Synthesis and evaluation of the biological activities of some 3-{[5-(6-methyl-4-aryl-2-oxo-1,2,3,4-tetrahydropyrimidin-5-yl)-1,3,4-oxadiazol-2-yl]-imino}-1,3-dihydro-2H-indol-2-one derivatives

Dual activity of indolin-2-ones containing an arylidene motif: DNA and BSA interaction

Applying a multistep approach, novel indolin-2-ones (IND) that possess an arylidene motif have been synthesized. Eight compounds were chosen for different biological tests (antimicrobial and cytotoxicity). IND containing 2-thienyl (4h) fragment have been found to exhibit good antimicrobial activity against B. cereus. Molecules that have 3-aminophenyl (4d) or 2-pyridyl (4g) groups have shown the best antifungal activities against all tested fungi. These compounds have also been noticed as promising pharmaceuticals against MCF-7 cancer cell lines. Experimental outcomes from the investigation of the interaction of 4d with DNA implied its moderate binding to DNA (KSV = 1.35 × 104 and 3.05 × 104 M-1 for EB and Hoechst binder, respectively). However, considerably stronger binding of 4d to BSA has been evidenced (Ka = 6.1 × 106 M-1). In summary, IND that contains m-aminobenzylidene fragment (4d) exhibits a good dual biological activity making it a promising candidate for further investigation in the drug discovery sector.

Novel 2-Thiouracil-5-Sulfonamide Derivatives: Design, Synthesis, Molecular Docking, and Biological Evaluation as Antioxidants with 15-LOX Inhibition

New antioxidant agents are urgently required to combat oxidative stress, which is linked to the emergence of serious diseases. In an effort to discover potent antioxidant agents, a novel series of 2-thiouracil-5-sulfonamides (4-9) were designed and synthesized. In line with this approach, our target new compounds were prepared from methyl ketone derivative 3, which was used as a blocking unit for further synthesis of a novel series of chalcone derivatives 4a-d, thiosemicarbazone derivatives 5a-d, pyridine derivatives 6a-d and 7a-d, bromo acetyl derivative 8, and thiazole derivatives 9a-d. All compounds were evaluated as antioxidants against 2,2-diphenyl-1-picrylhydrazyl (DPPH), hydrogen peroxide (H₂O₂), lipid peroxidation, and 15-lipoxygenase (15-LOX) inhibition activity. Compounds 5c, 6d, 7d, 9b, 9c, and 9d demonstrated significant RSA in all three techniques in comparison with ascorbic acid and 15-LOX inhibitory effectiveness using quercetin as a standard. Molecular docking of compound 9b endorsed its proper binding at the active site pocket of the human 15-LOX which explains its potent antioxidant activity in comparison with standard ascorbic acid.

The Molecular Diversity of 1H-Indole-3-Carbaldehyde Derivatives and Their Role in Multicomponent Reactions

1H-Indole-3-carbaldehyde and related members of the indole family are ideal precursors for the synthesis of active molecules. 1H-Indole-3-carbaldehyde and its derivatives are essential and efficient chemical precursors for generating biologically active structures. Multicomponent reactions (MCRs) offer access to complex molecules. This review highlights the recent applications of 1H-indole-3-carbaldehyde in such inherently sustainable multicomponent reactions from the period, 2014 to 2021 and provides an overview of the field that awaits further exploitation in the assembly of pharmaceutically interesting scaffolds.

Synthesis, crystal structures, antiproliferative activities and reverse docking studies of eight novel Schiff bases derived from benzil

Eight novel Schiff bases derived from benzil dihydrazone (BDH) or benzil monohydrazone (BMH) and four fused-ring carbonyl compounds (3-formylindole, FI; 3-acetylindole, AI; 3-formyl-1-methylindole, MFI; 1-formylnaphthalene, FN) were synthesized and characterized by elemental analysis, ESI-QTOF-MS, ¹H and ¹³C NMR spectroscopy, as well as single-crystal X-ray diffraction. They are (1Z,2Z)-1,2-bis{(E)-[(1H-indol-3-yl)methylidene]hydrazinylidene}-1,2-diphenylethane (BDHFI), C₃₂H₂₄N₆, (1Z,2Z)-1,2-bis{(E)-[1-(1H-indol-3-yl)ethylidene]hydrazinylidene}-1,2-diphenylethane (BDHAI), C₃₄H₂₈N₆, (1Z,2Z)-1,2-bis{(E)-[(1-methyl-1H-indol-3-yl)methylidene]hydrazinylidene}-1,2-diphenylethane (BMHMFI) acetonitrile hemisolvate, C₃₄H₂₈N₆·0.5CH₃CN, (1Z,2Z)-1,2-bis{(E)-[(naphthalen-1-yl)methylidene]hydrazinylidene}-1,2-diphenylethane (BDHFN), C₃₆H₂₆N₄, (Z)-2-{(E)-[(1H-indol-3-yl)methylidene]hydrazinylidene}-1,2-diphenylethanone (BMHFI), C₂₃H₁₇N₃O, (Z)-2-{(E)-[1-(1H-indol-3-yl)ethylidene]hydrazinylidene}-1,2-diphenylethanone (BMHAI), C₂₄H₁₉N₃O, (Z)-2-{(E)-[(1-methyl-1H-indol-3-yl)methylidene]hydrazinylidene}-1,2-diphenylethanone (BMHMFI), C₂₄H₁₉N₃O, and (Z)-2-{(E)-[(naphthalen-1-yl)methylidene]hydrazinylidene}-1,2-diphenylethanone (BMHFN) C₂₅H₁₈N₂O. Moreover, the in vitro cytotoxicity of the eight title compounds was evaluated against two tumour cell lines (A549 human lung cancer and 4T₁ mouse breast cancer) and two normal cell lines (MRC-5 normal lung cells and NIH 3T3 fibroblasts) by MTT assay. The results indicate that four (BDHMFI, BDHFN, BMHMFI and BMHFN) are inactive and the other four (BDHFI, BDHAI, BMHFI and BMHAI) show severe toxicities against human A549 and mouse 4T₁ cells, similar to the standard cisplatin. All the compounds exhibited weaker cytotoxicity against normal cells than cancer cells. The Swiss Target Prediction web server was applied for the prediction of protein targets. After analyzing the differences in frequency hits between these active and inactive Schiff bases, 18 probable targets were selected for reverse docking with the Surflex-dock function in SYBYL-X 2.0 software. Three target proteins, i.e. human ether-á-go-go-related (hERG) potassium channel, the inhibitor of apoptosis protein 3 and serine/threonine-protein kinase PIM1, were chosen as the targets. Finally, the ligand-based structure-activity relationships were analyzed based on the putative protein target (hERG) docking results, which will be used to design and synthesize novel hERG ion channel inhibitors.

mPEG-icariin nanoparticles for treating myocardial ischaemia

Icariin (ICA), a major active ingredient from Chinese medicine, has unique pharmacological effects on ischaemic heart disease. However, its hydrophobic property limits its administration and leads to poor efficacy. This work aimed to change its hydrophobic property and improve the treatment efficacy. We designed a new nano-drug to increase the ICA delivery. ICA was modified with hydrophilic polyethylene glycol monomethyl ether (mPEG) by a succinic anhydride linker to form a polyethylene glycol-icariin (mPEG-ICA) polymer. The structure of this polymer was identified by Fourier transform infrared spectroscopy and nuclear magnetic resonance spectroscopy. The content of ICA in the polymer was 32% as detected by ultraviolet spectrophotometry. mPEG-ICA nanoparticles, of 143.3 nm, were prepared by the dialysis method, and zeta potential was 0.439 mV by dynamic light scattering. The nanoparticles had a spherical shape on transmission electron microscopy. In media with pH 7.4 and 6.8, ICA release from mPEG-ICA nanoparticles after 72 h was about 0.78% and 64.05%, respectively, so the ICA release depended on the release media pH. On MTT and lactate dehydrogenase activity assay, mPEG-ICA nanoparticles could reduce cell damage induced by oxgen-glucose deprivation. Hoechst 33258 staining and TUNEL and AnnexinV-FITC/PI double staining showed that ICA nanoparticles could increase the activity of H9c2 cardiomyocytes under oxgen-glucose deprivation conditions by decreasing apoptosis. ICA modified by hydrophilic mPEG could improve its efficacy.

Synthesis, biological activity and molecular modeling study of new Schiff bases incorporated with indole moiety

A new series of heterocyclic Schiff bases 2-9 containing indole moiety were synthesized by facile and efficient condensation of indole-3/2/5-carboxaldehyde (1a/1b/1c) with different aromatic and heterocyclic primary amines using conventional and/or microwave irradiation methods. The structures of the obtained compounds were assigned by sophisticated spectroscopic and spectrometric techniques (1D-NMR, 2D-NMR and MS). The synthesized compounds were screened for their cytotoxicity and antibacterial activities. In vitro cytotoxicity screening revealed that compound 5 exhibited moderate activity against KB-3-1 cell line (IC50=57.7 μM) while 5-indolylimino derivative 7 indicated close to the activity (IC50=19.6 μM) in comparison with the positive control (+)-Griseofulvin (IC50=19.2 μM), while the tested compounds 5, 6b, 7 and 9 revealed good or moderate antibacterial activity. In addition, molecular docking study of Schiff bases 2-9 was performed by Molecular Operating Environment (MOE 2014.09) program on the matrix metalloproteinase-8 (MMP-8) (Protein Data Bank (PDB) ID: 1MNC) in an attempt to explore their mode of action as anticancer drugs.

2-[(4-Chlorophenyl)(2-phenyl-1H-indol-3-yl)methyl]cyclohexan-1-one

In the title compound, C27H24ClNO, the indole ring is almost orthogonal to the chlorophenyl ring and the mean plane of the cyclohexanone ring, making a dihedral angles of 82.11 (6) and 89.96 (4)°, respectively. In the crystal, a strong N—H...O hydrogen bond links the molecules, forming chains running along thecaxis. The chains are linked by weak C—H...π interactions, forming layers parallel to theacplane.

Synthesis, cytotoxic and urease inhibitory activities of some novel isatin-derived bis-Schiff bases and their copper(ii) complexes

The putative binding mode of the most active compound 3b in the active site of Jack bean urease.

Structure activity relationship, cytotoxicity and evaluation of antioxidant activity of curcumin derivatives

Series of curcumin derivatives/analogues were designed and efficient method for synthesis thereof is described. All the synthesized compounds have been screened for their cytotoxicity and evaluated their antioxidant activity. Cytotoxicity effect has been evaluated against three cell lines Hep-G2, HCT-116 and QG-56 by MTT assay method. Structure activity relationship has revealed that particularly, compound 3c, (IC50 value 6.25 μM) has shown better cytotoxicity effect against three cell lines. According to results of SAR study, it was found that 4H-pyrimido[2,1-b]benzothiazole derivatives (2e and 2f), pyrazoles (3a, 3b, 3c and 3d) benzylidenes (4d) exhibited better antioxidant activity than curcumin. A correlation of structure and activities relationship of these compounds with respect to drug score profiles and other physico-chemical properties of drugs are described and verified experimentally.

Synthesis and antioxidant activity of novel Mannich base of 1,3,4-oxadiazole derivatives possessing 1,4-benzodioxan

A new series of Mannich base of 1,3,4-oxadiazole derivatives possessing 1,4-benzodioxan (6a-6ae) were synthesized and characterized by (1)H NMR, ESI-MS and elemental analysis. The structure of 6b was further confirmed by single crystal X-ray diffraction. All these novel compounds were screened for their in vitro antioxidant activity employing 2,2'-diphenyl-1-picrylhydrazyl radical (DPPH), 2,2'-azinobis (3-ethylbenzothiazoline-6-sulfonate) cationic radical (ABTS(+)) and ferric reducing antioxidant power (FRAP) scavenging assays. Due to the combination of 1,4-benzodioxan, 1,3,4-oxadiazoles and substituted phenyl ring, most of them exhibited nice antioxidant activities. In all of these three assays mentioned above, compounds 6f and 6e showed significant radical scavenging ability comparable to the commonly used antioxidants, BHT and Trolox. Seven compounds with representative substituents or activities were selected for further assays in chemical simulation biological systems-inhibition of microsomal lipid peroxidation (LPO) and protection against 2,2'-azobis (2-amidinopropane hydrochloride) (AAPH) induced DNA strand breakage, in which, 6f and 6e were demonstrated to be of the most potent antioxidant activities.

Synthesis, antimicrobial and anti-cancer activities of some new N-ethyl, N-benzyl and N-benzoyl-3-indolyl heterocycles

A series of 1-(N-substituted-1H-indol-3-yl)-3-arylprop-2-ene-1-ones (2a, b-4a, b) were prepared and allowed to react with urea, thiourea or guanidine to give pyrimidine derivatives 5a, b-13a, b. Reaction of 2a, b-4a, b with ethyl acetoacetate in the presence of a base gave cyclohexanone derivatives 14a, b-16a, b. Reaction of the latter compounds with hydrazine hydrate afforded indazole derivatives 17a, b-19a, b. On the other hand, reaction of 2a, b-4a, b with some hydrazine derivatives, namely hydrazine hydrate, acetyl hydrazine, phenylhydrazine and benzylhydrazine hydrochloride, led to the formation of pyrazole derivatives 20a, b-31a, b. Moreover, reaction of 2a, b-4a, b with hydroxylamine hydrochloride gave isoxazole derivatives 32a, b-34a, b. The newly synthesized compounds were tested for their antimicrobial activity and showed that 4-(N-ethyl-1H-indol-3-yl)-6-(p-chlorophenyl)-pyrimidine-2-amine (11b) was the most active of all the test compounds towards Candida albicans compared to the reference drug cycloheximide. Eighteen new compounds, namely pyrimidin-2(1H)-ones 5a, b-7a, b, pyrimidin-2(1H)-thiones 8a, b-10a, b and pyrimidin-2-amines 11a, b-13a, b derivatives, were tested for their in vitro antiproliferative activity against HEPG2, MCF7 and HCT-116 cancer cell lines. 4-(N-ethyl-1H-indol-3-yl)-6-(p-methoxyphenyl)-pyrimidin-2-amine (11a) was found to be highly active with IC(50) of 0.7 μmol L⁻¹.

Antioxidant capacity and environmentally friendly synthesis of dihydropyrimidin-(2H)-ones promoted by naturally occurring organic acids

The Biginelli reaction is a multicomponent reaction involving the condensation between an aldehyde, a β-ketoester, and urea or thiourea, in the presence of an acid catalyst, producing dihydropyrimidinones (DHPMs). Owing to their important pharmacological properties, the DHPMs have been studied by many authors. However, most of the methodologies used for the synthesis of these compounds require drastic reaction conditions. In the current study, we report an efficient and clean procedure for preparing DHPMs by the use of citric acid or tartaric acid as a promoter of the Biginelli synthesis in ethanol as solvent. In addition, we have evaluated the antioxidant capacity of the compounds synthesized by the 2,2-diphenyl-1-picrylhydrazyl radical scavenging assay and the thiobarbituric acid-reactive species test. Two compounds presented antioxidant activity and also reduced lipid peroxidation at concentrations of 200 and 300 µM. In summary, we report an environmentally friendly procedure for the preparation of DHPMs and demonstrate the antioxidant capacity of some of the compounds.

Synthesis and potential biological activity of some novel 3-[(N-substituted indol-3-yl)methyleneamino]-6-amino-4-aryl-pyrano(2,3-c)pyrazole-5-carbonitriles and 3,6-diamino-4-(N-substituted indol-3-yl)pyrano(2,3-c)pyrazole-5-carbonitriles

Starting from N-substituted indole-3-carboxaldehydes (1a-g) a series of new 3-[(N-substituted indol-3-yl)methyleneamino]-6-amino-4-aryl-pyrano(2,3-c)pyrazole-5-carbonitriles (3a-g and 4a-g) have been synthesized via the acid catalyzed condensation reaction of 1a-g with 3-amino-5-pyrazolone, followed by the reaction with arylidene malononitriles. A series of new 3,6-diamino-4-(N-substituted indol-3-yl)pyrano(2,3-c)pyrazole-5-carbonitriles (7a-g) have been prepared either via the base catalyzed condensation reaction of 1a-g with 3-amino-5-pyrazolone to give 6a-g, followed by the reaction with malononitrile or by the reaction of N-substituted-3-indolylidene malononitriles (5a-g) with 3-amino-5-pyrazolone. According to the obtained results, the newly synthesized compounds possess significant anti-inflammatory, analgesic and anticonvulsant activities. The anticonvulsant potency of certain tested compounds was more pronounced than both anti-inflammatory and analgesic activities. Moreover, most of the newly synthesized compounds possess potential antimicrobial activity against Escherichia coli and Pseudomonas aeruginosa.