In the current research work, different N-(substituted-phenyl)-4-{(4-[(E)-3-phenyl-2-propenyl]-1-piperazinyl}butanamides have been synthesized according to the protocol described in scheme 1. The synthesis was initiated by reacting various substituted anilines (1a-e) with 4-chlorobutanoyl chloride (2) in aqueous basic medium to give various electrophiles, 4-chloro-N-(substituted-phenyl)butanamides (3a-e). These electrophiles were then coupled with 1-[(E)-3-phenyl-2-propenyl]piperazine (4) in polar aprotic medium to attain the targeted N-(substituted-phenyl)-4-{(4-[(E)-3-phenyl-2-propenyl]-1-piperazinyl}butanamides (5a-e). The structures of all derivatives were identified and characterized by proton-nuclear magnetic resonance (1H NMR), carbon-nuclear magnetic resonance (13C NMR) and Infra-Red (IR) spectral data along with CHN analysis. The in vitro inhibitory potential of these butanamides was evaluated against Mushroom tyrosinase, whereby all compounds were found to be biologically active. Among them, 5b exhibited highest inhibitory potential with IC50 value of 0.013 ± 0.001 µM. The same compound 5b was also assayed through in vivo approach, and it was explored that it significantly reduced the pigments in zebrafish. The in silico studies were also in agreement with aforesaid results. Moreover, these molecules were profiled for their cytotoxicity through hemolytic activity, and it was found that except 5e, all other compounds showed minimal toxicity. The compound 5a also exhibited comparable results. Hence, some of these compounds might be worthy candidates for the formulation and development of depigmentation drugs with minimum side effects.
Biscoumarin analogs 1-18 have been synthesized, characterized by EI-MS and (1)H NMR and evaluated for α-glucosidase inhibitory potential. All compounds showed variety of α-glucosidase inhibitory potential ranging in between 13.5±0.39 and 104.62±0.3μM when compared with standard acarbose having IC50 value 774.5±1.94μM. The binding interactions of the most active analogs were confirmed through molecular docking. The compounds showed very good interactions with enzyme. All synthesized compounds 1-18 are new. Our synthesized compounds can further be studied to developed lead compounds.
The present article describes the synthesis, in vitro urease inhibition and in silico molecular docking studies of a novel series of bi-heterocyclic bi-amides. The synthesis of title compounds was initiated by benzoylation, with benzoyl chloride (1), of the key starter ethyl 2-(2-amino-1,3-thiazol-4-yl)acetate (2) in weak basic aqueous medium followed by hydrazide formation, 4, and cyclization with CS2 to reach the parent bi-heterocyclic nucleophile, N-{4-[(5-sulfanyl-1,3,4-oxadiazol-2-yl)methyl]-1,3-thiazol-2-yl}benzamide (5). Various electrophiles, 8a-l, were synthesized by a two-step process and these were finally coupled with 5 to yield the targeted bi-heterocyclic bi-amide molecules, 9a-l. The structures of the newly synthesized products were corroborated by IR, 1H NMR, 13C NMR, EI-MS and elemental analysis. The in vitro screening of these molecules against urease explored that most of the compounds exhibit potent inhibitory potential against this enzyme. The compound 9j, with IC50 value of 2.58 ± 0.02 µM, exhibited most promising inhibitory activity among the series, relative to standard thiourea having IC50 value of 21.11 ± 0.12 µM. In silico studies fully augmented the experimental enzyme inhibition results. Chemo-informatics analysis showed that synthesized compounds (9a-l) mostly obeyed the Lipinski's rule. Molecular docking study suggested that ligand 9j exhibited good binding energy value (-7.10 kcal/mol) and binds within the active region of target protein. So, on the basis of present investigation, it was inferred that 9j may serve as a novel scaffold for designing more potent urease inhibitors.
Voglibose and acarbose are distinguished α-glucosidase inhibitors used for controlling of diabetes mellitus. Unfortunately, these distinguished and clinically used inhibitors have also numerous side effects. Subsequently, there is still needed to develop safer therapy. Despite of a broad spectrum of biological importance of benzimidazole, it is occasionally evaluated for α-glucosidase activity. Current study deals with the synthesis and biological screening of benzimidazole bearing bis-Schiff bases (1-19) for their α-glucosidase inhibitory activity. All analogues exhibited excellent to good inhibitory potential (IC50 = 2.20 ± 0.1to 88.60 ± 1.70 µM) when compared with standard drug acarbose (IC50 = 38.45 ± 0.80 µM). A structure activity relationship has been established on the basis of electronic effects and position of different substituents present on phenyl ring. In order to rationalize the binding interactions of most active analogues with the active site of α-glucosidase enzyme, molecular docking study was conducted.
The present study comprises the synthesis of a new series of sulfonamides derived from 4-methoxyphenethylamine (1). The synthesis was initiated by the reaction of 1 with 4-methylbenzenesulfonyl chloride (2) in aqueous sodium carbonate solution at pH 9 to yield N-(4-methoxyphenethyl)-4-methylbenzensulfonamide (3).This parent molecule 3 was subsequently treated with various alkyl/aralkyl halides, (4a-j), using N,N-dimethylformamide (DMF) as solvent and LiH as activator to produce a series of new N-(4-methoxyphenethyl)-N-(substituted)-4-methylbenzenesulfonamides (5a-j). The structural characterization of these derivatives was carried out by spectroscopic techniques like IR, 1H-NMR, and 13C-NMR. The elemental analysis data was also coherent with spectral data of these molecules. The inhibitory effects on acetylcholinesterase and DPPH were evaluated and it was observed that N-(4-Methoxyphenethyl)-4-methyl-N-(2-propyl)benzensulfonamide (5c) showed acetylcholinesterase inhibitory activity 0.075 ± 0.001 (IC50 0.075 ± 0.001 µM) comparable to Neostigmine methylsulfate (IC50 2.038 ± 0.039 µM).The docking studies of synthesized ligands 5a-j were also carried out against acetylcholinesterase (PDBID 4PQE) to compare the binding affinities with IC50 values. The kinetic mechanism analyzed by Lineweaver-Burk plots demonstrated that compound (5c) inhibits the acetylcholinesterase competitively to form an enzyme inhibitor complex. The inhibition constants Ki calculated from Dixon plots for compound (5c) is 2.5 µM. It was also found from kinetic analysis that derivative 5c irreversible enzyme inhibitor complex. It is proposed on the basis of our investigation that title compound 5c may serve as lead structure for the design of more potent acetylcholinesterase inhibitors.
This paper reports the synthesis, characterization, anticancer screening and quantum chemical calculation of a tetradentate Schiff base 2,2'-((1E,1'E)-((2,2-dimethylpropane-1,3-diyl)bis- (azanylylidene))bis(methanylylidene))bis(4-fluorophenol) (L2F) and its Pd (II) complex (PdL2F). The compounds were characterized via UV-Visible, NMR, IR spectroscopy and single crystal x-ray diffraction. Density Functional Theory (DFT) and time-dependent DFT calculations in gas and solvent phases were carried out using B3LYP, B3P86, CAM-B3LYP and PBE0 hybrid functionals combined with LanL2DZ basis set. Complexation of L2F to form PdL2F was observed to cause a bathochromic shift of the maximum absorption bands of n-π* from 327 to 410 nm; an upfield shift for δ (HC = N) from 8.30 to 7.96 ppm and a decreased wavenumber for ν(C = N) from 1637 to 1616 cm-1. Overall, the UV-Vis, NMR and IR spectral data are relatively well reproduced through DFT and TD-DFT methods. L2F and PdL2F showed IC50 of 90.00 and 4.10 μg/mL, respectively, against human colorectal carcinoma (HCT116) cell lines, signifying increased anticancer activity upon complexation with Pd (II).
Two new synthesized and characterized quinazoline Schiff bases 1 and 2 were investigated for anticancer activity against MCF-7 human breast cancer cell line. Compounds 1 and 2 demonstrated a remarkable antiproliferative effect, with an IC50 value of 6.246×10(-6) mol/L and 5.910×10(-6) mol/L, respectively, after 72 hours of treatment. Most apoptosis morphological features in treated MCF-7 cells were observed by AO/PI staining. The results of cell cycle analysis indicate that compounds did not induce S and M phase arrest in cell after 24 hours of treatment. Furthermore, MCF-7 cells treated with 1 and 2 subjected to apoptosis death, as exhibited by perturbation of mitochondrial membrane potential and cytochrome c release as well as increase in ROS formation. We also found activation of caspases-3/7, -8, and -9 in compounds 1 and 2. Moreover, inhibition of NF-κB translocation in MCF-7 cells treated by compound 1 significantly exhibited the association of extrinsic apoptosis pathway. Acute toxicity results demonstrated the nontoxic nature of the compounds in mice. Our results showed significant activity towards MCF-7 cells via either intrinsic or extrinsic mitochondrial pathway and are potential candidate for further in vivo and clinical breast cancer studies.
Introduction: The spread of multidrug-resistant malaria parasite – Plasmodium sp. to commercially available antimalarial drugs, i.e. artemisinin-based combination therapies (ACTs) and chloroquine (CQ), has become a global treat to eliminate malaria. To limit the impact of antimalarial drug resistance, a new potent and affordable alternative is urgently needed. A number of metal-based compounds (metallodrugs) have been found active against Plasmodium falciparum, the species that causes potentially fatal cerebral malaria, as they are ease in ligand grafting of multi-functional groups. Ferroquine (FQ) is one of the metalloantimalarial drugs that is currently undergoing clinical trials. Methods: In this study, a series of ternary copper(II) and zinc(II) complexes – Cu(phen)(edda) 1, Zn(phen)(edda) 2, [Cu(phen)(cdmg)] NO3 3 and [Zn(phen)(c-dmg)]NO3 4 were synthesized and characterized by the following tests: Fourier transformed infrared (FTIR), CHN elemental analysis, UV-Vis spectroscopy, molar conductivity and magnetic susceptibility measurements. Results: In vitro hemolytic and antimalarial assays using SYBR Green I dye were done to determine the biological properties of these complexes. Preliminary biological evaluation demonstrated that all the complexes 1, 2, 3 and 4 exhibit toxicity against the sensitive blood-stage Plasmodium falciparum 3D7 with IC50 in μM range. Conclusion: Thus, metal complex is a potentially viable candidate as antimalarial drug to overcome the emergence of drug resistance.
The synthesis and characterization of two cobalt(II) complexes, Co(phen)(ma)Cl 1 and Co(ma)(2)(phen) 2, (phen=1,10-phenanthroline, ma(-)=maltolate or 2-methyl-4-oxo-4H-pyran-3-olate) are reported herein. The complexes have been characterized by FTIR, CHN analysis, fluorescence spectroscopy, UV-visible spectroscopy, conductivity measurement and X-ray crystallography. The number of chelated maltolate ligands seems to influence their DNA recognition, topoisomerase I inhibition and antiproliferative properties.
The two cationic palladium(ii) complexes, [Pd(Len)2][OTf]2 (4) and [Pd(Lphen)2][OTf]2 (5), were synthesized by treatment of bis(benzonitrile)dichloropalladium(ii) with [H2Len][OTf]2 (2) or [H2Lphen][OTf]2 (3), respectively, in the presence of a weak base. The pro-ligands 2 and 3 were synthesized by melt reactions between N-methyl-4-chloropyridinium triflate (1) and the amines ethylenediamine or phenylenediamine, respectively. The water-soluble compounds 2-5 were fully characterized, including by single-crystal X-ray crystal structure determinations for 2-4. UV-Vis and fluorescence spectroscopy were used to study the binding interactions of 2-5 with CT-DNA. The spectroscopic data suggested the presence of intercalative and groove binding modes and this was supported by molecular docking studies. The in vitro cytotoxicity studies (IC50 values) showed that the human breast cancer cell lines MCF-7 and T47D were more sensitive towards 3, 4 and 5 than cisplatin. The cytotoxicity of the new compounds decreased in the order 5 > 4 > 3 > 2. Furthermore, the annexin V-FITC staining method strongly suggested the presence of phosphatidylserine (PS) on the outer membrane of the treated cells, which is a hallmark of apoptosis.
Diabetes is an emerging metabolic disorder. α-Glucosidase inhibitors, such as acarbose, delay the hydrolysis of carbohydrates by interfering with the digestive enzymes. This action decreases the glucose absorption and the postprandial glucose level. We have synthesized 25 tricyclic 2-phenoxypyrido[3,2-e][1,2,4]triazolo[1,5-a]pyrimidin-5(4H)-ones hybrids and evaluated their α-glucosidase inhibitory activity. Compounds 6h and 6d have shown stronger activity than that of acarbose. Compound 6h exhibited the highest inhibition with an IC50 of 104.07 µM. Molecular modelling studies revealed that compound 6h inhibits α-glucosidase due to the formation of a stable ligand-α-glucosidase complex and extra hydrogen bond interactions, and directed in the binding site by Trp329.25 tricyclic 2-phenoxypyrido[3,2-e][1,2,4]triazolo[1,5-a]pyrimidin-5(4H)-ones hybrids have been synthesized and evaluated their α-glucosidase inhibitory activity. Compounds 6h have shown stronger activity than that of acarbose.
A series of N'-(substituted benzylidene)-2-(benzo[d]oxazol-3(2H)-yl)acetohydrazide derivatives was synthesized and evaluated for its in vitro antimicrobial and anticancer activities. Antimicrobial activity results revealed that compound 12 was found to be the most potent antimicrobial agent. Results of anticancer study indicated that the synthesized compounds exhibited average anticancer potential. Compound 7 (IC 50 =3.12 µM) and compound 16 (IC 50 =2.88 µM) were found to be most potent against breast cancer (MCF7) cell lines. In conclusion, compound 12 and 16 have the potential to be selected as lead compound for the developing of novel antimicrobial and anticancer agents respectively.
We have synthesized new series of bisindole analogs (1-27), characterized by 1HNMR and HR-EI-MS and evaluated for their anti-leishmanial potential. All compounds showed outstanding inhibitory potential with IC50 values ranging from 0.7 ± 0.01 to 13.30 ± 0.50 µM respectively when compared with standard pentamidine with IC50 value of 7.20 ± 0.20 µM. All analogs showed greater potential than standard except 10, 19 and 23 when compared with standard. Structure activity relationship has been also established for all compounds. Molecular docking studies were carried out to understand the binding interaction of active molecules.
Synthesis and anticancer studies of three symmetrically and non-symmetrically substituted silver(I)-N-Heterocyclic carbene complexes of type [(NHC)2-Ag]PF6 (7-9) and their respective (ligands) benzimidazolium salts (4-6) are described herein. Compound 5 and Ag-NHC-complex 7 were characterized by the single crystal X-ray diffraction technique. Structural studies for 7 showed that the silver(I) center has linear C-Ag-C coordination geometry (180.00(10)o). Other azolium and Ag-NHC analogues were confirmed by H1 and C13-NMR spectroscopy. The synthesized analogues were biologically characterized for in vitro anticancer activity against three cancer cell lines including human colorectal cancer (HCT 116), breast cancer (MCF-7), and erythromyeloblastoid leukemia (K-562) cell lines and in terms of in vivo acute oral toxicity (IAOT) in view of agility and body weight of female rats. In vitro anticancer activity showed the values of IC50 in range 0.31-17.9 μM in case of K-562 and HCT-116 cancer cell lines and 15.1-35.2 μM in case of MCF-7 while taking commercially known anticancer agents 5-fluorouracil, tamoxifen, and betulinic acid which have IC50 values 5.2, 5.5, and 17.0 μM, respectively. In vivo study revealed vigor and agility of all test animals which explores the biocompatibility and non-toxicity of the test analogues.
In this study, a new series of sulfonamides derivatives was synthesized and their inhibitory effects on DPPH and jack bean urease were evaluated. The in silico studies were also applied to ascertain the interactions of these molecules with active site of the enzyme. Synthesis was initiated by the nucleophilic substitution reaction of 2-(4-methoxyphenyl)-1-ethanamine (1: ) with 4-(acetylamino)benzenesulfonyl chloride (2): in aqueous sodium carbonate at pH 9. Precipitates collected were washed and dried to obtain the parent molecule, N-(4-{[(4-methoxyphenethyl)amino]sulfonyl}phenyl)acetamide (3): . Then, this parent was reacted with different alkyl/aralkyl halides, (4A-M: ), using dimethylformamide (DMF) as solvent and LiH as an activator to produce a series of new N-(4-{[(4-methoxyphenethyl)-(substituted)amino]sulfonyl}phenyl)acetamides (5A-M: ). All the synthesized compounds were characterized by IR, EI-MS, 1H-NMR, 13C-NMR and CHN analysis data. All of the synthesized compounds showed higher urease inhibitory activity than the standard thiourea. The compound 5 F: exhibited very excellent enzyme inhibitory activity with IC50 value of 0.0171±0.0070 µM relative to standard thiourea having IC50 value of 4.7455±0.0546 µM. Molecular docking studies suggested that ligands have good binding energy values and bind within the active region of taget protein. Chemo-informatics properties were evaluated by computational approaches and it was found that synthesized compounds mostly obeyed the Lipinski' rule.
Sixty-nine novel α,β-unsaturated carbonyl based compounds, including cyclohexanone, tetralone, oxime, and oxime ether analogs, were synthesized. The antiproliferative activity determined by using seven different human cancer cell lines provided a structure-activity relationship. Compound 8ag exhibited high antiproliferative activity against Panc-1, PaCa-2, A-549, and PC-3 cell lines, with IC50 value of 0.02 μM, comparable to the positive control Erlotinib. The ten most active antiproliferative compounds were assessed for mechanistic effects on BRAF(V600E), EGFR TK kinases, and tubulin polymerization, and were investigated in vitro to reverse efflux-mediated resistance developed by cancer cells. Compound 8af exhibited the most potent BRAF(V600E) inhibitory activity with an IC50 value of 0.9 μM. Oxime analog 7o displayed the most potent EGFR TK inhibitory activity with an IC50 of 0.07 μM, which was analogous to the positive control. Some analogs including 7f, 8af, and 8ag showed a dual role as anticancer and MDR reversal agents.
A series of novel carbonyl compounds was synthesized by a simple, eco-friendly and efficient method. These compounds were screened for anti-oxidant activity, in vitro cytotoxicity and for inhibitory activity for acetylcholinesterase and butyrylcholinesterase. The effect of these compounds against amyloid β-induced cytotoxicity was also investigated. Among them, compound 14 exhibited strong free radical scavenging activity (18.39 μM) while six compounds (1, 3, 4, 13, 14, and 19) were found to be the most protective against Aβ-induced neuronal cell death in PC12 cells. Compounds 4 and 14, containing N-methyl-4-piperidone linker, showed high acetylcholinesterase inhibitory activity as compared to reference drug donepezil. Molecular docking and QSAR (Quantitative Structure-Activity Relationship) studies were also carried out to determine the structural features that are responsible for the acetylcholinesterase and butyrylcholinesterase inhibitory activity.
The syntheses and bioactivities of symmetrical curcumin and its analogues have been the subject of interest by many medicinal chemists and pharmacologists over the years. To improve our understanding, we have synthesized a series of unsymmetrical monocarbonyl curcumin analogues and evaluated their effects on prostaglandin E2 production in lipopolysaccharide-induced RAW264.7 and U937 cells. Initially, compounds 8b and 8c exhibited strong inhibition on the production of PGE2 in both LPS-stimulated RAW264.7 (8b, IC50=12.01μM and 8c, IC50=4.86μM) and U937 (8b, IC50=3.44μM and 8c, IC50=1.65μM) cells. Placing vanillin at position Ar2 further improved the potency when both compounds 15a and 15b significantly lowered the PGE2 secretion level (RAW264.7: 15a, IC50=0.78μM and 15b, IC50=1.9μM while U937: 15a, IC50=0.95μM and 15b, IC50=0.92μM). Further experiment showed that compounds 8b, 8c, 15a and 15b did not target the activity of downstream inflammatory COX-2 mediator. Finally, docking simulation on protein targets COX-2, IKK-β, ERK, JNK2, p38α and p38β were performed using the conformation of 15a determined by single-crystal XRD.
Disulfide analogs (1-20) have been synthesized, characterized by HR-MS, (1)H NMR and (13)C NMR and screened for urease inhibitory potential. All compounds were found to have varied degree of urease inhibitory potential ranging in between 0.4 ± 0.01 and 18.60 ± 1.24 μM when compared with standard inhibitor thiourea with IC50 19.46 ± 1.20 μM. Structure activity relationship has been established. The binding interactions of compounds with enzyme were confirmed through molecular docking. All the synthesized compounds 1-20 are new. Our compounds are cheaply synthesizable with high yield and can further be studied to discovery lead compounds. We further, tested for carbonic anhydrase, PDE1 and butyrylcholinesterase but they show no activity. On the other hand we evaluated all compounds for cytotoxicity they showed no toxicity.
We synthesized a series of novel 5-24 derivatives of oxindole. The synthesis started from 5-chlorooxindole, which was condensed with methyl 4-carboxybezoate and result in the formation of benzolyester derivatives of oxindole which was then treated with hydrazine hydrate. The oxindole benzoylhydrazide was treated with aryl acetophenones and aldehydes to get target compounds 5-24. The synthesized compounds were evaluated for urease inhibition; the compound 5 (IC50 = 13.00 ± 0.35 μM) and 11 (IC50 = 19.20 ± 0.50 μM) showed potent activity as compared to the standard drug thiourea (IC50 = 21.00 ± 0.01 μM). Other compounds showed moderate to weak activity. All synthetic compounds were characterized by different spectroscopic techniques including (1)H NMR, (13)C NMR, IR and EI MS. The molecular interactions of the active compounds within the binding site of urease enzyme were studied through molecular docking simulations.