Effects of Lidocaine-Derived Organic Compounds on Eosinophil Activation and Survival.

Lidocaine, a local anesthetic, is known to possess anti-inflammatory properties. However, its clinical use is limited by inconveniences, such as its local synesthetic effects. This study evaluated lidocaine analogs designed and synthesized to overcome the disadvantages of lidocaine, having anti-inflammatory properties. Interleukin 5 (IL-5)-induced eosinophil activation and survival were evaluated using 36 lidocaine analogs with modified lidocaine structure on the aromatic or the acyl moiety or both. Eosinophil survival was evaluated using a CellTiter 96® aqueous cell proliferation assay kit. Superoxide production was determined using the superoxide dismutase-inhibitable reduction of cytochrome C method. Eosinophil cationic protein (ECP), IL-8, and transcription factor expression were determined using enzyme-linked immunosorbent assay. The platelet-activating factor (PAF)-induced migration assay was performed using a Transwell insert system. Compounds EI137 and EI341 inhibited IL-5-induced eosinophil survival and superoxide and ECP production in a concentration-dependent manner. These compounds also significantly reduced IL-8 production. Although compounds EI137 and EI341 significantly reduced phosphorylated ERK 1/2 expression, they did not influence other total and phosphorylated transcription factors. Moreover, 1000 µM of compound EI341 only inhibited PAF-induced migration of eosinophils. Lidocaine analogs EI137 and EI341 inhibited IL-5-mediated activation and survival of eosinophils. These compounds could be new therapeutic agents to treat eosinophilic inflammatory diseases.

Novel Azine Linked Hybrids of 2-Indolinone and Thiazolodinone Scaffolds as CDK2 Inhibitors with Potential Anticancer Activity: In Silico Design, Synthesis, Biological, Molecular Dynamics and Binding Free Energy Studies.

Molecular hybrid of 2-indolinone-thiazolidinone is a well known scaffold for variable biological activities including anticancer activity. Accordingly, in the current work aided with structure-based molecular modeling studies, a library of novel twenty-six hybrids, 4(a-z), was designed and synthesized. Docking studies in the active site of CDK2, one of the key checkpoints enzymes, revealed that the binding scores of the designed molecules are comparable to the reference enzyme's inhibitors Sunitinib, Nintedanib, and Semaxanib. Variable antiproliferative activities are shown for these molecules against human liver (HepG2), breast (MCF7), and colon (HCT-29) cell lines considering Doxrubacin as a refrence drug. Compared to cytotoxic activities on the normal fibroblasts (WI-38), the tested molecules had better selectivity against the cancerous cells, expressed by their selectivity index (SI), than Doxrubacin and compound 4i was the safest compound. CDK2 inhibitory results of compounds 4f, 4g, 4h, and 4w showed IC50 at 59.43, 143.6, 27.42, and 61.63 nM respectively, while that of Sunitinib was 23.8 nM. To clarify the obtained biological activities of these molecules, broad docking and molecular dynamic simulations studies were undertaken and confirmed the consistency between the computational and the in vitro CDK2 inhibitory activities. Furthermore, in silico ADME/Tox profiles were done for the most active molecules using SwissADME and pkCSM-pharmacokinetics web-based methods predicted good pharmacokinetics, bioavailability, and toxicity profiles for the tested compounds.

New cell cycle checkpoint pathways regulators with 2-Oxo-indoline scaffold as potential anticancer agents: Design, synthesis, biological activities and in silico studies.

3-Arylidene-2-oxo-indoline derivatives are at the heart of a wide range of clinically, medicinally and biologically important compounds among the 2-oxo-indolines. A number of 3-arylidene-2-oxo-indolines have been approved for clinical application. Accordingly, the current work describes the structural based design of 3-arylidene-2-oxindole derivatives through docking of their structures in the active site of CDK2 as one of the dominant enzyme checkpoints. Based on the docking studies a range of 3-arylidene-2-oxindole derivatives, 5(a-n) and 6(a-x), with variable substituents at positions 1 and 5 of the 2-oxindole as well as 3 and 4 of the aryl moieties were synthesized. These molecules exist in either E or Z diastereomer about the exocyclic double bond at position 3 of oxindole nucleus. Their structures were confirmed by spectral and elemental methods of analyses and the E/Z-configuration of the diastereomers was confirmed by 2D NOE analysis. In vitro cytotoxicity of these molecules was tested against four cancerous cell lines, namely, breast cancer cell line (MCF7), liver carcinoma cell line (HepG2), cervix carcinoma cell line (HeLa), colon cancer cell line (HCT116) in addition to the diploid human normal non-cancerous cell line (F180) using SRB and MTT assays. The tested molecules showed variable cytotoxic effects on the four cancer cell lines with pronounced selectivity compared to the normal one (F180) with no significant difference between E and Z diastereomers. Compounds 5a, 5b, 5e1, 5m, 6f and 6j were tested for the effect on the expression on CDK2, p53, caspase-3 and caspase-9 proteins, and revealed variable activities compared to the positive controls Sunitinib and Staurosporine. These molecules seem to have multiple cellular targets as they induced expression of p53 and caspases while inhibited that of CDK2. Apoptotic effect of compound 6j was further investigated using annexin V-FITC/PI dual staining assay and showed that cells treated with 6j have nearly 15 folds greater apoptotic effect than that of the control cells. Furthermore, inhibitory activity of compounds 5a, 5b, 5e1, 5m, 6f and 6j on CDK2 enzyme were tested and revealed that compound 6f, with the N-4-flourobenzyl- 2-oxindole and 3-p-chlorobenzylidene moieties, has a comparable inhibitory activity to the reference drug sunitinib.

Inversion kinetics of some E/Z 3-(benzylidene)-2-oxo-indoline derivatives and their in silico CDK2 docking studies.

The structure-based design of some CDK2 inhibitors with a 3-(benzylidene)indolin-2-one scaffold as potential anticancer agents was realized. Target compounds were obtained as E/Z mixtures and were resolved to corresponding E- and Z-diastereomers. In silico studies using MOE 2019.01 software revealed better docking on the targeted enzyme for the Z-diastereomer compared to the E-one. A time-dependent kinetic isomerization study was carried out for the inversion of E/Z diastereomers in DMSO-d6 at room temperature, and were found to obey the first order kinetic reactions. Furthermore, a determination of the kinetic inter-conversion rate order by graphical analysis method and calculation of the rate constant and half-life of this kinetic process were carried out. For the prediction of the stability of the diastereomer(s), a good multiple regression equation was generated between the reaction rates of isomerization and some QM parameters with significant p value.

Design and synthesis of novel isatin-based derivatives targeting cell cycle checkpoint pathways as potential anticancer agents.

In recent years, cell cycle and checkpoint pathways regulation are offering new therapeutic approaches against cancer. Isatin, is a well exploited scaffold in the anticancer domain. Accordingly, the current work describes the design and synthesis of two series of (Z)-3-substituted-2-(((E/Z)-5-substituted-2-oxo-1-substituted-indolin-3-ylidene)hydrazinylidene)-thiazolidin-4-ones, 4(a-s) and (E/Z)-1-substituted-3-(((Z)-3-substituted-4-methylthiazol-2(3H)-ylidene)hydrazineylidene)-5-substituted-indolin-2-ones, 5(a-s). The structures of the synthesized molecules were confirmed by spectral and elemental methods of analyses. Pure diastereomers were further identified with 1H-1H-NOESY and confirmed with X-ray crystallography. The target compounds were tested in vitro for their cytotoxicity against three human epithelial cell lines, liver (HepG2), breast (MCF-7), and colon (HT-29) in addition to the diploid human normal cells (WI-38) compared to doxorubicin as a reference drug. Variable cytotoxic effects (IC50 3.29-100 µmol) were reported on the three cancer cell lines with pronounced selectivity compared to the normal one WI-38. The potency of the most active compounds, 4o, 4s, 5e, 5f, 5l, 5m and 5o (IC50 3.29-9.92 µmol), in both series associated with the (Z) configurations of N = thiazolidin/ene or one, however, the configuration of the N = isatin moiety seemed to be of no importance to the activity. The tested compounds were grouped for their possible mechanism of action into 4 categories. Compound 4o with no apparent effect on all genes examined. Compounds 4s and 5o affected all genes investigated and seem to have multiple cellular targets; induced the expression of p53 and caspases, and downregulated that of CDK1. Compounds 5l and 5m directly elevated the expression of initiator and effector caspases without going through p53 pathway. Finally, compounds 5e and 5f elevated the expression of p53 and inhibited CDK1. Compounds 4s, 5e, 5f, 5l, 5m, and 5o caused a significant elevation in the activity of cleaved caspase 3 as well. Docking studies on CDK1 revealed that the active molecules bind to the tested enzyme by the same manner of the co-crystallized ligands and the isatin-thiazoldinone/ene scaffold is essential for binding of these molecules.

Pharmacokinetic studies of naproxen amides of some amino acid esters with promising colorectal cancer chemopreventive activity.

Naproxen (nap) is belonging to Non-steriodal anti-inflammatory drugs (NSAIDs) group of drugs that characterized by their free carboxylic group. The therapeutic activity of nap is usually accompanied by GI untoward side effects. Recently synthesized naproxen amides of some amino acid esters prodrugs to mask the free carboxylic group were reported. Those prodrugs showed a promising colorectal cancer chemopreventive activity. The current study aims to investigate the fate and hydrolysis of the prodrugs kinetically in different pH conditions, simulated gastric and intestinal fluids with pHs of 1.2, 5.5 and 7.4 in vitro at 37 °C. The effect of enzymes on the hydrolysis of prodrugs was also studied through incubation of these prodrugs at 37 °C in human plasma and rat liver homogenates. The pharmacokinetic parameters of selected prodrugs and the liberated nap were studied after oral and intraperitoneal administration in male wistar rats. The results showed the hydrolysis of naproxen amides of amino acid esters to nap through two steps first by degradation of the ester moiety to form the amide of nap with amino acid and the second was through the degradation of the amide link to liberate nap. The two reactions were followed and studied kinetically where K1 and K2 (rate constants of degradation) is reported. The hydrolysis of prodrugs was faster in liver homogenates than in plasma. The relative bioavailability of the liberated nap in vivo was higher in case of prodrug containing ethyl glycinate moiety than that occupied l-valine ethyl ester moiety. Each of nap. prodrugs containing ethyl glycinate and l-valine ethyl ester moieties appears promising in liberating nap, decreasing direct GI side effect and consequently their colorectal cancer chemopreventive activity.

Synthesis, characterization and pharmacological evaluation of certain enzymatically cleavable NSAIDs amide prodrugs.

The presence of free carboxylic acid group in majority of non-steroidal anti-inflammatory drug (NSAIDs) is responsible from GI irritation. Coupling of the appropriate NSAIDs (diclofenac, naproxen, dexibuprofen and meclofenamic acid) 1-4, respectively with the appropriate amino acid ester 5 using dicyclohexylcarbodiimide afforded prodrugs 6-13. The structures of the prodrugs were verified based on spectral data. Chemical hydrolysis studies performed in three different non enzymatic buffer solutions at pH 1.2, 5.5 and 7.4, as well as in 80% human plasma and 10% rat liver homogenate using HPLC indicate no conversion of prodrugs to their respective NSAID in the studied buffers, while they underwent a reasonable plasma and rat liver homogenate hydrolysis. Furthermore, ulcerogenicity of prodrugs 9 and 12 were studied and results revealed no gastro-ulcerogenic effects.

Synthesis and anti-mycobacterial activity of 4-(4-phenyl-1H-1,2,3-triazol-1-yl)salicylhydrazones: revitalizing an old drug.

The antitubercular drug; para-aminosalicylic acid (PAS) was used as the core scaffold for the design of a series of 1H-1,2,3-triazolylsalicylhydrazones upon coupling with triazole and arylhydrazone moietis to furnish a single molecular architecture. The obtained derivatives were screened against Mycobacterium tuberculosis H37Rv revealing good to high activity for the active compounds (MIC values of 0.39-1.5 µg/mL) compared to the marketed drugs isoniazid, rifampicin and ethambutol. Moreover, the most active analogue N-(1-(4-chlorobenzyl)-2-oxoindolin-3-ylidene)-2-hydroxy-4-(4-phenyl-1H-1,2,3-triazol-1-yl)-benzohydrazide (20) was found to be ten-fold more potent than PAS and equipotent to rifampicin (MIC 0.39 µg/mL), while exhibiting low cytotoxicity with a selectivity index of >128. In addition, this compound was shown to be active against persistent forms of mycobacteria comparable to standard drugs in nutrient starvation model. Accordingly, we introduce compound 20 as a valuable lead for further development. A 3D-QSAR study was also conducted to help in explaining the observed activity and to serve as a tool for further development.

Novel non-cyclooxygenase inhibitory derivatives of naproxen for colorectal cancer chemoprevention.

A structure-based medicinal chemistry strategy was applied to design new naproxen derivatives that show growth inhibitory activity against human colon tumor cells through a cyclooxygenase (COX)-independent mechanism. In vitro testing of the synthesized compounds against the human HT-29 colon tumor cell line revealed enhanced growth inhibitory activity compared to the parent naproxen with 3a showing IC50 of 11.4 µM (two orders of magnitude more potent than naproxen). Selectivity of 3a was investigated against a panel of three tumor and one normal colon cell lines and showed up to six times less toxicity against normal colonocytes. Compound 3a was shown to induce dose-dependent apoptosis of HT116 colon tumor cells as evidenced by measuring the activity of caspases-3 and 7. None of the synthesized compounds showed activity against COX-1 or COX-2 isozymes, confirming a COX-independent mechanism of action. Compound 3k was found to have no ulcerogenic effect in rats as indicated by electron microscope scanning of the stomach after oral administration. A pharmacophore model was developed for elucidating structure-activity relationships and subsequent chemical optimization for this series of compounds as colorectal cancer chemopreventive drugs.

Design, synthesis and pharmacophoric model building of novel substituted nicotinic acid hydrazones with potential antiproliferative activity.

Novel 6-aryl-2-methylnicotinic acid hydrazides 4a-c and their corresponding hydrazones 5a-c and 6a-i were synthesized. X-ray single crystal diffraction of 6h confirmed the chemical structure of hydrazones 6a-i. Antiproliferative activity of the synthetic compounds was investigated against K562 leukemia cell lines. Variable cell growth inhibitory activities were obtained with IC50 range from 24.99 to 66.78 µM where the compound 6c exhibited the maximum activity. Structure activity relationship analysis has been performed and a common pharmacophore model for the synthesized derivatives has been obtained by using the pharmacophore elucidation module of the software MOE. The best model obtained is characterized by two projected locations of potential H-bond donors (F 3 and F4) and two Aromatic annotations (F1 and F2).

Schiff bases of indoline-2,3-dione (isatin) with potential antiproliferative activity.

BACKGROUND: Cancer is one of the most dreaded diseases and it is a leading cause of mankind death worldwide. Recent reports documented a remarkable antiproliferative activity of isatin nucleus against various cancer cell lines. The current work describes the antiproliferative activity of Schiff bases of combinatorial mixtures of the isatin derivatives M1-M22 as well as the individual compounds 1-11(A-K) of these combinatorial mixtures. RESULTS: The designed combinatorial library composed from eleven hydrazides A-K and eleven isatin derivatives 1-11 has been synthesized to formally generate 22 mixtures, M1-M22 of 121 Schiff bases, and their antiproliferative activity against K562 chronic myelogenous leukemia cells was evaluated. The indexed method of analysis of the prepared library was applied to elucidate the active components in the tested mixtures M1-M22. The predictions from the crossing procedure was validated through evaluation of the antiproliferative activity of individual compounds 1-11(A-K) of the library. Individual compounds 1-11(A-K) were also evaluated against the non-tumorigenic MCF-12A cell line to investigate their selectivity. A pharmacophore model was developed to further optimize the antiproliferative activity among this series of compounds. CONCLUSIONS: Variable antiproliferative activity was revealed with the investigated mixtures M1-M22 and the individual compounds 1-11(A-K). Most of the tested mixtures and several individual Schiff bases displayed high potency with IC50 values in the low micromolar range. A considerable selectivity of some individual compounds to the tumorigenic K562 cell line compared with the non-tumorigenic MCF-12A cell line was observed as indicated by their selectivity index (SI).

3,5-disubstituted thiadiazine-2-thiones: new cell-cycle inhibitors.

Two series, a and b, of 3-cyclopentyl or (3-cyclohexyl)-5-substituted-3,4,5,6-tetrahydro-2H-1,3,5-thiadiazine-2-thiones (THTT) 2a-9a and 3b, 4b, 6b-9b, were synthesized to develop new cell cycle inhibitors. Variable and promising in vitro antiproliferative activities were shown with the synthesized THTT derivatives. Compound 5a with a 5-cyclopentyl group on position-3 and a glutamine residue on position-5 of the THTT moiety showed maximum activity (IC(50) = 8.98 µM). Compound 5a possessed notable cell cycle disrupting and apoptotic activities with enhanced selectivity against cancer cells, suggesting the potential for the development of new selective cell cycle inhibitors. There is no evident relationship between the cytotoxic activity of the tested compounds and their lipophilicity. In addition, a pharmacophore based study was performed to explain the biological activity on structural bases. A successful model was generated with a good correlation with the observed activity.

Schiff bases of indoline-2,3-dione: potential novel inhibitors of Mycobacterium tuberculosis (Mtb) DNA gyrase.

In the present study a series of Schiff bases of indoline-2,3-dione were synthesized and investigated for their Mtb gyrase inhibitory activity. Promising inhibitory activity was demonstrated with some of these derivatives, which exhibited IC(50) values ranging from 50-157 mM. The orientation and the ligand-receptor interactions of such molecules within the Mtb DNA gyrase A subunit active site were investigated applying a multi-step docking protocol using Molecular Operating Environment (MOE) and Autodock4 docking software. The results revealed the importance of the isatin moiety and the connecting side chain for strong interactions with the enzyme active site. Among the tested compounds the terminal aromatic ring benzofuran showed the best activity. Promising new leads for developing a novel class of Mtb gyrase inhibitors were obtained from Schiff bases of indoline-2,3-dione.

(Z)-Ethyl 2-cyano-2-{2-[5,6-dimethyl-4-(thio-phen-2-yl)-1H-pyrazolo-[3,4-b]pyridin-3-yl]hydrazinylidene}acetate.

In the title compound, C(17)H(16)N(6)O(2)S, an intra-molecular N-H⋯O inter-action generates an S(6) ring. The pyridine ring makes a dihedral angle of 71.38 (11)° with the thio-phene ring. In the crystal, mol-ecules are linked by a pair of N-H⋯N hydrogen bonds, forming an inversion dimer. The dimers are stacked in columns along the b axis through weak inter-molecular C-H⋯N hydrogen bonds.

Microwave-assisted solution-phase synthesis and DART-mass spectrometric monitoring of a combinatorial library of indolin-2,3-dione schiff bases with potential antimycobacterial activity.

A combinatorial library composed of eleven hydrazides A-K and eleven indolin-1,2-dione derivatives 1-11 has been designed to formally generate sublibraries of 22 mixtures, M(1)-M(22) comprising of 121 Schiff bases, A-K(1-11). The designed library has been synthesized by the solution-phase method and microwave-assisted synthetic techniques. The formation of individual compounds of each mixture was confirmed by Direct Analysis in Real Time (DART) as ionization technique connected to an Ion Trap as a mass detector. The synthesized mixtures were evaluated for their antimycobacterial activity against four Mycobacterium strains; M. intercellulari, M. xenopi, M. cheleneoi and M. smegmatis. Variable antimycobacterial activity was revealed with the investigated mixtures and maximum activity was shown by M(8), M(10), M(11), and M(15) with MIC values of 1.5, 3.1, 6.2 and 0.09 µg/mL, respectively. Application of the indexed method of analysis on these active mixtures revealed that compounds D(8), D(10) and D(11) may contribute to the activity of the tested mixtures.

Microwave-assisted one-step synthesis of fenamic acid hydrazides from the corresponding acids.

A facile and efficient method for synthesis of fenamic acid hydrazides from their acids in one-step reaction under microwave irradiation and solvent-free conditions was developed. Compared with the two-step conventional heating method, the process was simple, the reaction time was very short and the yields were almost quantitative.

Schiff bases of indoline-2,3-dione (isatin) derivatives and nalidixic acid carbohydrazide, synthesis, antitubercular activity and pharmacophoric model building.

Tuberculosis (TB) remains among the world's great public health challenges. Worldwide resurgence of TB is due to two major problems: the AIDS epidemic, which started in the mid-1980s, and the outbreak of multidrug resistant (MDR) TB. Thus, there is an urgent need for anti-TB drugs with enhanced activity against MDR strains. In recent years, Schiff bases of 1H-indole-2,3-diones are reported to exhibit anti-TB activity. On the other hand, several quinolone antibacterial agents have been examined as inhibitors of TB, as well as other mycobacterial infections. Accordingly, the current work involved design and synthesis of Schiff bases of nalidixic acid carbohydrazide and isatin derivatives (5,6a-f and 7,8a-c). Structures of the synthesized derivatives were confirmed on the bases of spectral methods of analyses. Anti-TB activity of the synthesized derivatives was investigated against four Mycobacterium strains: Mycobacterium intercellulari, Mycobacterium xenopi, Mycobacterium cheleneo and Mycobacterium smegmatis. Modest anti-TB activity was observed within the investigated compounds, however, compound 5f revealed potent anti-TB activity with MIC 0.625 microg/ml, which is 20 times greater than the reference drug isoniazid, INH, (MIC = 12.5 microg/ml). A hypothetical pharmacophore model was built using Molecular Operating Environment (MOE) program and 10 compounds structurally related to the synthesized ones with reported anti-TB activity. The Pharmacophoric model built revealed the necessity of the following pharmacophoric features for anti-TB activity: aromatic center, hydrogen bond acceptor/metal ligator center, hydrogen bond donor center and aromatic center/hydrophobic area. Theses features were consistent with the found anti-TB activity of the tested compounds.

Cell cycle disruption and apoptotic activity of 3-aminothiazolo[3,2-a]benzimidazole-2-carbonitrile and its homologues.

3-aminothiazolo[3,2-a]benzimidazole-2-carbonitrile (2) was prepared and upon hydrolysis using concentrated sulfuric acid or phosphoric acid resulted in the corresponding 3-aminothiazolo[3,2-a]benzimidazole-2-carboxamide derivative (3). Cyclization of the 2 using acetic anhydride or formic acid gave the corresponding pyrimido[4',5':4,5]thiazolo[3,2-a]benzimidazol-4(3H)-one (5) in good yields. Acetylation of 2 with acetic anhydride in pyridine afforded N-acetylaminothiazolo[3,2-a]benzimidazole-2-carbonitrile (6). In vitro antiproliferative activities of synthesized compounds were investigated at The National Cancer Institute (NCI), USA, according to their applied protocol. Compound 6 revealed significant antiproliferative activity, however, weak activity was shown by the other derivatives. Cell cycle disruption and apoptotic activity of 6 were studied, interestingly, 6 has the ability to arrest G2/M phase and it can induce apoptosis in time dependent manner.

Pharmacophoric model building for antitubercular activity of the individual Schiff bases of small combinatorial library.

Synthesis and evaluation of anti-TB activity of individual compounds of Schiff bases combinatorial library were done against Mycobacterium tuberculosis H(37)Rv at a single concentration of 6.25mug/mL according to the protocol of TAACF. Compounds 2C and 3D produced 99% inhibitory activity on the investigated organism, while the other tested compounds showed lower activity ranging from 35 to 84%. It was found that there are no relation between the anti-TB activity of the tested compounds and their lipophilicity expressed by ClogP of these compounds. A 3D pharmacophoric model has been generated by Molecular Operating Environment (MOE) using a training set of 10 reported anti-TB compounds and testing the synthesized compounds (1A, 1B, 1D, 1E, 2C, 3A, 3C, 3D, 3E and 4A-4E). The generated pharmacophoric features include, F1: hydrogen bond donors (Don), F2: aromatic rings (Aro), F3: hydrogen bond acceptors (Acc)/metal ligator (ML), F4: Aro/hydrophobic (Hyd). In all hit set, it was found that the amidic nitrogen CONH-NC fitted the region of the Don, F1, while the amidic carbonyl group fitted the region of the Acc/ML, F3. The distances bridging F1 to F2, F3 and F4 were essential for anti-TB activity in the developed pharmacophore model, as it was confirmed from model validation procedure.