New acetylphenol-based acyl thioureas broaden the scope of drug candidates for urease inhibition: synthesis, in vitro screening and in silico analysis.

Helicobacter pylori urease remains a validated drug target for the eradication of pervasive chronic stomach infection that leads to severe human health diseases such as gastritis and stomach cancer. The increased failure of current treatment protocols because of resistance to broadband antibiotics, severe side effects and low compliance underscore the need for a targeted eradication therapy. Therefore, in the present research, we have developed a new series of acetylphenol-based acyl thioureas that can potentially provide a new template for drug candidates to inhibit urease enzyme. Newly synthesized compounds 7a-j were evaluated for urease inhibitory strength using thiourea as a positive control. In vitro inhibitory results revealed that all the tested compounds were significantly potent than the standard drug. The most active lead 7f competitively inhibited the enzyme and displayed an IC50 value of 0.054 ± 0.002 µM, a ~413-fold strong inhibitory potential than thiourea (IC50 = 22.3 ± 0.031 µM). Various insightful structure-activity relationships were developed showing the key structural requirements for potent inhibitory effects. Molecular docking analysis of 7f inside the active pocket of urease suggested several important interactions with amino acid residues such as ILE411, MET637, ARG439, GLN635, ALA636 and ALA440. Finally, pharmacokinetic properties suggested that the tested derivatives are safe to develop as low-molecular-weight drugs to treat ureolytic bacterial infections.

Synthesis, characterization and biological evaluation of indomethacin derived thioureas as purinergic (P2Y1, P2Y2, P2Y4, and P2Y6) receptor antagonists.

G-protein-coupled receptors for extracellular nucleotides are known as P2Y receptors and are made up of eight members that are encoded by distinct genes and can be classified into two classes based on their affinity for specific G-proteins. P2Y receptor modulators have been studied extensively, but only a few small-molecule P2Y receptor antagonists have been discovered so far and approved by drug agencies. Derivatives of indole carboxamide have been identified as P2Y12 and P2X7 antagonist, as a result, we developed and tested a series of indole derivatives4a-lhaving thiourea moiety as P2Y receptor antagonist by using a fluorescence-based assay to measure the inhibition of intracellular calcium release in 1321N1 astrocytoma cells that had been stably transfected with the P2Y1, P2Y2, P2Y4 and P2Y6 receptors. Most of the compounds exhibited moderate to excellent inhibition activity against P2Y1 receptor subtype. The series most potent compound, 4h exhibited an IC50 value of 0.36 ± 0.01 µM selectivity against other subtypes of P2Y receptor. To investigate the ligand-receptor interactions, the molecular docking studies were carried out. Compound 4h is the most potent P2Y1 receptor antagonist due to interaction with an important amino acid residue Pro105, in addition to Ile108, Phe119, and Leu102.

Synthesis, X-ray, Hirshfeld surface analysis, exploration of DNA binding, urease enzyme inhibition and anticancer activities of novel adamantane-naphthyl thiourea conjugate.

1-(adamantane-1-carbonyl-3-(1-naphthyl)) thiourea (C22H24N2OS (4), was synthesized by the reaction of freshly prepared adamantane-1-carbonyl chloride from corresponding acid (3) with ammonium thiocyanate in 1:1 M ratio in dry acetone to afford the adamantane-1-carbonyl isothiocyanate (2) in situ followed by treatment with 1-naphthyl amine (3). The structure was established by elemental analyses, FTIR, 1H, 13C NMR and mass spectroscopy. The molecular and crystal structure were determined by single crystal X-ray analysis. It belongs to triclinic system P - 1 space group with a = 6.7832(5) Å, b = 11.1810(8) Å, c = 13.6660(10) Å, α = 105.941(6)°, ß = 103.730(6)°, γ = 104.562(6)°, Z = 2, V = 910.82(11) Å3. The naphthyl group is almost planar. In the crystal structure, intermolecular CH···O hydrogen bonds link the molecules into centrosymmetric dimers, enclosing R22(14) ring motifs, while the intramolecular NH···O hydrogen bonds enclose S(6) ring motifs, in which they may be effective in the stabilization of the structure. The Hirshfeld surface analysis of the crystal structure indicates that the most important contributions for the crystal packing are from H … H (59.3%), H … C/C … H (19.8%) and H … S/S … H (10.1%) interactions. Hydrogen bonding and van der Waals interactions are the dominant interactions in the crystal packing. DFT, molecular docking and urease inhibition studies revealed stability and electron withdrawing nature of 4 as compared to DNA base pairs and residues of urease. The DNA binding results from docking, UV- visible spectroscopy, and viscosity studies indicated significant binding of 4 with the DNA via intercalation and groove binding. Further investigation of the compound was done on hepatocellular carcinoma; Huh-7 cell line as well as normal human embryonic kidney; Hek-293 cell line. The compound showed significant cytotoxic activity against Huh-7 cells in comparison to normal Hek-293 cells indicating selective cytotoxicity towards cancer cells.

An efficient synthetic approach toward a sporadic heterocyclic scaffold: 1,3-Oxathiol-2-ylidenes; alkaline phosphatase inhibition and molecular docking studies.

We developed a simple and robust method for synthesis of 1,3-oxathiol-2-ylidene benzamides (4a-m) a sporadic class of heterocycles, by reacting freshly prepared aroyl isothiocyanates, with ethyl 2-chloroacetoacetate in presence of N-methylimidazole in dry acetonitrile. The synthesized compounds were explored for their inhibition against alkaline phosphatases and HeLa cancer cell lines. The results suggest that almost all the compounds possess good % inhibition against both enzymes, with compound 4m showing dual inhibition while 4g and 4i as potent and selective inhibitors of TNAP and c-IAP respectively. Structure activity relationship for the active members of series has been carried out based on molecular docking studies. The result of SAR shows the involvement of active inhibitors in H-bonding at various sites with different amino acid residues in addition to secondary metal ion interactions with Zn ions inside the active pocket of the enzyme. The π-π interactions between the 1,3-oxathiole ring and imidazole ring of His321 and His 317 further defines the dual mode of inhibition by compound 4m. These compounds also possess inhibition potential against cervical cell lines in the range of 2.42-69.03% with the maximum inhibition shown by the unsubstituted member 4a compared to the reference drug cisplatin.

Development of a deep-red fluorescent glucose-conjugated bioprobe for in vivo tumor targeting.

A C1-type d-glucose-conjugated fluorescent probe Glu-1-O-DCSN was synthesized and showed deep-red emission at 685 nm with a Stokes shift of up to 150 nm in DMSO. In in vitro live cell imaging, Glu-1-O-DCSN exhibited similar and competitive uptake behaviours to d-glucose and was selectively located in mitochondria. Furthermore, Glu-1-O-DCSN was successfully employed for in vivo hypermetabolic tumor targeting.

Design, synthesis and biological evaluation of trinary benzocoumarin-thiazoles-azomethines derivatives as effective and selective inhibitors of alkaline phosphatase.

Design, synthesis and characterization of new trinary Benzocoumarin-Thiazoles-Azomethine derivatives having three bioactive scaffolds in a single structural unit were carried out. The newly synthesized molecules were investigated for the inhibitory activity on human tissue nonspecific alkaline phosphatase (h-TNAP) and human intestinal alkaline phosphatase (h-IAP) isozymes. All the tested compounds exhibited the potent inhibition profile on both isozymes of alkaline phosphatase i.e., h-TNAP and h-IAP. Molecular docking studies were performed to explore the putative binding mode of interactions of selective inhibitors. Moreover, the synthesized derivatives were evaluated against cervical cancer cell line, HeLa and a few compounds exhibited significant inhibition in the range of 21.0-69.7%. The derivatives can be potential and selective alkaline phosphatase inhibitors for future studies.

3-Aminobenzenesulfonamides incorporating acylthiourea moieties selectively inhibit the tumor-associated carbonic anhydrase isoform IX over the off-target isoforms I, II and IV.

We describe the synthesis of a series of novel 1-aroyl/acyl-3-(3-aminosulfonylphenyl) thioureas (4a-k) acting as human carbonic anhydrase (hCA, EC 4.2.1.1) inhibitors. Reaction of alkyl/aryl isothiocyanates with 3-aminobenzenesulfonamide afforded a series of the title compounds incorporating a variety of short as well as highly lipophilic long tails. The newly synthesized sulfonamides were evaluated against 4 physiologically relevant CA isoforms (hCA I, II, IV, and IX). Several compounds showed interesting inhibitory activity. The tumor-associated hCA IX was the most sensitive isoform to inhibition with these compounds, with KIs in the range of 21.5-44.0 nM and selectivity ratios over the major cytosolic isoform hCA II in the range of 3.35-37.3. The sulfonamides incorporating the phenylacetylthioureido and pentadecanoylthioureido moieties were the most hCA IX-selective inhibitors detected in this work, making them of interest for further investigations.

Phytochemical profiling and antiviral activity of Ajuga bracteosa, Ajuga parviflora, Berberis lycium and Citrus lemon against Hepatitis C Virus.

Hepatitis C is a serious health issue and cause liver disorders in millions of people. Available therapeutic agents require long term administration with numerous side effects. Therefore, there is a dire need to find alternative treatment options for this disease. Since ancient times, medicinal plants are widely used to cure various diseases with no or less harmful effects. Therefore, this study was designed to find out phytochemicals and investigate antiviral activity of methanol extract of Ajuga bracteosa, Ajuga parviflora, Berberis lycium and Citrus lemon against Hepatitis C Virus (HCV infection). Phytochemical analysis of the plant extract was performed using various chemical tests. Toxicity of the plant extract was determined against using trypan blue exclusion method. Antiviral activity of the selected plant extract was find out against HCV infected HepG2 cells. For this purpose, HepG2 cells were seeded with HCV positive and negative serum and nontoxic doses of plant extract for 24 and 48 h. After this RNA was extracted and viral load was determined using Real-time PCR. Phytochemical analysis showed the presence of flavonoids and phenols in all plant extracts while amino acids, alkaloids and tannins were present in B. lycium and saponins were detected in C. lemon. Toxicity assay showed that all plant extracts were nontoxic at maximum concentration of 200 µg/ml except B. lycium, which showed mild toxicity at 40 µg/ml and were extremely toxic at 60 µg/ml and above doses. Real-time PCR quantitation result revealed that after 24 h treatments A. parviflora showed highest antiviral activity, followed by A. bracteosa, while B. lycium extract had low (35%) and C. lemon has no antiviral effects. The 48 h treatments showed an increase antiviral activity by A. bracteosa followed by A. parviflora and B. lycium while C. lemon showed negative effect. Our results depicted that mentioned plants might be used as an alternative therapeutic regime or in combination with existing treatments against HCV.

4-Aminopyridine based amide derivatives as dual inhibitors of tissue non-specific alkaline phosphatase and ecto-5'-nucleotidase with potential anticancer activity.

Ecto-nucleotidase members i.e., ecto-5'-nucleotidase and alkaline phosphatase, hydrolyze extracellular nucleotides and play an important role in purinergic signaling. Their overexpression are implicated in a variety of pathological states, including immunological diseases, bone mineralization, vascular calcification and cancer, and thus they represent an emerging drug targets. In order to design potent and selective inhibitors, new derivatives of 4-aminopyridine have been synthesized (10a-10m) and their structures were established on the basis of spectral data. The effect of nature and position of substituent was interestingly observed and justified on the basis of their detailed structure activity relationships (SARs) against both families of ecto-nucleotidase. Compound 10a displayed significant inhibition (IC50 ±â€¯SEM = 0.25 ±â€¯0.05 µM) that was found ≈168 fold more potent as compared to previously reported inhibitor suramin (IC50 ±â€¯SEM = 42.1 ±â€¯7.8 µM). This compound exhibited 6 times more selectivity towards h-TNAP over h-e5'NT. The anticancer potential and mechanism were also established using cell viability assay, flow cytometric analysis and nuclear staining. Molecular docking studies were also carried out to gain insight into the binding interaction of potent compounds within the respective enzyme pockets and herring-sperm DNA.

Substituted (E)-2-(2-benzylidenehydrazinyl)-4-methylthiazole-5-carboxylates as dual inhibitors of 15-lipoxygenase & carbonic anhydrase II: synthesis, biochemical evaluation and docking studies.

15-Lipoxygenase (15-LOX) plays a major role in many inflammatory lung diseases including chronic obstructive pulmonary disease (COPD), asthma and chronic bronchitis. Over-expression of 15-LOX is related with some specific carcinomas including pancreatic, gastric and brain tumor. Similarly among different isozymes of carbonic anhydrase (CA), CA II is expressed in pancreatic, gastric carcinomas as well as in brain tumors. Therefore, novel potent inhibitors of both 15-LOX and CA II are required to explore the role of these enzymes further and to enable the drug discovery efforts. For this purpose, a series of benzyledinyl-hydrazinyl substituted thiazole derivatives were designed, synthesized and characterized by FTIR, 1H, &13C NMR spectroscopy. The derivatives were then evaluated for their potential to inhibit 15-LOX and bovine carbonic anhydrase II (bCA II). Most of these compounds showed excellent inhibitory potential for 15-LOX with an IC50 of 0.12 ± 0.002 to 0.69 ± 0.5 µM and showed moderate inhibition potency for bCA II with compound 5h (IC50 = 1.26 ± 0.24 µM) being the most active. The most potent compound 5a that emerged as a dual inhibitor of both enzymes, exhibiting 24 times greater selectivity for 15-LOX over bCA II. Compound 5a exhibited dual potent inhibitory activity against both 15-LOX and bCA II enzymes having IC50 values of 0.12 ± 0.002 and 2.93 ± 0.22 µM, respectively. Molecular docking studies of potent as well as dual inhibitors were also carried out to provide an insight into the binding site interactions.

Antioxidant, antimicrobial properties and phenolics of different solvent extracts from bark, leaves and seeds of Pongamia pinnata (L.) Pierre.

This study appraises the antioxidant and antimicrobial attributes of various solvent extracts (absolute methanol, aqueous methanol, absolute ethanol, aqueous ethanol, absolute acetone, aqueous acetone, and deionized water) from bark, leaves and seeds of Pongamia pinnata (L.) Pierre. Maximum extraction yield of antioxidant components from bark (16.31%), leaves (11.42%) and seeds (21.51%) of P. pinnata was obtained using aqueous methanol (20:80). Of the extracts tested, the bark extract, obtained with aqueous methanol, exhibited greater levels of total phenolics [6.94 g GAE/100 g dry weight (DW)], total flavonoids (3.44 g CE/100 g DW), inhibition of linoleic acid peroxidation (69.23%) and DPPH radical scavenging activity (IC(50) value, 3.21 µg/mL), followed by leaves and seeds extracts. Bark extract tested against a set of bacterial and fungal strains also revealed the strongest antimicrobial activity with the largest inhibition zone and lowest minimum inhibitory concentration (MIC). HPLC analysis of aqueous methanol extracts from bark, leaves and seeds indicated the presence of protocatechuic, ellagic, ferulic, gallic, gentisic, 4-hydroxybenzoic and 4-hydroxycinnamic acids in bark (1.50-6.70 mg/100 g DW); sorbic, ferulic, gallic, salicylic and p-coumaric acids in leaves (1.18-4.71 mg/100 g DW); vanillic, gallic and tannic acids in seeds (0.52-0.65 mg/100 g DW) as the main phenolic acids. The present investigation concludes that the tested parts of P. pinnata, in particular the bark, have strong potential for the isolation of antioxidant and antimicrobial agents for functional food and pharmaceutical uses.

Antioxidant and antimicrobial attributes and phenolics of different solvent extracts from leaves, flowers and bark of Gold Mohar [Delonix regia (Bojer ex Hook.) Raf].

This paper describes the antioxidant and antimicrobial activities and phenolic components of different solvent (absolute methanol, absolute ethanol, absolute acetone, 80% methanol, 80% ethanol, 80% acetone and deionized water) extracts of leaves, flowers and bark of Gold Mohar [Delonix regia (Bojer ex Hook.) Raf.]. The extract yields from leaves, flowers and bark ranged from 10.19 to 36.24, 12.97 to 48.47 and 4.22 to 8.48 g/100 g dry weight (DW), respectively. Overall, 80% methanol extract produced from the leaves exhibited significantly (P < 0.05) higher antioxidant activity, with high phenolic contents (3.63 g GAE/100 g DW), total flavonoid contents (1.19 g CE/100 g DW), inhibition of peroxidation (85.54%), DPPH scavenging capacity (IC(50) value 8.89 µg/mL) and reducing power (1.87). Similarly, this 80% methanol leaves extract also showed superior antimicrobial activity. HPLC analysis of the 80% methanol extracts for individual phenolics revealed the presence of gallic, protocatechuic and salicylic acid in leaves; gallic, protocatechuic, salicylic, trans-cinnamic and chlorogenic acid in flowers, and gallic acid in bark as the main (amount > 1.50 mg/100 g DW) phenolic acids. Besides, small amounts ( < 1.50 mg/100 g DW) of some other phenolic acids such as sorbic, sinapic, p-coumaric, m-coumaric, ferulic, caffeic, 3-hydroxybenzoic, 4-hydroxycinnamic and 4-hydroxybenzoic acids were also detected. The extracts of the tested parts of Gold Mohar, especially, the leaves, might be valuable for functional food and therapeutic applications.

Method development and validation for the GC-FID assay of p-cymene in tea tree oil formulation.

This paper describes the development and validation of an isothermal gas chromatography-flame ionisation detection (GC-FID) method for the assay of pure tea tree oil. The chromatographic conditions of the method employ a 5% carbowax packed column (20 m x 0.25 mm), isothermal elution with hydrogen at a column flow of 36 ml/min, injector and detector temperature at 220 degrees C and oven temperature at 100 degrees C, and a 1.5 microl injection volume. Samples and standard were diluted in hexane. The calibration curve for p-cymene was linear (r2=0.9995) from 20 to 120% range of the analytical concentration of 100 microg/ml. The precision of this method was calculated as the relative standard deviation (R.S.D.) was 0.66% (n=6). The R.S.D. for intermediate precision study was 0.13 and recovery of the p-cymene ranged between 93.39 and 97.86%. The limits of detection and quantitation were determined to be 2.08 and 10.39 ng/ml, respectively.

Validation of a reversed-phase HPLC method for 1,10-phenanthroline-5,6-dione and analysis of its impurities by HPLC-MS.

A reversed-phase HPLC analytical method for the assay of 1,10-phenanthroline-5,6-dione (I) has been developed and validated. A C18 column (150 x 4.6 mm; 5 microm) was employed together with a mobile phase of methanol-water (50:50, v/v) containing 0.1% triethylamine. UV detection was performed at 254 nm. Dione (I) eluted as a spectrally pure peak resolved from its impurities allowing the method to be applied to the purity evaluation of samples obtained via two synthetic routes. In addition, 4,5-diazafluoren-9-one (V) was identified as the main impurity by employing the method in HPLC-MS mode with photodiode array UV detection.