Design, Synthesis, and Bioactive Screen In Vitro of Cyclohexyl (E)-4-(Hydroxyimino)-4-Phenylbutanoates and Their Ethers for Anti-Hepatitis B Virus Agents.

A series of oxime Cyclohexyl (E)-4-(hydroxyimino)-4-phenylbutanoates and their ethers were designed, synthesized, and evaluated for anti-hepatitis B virus (HBV) activities with HepG 2.2.15 cell line in vitro. Most of these compounds possessed anti-HBV activities, and among them, compound 4B-2 showed significant inhibiting effects on the secretion of HBsAg (IC50 = 63.85 ± 6.26 µM, SI = 13.41) and HBeAg (IC50 = 49.39 ± 4.17 µM, SI = 17.34) comparing to lamivudine (3TC) in HBsAg (IC50 = 234.2 ± 17.17 µM, SI = 2.2) and HBeAg (IC50 = 249.9 ± 21.51 µM, SI = 2.07). Docking study of these compounds binding to a protein residue (PDB ID: 3OX8) from HLA-A2 that with the immunodominant HBcAg18-27 epitope (HLA-A2.1- restricted CTL epitope) active site was carried out by using molecular operation environment (MOE) software. Docking results showed that behaviors of these compounds binding to the active site in HLA-A protein residue partly coincided with their behaviors in vitro anti-HBV active screening.

Synthesis and biological evaluation of a new series of cinnamic acid amide derivatives as potent haemostatic agents containing a 2-aminothiazole substructure.

Ten new cinnamic acid derivatives containing a 2-aminothiazole substructure were designed and synthesized. This series of compounds exhibited good thermostabilities as demonstrated by thermogravimetric analysis. In coagulation assays (prothrombin time, activated partial thromboplastin time and thrombin time) in vitro, most compounds demonstrated excellent activities to promote blood coagulation. Among the studied series, compounds N1, N4, N5 and W5 exhibited a significant coagulation activity. Further studies indicated that compound N5 (IC50=1.87µmol/L) displayed the most suitable efficacy of promoting platelet aggregation than the clinically used haemostatic drug etamsylate (IC50=46.22µmol/L). Furthermore, the relationship between the functional groups of the compounds and the corresponding blood coagulant activity was explored in this study.

Study on the Anticoagulant or Procoagulant Activities of Type II Phenolic Acid Derivatives.

In this study, three type II phenolic acids (caffeic acid, p-hydroxycinnamic acid, and ferulic acid) were used to synthesize a total of 18 phenolic acid derivatives. With molecular docking for molecule design and target protein (factors) screening, in combination with the confirmation of target proteins (factors) by surface plasmon resonance, and the evaluation of haemostatic and anticoagulant activities with five blood assays (plasma recalcification time, prothrombin time, activated partial thromboplastin time, fibrinogen, and thrombin time), the data indicated that caffeic acid derivatives showed certain anticoagulant or procoagulant activities and that two other series contained compounds with the best anticoagulant activities. Using Materials Studio analysis, particular functional groups that affect anticoagulant or procoagulant activities were revealed, and these conclusions can guide the discovery of compounds with better activities.

Synthesis, Biological Evaluation, and Docking Studies of a Novel Sulfonamido-Based Gallate as Pro-Chondrogenic Agent for the Treatment of Cartilage.

Gallic acid (GA) and its derivatives are anti-inflammatory agents and are reported to have potent effects on Osteoarthritis (OA) treatment. Nonetheless, it is generally accepted that the therapeutic effect and biocompatibility of GA is much weaker than its esters due to the high hydrophilicity. The therapeutic effect of GA on OA could be improved if certain structural modifications were made to increase its hydrophobicity. In this study, a novel sulfonamido-based gallate was synthesized by bonding sulfonamide with GA, and its biological evaluations on OA were investigated. Results show that 5-[4-(Pyrimidin-2-ylsulfamoylphenyl)]-carbamoyl-benzene-1,2,3-triyl triacetate (HAMDC) was able to reverse the effects induced by Interleukin-1 (IL-1) stimulation, and it also had a great effect on chondro-protection via promoting cell proliferation and maintaining the phenotype of articular chondrocytes, as well as enhancing synthesis of cartilage specific markers such as aggrecan, collagen II and Sox9. Furthermore, a docking study showed that HAMDC fits into the core of the active site of a disintegrin and metalloproteinase with thrombospondin motifs 5 (ADAMTS-5), which provides an explanation for its activity and selectivity.

Stimulating effect of a newly synthesized sulfonamido-based gallate on articular chondrocytes in vitro.

BACKGROUND: The phenotype of chondrocyte is easy to be lost when expanded in vitro by a process defined "dedifferentiation". Traditional growth factors such as transforming growth factor (TGF-ß1) are effective in preventing of dedifferentiation, but high costs and loss of activity limited their use. It is of significance to find substitutes which can reduce dedifferentiation and preserve chondrocytes phenotype to ensure sufficient differentiated cells for further study. METHODS: We synthesized new type of sulfonamido-based gallates named ZXHA-C and investigated its effect on primary articular chondrocytes of rats. After preliminary screening by cytotoxicity test, ZXHA-C of 1.06 × 10-8, 1.06 × 10-7 and 1.06 × 10-6M were chosen for further studies. Cell proliferation, morphology, viability, GAG synthesis and cartilage specific gene expression were detected. Also the effects of ZXHA-C on Wnt/ß-catenin signaling pathway were investigated. RESULTS: ZXHA-C could significantly promote chondrocytes growth. And it could enhance ECM synthesis by up-regulating expression levels of cartilage specific markers like aggrecan, collagen II and Sox9. Expression of collagen I which marked chondrocytes dedifferentiation was also significantly down-regulated after treated by ZXHA-C. Further exploration of the molecular mechanism indicated that ZXHA-C activated the Wnt/ß-catenin signal pathway in chondrocytes, as evidenced by up-regulated gene expression of ß-catenin, Wnt-4, cyclin D1 and Frizzled-2 and decreased glycogen synthase kinase 3ß (GSK-3ß). Among the various concentrations, ZXHA-C of 1.06 × 10-7 M showed the best performance, which was close to positive control (group with TGF-ß1). CONCLUSION: ZXHA-C might be potential a novel agent for the maintenances of chondrocytes phenotype.

Study on the synthesis of sulfonamide derivatives and their interaction with bovine serum albumin.

Three sulfonamide derivatives (SAD) were first synthesized from p-hydroxybenzoic acid and sulfonamides (sulfadimidine, sulfamethoxazole and sulfachloropyridazine sodium) and were characterized by elemental analysis, (1) H NMR and MS. The interaction between bovine serum albumin (BSA) and SAD was studied using UV/vis absorption spectroscopy, fluorescence spectroscopy, time-resolved fluorescence spectroscopy and circular dichroism spectra under imitated physiological conditions. The experimental results indicated that SAD effectively quenched the intrinsic fluorescence of BSA via a static quenching process. The thermodynamic parameters showed that hydrogen bonding and van der Waal's forces were the predominant intermolecular forces between BSA and two SADs [4-((4-(N-(4,6-dimethylpyrimidin-2-yl)sulfamoyl)phenyl)carbamoyl)phenyl acetate and 4-((4-(N-(5-methylisoxazol-3-yl)sulfamoyl)phenyl)carbamoyl)phenyl acetate], but hydrophobic forces played a major role in the binding process of BSA and 4-((4-(N-(6-chloropyridazin-3-yl)sulfamoyl)phenyl) carbamoyl)phenyl acetate. In addition, the effect of SAD on the conformation of BSA was investigated using synchronous fluorescence spectroscopy and circular dichroism spectra. Molecular modeling results showed that SAD was situated in subdomain IIA of BSA.

In vitro effect of a synthesized sulfonamido-based gallate on articular chondrocyte metabolism.

Autologous chondrocyte implantation (ACI) is a promising strategy for cartilage repair and reconstitution. However, limited cell numbers and the dedifferentiation of chondrocytes present major difficulties to the success of ACI therapy. Therefore, it is important to find effective pro-chondrogenic agents that restore these defects to ensure a successful therapy. In this study, we synthesized a sulfonamido-based gallate, namely N-[4-(4,6-dimethyl-pyrimidin-2-ylsulfamoyl)-phenyl]-3,4,5-trihydroxy-benzamide (EJTC), and investigated its effects on rabbit articular chondrocytes through an examination of its specific effects on cell proliferation, morphology, viability, GAG synthesis, and cartilage-specific gene expression. The results show that EJTC can effectively promote chondrocyte growth and enhance the secretion and synthesis of cartilage ECM by upregulating the expression levels of the aggrecan, collagen II, and Sox9 genes. The expression of the collagen I gene was effectively downregulated, which indicates that EJTC inhibits chondrocytes dedifferentiation. Chondrocyte hypertrophy, which may lead to chondrocyte ossification, was also undetectable in the EJTC-treated groups. The recommended dose of EJTC ranges from 3.125 µg/mL to 7.8125 µg/mL, and the most profound response was observed with 7.8125 µg/mL. This study may provide a basis for the development of a novel agent for the treatment of articular cartilage defects.

A novel synthesized sulfonamido-based gallic acid--LDQN-C: effects on chondrocytes growth and phenotype maintenance.

Chondrocyte based therapy is promising to treat symptomatic chondral and osteochondral lesions. Growth factors to accelerate the proliferation and retain the phenotype of chondrocytes in vitro are imperative. However, the high cost and rapid degradation of growth factors limited their further application. Therefore, it is significant to find substitutes that can preserve chondrocytes phenotype and ensure sufficient cells for cytotherapy. Antioxidant and anti-inflammatory agents or their derivatives that have effect on arthritis may be an alternative. In this study, we synthesized sulfonamido-based gallate - LDQN-C and investigated its effect on rat articular chondrocytes through examination of the cell proliferation, morphology, viability, glycosaminoglycans (GAGs) synthesis and cartilage specific gene expression. Results showed that LDQN-C could enhance secretion and synthesis of cartilage extracellular matrix (ECM) by up-regulating expression levels of aggrecan, collagen II and Sox9 genes compared to the GA treated group and control group. Expression of collagen type II was effectively up-regulated while collagen I was down-regulated, which demonstrated that the inhibition of chondrocytes dedifferentiation by LDQN-C. Range of 1.36×10(-9)M to 1.36×10(-7)M is recommended dose of LDQN-C, among which the most profound response was observed with 1.36×10(-8)M. GA at concentration of 0.125µg/mL was compared. This study might provide a basis for the development of a novel agent for the treatment of articular cartilage defect.

Study of the interaction between sodium salts of (2E)-3-(4'-halophenyl)prop-2-enoyl sulfachloropyrazine and bovine serum albumin by fluorescence spectroscopy.

Three sodium salts of (2E)-3-(4'-halophenyl)prop-2-enoyl sulfachloropyrazine (CCSCP) were synthesized and their structures were determined by (1)H and (13)C NMR, LC-MS and IR. The binding properties between CCSCPs and bovine serum albumin (BSA) were studied using fluorescence spectroscopy in combination with UV-vis absorbance spectroscopy. The results indicate that the fluorescence quenching mechanisms between BSA and CCSCPs were static quenching at low concentrations of CCSCPs or combined quenching (static and dynamic) at higher CCSCP concentrations of 298, 303 and 308 K. The binding constants, binding sites and corresponding thermodynamic parameters (ΔH, ΔS, ΔG) were calculated at different temperatures. All ΔG values were negative, which revealed that the binding processes were spontaneous. Although all CCSCPs had negative ΔH and positive ΔS, the contributions of ΔH and ΔS to ΔG values were different. When the 4'-substituent was fluorine or chlorine, van der Waals interactions and hydrogen bonds were the main interaction forces. However, when the halogen was bromine, ionic interaction and proton transfer controlled the overall energetics. The binding distances between CCSCPs and BSA were determined using the Förster non-radiation energy transfer theory and the effects of CCSCPs on the conformation of BSA were analyzed by synchronous fluorescence spectroscopy.

Synthesis and interaction of bovine serum albumin with p-hydroxybenzoic acid derivatives.

Three novel p-hydroxybenzoic acid derivatives (HSOP, HSOX, HSCP) were synthesized from p-hydroxybenzoic acid and sulfonamides (sulfamonomethoxine sodium, sulfamethoxazole and sulfachloropyridazine sodium) and characterized by elemental analysis, HNMR and MS. Interactions between derivatives and bovine serum albumin (BSA) were studied by fluorescence quenching spectra, UV-vis absorption spectra and time-resolved fluorescence spectra. Based on fluorescence quenching calculation and Förster's non-radioactive energy transfer theory, the values of the binding constants, basic thermodynamic parameters and binding distances were obtained. Experimental results indicated that the three derivatives had a strong ability to quench fluorescence from BSA and that the binding reactions of the derivatives with BSA were a static quenching process. Thermodynamic parameters showed that binding reactions were spontaneous and exothermic and hydrogen bond and van der Waals force were predominant intermolecular forces between the derivatives and BSA. Synchronous fluorescence spectra suggested that HSOX and HSCP had little effect on the microenvironment and conformation of BSA in the binding reactions but the microenvironments around tyrosine residues were disturbed and polarity around tyrosine residues increased in the presence of HSOP.

4-Hy-droxy-3,5-dimeth-oxy-N-{4-[(5-methyl-1,2-oxazol-3-yl)sulfamo-yl]phen-yl}benzamide methanol monosolvate.

The title compound, C(19)H(19)N(3)O(7)S·CH(3)OH, was synthesized from syringic acid and sulfamethoxazole. The benzene rings make a dihedral angle of 41.8 (1)° and the isoxazole ring is twisted by 74.3 (1)° from the central benzene ring. The crystal packing features O-H⋯O and O-H⋯N hydrogen bonds in which the hy-droxy groups from the main mol-ecule and methanol solvent mol-ecules serve as donor groups.

(E)-Methyl 3-(3,4-dihy-droxy-phen-yl)acrylate.

The benzene ring in the title compound, C(10)H(10)O(4), makes an angle of 4.4 (1)° with the C-C-C-O linker. The hy-droxy groups are involved in both intra- and inter-molecular O-H⋯O hydrogen bonds. The crystal packing is stabilized by O-H⋯O hydrogen-bonding inter-actions. The mol-ecules of the caffeic acid ester form a dimeric structure in a head-to-head manner along the a axis through O-H⋯O hydrogen bonds. The dimers inter-act with one another through O-H⋯O hydrogen bonds, forming supermolecular chains. These chains are further extended through C-H⋯O hydrogen bonds as well as van der Waals inter-actions into the final three-dimensional architecture.

Isolation and structure determination of a sesquiterpene lactone (vernodalinol) from Vernonia amygdalina extracts.

CONTEXT: Vernonia amygdalina Del. (VA; Asteraceae or Compositae) is a small tree growing throughout tropical Africa. It is widely used for food and medicinal purposes by local people. It was reported that it had several qualities, including anticancer activity. OBJECTIVE: A sesquiterpene lactone, vernodalinol, was isolated from VA leaves. The first reported source of vernodalinol was in 2009 from a different plant, only (1)H NMR spectrum and no detailed structural analysis were carried out. No whole spectroscopic data were provided. MATERIALS AND METHODS: VA dried leaves were extracted with 85% ethanol followed by further separation into four fractions by liquid-liquid extraction technique using various solvents: hexane, chloroform, and n-butanol. Vernodalinol was separated from the n-butanol fraction by column chromatography. The biological activity of vernodalinol was evaluated in estrogen receptor-positive (ER(+)) human breast carcinoma cells (MCF-7) in vitro. RESULTS: Results indicated that vernodalinol (25 and 50 µg/mL) inhibited breast cancerous cell growth (DNA synthesis) by 34% (P < 0.025) and 40% (P < 0.025), respectively. It is reasonable to expect an LC(50) of 70-75 µg/mL for vernodalinol in MCF-7 cells. DISCUSSION AND CONCLUSION: Vernodalinol structure was confirmed using a battery of spectroscopic methods, 1D and 2D NMR, high-resolution mass spectrometry (HR-MS), UV, IR, and X-ray. These results suggest that vernodalinol, although it has some biological activity, is likely to work in concert with other ingredients responsible for the anticancer activity exhibited of VA.

[Corrigendum] Beneficial effects of sulfonamide­based gallates on osteoblasts in vitro.

Following the publication of the above article, an interested reader drew to the authors' attention that three figures in their paper (namely Figs. 2, 4 and 5) appeared to feature panels containing overlapping data. The authors re­examined their original data, and realized that they had made inadvertent errors in the compilation of the data in these figures; specifically, the data shown in the panels for Fig. 2G, Fig. 4C, D and I, and Fig. 5E and I had been selected incorrectly. The corrected versions of Figs. 2, 4 and 5 are shown below and on the next page. All the authors approve of this corrigendum, and are grateful of the Editor of Molecular Medicine Reports for granting them the opportunity to publish this corrigendum. Furthermore, they regret that these errors were introduced into the paper, even though they did not substantially alter any of the major conclusions reported in the paper, and apologize to the readership for any inconvenience caused. [the original article was published in Molecular Medicine Reports 15: 1149­1156, 2017; DOI: 10.3892/mmr.2017.6142].

In Situ One-Pot Synthesis of C-Decorated and Cl-Doped Sea-Urchin-like Rutile Titanium Dioxide with Highly Efficient Visible-Light Photocatalytic Activity.

Titanium dioxide (TiO2) that offers high light-harvesting capacity and efficient charge separation holds great promise in photocatalysis. In this work, an in situ one-pot hydrothermal synthesis was explored to prepare a C-decorated and Cl-doped sea-urchin-like rutile TiO2 (Cl-TiO2/C). The growth of sea-urchin-like 3D hierarchical nanostructures was governed by a mechanism of nucleation and nuclei growth-dissolution-recrystallization growth from time-dependent morphology evolution. The crystal morphology and the content of Cl and C could be controlled by the volume ratio of HCl to TBOT. Systematic studies indicated that the 0.4Cl-TiO2/C sample (the volume ratio of HCl to TBOT was 0.4) exhibited the highest visible-light photocatalytic activity for the degradation of rhodamine B, with kinetic rate constant (k) of 0.0221 min-1, being 6.5 and 3.75 times higher than that of TiO2 and Cl-TiO2. The enhanced photocatalytic performance could be attributed to the high charge separation and transfer efficiency induced by Cl-doping and C decoration and the excellent light-harvesting capacity caused by its sea-urchin-like nanostructure. Moreover, the 0.4Cl-TiO2/C sample exhibited good reusability and excellent structural stability for five cycles. This facile one-pot approach provides new insight for the preparation of a TiO2-based photocatalyst with excellent photocatalytic performance for potential application in practical wastewater treatment.

catena-Poly[[[diaqua-sodium]-di-µ-aqua] 2-(2-pyrid-yl)quinoline-4-carboxyl-ate].

In the title compound, [Na(H(2)O)(4)](C(15)H(9)N(2)O(2)), the Na(+) ion is coordinated by six water mol-ecules in an octa-hedral geometry. The NaO(6) octa-hedra are connected by sharing edges, forming a cationic chain along the b-axis direction. O-H⋯O and O-H⋯N hydrogen bonds link the chains and the 2-(2-pyrid-yl)quinoline-4-carboxyl-ate anions into a two-dimensional network parallel to (100).

Synthesis of caffeic acid sulfonamide derivatives and their protective effect against H2O2 induced oxidative damage in A549 cells.

Exogenous antioxidants are considered as important therapeutic tools for oxidative stress associated disorders as they can regulate the redox state, which is associated with cell and organ function. Inspired by natural polyphenols, six new caffeic acid sulfonamide derivatives were synthesized by coupling sulfonamides to the backbone of caffeic acid with good yields. Their structure and lipophilicity were characterized by 1H nuclear magnetic resonance (NMR), 13C{1H} NMR, infrared spectroscopy (IR) and oil-water partition coefficient assay. Their free radical scavenging activity and antioxidant activity were assessed by DPPH assay and hydrogen peroxide (H2O2) induced oxidative stress in human lung carcinoma A549 cells. The oil-water partition coefficient results indicate that the conjugation of sulfonamides increases the lipophilicity of caffeic acid. The CASMD, CASDZ and CASN results show higher free radical scavenging effects compared with vitamin C. The derivatives do not show any inhibitory effect on the proliferation of A549 cells up to a concentration of 200 µM, except CASDZ which significantly inhibits the growth of A549 cells at a concentration of 200 µM. In addition, the obtained derivatives markedly attenuate H2O2 induced decrease of cell viability, inhibit the production of ROS and MDA, and promote the activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px). Besides, treatment of H2O2 stimulated A549 cells with caffeic acid sulfonamide derivatives further increases mRNA expression of NF-E2-related factor 2 (Nrf2) and its target genes, including heme oxygenase-1 (HO-1), NAD(P)H quinone dehydrogenase 1 (NQO1) and thioredoxin reductase 1 (TXNRD1). These results suggest that these new caffeic acid sulfonamide derivatives have higher lipophilicity and better antioxidant activities than the parent caffeic acid, and they might be able to control the antioxidant response in cells via the Nrf2 pathway.

Synthesis of novel caffeic acid derivatives and their protective effect against hydrogen peroxide induced oxidative stress via Nrf2 pathway.

AIM: This study was aimed to synthesize novel caffeic acid derivatives and evaluate their potential applications for the treatment of oxidative stress associated disease. MAIN METHODS: Caffeic acid sulfonamide derivatives were synthesized by coupling sulfonamides to the backbone of caffeic acid and fully characterized by melting point test, FT-IR, MS, NMR, UV-vis and n-octanol-water distribution assay. Their free radical scavenging ability was evaluated using DPPH assay and cytotoxicity against A549 cells were determined by MTT assay. The protective effect of these derivatives against hydrogen peroxide (H2O2) induced oxidative injury was assessed in A549 cells from cell viability, production of reactive oxygen species (ROS) and malondialdehyde (MDA), alternation of antioxidase activities, and expressions of Nrf2 and its target genes. KEY FINDINGS: Six novel caffeic acid sulfonamide derivatives were obtained. The derivatives showed better liphophilicity than the parent caffeic acid. CASMZ, CAST and CASQ exhibited similar DPPH scavenging capability as caffeic acid, while the protection of hydroxyl groups on the benzene ring with acetyl groups caused decrease in radical scavenging activity. No inhibitory effect on the proliferation of A549 cells were observed up to a concentration of 50 µM. Pre-treatment of cells with these derivatives strongly inhibited H2O2 induced decrease of cell viability, reduced the production of ROS and MDA, promoted antioxidase activities, and further upregulated the expression of Nrf2 and its target genes. SIGNIFICANCE: Caffeic acid sulfonamide derivatives were synthesized with simple reactions under mild conditions. They might protect cells from H2O2-induced oxidative injury via Nrf2 pathway.

Correction: A Novel Synthesized Sulfonamido-Based Gallate-JEZ-C as Potential Therapeutic Agents for Osteoarthritis.

[This corrects the article DOI: 10.1371/journal.pone.0125930.].

Tris[6-(3,5-dimethyl-1H-pyrazol-1-yl)picolinato]gadolinium(III) methanol hemisolvate 2.5-hydrate.

In the title complex, [Gd(C(11)H(10)N(3)O(2))(3)]·0.5CH(4)O·2.5H(2)O, the Gd atom is coordinated by six N atoms and three O atoms derived from three tridentate monoanionic 6-(3,5-dimethyl-1H-pyrazol-1-yl)picolinate ligands. The mol-ecules are linked together via hydrogen bonds involving the solvent water and methanol mol-ecules.