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0974-360X (Online)

RESEARCH ARTICLE

Design and Synthesis of Some Novel Schiff’s Base Aryl Imidazole Derivatives, Characterization, Docking and Study of their Anti-Microbial Activity

Dr. K. Girija*, B. Jamuna

Department of Pharmaceutical Chemistry, College of Pharmacy, Mother Theresa Post Graduate and Research Institute of Health Sciences,

(A Govt. of Puducherry Institution), Indira Nagar, Gorimedu, Puducherry-06, India.

*Corresponding Author E-mail: girijanarasimhan66@gmail.com

ABSTRACT:

A growing threat of resistance to antibiotics by various microorganisms, an attempt has been made to identify the potent Aryl imidazole derivatives for its antimicrobial activities. A series of Aryl imidazole derivatives were synthesized by the condensation of various primary aromatic amines with aromatic aldehyde to form respective schiff’s base which on further undergone reaction with ammonium acetate and Isatin in presence of glacial acetic acid to form the title compounds. The structures of the synthesized compounds were characterized by FT-IR, ¹H-NMR and ¹³C-NMR spectral studies. Based on AutoDock score, the potent aryl imidazole derivatives were selected for their Antimicrobial study. The screened compounds showed moderate to good antibacterial activity against Staphylococcus aureus, Bacillus cereus, E.coli, Salmonella typhi when compared to standard (Ciprofloxacin-30mcg/disc). In the antifungal study among the screened compounds, JG3 only showed moderate antifungal activity against Candida albicans when compared to standard (Clotrimazole-30mcg).

KEYWORDS: Aryl Imidazole, Schiffs base, Anti-bacterial, anti-fungal activity.

INTRODUCTION:

Imidazole has occupied a unique position in heterocyclic chemistry and its derivatives have attracted considerable interests in recent years for their versatile properties in chemistry and Pharmacology. Thus, imidazole compounds have been an interesting source for researchers for more than a century. Imidazole is nitrogen containing heterocyclic ring which possesses biological and pharmaceutical importance.

Received on 24.01.2015 Modified on 20.02.2015

Accepted on 25.02.2015 © RJPT All right reserved

Research J. Pharm. and Tech. 8(4): April, 2015; Page 407-415

DOI: 10.5958/0974-360X.2015.00069.4

The imidazole derivatives possess extensive spectrum of biological activities such as antibacterial, anticancer, antiprotozoal, antitubercular, antifungal, analgesic, anti-HIV^1-12 activities. Imidazole can be found in many other drugs such as Dacarbazine, Metronidazole¹³, Cimetidine¹⁴, Flumazenil, Thyroliberin, Methimazole, Pilocarpine and Etomidate which are used as Antineoplastic antibiotic, Antiulcerative, Benzodiazepine antagonist¹⁵, Prohormone, Anti-thyroid, Muscarinic receptor antagonist and Hypnotic agents respectively. In view of such reports, the present study involves the synthesis of substituted aryl imidazole derivatives via Schiff’s base and screened for its anti-microbial activity^18-30.

MATERIALS AND METHOD:

The chemicals employed in the studies were of analytical reagent grade. Melting points were determined using open capillary tubes and are uncorrected.

The structures of the synthesized compounds were recorded on Perkin-Elmer IR spectrometer 8400s using KBr disc. The ¹H-NMR and ¹³C-NMR Spectra were obtained on Bruker DRX-600MHz spectrometer using TMS as internal standard. Completion of the reaction and purity of the compounds were checked by TLC using Silica gel-G as stationary phase using chloroform and methanol (9:1) as mobile phase and the spot is visualized by UV- Chamber. The synthetic route for the title compounds were depicted in Scheme 1.

Scheme 1:

General Procedure for the Preparation of Aryl Imidazole Derivatives:

Equimolar amount (0.01M) of primary aromatic amine and aromatic aldehyde (0.01M) were transferred to 250ml RBF containing 15ml glacial acetic and refluxed for 5-6 hours. The reaction mixture was allowed to cool to give respective Schiff’s base. Isatin (0.01M) and ammonium acetate (0.1M) were transferred in to RBF containing the Schiff’s base (0.01M) and add glacial acetic acid. Then the reaction mixture was refluxed for about 12-15 hours. The completion of reaction was monitored through TLC by using Chloroform: Methanol. The reaction mixture was poured in to 250ml of cold water to remove ammonium acetate and glacial acetic acid and it was filtered and recrystallized with absolute alcohol.

JD1: 4-[2-(4-chlorophenyl)-3H,4H imidazo[4,5-b] indol-3-yl]-N(4,6 dimethylpyrimidine-2-yl) benzene-1-sulfonamide:

To the 250 ml Round bottom flask add 0.01M of Sulphadimidine, 0.01M of Para-Chlorobenzaldehyde and are refluxed for 5 to 6 hours in the presence of 15 ml glacial acetic acid. The reaction mixture was allowed to cool in order to form a respective Schiff’s base. The completion of the reaction was monitored by using TLC (Chloroform: Methanol).To the Schiff’s base add 0.01M of Isatin and 0.1M of Ammonium acetate in the presence of 15ml glacial acetic acid are refluxed for 12 to 15 hours. The reaction mixture was poured in 250ml of cold water to separate ammonium acetate and glacial acetic acid. The completion of the reaction was monitored by using TLC (Chloroform: Methanol).Then the crude product was recrystallized by using absolute alcohol. Elemental analysis calculated: C (61.30%), H (4.00%), Cl (6.70%), N (15.89%), O (6.05%), S (6.06%), IR (KBr): 3062 (N-H,Ar), 1578 (C-H), 1525 (C=N), 1404 (S=O,NH), 838 (C-Cl), ¹H-NMR δ (ppm): 6.9-7.5 (m,Ar-H), 3.37 (s,NH,H), 2.3 (Ar- methyl), 10.2 (IndoleNH), 6.0 (2-Pyrimidine CH), ¹³C-NMR δ (ppm): 112.582, 125.695, 127.168, 129.492, 129.514, 129.830, 130.364, 134.334, 134.804, 135.630, 153.437, 157.593, 163.746.

JG2: 1-({4-[2-(4-nitrophenyl)-3H, 4H-imidazo[4,5-b]indol-3-yl}benzene)sulfonyl] guanidine:

To the 250 ml Round bottom flask add 0.01M of Sulphaguanidine, 0.01M of Para-Chlorobenzaldehyde and are refluxed for 5 to 6 hours in the presence of 15 ml glacial acetic acid. The reaction mixture was allowed to cool in order to form a respective Schiff’s base. The completion of the reaction was monitored by using TLC (Chloroform: Methanol) To 0.01M of Schiff’s base add 0.01M Isatin and 0.1M of Ammonium acetate in the presence of 15ml glacial acetic acid are refluxed for 12 to 15 hours. The reaction mixture was poured in 250ml of cold water to separate ammonium acetate and glacial acetic acid. The completion of the reaction was monitored by using TLC (Chloroform: Methanol).Then the crude product was recrystallized by using absolute alcohol. Elemental analysis calculated: C (56.83%), H (3.69%), Cl (7.63%), N (18.08%), O (6.88%), S(6.90%), IR (KBr): 3411 (N-H, Ar), 3340 (N-H str), 2319 (C-H), 1602 (C=N), 1332 (S=O,NH), 821 (C-Cl), ¹H-NMR δ (ppm): 6.5-8 (m, Ar-H), 2.07 (s, NH, H), 10.2 (Indole NH), ¹³CNMR δ (ppm): 45.659, 111.464, 127.627, 128.789, 129.237, 129.391, 130.288, 131.724, 139.142, 151.012,158.235

JG3: 1-({4-[2-(4-nitrophenyl)- 3H,4H-imidazo[4,5-b]indol-3-yl}benzene)sulfonyl] guanidine:

To the 250 ml Round bottom flask add 0.01M of Sulphaguanidine, 0.01M of Para-Nitrobenzaldehyde and are refluxed for 5 to 6 hours in the presence of 15 ml glacial acetic acid. The reaction mixture was allowed to cool in order to form a respective Schiff’s base. The completion of the reaction was monitored by using TLC (Chloroform: Methanol). To 0.01M of Schiff’s base add 0.01M Isatin and 0.1M of Ammonium acetate in the presence of 15ml glacial acetic acid are refluxed for 12 to 15 hours. The reaction mixture was poured in 250ml of cold water to separate ammonium acetate and glacial acetic acid. The completion of the reaction was monitored by using TLC (Chloroform: Methanol).Then the crude product was recrystallized by using absolute alcohol. Elemental analysis calculated: C (55.57%), H (3.60%),N (20.62%), O (13.46%),S (6.74%) IR (KBr): 3113 (N-H), 2319 (C-H),1600 (C=N), 1343 (S=O,NH), 1516 (C-NO₂), ¹H-NMR δ (ppm) : 6.5-8.2 (m, Ar-H), 2.5(s, NH, H), 10.1(Indole NH), ¹³CNMR δ (ppm): 45.841, 111.544, 124.057, 124.410,127.684, 128.503, 128.858, 128.987,129.695, 132.058,135.228, 146.950, 148.657, 149.247, 150.789, 151.10,158.269.

JG4: 1-({4-[2-(2-hydroxyphenyl) 3H,4H-imidazo[4,5-b]indol-3-yl}benzene)sulfonyl] guanidine:

To the 250 ml Round bottom flask add 0.01M of Sulphaguanidine, 0.01M of Salicylaldehyde and are refluxed for 5 to 6 hours in the presence of 15 ml glacial acetic acid. The reaction mixture was allowed to cool in order to form a respective Schiff’s base. The completion of the reaction was monitored by using TLC (Chloroform: Methanol). To 0.01M of Schiff’s base add 0.01M Isatin and 0.1M of Ammonium acetate in the presence of 15ml glacial acetic acid are refluxed for 12 to 15 hours. The reaction mixture was poured in 250ml of cold water to separate ammonium acetate and glacial acetic acid. The completion of the reaction was monitored by using TLC (Chloroform: Methanol).Then the crude product was recrystallized by using absolute alcohol. Elemental analysis calculated: C (59.18%), H (4.06%), N (18.82%), O (10.75%),S(7.18%), IR(KBr): 3352, (N-H), 1618 (C-H), 1532 (C=N), 1240 (S=O, NH), 3352 (-OH), ¹H-NMR δ (ppm) : 5 (Ar-OH), 2.5 (s, NH,H), 10.2 (Indole NH), 6.5-8.5 (Ar-H) ¹³CNMR δ (ppm): 22.257, 22.963, 112.794, 116.283, 118.730, 119.234, 119.821, 127.0, 127.598, 127.706, 131.312, 133.530, 134.505, 151.822, 158.310, 170.423, 173.088

JG5:[1-(4-[2-(4-hydroxy-3-methoxyphenyl]-3H,4H-imidazo[4,5-b]indol-3-yl}benzene)sulfonyl] guanidine:

To the 250 ml Round bottom flask add 0.01M of Sulphaguanidine, 0.01M of Vanallin and are refluxed for 5 to 6 hours in the presence of 15 ml glacial acetic acid. The reaction mixture was allowed to cool in order to form a respective Schiff’s base. The completion of the reaction was monitored by using TLC (Chloroform: Methanol). To 0.01M of Schiff’s base add 0.01M Isatin and 0.1M of Ammonium acetate in the presence of 15ml glacial acetic acid are refluxed for 12 to 15 hours. The reaction mixture was poured in 250ml of cold water to separate ammonium acetate and glacial acetic acid. The completion of the reaction was monitored by using TLC (Chloroform: Methanol).Then the crude product was recrystallized by using absolute alcohol. Elemental analysis calculated: C (57.97%), H (4.23%),N (17.64%), O (13.43%),S (6.73%), IR (KBr): 3570 (N-H, Ar), 3432 (N-H str), 1629 (C-H),1526 (C=N), 1133 (S=O,NH), 3338 (-OH), ¹H-NMR δ(ppm) : 6.6A-8 (m, r-H), 2.07(s, NH, H), 10.2 (IndoleNH), 5(Ar-OH), 3.4(Aromatic methoxy) ¹³C-NMR δ (ppm): 24.547, 118.724, 127.013, 139.071, 142.126, 158.497, 169.236

JG6: 1-({4-[2-(2-chlorophenyl]-3H,4H-imidazo[4,5-b]indol-3-yl}benzene)sulfonyl] guanidine:

To the 250 ml Round bottom flask add 0.01M of Sulphaguanidine, 0.01M of Ortho-Chlorobenzaldehyde and are refluxed for 5 to 6 hours in the presence of 15 ml glacial acetic acid. The reaction mixture was allowed to cool in order to form a respective Schiff’s base. The completion of the reaction was monitored by using TLC (Chloroform: Methanol). To 0.01M of Schiff’s base add 0.01M Isatin and 0.1M of Ammonium acetate in the presence of 15ml glacial acetic acid are refluxed for 12 to 15 hours. The reaction mixture was poured in 250ml of cold water to separate ammonium acetate and glacial acetic acid. The completion of the reaction was monitored by using TLC (Chloroform: Methanol).Then the crude product was recrystallized by using absolute alcohol. Elemental analysis calculated: C (56.83%), H (3.69%), N (18.08%),O (6.88%), S (6.90%),Cl (7.63%) IR(KBr): 3179 (N-H), 1731 (C-H), 1617 (C=N), 1133 (S=O, NH), 754 (C-Cl), ¹H-NMR δ (ppm): 7.1-7.4 (m, Ar-H), 2.90 (s, NH,H), 10.1 (IndoleNH), ¹³C-NMR δ (ppm): 120, 122.7, 127.4, 128.9, 128.2, 129.4, 132.3, 138, 139.2, 140.6,144

JG7:1-[(4-{2-[4-(dimethylamino)phenyl]-3H,4H-imidazo[4,5-b]indol-3-yl}benzene)sulfonyl] guanidine:

To the 250 ml Round bottom flask add 0.01M of Sulphaguanidine, 0.01M of P Dimethyl amino benzaldehyde and are refluxed for 5 to 6 hours in the presence of 15 ml glacial acetic acid. The reaction mixture was allowed to cool in order to form a respective Schiff’s base. The completion of the reaction was monitored by using TLC (Chloroform: Methanol).To 0.01M of Schiff’s base add 0.01M Isatin and 0.1M of Ammonium acetate in the presence of 15ml glacial acetic acid are refluxed for 12 to 15 hours. The reaction mixture was poured in 250ml of cold water to separate ammonium acetate and glacial acetic acid. The completion of the reaction was monitored by using TLC (Chloroform: Methanol).Then the crude product was recrystallized by using absolute alcohol. Elemental analysis calculated: C (60.87%), H (4.90%), N (20.70%),O (6.76%), S (6.77%), IR (KBr): 3187 (NH), 1596 (CH), 1535 (C=N),1166 (S=O,NH), 1372 N(CH₃)_2, ¹H-NMR δ (ppm): 6.7-7.6 (m, Ar-H), 2 (s, NH, H), 10.0 (Indole NH), 3.1N(CH₃), ¹³C-NMR δ(ppm): 111.529, 112.028,112.793,118.731,124.980,127.015,128.188,129.332, 129.916 ,132.020,154.671,190.331

JG8: 1-[(4-{2-phenyl)-3H, 4H-imidazo[4,5-b]indol-3-yl}benzene)sulfonyl] guanidine:

To the 250 ml Round bottom flask add 0.01M of Sulphaguanidine, 0.01M of Benzaldehyde and are refluxed for 5 to 6 hours in the presence of 15 ml glacial acetic acid. The reaction mixture was allowed to cool in order to form a respective Schiff’s base. The completion of the reaction was monitored by using TLC (Chloroform: Methanol). To 0.01M of Schiff’s base add 0.01M Isatin and 0.1M of Ammonium acetate in the presence of 15ml glacial acetic acid are refluxed for 12 to 15 hours. The reaction mixture was poured in 250ml of cold water to separate ammonium acetate and glacial acetic acid. The completion of the reaction was monitored by using TLC (Chloroform: Methanol).Then the crude product was recrystallized by using absolute alcohol. Elemental analysis calculated: C(61.38%), H (4.21%), N (19.52%), O (7.43%), S (7.45%), IR (KBr): 3185 (N-H), 1730 (C-H), 1617(C=N),1134 (S=O,NH), ¹H-NMR δ (ppm): 7.3-7.6(m, Ar-H), 2.34(s, NH, H),10.2 (Indole NH), ¹³C-NMR δ(ppm): 39.356, 39.565 39.774, 39.983, 40.191, 40.400, 40.608.

JG9: 1-(4-[2-(3-chlorophenyl)-3H,4H-imidazo[4,5-b]indol-3-yl]benzene)sulfonyl guanidine:

To the 250 ml Round bottom flask add 0.01M of Sulphaguanidine, 0.01M of m-Chlorobenzaldehyde and are refluxed for 5 to 6 hours in the presence of 15 ml glacial acetic acid. The reaction mixture was allowed to cool in order to form a respective Schiff’s base. The completion of the reaction was monitored by using TLC (Chloroform: Methanol). To 0.01M of Schiff’s base add 0.01M Isatin and 0.1M of Ammonium acetate in the presence of 15ml glacial acetic acid are refluxed for 12 to 15 hours. The reaction mixture was poured in 250ml of cold water to separate ammonium acetate and glacial acetic acid. The completion of the reaction was monitored by using TLC (Chloroform: Methanol).Then the crude product was recrystallized by using absolute alcohol. IR (KBr): 3480 (N-H), 465 (C-H), 2219 (C=N), 1322 (S=O, NH), 687 (C-Cl), Elemental analysis calculated: C (56.83%), H (3.69%), Cl (7.63%), N (18.08%), O (6.88%), S (6.90%),¹H-NMR δ (ppm): 7.1-9 (m, Ar-H), 2.0(s, NH, H), 10.1(Indole NH),

¹³C-NMR δ (ppm): 124.078, 124.375, 124.476, 127.833, 128.471, 128.583, 128.755, 129.647 ,129.715, 135.026, 135.779,149.187.

JD10: N-(4,6-dimethyl pyrimidin-2yl)-4-[2,(4-nitrophenyl)-3H,4H imidazo[4,5-b]indol-3-yl]benzene -1-sulphonamide:

To the 250 ml Round bottom flask add 0.01M of Sulphadimidine, 0.01M of Para-nitrobenzaldehyde and are refluxed for 5 to 6 hours in the presence of 15 ml glacial acetic acid. The reaction mixture was allowed to cool in order to form a respective Schiff’s base. The completion of the reaction was monitored by using TLC (Chloroform: Methanol). To 0.01M of Schiff’s base add 0.01M Isatin and 0.1M of Ammonium acetate in the presence of 15ml glacial acetic acid are refluxed for 12 to 15 hours. The reaction mixture was poured in 250ml of cold water to separate ammonium acetate and glacial acetic acid. The completion of the reaction was monitored by using TLC (Chloroform: Methanol).Then the crude product was recrystallized by using absolute alcohol. Elemental analysis calculated; C (60.10%), H (3.92%), N (18.17%), O (11.86%), S (5.94%), IR (KBr): 3426 (N-H, Ar), 3334 (NH str), 3063 (C-H Ar), 1732 (C=N), 1333 (S=O, NH), 1536 (NO₂), ¹H-NMR δ (ppm): 7.7-8.14 (m, Ar-H), 4.3 (s, NH,H), 2.0 (Ar- methyl), 10.0 (IndoleNH), 6.2(2-Pyrimidine CH),¹³C-NMR δ(ppm): 45.767, 111.494, 112.668, 126.219, 127.144, 127.203, 127.301, 127.649, 128.085, 128.932, 130.738, 131.154, 131.258, 131.826, 133.559, 134.162, 135.467, 139.747, 142.889, 150.958, 151.442, 158.245

Molecular Docking Study:

Protein preparation:

The crystallographic structure of Glucosamine-6-phosphate synthase (PDB code: 2VF5) and Dihydrofolate reductase (PDB code:1AI9) which were retrieved from the RCSB Protein Data Bank serves as docking receptor (Fig. 1) and all the designed compounds are selected as ligand molecules. Before docking the screened ligands into the protein active site, the protein was prepared by deleting the substrate cofactor as well as the crystallographically observed water molecules and then protein was defined for generating the grid.

RESULTS AND DISCUSSION:

Table: 1 Physico-Chemical Parameters of the Synthesized Compounds

l	Compound code	Molecular formula	Molecular weight	% yield	Melting point	Log P	Rf value
1	JD1	C27H21N6O2ClS	529.0	80	130ºC	5.709	0.652
2	JG2	C22H17N6O2ClS	464.9	60	142ºC	4.032	0.5
3	JG3	C22H17N7O4S	475.4	75	160ºC	3.313	0.8
4	JG4	C22H18N6O3S	446.4	70	90ºC	3.087	0.77
5	JG5	C23H20N6O4S	476.5	82	152ºC	2.693	0.93
6	JG6	C22H17N6O2SCl	464.9	65	92ºC	3.984	0.92
7	JG7	C24H23N7O2S	473.5	88	75ºC	3.457	0.83
8	JG8	C22H18N6O2S	430.4	77	80ºC	3.354	0.65
9	JG9	C22H17N6O2SCl	464.9	69	78ºC	4.008	0.7
10	JG10	C27H21N7O4S	539	73	120ºC	4.99	0.91

Table:2 Molecular Properties of the Synthesized Compounds

Compound code	Log P	TPSA	n atoms	n ON	n OHNH	n violation’s	n rotb	volume
JD1	5.709	105.57	37	8	2	2	5	434.62
JG2	4.032	129.66	32	8	5	0	5	371.99
JG3	3.313	175.48	34	11	5	1	6	381.79
JG4	3.087	149.88	32	9	6	1	5	366.47
JG5	2.693	159.12	34	10	6	1	6	392.02
JG6	3.984	129.66	32	8	5	0	5	371.99
JG7	3.457	132.89	34	9	5	0	6	404.36
JG8	3.354	129.66	31	8	5	0	5	358.46
JG9	4.008	129.66	32	8	5	0	5	371.99
JD10	4.99	151.39	39	11	2	2	6	444.42

Table:3 Drug -Likeliness Score

Compound code	GPCR-ligand	Ion channel modulator	Kinase Inhibitor	Nuclear receptor ligand	Protease Inhibitor	Enzyme Inhibitor
JD1	-0.06	-0.47	-0.07	-0.48	-0.41	-0.17
JG2	0.13	-0.04	0.05	-0.53	0.07	-0.05
JG3	0.01	-0.07	-0.05	-0.56	-0.02	-0.11
JG4	0.13	-0.05	0.06	-0.46	0.10	0.01
JG5	0.10	-0.06	0.08	-0.46	0.03	-0.01
JG6	0.15	-0.07	0.06	-0.49	0.08	-0.05
JG7	0.12	-0.05	0.08	-0.48	0.07	-0.04
JG8	0.13	-0.03	0.07	-0.52	0.11	-0.02
JG9	0.13	-0.04	0.05	-0.51	0.06	-0.04
JD10	-0.15	-0.58	-0.17	-0.54	-0.46	-0.26

Table:4 Osiris Property (Molecular Property Prediction) of the Synthesized Compounds

Compound code	c log P	Solubility	Molecular weight	Drug likeness	Drug score	TPSA
JD1	5.709	-10.7	528	4.92	0.26	105.5
JG2	4.032	-8.64	464.9	5.63	0.37	129.6
JG3	3.313	-8.42	459	3.8	0.14	175.4
JG4	3.087	-7.61	446.4	4.93	0.42	149.8
JG5	2.693	-7.63	476.5	5.5	0.4	159.1
JG6	3.984	-8.64	464.9	5.35	0.37	129.6
JG7	3.457	-7.94	473.5	3.98	0.23	132.8
JG8	3.354	-7.91	430.4	5.67	0.42	129.6
JG9	4.008	-8.64	464.9	4.87	0.37	129.6
JD10	4.99	-10.4	523	3.06	0.1	151.3

Ligand Preparation:

Chemsketch, the chemically intelligent drawing interface freeware (http://www.acdlabs.com/download) was used to draw the structures of aryl imidazole derivatives, followed by generation of 3D structure in PDB format using Marvin sketch.

Automated docking was used to locate the appropriate binding orientations and conformations of various inhibitors 2VF5 and 1AI9 binding pockets. To perform the task, the powerful genetic algorithm method implemented in the program Auto Dock 4.0.1 was employed. Grid maps were generated by Auto Grid program. Each Grid was centered at the crystal structure of the corresponding 2VF5 and 1AI9. Lamirckian Genetic Algorithm was employed as the docking algoritham. For all ligand, random starting positions, random orientations and torsions were used. During docking, grid parameters were specified for x, y and z as 40, 40 and 40 respectively. The Docking parameters, Number of Genetic Algorithm (GA) runs: 25, Population size: 150, Maximum number of evaluation : 2,500,000 , Maximum number of generation : 27000 were used for the study. The structure with the lowest binding free energy and the most cluster members was chosen for the optimum docking conformation. The binding interactions were shown in Fig 2.

Antimicrobial Activity:

Based on the docking score, the synthesized compounds were evaluated for its in vitro antibacterial and anti-fungal activity by Well-plate diffusion method^16-17 against Staphylococcus aureus, Bacillus cereus (Gram positive), E.coli, Salmonella typhii (Gram negative) and Candida albicans using the standard Ciprofloxacin and Clotrimazole as standard respectively. The sterilized (autoclaved at 120⁰C for 30 min) medium was inoculated with suspension of the microorganism and poured into a petridish. The test compounds of various concentration 50, 150, 250 and 350µg/ml in DMSO were poured into the well. Then the plates were incubated at 37⁰C for 24 hrs to allow the maximum growth of the organisms. The zone of inhibition of the synthesized compounds were measured and the results were shown in table 7 and 8.

Fig:1. Crystal structure of Glucosamine-6-phosphate synthase (Left side) and DHFR (Right side)

Docking images for Antibacterial study of synthesized compound:

Fig:2 Dotted lines(Yellow) represents the H-bonds realized by the ligand with amino acid residue of the protein active site, viewed through chimera software.

Table: 5 :Molecular Interaction of Ligand Compounds with Protein glucosamine-6-phosphate synthase (2VF5)

S.No	Compound Code	H-Bond Interaction	H-Bond Distance (Aº)	VDW HB desolved energy	Binding energy
1	JD1	Unk O: N Leu601: O	2.865	-8.41	-8.01
2	JG2	-	-	-6.91	-6.66
3	JG3	-	-	-5.18	-4.34
4	JG4	Unk O: N Ser449:OG	2.934	-6.59	-6.11
5	JG5	Unk O: N Ser604: O Unk O: N Ser604: O	2.968 2.781	-7.55	-7.04
6	JG6	Unk O:N Ser601: O	2.716	-7.17	-6.81
7	JG7	Unk O: N Ser604: O	2.848	-6.95	-6.32
8	JG8	-	-	-6.95	-6.8
9	JG9	-	-	-7.18	-7.46
10	JD10	-	2.879	-8.26	-7.47
11	Ciprofloxacin	Unk O:N Asp550:OD2	2.584	-3.19	-3.59

Docking images for Antifungal study of synthesized compound:

Fig:3 Dotted lines(Yellow) represents the H-bonds realized by the ligand with amino acid residue of the protein active site, viewed through chimera software.

Table:6: Molecular Interaction of Ligand Compounds With Protein DHF reductase (1AI9)

S.No	Compound Code	H-Bond Interaction	H-Bond Distance(Aº)	Vdw hb desolved energy	Binding energy
1	JD1	-	-	-5.64	-4.35
2	JG2	-	-	-6.16	-5.48
3	JG3	-	-	-8.39	-7.57
4	JG4	Unk O: O Ala115:N	2.764	-7.08	-5.94
5	JG5	Unk O: N Ser61:OG Unk O: O Tyr21:N Unk O: O Asp146:OD1, Thr147:OG1	2.934 2.768 2.87 2.94	-11.35	-10.01
6	JG6	Unk O:N Ser61:OG	2.957	-10.12	-9.21
7	JG7	Unk O:N Lys178: O	2.81	-6.53	-5.17
8	JG8	Unk O:N Leu77: O Unk O:O Ile117:N	2.727 2.53	-8.21	-6.87
9	JG9	Unk O:N Ser61:OG	2.796	-10.39	-9.45
10	JD10	-	-	-7.92	-6.61
11	Clotrimazole	Unk O:N Ser61:OG	2.869	-8.21	-7.03

Table:7 Invitro Anti-Bacterial Activity of the Synthesized Compounds:

Compound code	Name of the organism	Zone of inhibition in mm
		Standard 30mcg/disc	50µg/ml	150 µg/ml	250 µg/ml	350 µg/ml
JD1	Staphylococcus aureus	18	-	11	13	15
	Bacillus cereus	36	-	-	-	10
	E.Coli	30	-	-	-	-
	Salmonella typhi	39	-	-	-	-
JG5	Staphylococcus aureus	14	14	20	22	25
	Bacillus cereus	35	-	14	18	19
	E.Coli	32	-	-	-	-
	Salmonella typhi	34	-	-	-	-
JG9	Staphylococcus aureus	16	19	24	25	27
	Bacillus cereus	37	-	16	19	24
	E.coli	33	-	-	-	-
	Salmonella typhi	36	-	-	-	-
JD10	Staphylococcus aureus	17	-	18	20	25
	Bacillus cereus	38	-	-	10	15
	E.coli	34	-	-	-	-
	Salmonella typhi	34	-	-	-	-

Std-ciprofloxacin 30mcg/disc, ”_” indicates that the compound is inactive.

Table:8 Invitro Antifungal Activity of the Synthesized Compounds:

Compound code	Name of the organism	Zone of inhibition in mm
		Standard 30mcg/disc	50µg/ml	150 µg/ml	250 µg/ml	350 µg/ml
JG3	Candida albicans	13	-	-	-	10
JG5	Candida albicans	14	-	-	-	-
JG6	Candida albicans	11	-	-	-	-
JG9	Candida albicans	14	-	-	-	-

Note : Std-Clotrimazole 30mcg/disc, ”_” indicates that the compound is inactive.

CONCLUSION:

Aryl imidazole derivatives were synthesized and characterized for their physiochemical parameters and spectral data’s. Lipinski’s rule of five was calculated for all the synthesized compounds and it was found that all the compounds satisfied the rule for potent promoters. The synthesized compounds were evaluated for the drug likeness score using Molinspiration software (www.molinspiration.com). The derivatives were act as a ligand for various receptors like G-protein coupled receptor (GPCR), Ion channel modulator, kinase receptor and neuron receptor. The results were within the limits (-3 to +3). Docking study showed that compounds JD1, JD5, JG9 and JD10 exhibited good hydrogen bond interaction between the atoms of the synthesized compounds and amino acid residues of Glucosamine-6-phosphate synthase and DHFR. The synthesized compounds were screened for their invitro antibacterial and antifungal activities at the concentration of 50,150,250 and 350μg/ml against Staphylococcus aureus, Bacillus cereus, E.coli, Salmonella typhi and Candida albicans using ciprofloxacin and clotrimazole (30mcg/disc) respectively. In antibacterial activity, Compound JG9 showed comparable zone of inhibition as standard (ciprofloxacin-30mcg/disc) where as compound JD1, JD 5, JD10 produce moderate zone of inhibition. In antifungal activity only Compound JG3 showed moderate zone of inhibition where as the other compounds were inactive. In conclusion, the arylimidazole containing sulphaguanidine (JG9) showed good antibacterial activity with high binding energy.

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