Evaluation of crotamine based probes as intracellular targeted contrast agents for magnetic resonance imaging.

Crotamine is a lysine and cysteine rich 42 amino acids long bio-active polypeptide, isolated from the venom of a South American rattlesnake, that can also be used as cell penetrating peptide. A facile synthetic scheme for coupling cargo molecules like fluorophores (carboxyfluorescein) or MRI probes (Gd-DO3A-based macrocycle) is presented. The toxicity, cellular internalization and steady-state accumulation after long-term incubation for 18 h, as well as magnetic resonance relaxivities and cellular relaxation rates of crotamine based probes were evaluated and compared to its shorter synthetic fragment CyLoP-1. The longitudinal relaxivity (r1) of the conjugates of CyLoP-1 and crotamine is significantly lower in medium than in water indicating to the lower contrast enhancement efficacy of DO3A-based probes in biological samples. Carboxyfluorescein labeled crotamine did not exhibit toxicity up to a concentration of 2.5 µM. CyLoP-1 accumulated about four times better within the cells compared to crotamine. Fluorescence microscopy suggests different predominant uptake mechanisms for crotamine and CyLoP-1 in 3T3 cells. While crotamine is predominantly localized in vesicular structures (most likely endosomes and lysosomes) within the cell, CyLoP-1 is mainly homogeneously distributed in the cytosol. The cellular relaxation rate (R1, cell) of the crotamine based probe was not significantly increased whereas the corresponding CyLoP-1-derivative showed a slightly elevated R1, cell. This study indicates the potential of crotamine and in particular the shorter fragment CyLoP-1 to be useful for an efficient transmembrane delivery of agents directed to intracellular (cytosolic) targets. However, the applicability of the conjugates synthesized here as contrast agents in MR imaging is limited. Further improvement is needed to prepare more efficient probes for MRI applications, i.e., by replacing the DO3A- with a DOTA-based chelate.

Design, Synthesis, and Biological Evaluation of Novel MAO-A Inhibitors Targeting Lung Cancer.

Lung cancer is one of the most common causes of cancer-related deaths worldwide. Monoamine Oxidase-A (MAO-A) enzyme mediates the production of reactive oxygen species (ROS) that trigger DNA damage and oxidative injury of cells resulting in tumor initiation and progression. Available MAO-A inhibitors are used as antidepressants, however, their role as anticancer agents is still under investigation. Ligand- and structure-based drug design approaches guided the discovery and development of novel MAO-A inhibitors. A series of 1H indole-2-carboxamide derivatives was prepared and characterized using 1H-NMR, 13C-NMR, and IR. The antiproliferative effects of MAO-A inhibitors were evaluated using the cell viability assay (MTT), and MAO-A activity was evaluated using MAO-A activity assay. The presumed inhibitors significantly inhibited the growth of lung cell lines in a dose- and time dependent manner. The half maximal inhibitory concentration (IC50) values of MAO-A inhibitors (S1, S2, S4, S7, and S10) were 33.37, 146.1, 208.99, 307.7, and 147.2 µM, respectively, in A549. Glide docking against MAO-A showed that the derivatives accommodate MAO-A binding cleft and engage with key binding residues. MAO-A inhibitors provide significant and consistent evidence on MAO-A activity in lung cancer and present a potential target for the development of new chemotherapeutic agents.

Correction: Saadeh et al. Recent Advances in the Synthesis and Biological Activity of 8-Hydroxyquinolines. Molecules 2020, 25, 4321.

The author wishes to make the following correction to this paper [...].

Recent Advances in the Synthesis and Biological Activity of 8-Hydroxyquinolines.

Compounds containing the 8-hydroxyquinoline (8-HQ) 1 nucleus exhibit a wide range of biological activities, including antimicrobial, anticancer, and antifungal effects. The chemistry and biology of this group have attracted the attention of chemists, medicinal chemists, and professionals in health sciences. A number of prescribed drugs incorporate this group, and numerous 8-HQ- based molecules can be used to develop potent lead compounds with good efficacy and low toxicity. This review focusses on the recent advances in the synthesis of 8-HQ derivatives with different pharmacological properties, including anticancer, antiviral, and antibacterial activities. For this purpose, recent relevant references were searched in different known databases and search engines, such as MEDLINE (PubMed), Google Scholar, Science Direct, Scopus, Cochrane, Scientific Information Database (SID), SciFinder, and Institute for Scientific Information (ISI) Web of Knowledge. This review article provides a literature overview of the various synthetic strategies and biological activities of 8-HQ derivatives and covers the recent related literature. Taken together, compounds containing the 8-HQ moiety have huge therapeutic value and can act as potential building blocks for various pharmacologically active scaffolds. In addition, several described compounds in this review could act leads for the development of drugs against numerous diseases including cancer.

N-Phenyl-6-Chloro-4-Hydroxy-2-Quinolone-3-CarboxAmides: Molecular Docking, Synthesis, and Biological Investigation as Anticancer Agents.

Cancer is a multifactorial disease and the second leading cause of death worldwide. Diverse factors induce carcinogenesis, such as diet, smoking, radiation, and genetic defects. The phosphatidylinositol 3-kinase (PI3Kα) has emerged as an attractive target for anticancer drug design. Eighteen derivatives of N-phenyl-6-chloro-4-hydroxy-2-quinolone-3-carboxamide were synthesized and characterized using FT-IR, NMR (1H and 13C), and high-resolution mass spectra (HRMS). The series exhibited distinct antiproliferative activity (IC50 µM) against human epithelial colorectal adenocarcinoma (Caco-2) and colon carcinoma (HCT-116) cell lines, respectively: compounds 16 (37.4, 8.9 µM), 18 (50.9, 3.3 µM), 19 (17.0, 5.3 µM), and 21 (18.9, 4.9 µM). The induced-fit docking (IFD) studies against PI3Kαs showed that the derivatives occupy the PI3Kα binding site and engage with key binding residues.

Molecular Modeling, Synthesis and Biological Evaluation of N-Phenyl-4-Hydroxy-6-Methyl-2-Quinolone-3-CarboxAmides as Anticancer Agents.

The emergence of phosphatidylinositol 3-kinase (PI3Kα) in cancer development has accentuated its significance as a potential target for anticancer drug design. Twenty one derivatives of N-phenyl-4-hydroxy-6-methyl-2-quinolone-3-carboxamide were synthesized and characterized using NMR (1H and 13C) and HRMS. The derivatives displayed inhibitory activity against human epithelial colorectal adenocarcinoma (Caco-2) and human colon cancer (HCT-116) cell lines: compounds 8 (IC50 Caco-2 = 98 µM, IC50 HCT-116 = 337 µM) and 16 (IC50 Caco-2 = 13 µM, IC50 HCT-116 = 240.2 µM). Results showed that compound 16 significantly affected the gene encoding AKT, BAD, and PI3K. The induced-fit docking (IFD) studies against PI3Kα demonstrated that the scaffold accommodates the kinase domains and forms H-bonds with significant binding residues.

Synthesis and in Vivo Lipid-Lowering Activity of Novel Imidazoles-5-carboxamide Derivatives in Triton-WR-1339-Induced Hyperlipidemic Wistar Rats.

A new series of imidazole-5-carboxamide derivatives were prepared and tested for their anti-hyperlipidemic activity in Triton-WR-1339-induced hyperlipidemic Wistar rats. The purpose of this research was to improve benzophenone carboxamides water solubility maintaining at the same time the antihyperlipidemic activity. Compounds 4, 6, 10, and 11 were synthesized through a coupling reaction between imidazoles-5-carbonyl chloride and amino benzophenones. The tested animals (n=48) were divided into six groups: the first group (hyperlipidemic control group; HCG) received an intraperitoneal injection (i.p.) of (300 mg/kg) Triton WR-1339. The second group received i.p. injection of Triton WR-1339 followed by an intra-gastric administration of bezafibrate (100 mg/kg) (bezafibrate; BF). The third, fourth, fifth, and sixth groups received i.p. injection of Triton WR-1339 followed by an intra-gastric administration of (30 mg/kg) of compounds 4, 6, 10, and 11, respectively. At a dose of 30 mg/kg body weight compounds 4, 6, 10, and 11 significantly (p<0.0001) decreased the plasma level of triglyceride (TG), low-density lipoprotein (LDL) and total cholesterol (TC) levels after 18 h of treatment. Additionally, compounds 4, 6, 11 and bezafibrate (100 mg/kg) significantly (p<0.0001) increased the plasma level of high-density lipoprotein (HDL) levels, which is known for its preventive role against atherogenesis. These results demonstrate the possibility of pharmacokinetic properties improvement maintaining the biological and pharmacological profile of these compounds.

Computer-aided design, synthesis, and biological evaluation of new indole-2-carboxamide derivatives as PI3Kα/EGFR inhibitors.

Structure-based drug design and molecular modeling were employed to identify a new series of indole-2-carboxamides as potential anticancer agents. These compounds were synthesized and characterized with the aid of several spectroscopic techniques, such as FT-IR, NMR, and mass spectrometry as well as by elemental analysis. Molecular docking studies confirmed that the newly synthesized compounds accommodate PI3Kα and EGFR kinase catalytic sites and form H-bonding with the key binding residues. The antitumor activity of these new compounds against an array of cancer cell lines (human colon carcinoma (HCT116), leukemia (K562), and breast cancer (MDA231) was evaluated. Results revealed that these compounds were selective against the kinase domain, and none of them showed any inhibitory activity against K562. In addition, results showed that compound 13 exhibited high potency in HCT116 and MDA231 with IC50 values of 19 and 15µM, respectively. Our findings recommend that further optimization of this series would be beneficial for colon and breast cancer treatment.

Molecular modeling based approach, synthesis, and cytotoxic activity of novel benzoin derivatives targeting phosphoinostide 3-kinase (PI3Kα).

The oncogenic potential of phosphatidylinositol 3-kinase (PI3Kα) has made it an attractive target for anticancer drug design. In this work, we describe our efforts to optimize the lead PI3Kα inhibitor 2-hydroxy-1,2-diphenylethanone (benzoin). A series of 2-oxo-1,2-diphenylethyl benzoate analogs were identified as potential PI3Kα inhibitors. Docking studies confirmed that the aromatic interaction is mediating ligand/protein complex formation and identified Lys802 and Val851 as H-bonding key residues. Our biological data in human colon carcinoma HCT116 showed that the structure analogs inhibited cell proliferation and induced apoptosis.

Bis(methyl-sulfon-yl)methane.

In the title compound, C3H8O4S2, the two central S-C(H2) bond lengths are almost identical [1.781 (2) and 1.789 (2) Å]. In the crystal, each mol-ecule utilizes CH2 and CH3 bonds to form weak C-H⋯O hydrogen bonds to six other mol-ecules, thus linking mol-ecules into a three-dimensional network.

Crystal structure of 1,3-di-cyclo-hexyl-4,5-dimethyl-1H-imidazol-3-ium-2-carbodi-thio-ate chloro-form monosolvate.

The title compound, C18H28N2S2·CHCl3, crystallizes as a zwitterion. The C-S bonds are almost equivalent, with lengths of 1.666 (3) and 1.657 (3) Å. The S-C-S bond angle is expanded to 129.54 (16)° and the N-C-N angle is reduced to the tetra-hedal value of 108.8 (2)°. In the crystal, adjacent mol-ecules are linked via C-H⋯S hydrogen bonds, forming chains along [100]. The chloro-form solvent mol-ecule, which is disordered over two positions [occupancy ratio = 0.51 (2):0.49 (2)], is linked to the chain by bifurcated C-H⋯(S,S) hydrogen bonds.

The pharmacological effects of novel 5-fluoro-N-(9,10-dihydro-9,10-dioxoanthracen-8-yl)-1H-indole-2-carboxamide derivatives on plasma lipid profile of Triton-WR-1339-induced Wistar rats.

A novel series of 5-fluoro-N-(9,10-dihydro-9,10-dioxoanthracen-8-yl)-1H-indole-2-carboxamides (3c-3g) were synthesized. The present study was undertaken to investigate the possible antihyperlipidemic effect of these novel compounds on hyperlipidemic rats. Hyperlipidemia was induced by a single intraperitoneal injection of Triton WR-1339 (300 mg/kg). The tested animals were divided into normal control (NCG), hyperlipidemic control (HCG), compounds 3c-, 3d-, 3e-, 3f-, 3g- and bezafibrate (BF)-treated groups. At a dose of 15 mg/kg, compounds 3c-3g and BF (100 mg/kg) significantly (p < 0.0001) reduced elevated plasma triglycerides levels after 12 and 24 h compared to the hyperlipidemic control group. However, only compounds 3e and 3g obviously showed a significant (p < 0.0001) reduction in plasma total cholesterol levels after 12 and 24 h. Moreover, high-density lipoprotein cholesterol levels were significantly increased in all treated groups. The current study demonstrates that 5-fluoro-N-(9,10-dihydro-9,10-dioxoanthracen-8-yl)-1H-indole-2-carboxamides (3c-3g) have a definite antihyperlipidemic potential and these beneficial activities may contribute to their cardioprotective and antiatherosclerotic role.

5-[1-(1,3-Dimethyl-2,4,6-trioxohexa-hydropyrimidin-5-yl)-2-oxoprop-yl]-1,3-di-methyl-pyrimidine-2,4,6(1H,3H,5H)-trione.

The title compound, C15H18N4O7, is a product of the substitution reaction of 5,5-di-bromo-1,3-di-methyl-barbituric acid with sodium sulfide in aqueous acetone. In the crystal, mol-ecules display neither inter-molecular nor intra-molecular hydrogen bonding and the two barbiturate rings adopt the keto form.

4-Chloro-butyl 7-chloro-1-cyclo-propyl-4-(1,3-diethyl-4,6-dioxo-2-sulfanyl-idene-1,3-diazinan-5-yl-idene)-6-fluoro-1,4-di-hydro-quinoline-3-carboxyl-ate.

The title compound, C25H26Cl2FN3O4S, contains two bio-active moieties (thio-barbituric acid and fluoro-quinolone). In the crystal, mol-ecules are linked via C-H⋯O and C-H⋯F hydrogen bonds, forming two-dimensional slab-like networks lying parallel to the bc plane. The benzene ring substituted by F and Cl atoms and the 4-chloro-butyl group seem to be partly disordered, however attempts to model the disorder were unsuccessful.

In vivo antihyperlipidemic activity of a new series of N-(benzoylphenyl) and N-(acetylphenyl)-1-benzofuran-2-carboxamides in rats.

A new series of N-(benzoylphenyl) and N-(acetylphenyl)-1-benzofuran-2-carboxamides (3a-3d and 4a'-4c') were synthesized. Compounds (3a, 3b, and 4a'-4c') were tested in vivo using Triton-WR-1339-induced hyperlipidemic rats as an experimental model for their hypolipidemic activity. The tested animals were divided into eight groups: control, hyperlipidemic, 3a, 3b, 4a', 4b', 4c', and bezafibrate. At a dose of 15 mg/kg, the elevated plasma triglyceride (TG) levels were significantly reduced in compounds 3b (p <0.0001) and 4c' (p <0.05) after 12 and 24 h compared to the normal control group. Furthermore, high-density lipoprotein-cholesterol levels were remarkably increased in compounds 3b (p <0.001) and 4c' (p <0.05). Meanwhile, compound 4b' slightly reduced the TG levels after 12 and 24 h. The present study demonstrated new properties of the novel series of benzofuran-2-carboxamides 3b and 4c' as potent lipid-lowering agents. It is, therefore, reasonable to assume that compounds 3b and 4c' may have a promising potential in the treatment of hyperlipidemia and coronary heart diseases.

2-Bromo-1,3-diisopropyl-4,5-dimethyl-1H-imidazol-3-ium dicyanidoargentate.

The title structure, (C(11)H(20)BrN(2))[Ag(CN)(2))], is built up from an approximately C(2v)-symmetric imidazolium cation and a nearly linear dicyanidoargentate anion [N-Ag-N = 176.6 (9)° and Ag-C-N = 178.8 (9) and 177.2 (11)°]. These two constituents are linked by a remarkably short inter-action between the Br atom of the imidazolium cation [C-Br = 1.85 (3) Å] and one N atom of the cyanidoargentate anion [Br⋯N = 2.96 (2) Å], which is much less than the sum of the van der Waals radii (3.40 Å). The crystal studied was twinned by merohedry.

Formulation and in vitro evaluation of xanthan gum or carbopol 934-based mucoadhesive patches, loaded with nicotine.

Bilayer nicotine mucoadhesive patches were prepared and evaluated to determine the feasibility of the formulation as a nicotine replacement product to aid in smoking cessation. Nicotine patches were prepared using xanthan gum or carbopol 934 as a mucoadhesive polymers and ethyl cellulose as a backing layer. The patches were evaluated for their thickness, weight and content uniformity, swelling behavior, drug-polymers interaction, adhesive properties, and drug release. The physicochemical interactions between nicotine and the polymers were investigated by Fourier transform infrared (FTIR) spectroscopy. Mucoadhesion was assessed using two-arm balance method, and the in vitro release was studied using the Franz cell. FTIR revealed that there was an acid base interaction between nicotine and carbopol as well as nicotine and xanthan. Interestingly, the mucoadhesion and in vitro release studies indicated that this interaction was strong between the drug and carbopol whereas it was weak between the drug and xanthan. Loading nicotine concentration to non-medicated patches showed a significant decrease in the mucoadhesion strength of carbopol patches and no significant effect on the mucoadhesion strength of xanthan patches. In vitro release studies of the xanthan patches showed a reasonable fast initial release profile followed by controlled drug release over a 10-h period.

1,3-Diisopropyl-4,5-dimethyl-imidazolium benzene-sulfonate.

In the title salt, C(11)H(21)N(2) (+)·C(6)H(5)O(3)S(-), which has two cation-anion pairs in the asymmetric unit, the two imidazolium cations are linked to two separate acceptor O atoms of one of the benzene-sulfonate anions through aromatic C-H⋯O hydrogen bonds, while the second anion is unassociated.

An Integrative Informatics Approach to Explain the Mechanism of Action of N1-(Anthraquinon-2-yl) Amidrazones as BCR/ABL Inhibitors.

BACKGROUND: Drugs incorporating heterocyclic chemical skeletons possess a plethora of therapeutic activities such as anticancer, antimicrobial, antihypertensive, and antipsychiatric effects. It is becoming routine, nowadays, to use cheminformatics and bioinformatics methods to elucidate the mechanism(s) of action of such drugs. OBJECTIVE: This study aimed to probe the activity of a recently published series of N1- (anthraquinon-2-yl) amidrazone piperazine derivatives employing computational strategies[1], identify their structural basis of binding to BCR/ABL kinase domain, and explain their anticancer activities in human breast adenocarcinoma (MCF-7) and chronic myelogenous leukemia (K562) cell lines. METHODS: We applied an in silico integrative informatics approach integrating molecular descriptors, docking studies, cheminformatics, and network analysis. RESULTS: Our results highlighted the possible involvement of the BCR/ABL and DRD2 pathways in the anticancer activity of the studied compounds, and induced fit docking (IFD) indicated that the BCR/ABL kinase domain is a putative drug target. Additionally, high-scoring docking poses identified a unique network of hydrogen bonding with amino acids Y253, K271, E286, V299, L301, T315, M318, I360, R362, V379, and D3810. CONCLUSION: Using an integrative informatics approach to characterize our anticancer compounds, we were able to explain the biological differences between synthesized and biologically validated amidrazone piperazine anticancer agents. We were also able to postulate a mechanism of action of this novel group of anticancer agents.

New derivatives of sulfonylhydrazone as potential antitumor agents: Design, synthesis and cheminformatics evaluation.

Phosphoinositide 3-kinase α (PI3Kα) is a propitious target for designing anticancer drugs. A series of new N'-(diphenylmethylene)benzenesulfonohydrazide was synthesized and characterized using FT-IR, NMR (1H and 13C), HRMS, and elemental analysis. Target compounds exhibited an antiproliferative effect against the human colon carcinoma (HCT-116) cell line. Our cheminformatics analysis indicated that the para-tailored derivatives [p-NO2 (3) and p-CF3 (7)] have better ionization potentials based on calculated Moran autocorrelations and ionization potentials. Subsequent in vitro cell proliferation assays validated our cheminformatics results by providing experimental evidence that both derivatives 3 and 7 exhibited improved antiproliferative activities against HCT-116. Hence, our results emphasized the importance of electron-withdrawing groups and hydrogen bond-acceptors in the rational design of small-molecule chemical ligands targeting PI3Kα. These results agreed with the induced-fit docking against PI3Kα, highlighting the role of p-substituted aromatic rings in guiding the ligand-PI3Kα complex formation, by targeting a hydrophobic pocket in the ligand-binding site and forming π-stacking interactions with a nearby tryptophan residue.