[20–26]

. Additionally, our laboratory

synthesized a series of bis(hydroxyphenyl)-1-

Al-Sa’doni et al.

2

methyl-1H-1,2,4-triazoles as nonsteroidal inhibi-

tors of 17-hydroxysteroid dehydrogenase type 1

(17-HSD1) [27,28]

.

Nematodes are well known as worm-like

invertebrates that are highly diverse in their

habitats. They may exist as free-living

nematodes, plant parasitic nematodes (phyto-

parasitic nematodes) and animal parasitic

nematodes (zooparasitic nematodes). These

parasitic species have been reported to cause a

tremendous destruction to a wide range of

organisms, including animals, microorganisms

and plants, such as common vegetables, fruits

and trees[29]

. As a result, there have been signifi-

cant damages to public health, economy and

environment worldwide. These reasons attracted

the attention of many investigators to look for

other solutions to reduce or eliminate these

parasitic nematode populations. It is important to

note that a wide variety of compounds from

various plant extracts have been shown to have

nematicidal activities in vitro and in soil,

including alkaloids, diterpenes, fatty acids,

glucosinolates, isothiocyanates, phenols, poly-

acetylenes, sesquiterpenes and thienyls[30–32]

.

Despite these efforts, most of these studies failed

to reveal and/or commercially develop efficient

natural nematicidal compounds using these

various plants extracts.

Furthermore, various synthetic compounds

with nematicidal activities have also been

synthesized and tested in vitro or in soil. These

include ethylene dibromide, 1,3-dichloropro-

pene, dibromochloropropane, organophosphates,

carbamates, dazomet, methyl isothiocyanate,

sodium tetrathiocarbonate, imidazothiazole,

tetrahydropyrimidines, levamisole, pyrante,

morantel, pyrimidine, piperazine, avermectins,

milbemycins, benzimidazoles, diethylcarbama-

zine and many others. The negative impacts of

various synthetic nematicidal compounds on the

environment have long been recognized, such as

groundwater contamination, atmospheric ozone

depletion and others[33,34]

. Moreover, worries

about human health safety have been centered on

the fears that the wide use of these nematicidal

compounds might cause human cancer, sterility

and other deleterious effects[35,36]

.

Figure 1. Drugs bearing 1.2.4-triazole ring used in medicine.

It is also worth to note that some of these

compounds are not suited as nematicides

because of lack of desirable properties, such as

solubility and mobility in soil, long-term

suppression of nematodes, low cost and others.

Thus, the uses of most of these compounds have

been prohibited or restricted due to their

undesirable properties. Thus, the search for

alternative or new effective nematicides to

replace some of these undesirable compounds is

still an ongoing effort and it is being driven by

the need for safe and environment- friendly

Synthesis, Molecular Docking and Evaluation of Hetaryl Fragment Tagged…

3

compounds with maximum efficacy. For this

purpose, we synthesized some novel hetaryl

fragment tagged 1H-1,2,4-triazole derivatives

using a microwave-assisted synthesis method

and their nematicidal properties were examined.

Materials and Methods

Starting materials were purchased from

Aldrich, Acros, Lancaster, Merck or Fluka and

were used without further purification.

Preparative thin-layer chromatography (TLC) on

1-mm SIL G-100 UV254 glass plates

(Macherey-Nagel) was prepared. The reaction

progress was monitored by TLC on Alugram SIL

G UV254 (Macherey-Nagel). Melting-points

were measured on a Mettler FP1 melting point

apparatus and uncorrected.

All new compounds were analyzed for C, H

and N and the observed results agreed with the

calculated percentages within ±0.4%. 1H and

13C-NMR spectra were recorded on a Bruker

DPX-500 instrument. Chemical shifts are given

in parts per million (ppm) and tetramethylsilane

(TMS) was used as internal standard for spectra

obtained in CDCl3. All coupling constants (J) are

given in Hertz. Mass spectra (ESI) were

measured on a TSQ Quantum (Thermo Electron

Corporation) instrument with an RP18 100-3

column (Macherey Nagel) and with

water/acetonitrile mixtures as eluents. All

microwave irradiation experiments were carried

out in a CEM-Discover monomode microwave

apparatus.

General Procedure for the Synthesis of

Compounds 4–6

A solution of acyl chloride (1 mol) in 10

mL dichloromethane was added dropwise to a

mixture of ethyl imino ester (1 mol) and

anhydrous triethylamine (1 mol) in 20 mL

dichloromethane at rt. The reaction mixture was

heated to 30-35 °C for 6 h. After cooling to rt,

the material was poured into a 3% sodium

hydrogen carbonate solution (25 mL). The layers

were separated and the organic layer was washed

with water, dried over sodium sulfate and

evaporated to dryness under reduced pressure.

The resulting N-acylimino esters 1-3 were heated

to 30-35°C with the methyl hydrazine (2 mol) in

dichloromethane for 4 h. The solvent was

removed under reduced pressure. The 1,2,4-

triazoles were purified by recrystallization using

CH2Cl2/Et2O.

5-(4-Bromophenyl)-3-phenyl-1-methyl-1H-1,2,4-

triazole (4)

White powder. Yield: 0.236 g (75%), mp 124-

126 °C (dec). 1H-NMR (500 MHz , CDCl3): 8.14

(d, J = 6.9 Hz, 2H), 7.92 (t, J = 1.8 Hz, 1H),

7.67–7.64 (m, 2H), 7.46-7.38 (m, 4H), 4.02 (s,

3H, NCH3). 13

C-NMR (125 MHz, CDCl3):

161.31, 154.11, 135.04, 134.96, 133.16, 131.77,

130.33, 129.27, 128.58, 127.20, 126.33, 122.97,

37.03(NCH3). MS (ESI): 315 [M + H]+. Anal.

Cacld. For C15H12BrN3: C, 57.34; H, 3.85; N,

13.37. Found: C, 57.52; H, 4.00; N, 13.54.

5-(4-Bromophenyl)-3-(3-methoxyphenyl)-1-

methyl-1H-1,2,4-triazole (5)[37]

5-(4-Bromophenyl)-3-(4-methoxyphenyl)-1-

methyl-1H-1,2,4-triazole (6)[37]

General Procedure for the Synthesis of

Compounds 7a–l

Boronic acid (0.75 mmol, 1 eq), 1,2,4-

triazolylbromide (1 eq) and tetrakis(triphenyl-

phosphane)palladium(0) (43 mg, 0.0375 mmol, 5

mol %) were suspended in 1.5 mL DMF in a 10

mL septum-capped tube containing a stirring

magnet. To this, a solution of NaHCO3 (189 mg,

2.25 mmol, 3 equivalents) in 1.5 mL water was

added; the vial was sealed with a Teflon cap.

The mixture was irradiated with microwaves for

15 min at a temperature of 150 °C with an initial

irradiation power of 100 W. The vial was then

cooled to 40 °C, the crude mixture was

partitioned between ethyl acetate and water and

the aqueous layer was extracted three times with

ethyl acetate. The combined organic layers were

dried over magnesium sulfate, filtered and

concentrated to dryness. The coupling products

were obtained after purification by preparative

TLC.

1-Methyl-3-phenyl-5-[4-(3-thienyl)phenyl]-1H-

1,2,4-triazole (7a)

White powder. Yield: 0.228 g (72%), mp 177–

179 °C (dec). 1H-NMR (500 MHz , CDCl3): 8.18

(d, J = 7.0 Hz, 2H), 7.78-7.72 (m, 4H), 7.56-7.55

(m, 1H), 7.47–7.40 (m, 5H), 4.03 (s, 3H, NCH3). 13

C-NMR (125 MHz, CDCl3): 161.10, 155.26,

141.11, 137.35, 130.97, 129.16, 129.09, 128.71,

128.51, 126.64, 126.47, 126.29, 126.07, 121.33,

37.02 (NCH3). MS (ESI): 318 [M + H]+. Anal.

Cacld. For C19H15N3S: C, 71.90; H, 4.76; N,

13.24. Found: C, 71.64; H, 4.85; N, 13.48.

Al-Sa’doni et al.

4

5-[4-(1-Benzothien-2-yl)phenyl]-1-methyl-3-

phenyl-1H-1,2,4-triazole (7b)


181 °C (dec). 1H-NMR (500 MHz, CDCl3): 8.17

(t, J = 1.5 Hz, 1H), 8.16 (t, J = 1.5 Hz, 1H),

7.87–7.65 (m, 4H), 7.55–7.49 (m, 4H), 7.47–

7.26 (m, 4H), 4.01 (s, 3H, NCH3). 13

C-NMR

(125 MHz, CDCl3): 161.12, 155.59, 154.99,

142.77, 140.50, 139.67, 135.91, 130.98, 129.24,

129.08, 128.81, 128.72, 127.52, 126.66, 124.79,

123.81, 122.29, 120.55, 36.90 (NCH3). MS

(ESI): 368 [M + H]+. Anal. Cacld. For

C23H17N3S: C, 75.18; H, 4.66; N, 11.44. Found:

C, 75.34; H, 4.55; N, 11.63.

3-(3-Methoxyphenyl)-1-methyl-5-[4-(3-

thienyl)phenyl]-1H-1,2,4-triazole (7c)


147 °C (dec). 1H-NMR (500 MHz , CDCl3):

7.80–7.72 (m, 6H), 7.57–7.56 (m, 1H), 7.46–

7.43 (m, 2H), 7.36 (t, J = 7.9 Hz, 1H), 6.98–6.95

(m, 1H), 4.06 (s, 3H, NCH3), 3.90 (s, 3H,

OCH3). 13

C-NMR (125 MHz, CDCl3): 160.97,

159.89, 155.25, 141.17, 137.53, 132.17, 129.64,

129.27, 126.74, 126.71, 126.34, 126.13, 121.42,

118.89, 115.91, 110.91, 55.43 (OCH3), 37.12

(NCH3). MS (ESI): 348 [M + H]+. Anal. Cacld.

For C20H17N3OS: C, 69.14; H, 4.93; N, 12.09.

Found: C, 69.22; H, 5.14; N, 12.33.

5-[4-(1-Benzothien-2-yl)phenyl]-3-(3-

methoxyphenyl)-1-methyl-1H-1,2,4-triazole (7d)


137 °C (dec). 1H-NMR (500 MHz , CDCl3):

7.88–7.65 (m, 8H), 7.52–7.34 (m, 4H), 6.97 (dd,

J = 1.9 Hz, 1H), 4.07 (s, 3H, NCH3), 3.90 (s, 3H,

OCH3). 13

C-NMR (125 MHz, CDCl3): 159.90,

142.79, 140.54, 139.72, 136.04, 132.17, 129.66,

129.63, 129.33, 128.96, 128.88, 126.74, 124.84,

124.76, 123.85, 122.34, 120.62, 118.88, 115.90,

110.93, 55.43 (OCH3), 37.20 (NCH3). MS (ESI):

398 [M + H]+. Anal. Cacld. For C24H19N3OS: C,

72.52; H, 4.82; N, 10.57. Found: C, 72.70; H,

4.85; N, 10.80.

5-(4-(3-(3-Methoxyphenyl)-1-methyl-1H-1,2,4-

triazol-5-yl)phenyl)thiophene-2-carbaldehyde (7e)

White powder. Yield: 0.270 g (73 %), mp 95–98

°C (dec). 1

H-NMR (500 MHz, CDCl3): 7.76–

7.70 (m, 4H); 7.52–7.50 (m, 4H), 7.35 (t, J=7.90

Hz, 1H), 6.96–6.94 (m, 1H), 4.01 (s, 3H, NCH3),

3.88 (s, 3H, OCH3). 13

C-NMR (CDCl3, 125

MHz): 161.0, 159.8, 155.6, 132.3, 130.1, 129.6,

128.8, 128.7, 128.0, 118.8, 115.8, 110.8, 55.4

(OCH3), 36.9 (NCH3). MS (ESI): 376 [M + H]+.

Anal. Cacld. For C21H17N3O2S: C, 67.18; H,

4.56; N, 11.19. Found: C, 67.27; H, 4.74; N,

11.35.

5-(4-(Furan-3-yl)phenyl)-3-(3-methoxyphenyl)-

1-methyl-1H-1,2,4-triazole (7f)


174 °C (dec). 1

H-NMR (500 MHz, CDCl3):

7.82–7.71 (m, 5H), 7.63–7.51 (m, 3H), 7.37–

6.75 (m, 3H), 4.02 (s, 3H, NCH3), 3.89 (s, 3H,

OCH3). 13

C-NMR (125 MHz, CDCl3): 161.0,

159.8, 155.3, 144.0, 139.2, 134.2, 132.3, 129.6,

129.2, 128.8, 128.7, 126.1, 118.8, 115.7, 110.9,

108.6, 55.4 (OCH3), 37.0 (NCH3). MS (ESI):

332 [M + H]+. Anal. Cacld. For C20H17N3O2: C,

72.49; H, 5.17; N, 12.68. Found: C, 72.67; H,

5.22; N, 12.88.

2-Methoxy-5-(4-(3-(3-methoxyphenyl)-1-methyl-

1H-1,2,4-triazol-5-yl)phenyl)pyridine (7g)



(d, J= 8.45 Hz, 1H), 7.86–7.82 (m, 3H), 7.77–

7.68 (m, 4H), 7.36 (t, J= 7.87 Hz, 1H), 6.97–6.95

(m, 1H), 6.86 (d, J= 8.55 Hz, 1H), 4.06 (s, 3H,

OCH3-pyridine), 4.00 (s, 3H, NCH3), 3.89 (s,

3H, OCH3-phenyl). 13

C-NMR (125 MHz,

CDCl3): 163.8, 160.9, 159.6, 154.9, 144.9, 139.4,

137.1, 132.1, 129.4, 128.7, 126.7, 126.6, 118.6,

115.6,110.8, 110.6, 55.2 (OCH3-phenyl), 53.4

(O-CH3-pyridine), 36.8 (NCH3). MS (ESI): 373

[M + H]+. Anal. Cacld. For C22H20N4O2: C,

70.95; H, 5.41; N, 15.04. Found: C, 70.77; H,

5.53; N, 15.29.

3-(4-Methoxyphenyl)-1-methyl-5-[4-(3-

thienyl)phenyl]-1H-1,2,4-triazole (7h)


180 °C (dec). 1H-NMR (500 MHz, DMSO-d6):

8.04 (s, 1H), 7.98 (d, J = 8.7 Hz, 2H), 7.92 (d, J

= 8.3 Hz, 2H), 7.87 (d, J = 8.3 Hz, 2H), 7.70–

7.66 (m, 2H), 7.03 (d, J = 8.8 Hz, 2H), 4.02 (s,

3H, NCH3), 3.81 (s, 3H, OCH3), 13

C-NMR (125

MHz, DMSO-d6): 159.89, 159.47, 154.30,

140.37, 136.38, 129.03, 127.35, 127.10, 126.22,

126.13, 126.06, 123.43, 122.10, 114.02, 55.08

(OCH3), 37.04 (NCH3). MS (ESI): 348 [M +

H]+. Anal. Cacld. For C20H17N3OS: C, 69.14; H,

4.93; N, 12.09. Found: C, 69.33; H, 5.04; N,

12.28.

5-[4-(5-Chloro-2-thienyl)phenyl]-3-(4-methoxy-

phenyl)-1-methyl-1H-1,2,4-triazole (7i)


165 °C (dec). 1H-NMR (500 MHz, DMSO-d6):

8.08 (d, J = 8.8 Hz, 2H), 7.77-7.74 (m, 3H), 7.41


5

(d, J = 3.6 Hz, 2H), 7.35 (d, J = 4.2 Hz, 2H),

7.13-7.11 (m, 2H), 6.97 (d, J = 8.8 Hz, 2H), 4.03

(s, 3H, NCH3), 3.86 (s, 3H, OCH3). 13

C-NMR

(125 MHz, DMSO-d6): 165.95, 160.53, 154.93,

143.11, 136.05, 129.38, 128.37, 127.80, 126.08,

125.84, 125.66, 124.06, 123.56, 113.96, 55.29

(OCH3), 37.03 (NCH3). MS (ESI): 382 [M +

H]+. Anal. Cacld. For C20H16ClN3OS: C, 62.90;

H, 4.22; N, 11.00. Found: C, 63.03; H, 4.24; N,

11.28.

5-{4-[3-(4-Methoxyphenyl)-1-methyl-1H-1,2,4-

triazol-5-yl]phenyl}thiophene-2-carbonitrile (7j)

White powder Yield: 0.257 g (69%), mp 122–


(d, J = 8.8 Hz, 2H), 7.77–7.75 (m, 3H), 7.41 (d, J

= 3.6 Hz, 1H), 7.35 (d, J = 5.9 Hz, 1H), 7.13–

7.11 (m, 1H), 6.97 (d, J = 8.8 Hz, 2H), 4.03 (s,

3H, NCH3), 3.86 (s, 3H, OCH3). 13

C-NMR (125

MHz, CDCl3): 160.93, 160.49, 155.40, 130.08,

128.83, 128.78, 127.97, 127.77, 123.62, 113.93,

55.27 (OCH3), 36.86 (NCH3). MS (ESI): 373 [M

+ H]+. Anal. Cacld. For C21H16N4OS: C, 67.72;

H, 4.33; N, 15.04. Found: C, 67.53; H, 4.59; N,

15.25.

5-[4-(1-Benzothien-2-yl)phenyl]-3-(4-methox-

yphenyl)-1-methyl-1H-1,2,4-triazole (7k)



(d, J = 8.7 Hz, 2H), 7.87–7.80 (m, 6H), 7.65 (s,

1H), 7.52–7.33 (m, 2H), 6.98 (d, J = 8.7 Hz,

2H), 4.04 (s, 3H, NCH3), 3.86 (s, 3H, OCH3); 13

C-NMR (125 MHz, CDCl3): 161.03, 160.54,

154.80, 142.82, 140.53, 139.70, 136.95, 129.29,

127.80, 127.48, 126.69, 124.81, 124.73, 123.83,

123.57, 122.32, 120.57, 113.27, 55.29 (OCH3),

37.07 (NCH3). MS (ESI): 398 [M + H]+. Anal.

Cacld. For C24H19N3OS: C, 72.52; H, 4.82; N,

10.57. Found: C, 72.67; H, 4.94; N, 10.73.

5-[4-(1-Benzofuran-2-yl)phenyl]-3-(4-methox-

yphenyl)-1-methyl-1H-1,2,4-triazole (7l)

White powder. Yield: 0.259 g (68%), m.p. 225–


(d, J = 8.8 Hz, 2H), 8.05 (d, J = 8.3 Hz, 2H),

7.83 (d, J = 8.3 Hz, 2H), 7.61 (d, J = 7.5 Hz,

1H), 7.55 (d, J = 8.1 Hz, 1H), 7.33 (t, J = 8.2 Hz,

1H), 7.25 (t, J = 7.3 Hz, 1H), 7.14 (s, 1H), 6.98

(d, J = 8.8 Hz, 2H), 4.04 (s, 3H, NCH3), 3.86 (s,

3H, OCH3). 13

C-NMR (125 MHz, CDCl3):

161.34, 160.77, 155.33, 155.13, 154.96, 132.18,

129.39, 129.22, 128.02, 127.96, 125.37, 125.11,

123.89, 123.42, 121.41, 114.21, 111.53, 103.01,

55.53 (OCH3), 37.32 (NCH3). MS (ESI): 382 [M

+ H]+. Anal. Cacld. For C24H19N3O2: C, 75.57;

H, 5.02; N, 11.02. Found: C, 75.70; H, 5.18; N,

10.89.

Nematicidal Activity

Concentrations of compounds under

investigation were dissolved in bio grad DMSO

and prepared in serial dilution (50–500 µM) in

Millipore water, 900 µL of each concentration

(each concentration in quarter times) were

introduced into wells of CellStar TM

24-well

plates (TC., Germany). In each well, 100 µL of

nematodes solution were added. The concentra-

tion of nematodes was about 250 nematodes

(mixture of juvenile and adult nematodes

approximately 1:10) per 100 µL of water.

Positive controls received 1% H2O2 in Millipore

water instead of tested compounds and negative

control is only 1% of bio grad DMSO Millipore

water and nematodes. Treated and control

nematodes were softly shaken on a shaker plate

(Heidolph, type, Titramax-1000, 230/240 V,

50/60 Hz), under normal room conditions. The

mortality of adult and juvenile nematodes was

recorded after 6 h by microscope inspection.

Nematodes were defined dead if their body was

straight and they did not move, even after

mechanical prodding. All treatments were

replicated three times.

Molecular Docking Study

Molecular docking simulations were

performed on most potent compounds, 7e, 7g

and 7h, against acetylcholinesterase crystal

structure (PDB code: 1ODC[40]

). The compounds

have been drawn and saved as mol files by

ChemSketch software and then converted into

pdb files via Discovery Studio. Ligand files in

pdb format were minimized utilizing

Avogadro[41]

optimizing tool. Each compound

was opened separately, charges were added and

all hydrogen atoms were merged. Molecular

docking simulations of the compounds were

performed utilizing AutoDock 4.2. Kollman and

Gasteiger charges were added to both proteins

and plant compounds, respectively. A set of grid

maps were created using AutoGrid 4 (The

Scripps Research Institute, San Diego, CA,

USA). A grid box was then utilized to select

which area of the protein structure to be mapped.

The box size was set to 18.75 Å3. Lamarckian

genetic algorithm (LGA) was applied for energy

optimization and minimization during docking

Al-Sa’doni et al.

6

simulation. Moreover, molecular docking

simulation was performed on the co-crystallised

ligand (Structure Code: A8B) to validate the

docking parameters[39]

.

Results and Discussion

In the present paper, twelve new hetaryl

fragment tagged 1H-1,2,4-triazole derivatives

7a–l (Sheme 1) were prepared by a short, simple

reaction sequence as described in the experi-

mental section. Furthermore, the synthesized

compounds were tested for their potential

nematicidal activity.

The starting material compounds 5 and 6

were reported and synthesized previously by our

research group[37,38]

. Similarly, compound 4 was

prepared in 75% yield from the N-acylimino

ester 1 which was prepared by the reaction of

acyl chloride with ethyl imino ester. 1,2,4-

Triazoles 7a–l were prepared by Suzuki coupling

between the bromo derivatives 4–6 with the

appropriate boronic acids (thiophen-3-yl-,

benzo[b]thiophen-2-yl-, 5-formylthiophen-2-yl-,

furan-2-yl-, 6-methoxypyridin-3-yl-, 5-chloro-

thiophen-2-yl-, 5-cyano thiophen-2-yl- and

benzo[b]furan-2-yl-boronic acid) in the presence

of Pd(PPh3)4 as a catalyst to give 7a–l in 61–

81% yield (Scheme 1).

Scheme 1. Reagents and conditions: a. CH2Cl2, Et3N, 30–40 °C, 6 h; b. CH3NHNH2, CH2Cl2,

30–40 °C, 4 h; c. NaHCO3, Pd(Ph3)4, DMF, MWI, 15 min.

The structures of the newly synthesized

compounds (Scheme 2) were unambigously

confirmed through physico-chemical analysis

(1H,

13C NMR and mass spectra). The

1H-NMR

of compound 4 showed multiplets at δ 8.18–7.26

ppm, attributed to the phenyl groups. The CH3

protons at N(1) of the triazole ring appeared as a

singlet in the region of δ 4.07–4.00 ppm and the

methoxy protons in compounds 7c–l appeared as

a singlet in the region of δ 3.90-3.81 ppm.

Compounds 3 as well as 7a–l were characterized

by 13

C-NMR spectroscopy (Materials and

Methods).

Nematicidal Activity

The compounds 7e, 7g, 7h and 7j–l were

tested for their nematicidal activity against

Bursaphelenchus xylophilus at different concen-

trations (Table 1). The results obtained revealed

that the majority of the tested compounds were

not able to kill the nematodes, compared to the

negative control (1% DMSO). In addition,

reduction in the normal mortality rate of the

nematodes in the negative control (1 % DMSO)

group was recognized for several compounds at

certain concentrations; i.e., the 17.1% mortality

rate of the negative control was reduced by the

compounds 7j, 7k and 7l by 74.85%, 73.09%

and 72.51%,, respectively at 50 µM (Figure 2).

However, 7j, 7k and 7l demonstrated weak

nematicidal activity at higher concentration

showing mortality average of 36.4%, 25.7% and

24.1%, respectively, at 500 µM. The highest

mortality of the nematodes was recorded for 7e

which showed a dose-dependent nematicidal

activity starting by 42.1% at 50 µM and reaching

88.1% at 500 µM. Furthermore, moderate

nematicidal effect was observed for 7h which

showed only 55.4% mortality at 500 µM. The

results shown in Table 1 give an indication of the


7

potential of the thiophene ring and its derivatives

as well as the methoxylation of the benzene ring

in the nematicidal activity. With this respect, the

nematicidal effect was observed only for the

compounds containing substituents on the thio-

phene ring; i.e., for 7e with an aldehyde group

on the thiophene ring and 7j (at higher

concentrations) with a cyanide group on the

thiophene ring. On the other hand, the

unsubstituted ring showed no effect (7a).

Scheme 2. Chemical structure of synthesized compounds 7a–l.

Figure 2. Nematicidal activity of 7e, 7g, 7h and 7j-l.

0.0

10.0

20.0

30.0

40.0

50.0

60.0

70.0

80.0

90.0

100.0

500 400 300 200 100 50

% o

f M

ort

alit

y

Concentration in µM

7e 7g 7j 7l 7k 7h Control

Al-Sa’doni et al.

8

Table 1. Nematocidal activity of different concentrations of 1,2,4-triazole containing compounds

against Bursaphelenchus xylophilus after 6 h of exposure.

Compound Mortality rate ± SD at different concentrations

50 µM 100 µM 200 µM 300 µM 400 µM 500 µM

7e 42.1 ± 3.4 52.1 ± 1.8 59.4 ± 5.2 67.5 ± 3.4 67.7 ± 1.5 88.1 ± 7.1

7g 12.5 ± 2.9 19.5 ± 4.4 20.5 ± 2.5 26.6 ± 1.7 30.3 ± 1.6 37.7 ± 1.6

7h 14.1 ± 2.9 17.7 ± 4.7 31.6 ± 3.8 37.1 ± 1.7 45.0 ± 3.5 55.4 ± 4.0

7j 4.3 ± 1.6 5.6 ± 2.4 9.2 ± 1.8 15.1 ± 2.7 34.2 ± 2.7 36.4 ± 1.8

7k 4.6 ± 1.5 9.0 ± 2.4 8.8 ± 1.9 14.1 ± 0.8 20.6 ± 1.8 25.7 ± 2.0

7l 4.7 ± 1.9 4.4 ± 1.9 7.2 ± 4.1 13.9 ± 6.1 24.2 ± 5.0 24.1 ± 5.4

DMSO 17.1 ± 4.4

Molecular Docking

The co-crystallized ligand (A8B) was

successfully re-docked against 1ODC crystal

structure with an RMSD less than 2.0 Å, as

shown in Figure 3. Molecular docking

simulations that showed an RMSD values of less

than 2.0 Å are believed to have performed

effectively[39]

. Similar parameters were used to

dock plant constituents within the active site.

The compounds were successfully docked

against acetylcholinesterase enzyme and the

results are shown in Table 2. According to the

energy results, 7e, 7g and 7h showed the lowest

binding energies, with -10.76, -11.06 and -10.68

kcal/mol, respectively. The intermolecular

interactions against acetylcholinesterase enzyme

are illustrated in Table 2 and Figure 4.

Compounds 7e, 7g and 7h performed hydrogen

bond interactions with Arg289 amino acid. The

other residues that contribute to hydrogen bond

interactions were Ser124, Tyr121 and Phe288.

The redocked ligand showed lower binding

energy with -11.45 kcal/mol and performed two

hydrogen bond interactions within the binding

site with Tyr70 and His440, as shown in

Figure4.

Figure 3. Flat-ribbon representation of Acetylcholinesterase (PDB code: 1ODC) crystal

structure bound with the co-crystallised ligand (grey) and the re-docked conformation (green).

Table 2. The lowest binding energies obtained and the interacting amino acids.

Compound LBE*

(kcal/mol)

Interacting amino acids

by HBD**

7e -10.76 Ser124, Arg289

7g -11.06 Tyr121, Arg289

7h -10.68 Phe288, Arg289

Redocked ligand -11.45 Tyr70, His440

* Lowest Binding Energy **Hydrogen Bond Interactions


9

Figure 4. Stick representation of compounds 7e, 7g and 7h and redocked ligand in the active site.

Conclusion

Novel hetaryl fragment tagged 1H-1,2,4-

triazole derivatives 7a-l were synthesized via

Suzuki coupling. The nematocidal effects of 6

different concentrations (50, 100, 200, 300, 400

and 500 µM) of these compounds were tested

against the pine wood nematode, Bursaphelen-

chus xylophilus. The highest mortality of the

nematodes was recorded for 7e which showed

dose-dependent nematicidal activity starting by

42.1% at 50 µM and reaching 88.1% at 500 µM.

The nematicidal activity results suggest that the

compounds containing thiophene ring in addition

to the methoxylation of the benzene ring might

act as a promising nematicidal agent for further

structural modification. The docking study for

the compounds 7e, 7g and 7h showed that all

these compounds performed hydrogen bond

interactions with Arg289 amino acid. The

predicted results from the docking study can help

designing novel 1,2,4-triazoles containing thio-

phene ring as nematicidal agents.

Acknowledgments

Authors wish to thank the Scientific Research

Support Fund / Ministry of Higher Education,

Jordan (Grant No. Bas 1/1/2017) for providing

necessary facilities and funds for conducting this

research.

References

[1] Kaproń, B.; Czarnomysy, R.; Wysokiński,

M.; Andrys, R.; Musilek, K.; Angeli, A.;

Supuran, C. T.; Plech, T., J. Enzyme Inhib.

Med. Chem. 2020, 35, 993–1002.

[2] Gupta, D.; Jain, D. K., J. Adv. Pharm.

Technol. Res. 2015, 6, 141–146.

[3] Tan, C. X.; Shi, Y. X.; Weng, J. Q.; Liu, X.

H.; Li, B. J., Zhao, W.G., Lett. Drug Des.

Discov. 2012, 9, 431–435.

[4] Singh, R.; Kashaw, S. K.; Mishra, V. K.;

Mishra, M.; Rajoriya, V.; Kashaw, V.,

Indian J. Pharm. Sci. 2018, 80, 36–45.

[5] Thakur, A.; Gupta, P. S.; Shukla, P. K.;

Verma, A.; Pathak, P., J. Curr. Res. Acad.

Rev. 2016, 4, 277–296.

[6] Li, X.; Li, X. Q.; Liu, H. M.; Zhou, X. Z.;

Shao, Z. H., Org. Med. Chem. Lett. 2012, 2,

1–5.

7e

7g 7h

Redocked

ligand

Al-Sa’doni et al.

10

[7] De Clercq, E., J. Clin. Virol. 2004, 30, 115–

133.

[8] El-Reedy, A. A. M.; Soliman, N. K., Sci.

Rep. 2020, 10, 1–18.

[9] Paprocka, R.; Wiese, M.; Eljaszewicz, A.;

Helmin-Basa, A.; Gzella, A.;

Modzelewska-Banachiewicz, B.;

Michalkiewicz, J., Bioorg. Med. Chem.

Lett. 2015, 25, 2664–2671.

[10] Guan, L. P.; Sui, X.; Deng, X. Q.; Quan, Y.

C.; Quan, Z. S., Eur. J. Med. Chem. 2010,

45, 1746–1752.

[11] El-Sherief, H. A. M.; Youssif, B. G. M.;

Bukhari, S. N. A.; Abdel-Aziz, M.; Abdel-

Rahman, H. M., Bioorg. Chem. 2018, 76,

314–325.

[12] Shahzad, S. A.; Yar, M.; Khan, Z. A.;

Shahzadi, L.; Naqvi, S. A. R.; Mahmood,

A.; Ullaha, S.; Shaikh, A. J.; Sherazi, T. A.;

Bale, A.T.; Kukułowicz, J.; Bajda M.,

Bioorg. Chem. 2019, 85, 209–220.

[13] Yüksek, H.; Alkan, M.; Akmak, İ.; Ocak,

Z.; Bahçeci, Ş.; Calapoğlu, M.; Elmastaş,

M.; Kolomuç, A.; Aksu, H., Int. J. Mol. Sci.

2008, 9, 12–32.

[14] Cetin A.; Geçibesler I. H., J. Appl. Pharm.

Sci. 2015, 5, 120–126.

[15] Sun, L.; Tianguang, H. T.; Alexej, D. A.;

Megan, E.; Meuser, M. E.; Zalloum, W. A.;

Chen, C. H.; Ding, X.; Gao, P.; Cocklin, S.;

Lee, K. H.; Zhan, P.; Liu, X., Eur. J. Med.

Chem. 2020, 190, 12085.

[16] Cai, S.; Li, Q. S.; Borchardt. R. T.;

Kuczera. K.; Schowen R. L., Bioorg. Med.

Chem. 2007, 15, 7281–7287.

[17] Rao, B. M.; Sangaraju, S.; Srinivasu, M. K.;

Madhavan, P.; Devi, M. L.; Kumar, P. R.;

Candrasekhar, K. B.; Arpitha, Ch.; Balaji,

T. S., J. Pharm. Biomed. Anal. 2006, 4,

1146–1151.

[18] Hancu, G.; Gaspar, A.; Gyeresi, A., J.

Biochem. Biophys. Methods, 2007, 69, 251–

259.

[19] Bajetti, E.; Zilembo, N.; Bichisao, E.;

Pozzi, P.; Toffolatti, L., Crit. Rev. Oncol.

Hematol. 2000, 33, 137–142.

[20] Al-Soud, Y. A.; Al-Masoudi, N. A., Arch.

Pharm. Pharm. Med. Chem. 1999, 332,

143–144.

[21] Al-Soud, Y. A.; Al-Masoudi, N. A.,

Pharmazie, 2001, 5, 372–375.

[22] Al-Soud, Y. A.; Halah, R. F.; Al-Masoudi,

N. A., Org. Prepar. Proced. Intern. 2002,

34, 648–654.

[23] Al-Soud, Y. A.; Al-Masoudi, N. A.;

Ferwanah, A. S., Bioorg. Med. Chem. 2003,

11, 1701–1708.

[24] Al-Soud, Y. A.; Al-Masoudi, N. A., IL

Farmaco, 2004, 59, 41–46.

[25] Al-Soud, Y. A.; Al-Dweri, M. N.; Al-

Masoudi, N. A., IL Farmaco, 2004, 59,

775–783.

[26] Al-Sa’doni, H. H.; Delmani, F-AD.; Al

Balushi, A. M.; Al-Ahmad, A. H.;

Alsawakhneh, S. O.; Al-Soud, Y. A., Eur.

J. Chem. 2020, 11, 113–119.

[27] Bey, E.; Marchais-Oberwinkler, S.; Werth,

R., Negri; M., Al-Soud, Y. A.; Kruchten,

P.; Oster, A.; Frotscher, M.; Birk, B.;

Hartmann, R. W., J. Med. Chem. 2008, 5,

6725–6739.

[28] Al-Soud, Y. A.; Bey, E.; Oster; A.;

Marchais-Oberwinkler, S.; Werth, R.;

Kruchten, P.; Frotscher, M.; Hartmann,

R.W., Mol. Cell. Endocrinol. 2009, 301,

212–215.

[29] Almohithef, A. H.; Al-Yahya, F. A.; Al-

Hazmi, A. S.; Dawabah, A. A. M.; Lafi H.

A., J. Saudi Soc. Agric. Sci. 2020, 19, 22–

25.

[30] Oka, Y.; Nacar, S.; Putievsky, E.; Ravid,

U.; Yaniv, Z.; Spiegel, Y., Phytopathology,

2000, 90, 710–715.

[31] Chitwood, D. J., Annu. Rev. Phytopathol.

2002, 40, 221–249.

[32] Samoylenko, V.; Dunbar, D. C.; Gafur, M.

A.; Khan, S. I., Ross, S. A.; Mossa, J. S.;

El-Feraly, F. S.; Tekwani, B. L.;

Bosselaers, J.; Muhammad, I., Phytother.

Res. 2008, 22, 1570–1576.

[33] Noling J. W.; Becker J.O., J. Nematol.

1994, 26, 573–586.


11

[34] Alam, M. M.; Jairpuri, M.S., CBS

Publishers & Distributors, Delhi, India

1990, 5–5,

[35] Twomey, H. B.; Kaslow, N. J.; Croft, S.,

Psychoanal. Psychol. 2000, 17, 313–335.

[36] Aspelin, A. L.; Grube, A. H., Biological

and economic analysis division, office of

pesticide programs, office of prevention,

pesticides and toxic substances, US

environmental protection agency, 1999.

[37] Al-Soud, Y. A.; Mohammed, H. A.; Abo-

Amer, A., Jord. J. Chem. 2010, 5, 119–129.

[38] Al-Soud, Y. A.; Heydel, M.; Hartmann, R.

W., Tetrahedron Lett. 2011, 50, 6372–

6375.

[39] Hevener, K. E.; Zhao, W.; Ball, D. M.;

Babaoglu, K.; Qi, J.; White, S. W.; Lee, R.

E., J. Chem. Inf. Model. 2009, 49, 444–460.

[40] Rydberg, E. H.; Brumshtein, B.; Greenblatt,

H. M.; Wong, D. M.; Shaya, D.; Williams,

L. D.; Carlier, P. R.; Pang, Y. P.; Silman, I.;

Sussman, J. L., J. Med. Chem. 2006, 49,

5491–5500.

[41] Hanwell, M. D.; Curtis, D. E.; Lonie, D. C.;

Vandermeersch, T.; Zurek, E.; Hutchison

G. R., J. Cheminformatics 2012, 4, 17–17.

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