Synthesis, molecular dynamics simulation, and evaluation of biological activity of novel flurbiprofen and ibuprofen-like compounds.

The frequent use of anti-inflammatory drugs and the side effects of existing drugs keep the need for new compounds constant. For this purpose, flurbiprofen and ibuprofen-like compounds, which are frequently used anti-inflammatory compounds in this study, were synthesized and their structures were elucidated. Like ibuprofen and flurbiprofen, the compounds contain a residue of phenylacetic acid. On the other hand, it contains a secondary amine residue. Thus, it is planned to reduce the acidity, which is the biggest side effect of NSAI drugs, even a little bit. The estimated ADME parameters of the compounds were evaluated. Apart from internal use, local use of anti-inflammatory compounds is also very important. For this reason, the skin permeability values of the compounds were also calculated. And it has been found to be compatible with reference drugs. The COX enzyme inhibitory effects of the obtained compounds were tested by in vitro experiments. Compound 2a showed significant activity against COX-1 enzyme with an IC50 = 0.123 + 0.005 µM. The interaction of the compound with the enzyme active site was clarified by molecular dynamics studies.

Selective in vitro Synergistic Evaluation of Probiotic Tolerant morpholinyl- and 4-ethylpiperazinyl-Imidazole-chalcone Derivatives on Gastrointestinal System Pathogens.

Imidazole-chalcone compounds are recognised for their broad-spectrum antimicrobial properties. Probiotic-friendly, selective new-generation antimicrobials prove to be more efficient in combating gastrointestinal system pathogens. The aim of this study is to identify imidazole-chalcone derivatives that probiotics tolerate and evaluate their in vitro synergistic antimicrobial effects on pathogens. In this study, fifteen previously identified imidazole-chalcone derivatives were analyzed for their in vitro antimicrobial properties against gastrointestinal microorganisms. Initially, the antimicrobial activity of pathogens was measured using the agar well diffusion method, while the susceptibility of probiotics was determined by microdilution. The chosen imidazole-chalcone derivatives were assessed for synergistic effects using the checkerboard method. Four imidazole-chalcone derivatives to which probiotic bacteria were tolerant exhibited antibacterial and antifungal activity against the human pathogens tested. To our knowledge, this study is the first to reveal the fractional inhibitory concentration (FIC) of combinations of imidazole-chalcone derivatives. Indeed, the minimum inhibitory concentrations (MIC) for morpholinyl- (ZDO-3f) and 4-ethylpiperazinyl- (ZDO-3 m) imidazole-chalcones were notably low when tested against E. coli and B. subtilis, with values of 31.25 µg/mL and 125 µg/mL, respectively. The combination of morpholinyl- and 4-ethylpiperazinyl derivatives demonstrated an indifferent effect against E. coli, but an additive effect was observed for B. subtilis. Additionally, it was observed that imidazole-chalcone derivatives did not exhibit any inhibitory effects on probiotic organisms like Lactobacillus fermentum (CECT-5716), Lactobacillus rhamnosus (GG), and Lactobacillus casei (RSSK-591). This study demonstrates that imidazole-chalcone derivatives that are well tolerated by probiotics can potentially exert a synergistic effect against gastrointestinal system pathogens.

New benzimidazole-oxadiazole derivatives as potent VEGFR-2 inhibitors: Synthesis, anticancer evaluation, and docking study.

We report herein, the design and synthesis of benzimidazole-oxadiazole derivatives as new inhibitors for vascular endothelial growth factor receptor-2 (VEGFR-2). The designed members were assessed for their in vitro anticancer activity against three cancer cell lines and two normal cell lines; A549, MCF-7, PANC-1, hTERT-HPNE and CCD-19Lu. Compounds 4c and 4d were found to be the most effective compounds against three cancer cell lines. Compounds 4c and 4d were then tested for their in vitro VEGFR-2 inhibitory activity, safety profiles, and selectivity indices using the normal hTERT-HPNE and CCD-19Lu cell lines. It was determined that compound 4c was the most effective and safe member of the produced chemical family. Vascular endothelial growth factor A (VEGFA) immunolocalizations of compounds 4c and 4d were evaluated relative to control by VEGFA immunofluorescence staining. Compounds 4c and 4d inhibited VEGFR-2 enzyme with half-maximal inhibitory concentration values of 0.475 ± 0.021 and 0.618 ± 0.028 µM, respectively. Molecular docking of the target compounds was carried out in the active site of VEGFR-2 (Protein Data Bank: 4ASD).

Synthesis of new compounds bearing methyl sulfonyl pharmacophore as selective COX-2 inhibitor.

Cyclooxygenase, also known as prostaglandin H2 synthase (PGH2), is one of the most important enzymes in pharmacology because inhibition of COX is the mechanism of action of most nonsteroidal anti-inflammatory drugs. In this study, ten thiazole derivative compounds had synthesized. The analysis of the obtained compounds was performed by 1 H NMR and 13 C NMR methods. By this method, the obtained compounds could be elucidated. The inhibitory effect of the obtained compounds on cyclooxygenase (COX) enzymes was investigated. The encoded compounds 5a, 5b, and 5c were found to be the most potent compared to the reference compounds ibuprofen (IC50 = 5.589 ± 0.278 µM), celecoxib (IC50 = 0.132 ± 0.004 µM), and nimesulide (IC50 = 1.692 ± 0.077 µM)against COX-2 isoenzyme. The inhibitory activity of 5a, 5b, and 5c is approximate, but the 5a derivative proved to be the most active in the series with an IC50 value of 0.180 ± 0.002 µM. The most potent COXs inhibitor was 5a, which was further investigated for its potential binding mode by a molecular docking study. Compound 5a was found to be localized at the active site of the enzyme, like celecoxib, which has a remarkable effect on COXs enzymes.

Design, synthesis, biological activities, and evaluation of molecular docking-dynamics studies of new thiosemicarbazones that may be effective against Alzheimer's disease.

Donepezil is one of the most used drugs in the treatment of Alzheimer's disease. Its activity as an AChE inhibitor makes new studies with these enzyme inhibitors attractive. For this purpose, in this study, 12 compounds including thiosemicarbazone pharmacophore, have been synthesized for the treatment of the Alzheimer's disease. 3,4-Dimethoxybenzene or 1,3-benzodioxolone rings were used for the PAS region. The substituted piperazine benzene structure is preferred for the CAS region. At the same time, the thiosemicarbazone pharmacophore structure with known ChE enzyme inhibition potential was used as a bridge connecting the CAS and PAS regions. Structure determination of compounds 3a-3l were revealed using 13 C-NMR, 1 H-NMR, and HRMS spectroscopic methods. The inhibition profile of obtained compounds (3a-3l) against ChE was evaluated using in vitro modified Ellman method. Compounds 3a, 3b, 3f, 3g and 3i exhibited inhibitory activity against the AChE enzyme. Compound 3a showed the highest inhibitory potential with an IC50 = 0.030 ± 0.001 µM. As a result of molecular docking studies, compound 3a displayed important interactions compared to other active derivatives. Molecular dynamics studies are important to see the stability of the complex formed by ligand and protein. RMSD, RMSF ang Rg parameters were calculated via dynamic studies. In conclusion, compound 3a may be a potential AChE enzyme inhibitor with its strong inhibitory potential and behavior in silico.

Synthesis of Imidazole-2,3-dihydrothiazole Compounds as VEGFR-2 Inhibitors and Their Support with in Silico Studies.

In this study, 12 novel 2-((1-(4-(1H-imidazol-1-yl)phenyl)ethylidene)hydrazineylidene)-3-ethyl-4-(substitutephenyl)-2,3-dihydrothiazole derivatives were obtained. Among these compounds, 2-((1-(4-(1H-imidazol-1-yl)phenyl)ethylidene)hydrazineylidene)-4-([1,1'-biphenyl]-4-yl)-3-ethyl-2,3-dihydrothiazole (4h) was chosen as the most active derivative in the series. According to the MTT results, compounds 4h and 4k showed activity with IC50 =4.566±0.246 µM and IC50 =4.537±0.463 µM, respectively. Unlike other derivatives, compound 4h carries a phenyl ring in the 4th position of the phenyl ring. This bulky group allowed the compound to settle in the enzyme active site. Dynamic studies show that the stability of the compound does not change over 40 ns. RMSD, RMSF and Rg parameters all remained within acceptable limits. The uninterrupted aromatic hydrogen bonding of the enzyme active site with the important amino acids Cys919, Glu885 and Asp1046 proves the inhibitory potential of compound 4h on the VEGFR-2 enzyme. It is thought that more active compounds will be reached with the derivatives to be synthesized starting from compound 4h.

Synthesis, Biological Evaluation, and Molecular Modeling Studies of New 1,3,4-Thiadiazole Derivatives as Potent Antimicrobial Agents.

In this work, the synthesis, characterization, and biological activities of a new series of 1,3,4-thiadiazole derivatives were investigated. The structures of final compounds were identified using 1 H-NMR, 13 C-NMR, elemental analysis, and HRMS. All the new synthesized compounds were then screened for their antimicrobial activity against four types of pathogenic bacteria and one fungal strain, by application of the MIC assays, using Ampicilin, Gentamycin, Vancomycin, and Fluconazole as standards. Among the compounds, the MIC values of 4 and 8 µg/mL of the compounds 3f and 3g, respectively, are remarkable and indicate that these compounds are good candidates for antifungal activity. The docking experiments were used to identify the binding forms of produced ligands with sterol 14-demethylase to acquire insight into relevant proteins. The MD performed about 100 ns simulations to validate selected compounds' theoretical studies. Finally, using density functional theory (DFT) to predict reactivity, the chemical characteristics and quantum factors of synthesized compounds were computed. These results were then correlated with the experimental data. Furthermore, computational estimation was performed to predict the ADME properties of the most active compound 3f.

New benzimidazole-oxadiazole derivatives: Synthesis, α-glucosidase, α-amylase activity, and molecular modeling studies as potential antidiabetic agents.

Benzimidazole-1,3,4-oxadiazole derivatives (5a-z) were synthesized and characterized with different spectroscopic techniques such as 1 H NMR, 13 C NMR, and HRMS. The synthesized analogs were examined against α-glucosidase and α-amylase enzymes to determine their antidiabetic potential. Compounds 5g and 5q showed the most activity with 35.04 ± 1.28 and 47.60 ± 2.16 µg/mL when compared with the reference drug acarbose (IC50 = 54.63 ± 1.95 µg/mL). Compounds 5g, 5o, 5s, and 5x were screened against the α-amylase enzyme and were found to show excellent potential, with IC50 values ranging from 22.39 ± 1.40 to 32.07 ± 1.55 µg/mL, when compared with the standard acarbose (IC50 = 46.21 ± 1.49 µg/mL). The antioxidant activities of the effective compounds (5o, 5g, 5s, 5x, and 5q) were evaluated by TAS methods. A molecular docking research study was conducted to identify the active site and explain the functions of the active chemicals. To investigate the most likely binding mode of the substances 5g, 5o, 5q, 5s, and 5x, a molecular dynamics simulation was also carried out.

Synthesis of novel thiosemicarbazone derivatives and investigation of their dual AChE and MAO-B inhibitor effects.

In this study, 15 thiosemicarbazone derivatives were synthesized. Analysis of the obtained compounds was performed by means of 1 H-NMR, 13 C-NMR and high resolution mass spectroscopy (HRMS) spectroscopic methods. The inhibition effect of the obtained compounds on cholinesterase and monoaminoxidase (MAO) enzymes were investigated with in vitro methods. None of the compounds showed significant activity on the butyrylcholinesterase enzyme. On the other hand, compounds 3b, 3c, 3e, 3k, 3l, 3m, 3n and 3o displayed significant activity on acetylcholinesterase (AChE) while compounds 3f, 3i, 3k, 3l, 3m, 3n, 3o also showed remarkable effects on monoamine oxidase-B (MAO-B) enzymes. For the selected compounds, docking studies were performed and the enzyme active site and binding modes were determined. It was revealed that the strongest interaction with AChE and MAO-B enzyme active sites was observed with the compound 3k. Another important factor in the treatment of diseases affecting the central nervous system such as Alzheimer's is the ability of the compounds to cross the blood-brain barrier (BBB). Additionally, the agents planned for the treatment of these diseases must also pass the blood-brain barrier. Therefore, in silico BBB penetration properties of active compounds were investigated.

Design, synthesis, molecular docking and molecular dynamics studies of novel triazolothiadiazine derivatives containing furan or thiophene rings as anticancer agents.

Breast cancer is the most common cancer type amoung post-menopausal women. Aromatase inhibitors were used in the treatment of patients. However, drug resistance may develop in long-term drug use, especially in 3rd and 4th stage (advanced) cancer cases. Therefore, there is a constant need for new agents. In this study, new triazolothiadiazine derivatives were synthesized and their anticancer activities were investigated. Compounds 2k, 2s, and 2w showed inhibitor activity against MCF-7 cell line with IC50 = 4.63 ± 0.10; 2.23 ± 0.16; 3.13 ± 0.08 µM value, respectively. As a result of in vitro aromatase enzyme inhibition test, compound 2s was the most active derivative with IC50 = 0.058 ± 0.023 µM. In addition, DNA synthesis inhibition percentages of the compounds were measured by the BrdU method. The intermolecular interactions of the promising compounds with aromatase enzyme were investigated through the SP docking approach, which revealed significant binding interaction energies associated with these compounds. Following that, the interaction's stability was assessed using a typical atomistic 100 ns dynamic simulation study. A number of parameters derived from MD simulation trajectories were computed and validated for the protein-ligand complex's stability under the dynamic conditions.

N-Substituted Arylidene-3-(Methylsulfonyl)-2-Oxoimidazolidine-1-Carbohydrazide as Cholinesterase Inhibitors: Design, Synthesis, and Molecular Docking Study.

The development of new enzyme inhibitors in degenerative brain diseases has gained more attention. Enzyme inhibitors play an effective role in controlling central nervous system diseases. For this purpose, a novel series of hydrazone derivatives containing imidazolidine ring aimed against Alzheimer's disease (AD), have been designed and synthesized. The acetylcholinesterase (AChE) enzyme inhibitory activity of these compounds was investigated. The structures of the compounds were determined by IR, 1 H and 13 C-NMR and mass spectroscopic methods. Inhibition studies on the cholinesterase (ChE) enzymes and ß-amyloid plaque inhibition test of the compounds were performed. Based on the experimental results, compound 3j bearing dimethoxy substituent on the aromatic ring like donepezil exhibited the most AChE inhibitory activity with the IC50 values of 0.023±0.001 µM. Owing to obtained biological activity and molecular docking study results, it is thought that the most active compound 3j may play a role in both symptomatic and palliative treatment of AD.

Synthesis of New Pyrimidine-Triazole Derivatives and Investigation of Their Anticancer Activities.

Aromatase inhibitors are the most used anticancer drug group in breast cancer cases. The development of resistance in cancer patients over time and the side effects of existing drugs make the need for new and effective agents permanent. In this study, 10 novel pyrimidine-triazole derivatives were synthesized and their anticancer activities were investigated. Compounds 5c and 5g showed inhibitor activity against MCF-7 cell line with IC50 =1.573±0.020; 3.698±0.056 µM value, respectively. As a result of in vitro aromatase enzyme inhibition test, compounds 5c and 5g were exhibited significant activity with IC50 =0.082±0.007 µM and IC50 =0.198±0.015 µM, respectively. Estimated physicochemical parameters were calculated using the online SwissADME program for all compounds. Interaction modes of the compounds 5c and 5g were investigated against aromatase enzyme by means of docking studies. As a result of the studies, the importance of the triazole ring for aromatase inhibition has been understood.

Design, synthesis, and biological activity of novel dithiocarbamate-methylsulfonyl hybrids as carbonic anhydrase inhibitors.

Carbonic anhydrase (CA) enzymes are involved in many physiological events. These enzymes, which contain Zn2+ in their structure, can be easily inhibited by dithiocarbamate compounds. In addition, CA enzyme inhibitory activities are known in groups such as sulfonamide and methylsulfonyl. For this purpose, in this study, a series of 23 new dithiocarbamate-methylsulfonyl derivatives were synthesized and their CA enzyme inhibitory activities were investigated. The inhibition potentials of the obtained compounds against the human CA I and CA II enzymes were investigated by the in vitro enzyme isolation method. It is seen that the compounds show activity at the nanomolar level. Molecular docking studies of the compounds were carried out by in silico methods. The poses of compounds 2a, 2e, 2o, and 2t are presented.

Design and synthesis of novel chalcone derivatives and evaluation of their inhibitory activities against acetylcholinesterase.

According to the cholinergic hypothesis, an increase in the acetylcholine level in Alzheimer's disease patients relatively slows down the symptoms of the disease. The most commonly used drug, donepezil, is a cholinesterase inhibitor. In this study, 12 new chalcones (2a-l) were designed and synthesized. In biological activity studies, the acetylcholinesterase (AChE) and butyrylcholinesterase inhibitory potentials of all compounds were evaluated using the in vitro Ellman method. The biological evaluation showed that compounds 2d, 2f, 2j, and 2l displayed significant activity against AChE. The compounds 2d, 2f, 2j, and 2l displayed IC50 values of 0.042, 0.024, 0.053, and 0.033 µM against AChE, respectively. The reference drug donepezil (IC50 = 0.021 µM) also displayed significant inhibition of AChE. The inhibitory activities of these compounds for ß-amyloid plaque aggregation were investigated. The enzyme kinetic study was performed to observe the effect of the most active compound 2f on the substrate-enzyme relationship, and a mixed-type inhibition of AchE was determined. Further, docking simulation also revealed that these compounds (2d, 2f, 2j, and 2l) interacted with the enzyme active site in a similar manner to donepezil. The most active derivative, compound 2f, interacted with the amino acids Trp286, Phe295, Tyr341, Trp86, and Glu202.

Design, synthesis, biological activity, molecular docking, and molecular dynamics of novel benzimidazole derivatives as potential AChE/MAO-B dual inhibitors.

To develop new acetylcholinesterase (AChE)-monoamine oxidase-B (MAO-B) dual inhibitors against Alzheimer's disease, the benzimidazole ring, which has a propargyl side chain with previously proven selective MAO-B inhibitory activity, was used as the main structure. Moreover, like donepezil, it was thought that the enzyme AChE would provide π-π interactions with the peripheral anionic side in this structure. Piperazine derivatives were chosen for the cationic active site. The synthesis of the compounds was carried out in five steps. The structures of the compounds were determined using 1 H-NMR (nuclear magnetic resonance), 13 C-NMR, and high-resolution mass spectrometry spectroscopic methods. First, the in vitro AChE, butyrylcholinesterase (BChE), MAO-A, and MAO-B inhibitory potentials of the obtained compounds were investigated. As a result of activity tests, compounds 5b, 5e, 5g, and 5h showed inhibitory activity against AChE; compounds 5e and 5g showed inhibitory activity against MAO-B. None of the compounds showed inhibitory activity against BChE or MAO-A. Compounds 5e and 5g showed dual inhibition. Among these compounds, compound 5g had inhibition potential similar to that of donepezil and selegiline. For compound 5g, further kinetic studies and Aß-plaque inhibitory potentials were investigated using in vitro methods. Molecular docking studies were performed using both AChE and hMAO-B crystals to elucidate the compound's interactions with the enzyme active site. The binding modes of the compound on AChE were fully elucidated by molecular dynamics studies.

Design, Synthesis, and Evaluation of Novel 2H-Benzo[b][1,4]thiazin-3(4H)-one Derivatives as New Acetylcholinesterase Inhibitors.

Alzheimer's disease (AD) is a slowly progressive neurodegenerative disease that causes dementia in people aged 65 and over. In the present study, a series of thiadiazole hybrid compounds with benzothiazine derivatives as acetylcholinesterase inhibitors were developed and evaluated for their biological activity. The AChE and BChE inhibition potentials of all compounds were evaluated by using the in vitro Ellman method. The biological evaluation showed that compounds 3i and 3j displayed significant inhibitory activity against AChE. Compounds 3i and 3j showed IC50 values of 0.027 µM and 0.025 µM against AChE, respectively. The reference drug donepezil (IC50 = 0.021 µM) also showed significant inhibition against AChE. Further docking simulation also revealed that these compounds (3i and 3j) interacted with the active site of the enzyme similarly to donepezil. The antioxidant study revealed that compounds 3i and 3j exhibited greater antioxidant effects. An in vitro blood-brain barrier permeability study showed that compounds 3i and 3j are promising compounds against AD. The cytotoxicity study of compounds 3i and 3j showed non-cytotoxic with an IC50 value of 98.29 ± 3.98 µM and 159.68 ± 5.53 µM against NIH/3T3 cells, respectively.

Design, synthesis, in vitro, and in silico studies of 1,2,4-triazole-piperazine hybrid derivatives as potential MAO inhibitors.

Monoamine oxidases (MAOs) have become promising drug targets for the development of central nervous system agents. In recent research, it was shown that numerous piperazine derivatives exhibit hMAO inhibitory activity. Therefore, in this study, a novel series of 1,2,4-triazole-piperazine derivatives (5a-j) were designed, synthesized, characterized, and screened for their hMAO-A and hMAO-B inhibitory activities. When the ADME predictions were examined, it was seen that the pharmacokinetic profiles of all synthesized compounds were appropriate. Compounds 5a, 5b, 5c, and 5e, with H, F, Cl, and NO2 groups on the 4-position of the phenyl ring, respectively, showed important MAO-A inhibitory activity. Compound 5c was found to be the most effective agent among the synthesized compounds with an IC50 value of 0.070 ± 0.002 µM against the MAO-A enzyme. The synthesized compounds appear to support the results of other studies to design MAO inhibitors to obtain more suitable drugs, especially for neurological disorders such as depression and anxiety.

Design, synthesis, in vitro and in silico studies of some novel thiazole-dihydrofuran derivatives as aromatase inhibitors.

Aromatase inhibitors used against hormone-dependent breast cancer, especially in post-menopausal women, are very susceptible to the development of resistance due to their limited number and long-term use. In this study, it is aimed to obtain new aromatase inhibitors including thiazole and dihydrofuran ring systems. Synthesis of compounds (2a-2l) were performed according to literature methods. Their structures were elucidated by 1H NMR, 13C NMR and APCI-MS spectroscopic methods. MTT test was carried out to assess the cell proliferation effects of the different compounds on two different pulmonary cell lines (A549, CCD-19Lu) and mammary cell line (MCF7). According to MTT assay, it was observed that the calculated IC50 values of some compounds for the CCD-19Lu cell line were found higher than for the A549 and MCF7 cell lines. Considering the viability results, it was found that the selected compounds (2a, 2c, 2e, 2g, 2h, 2l) showed favourable safety profile and have anticancer activities. Apoptotic activities of the selected compounds were investigated by flow cytometry analysis. And were found that have apoptotic effects on cancerous cell lines. In the light of this information, the aromatase inhibition potentials of 2g and 2l compounds, which are the most active derivatives, were examined in vitro and it was determined that they showed a similar inhibition profile with letrazole. Interaction modes between aromatase enzyme and compounds 2g and 2l were investigated by docking studies. In conclusion, findings of these study indicate that compounds 2g and 2l possess significant anticancer activity.

Synthesis of new hydrazone derivatives and evaluation of their monoamine oxidase inhibitory activity.

A novel series of hydrazone derivatives were designed and synthesized. Their structures were characterized by IR, 1H NMR, 13C NMR and HR-MS spectroscopic methods. The newly synthesized compounds were evaluated for their inhibitory activity against monoamine oxidase enzymes (MAO-A and MAO-B). Compounds 2a, 2k, 4a and 4i showed significant inhibitory activity against MAO-A, with IC50 value in the range of 0.084-0.207 µM compared to reference drug moclobemide (IC50 value = 6.061 µM). These compounds (2a, 2k, 4a and 4i) were exposed to cytotoxicity tests to establish their preliminary toxicological profiles and were found to be non-cytotoxic. Moreover, the most effective compound 4i was evaluated using enzyme kinetics and docking studies to elucidate the plausible mechanisms of inhibition of MAO-A. According to enzyme kinetic studies, compound 4i was a reversible and competitive inhibitor with similar inhibition features as the substrates. Also, it was seen that this compound was settled down very properly at the active site of MAO-A enzyme by doing important interactions owing to the docking studies. Finally, ADME predictions were applied to estimate pharmacokinetic profiles of synthesized compounds. According to calculated ADME predictions, all parameters of the compounds were within the standard ranges in terms of "Rule of Five" and "Rule of Three" and it was detected that the synthesized compounds (2a-4i) have good and promising pharmacokinetic profiles.

Novel 2,5-disubstituted-1,3,4-oxadiazole derivatives as MAO-B inhibitors: Synthesis, biological evaluation and molecular modeling studies.

Thirty novel 2,5-disubstituted-1,3,4-oxadiazole derivatives bearing urea moiety were designed and synthesized. IR, 1H-NMR, 13C-NMR and mass spectroscopic methods and elemental analysis were used to confirm the structures of the compounds. Their monoamine oxidase inhibitory activity was determined against the MAO-A and MAO-B isoforms. None of the compounds showed the potent MAO-A inhibitory activity, while the MAO-B inhibition was significantly found in the range of 62 to 98%. Among them, the compounds H8, H9 and H12 bearing chloro substituent at the fourth position of phenylurea were found to show potent monoamine oxidase B inhibitory activity with IC50 values 0.039-0.066 µM. To define and evaluate the interaction mechanism between compound H8 and monoamine oxidase B, molecular docking studies have been made.