Efficient Dimerization Disruption of Leishmania infantum Trypanothione Reductase by Triazole-phenyl-thiazoles

Inhibition of Leishmania infantum trypanothione disulfide reductase (LiTryR) by disruption of its homodimeric interface has proved to be an alternative and unexploited strategy in the search for novel antileishmanial agents. Proof of concept was first obtained by peptides and peptidomimetics. Building on previously reported dimerization disruptors containing an imidazole-phenyl-thiazole scaffold, we now report a new 1,2,3-triazole-based chemotype that yields noncompetitive, slow-binding inhibitors of LiTryR. Several compounds bearing (poly)aromatic substituents dramatically improve the ability to disrupt LiTryR dimerization relative to reference imidazoles. Molecular modeling studies identified an almost unexplored hydrophobic region at the interfacial domain as the putative binding site for these compounds. A subsequent structure-based design led to a symmetrical triazole analogue that displayed even more potent inhibitory activity over LiTryR and enhanced leishmanicidal activity. Remarkably, several of these novel triazole-bearing compounds were able to kill both extracellular and intracellular parasites in cell cultures.

Thiazole-Chalcone Hybrids as Prospective Antitubercular and Antiproliferative Agents: Design, Synthesis, Biological, Molecular Docking Studies and In Silico ADME Evaluation

Compounds bearing thiazole and chalcone pharmacophores have been reported to possess excellent antitubercular and anticancer activities. In view of this, we designed, synthesized and characterized a novel series of thiazole-chalcone hybrids (1-20) and further evaluated them for antitubercular and antiproliferative activities by employing standard protocols. Among the twenty compounds, chalcones 12 and 7, containing 2,4-difluorophenyl and 2,4-dichlorophenyl groups, showed potential antitubercular activity higher than the standard pyrazinamide (MIC = 25.34 µM) with MICs of 2.43 and 4.41 µM, respectively. Chalcone 20 containing heteroaryl 2-thiazolyl moiety exhibited promising antiproliferative activity against the prostate cancer cell line (DU-145), higher than the standard methotrexate (IC50 = 11 ± 1 µM) with an IC50 value of 6.86 ± 1 µM. Furthermore, cytotoxicity studies of these compounds against normal human liver cell lines (L02) revealed that the target molecules were comparatively less selective against L02. Additional computational studies using AutoDock predicted the key binding interactions responsible for the activity and the SwissADME tool computed the in silico drug likeliness properties. The lead compounds generated through this study, create a way for the optimization and development of novel drugs against tuberculosis infections and prostate cancer.

Thiazole-amino acids: influence of thiazole ring on conformational properties of amino acid residues

Post-translational modified thiazole-amino acid (Xaa-Tzl) residues have been found in macrocyclic peptides (e.g., thiopeptides and cyanobactins), which mostly inhibit protein synthesis in Gram + bacteria. Conformational study of the series of model compounds containing this structural motif with alanine, dehydroalanine, dehydrobutyrine and dehydrophenylalanine were performed using DFT method in various environments. The solid-state crystal structure conformations of thiazole-amino acid residues retrieved from the Cambridge Structural Database were also analysed. The studied structural units tend to adopt the unique semi-extended β2 conformation; which is stabilised mainly by N-H⋯NTzl hydrogen bond, and for dehydroamino acids also by π-electron conjugation. The conformational preferences of amino acids with a thiazole ring were compared with oxazole analogues and the role of the sulfur atom in stabilising the conformations of studied peptides was discussed.

Synthesis and Biological Activity of Acrylate Copolymers Containing 3-Oxo-N-allyl-1,2-benzisothiazole-3(2H)-carboxamide Monomer as a Marine Antifouling Coating

A type of grafted acrylate copolymer resins, containing 3-oxo-N-allyl-1,2-benzisothiazole-2(3H)-carboxamide monomer and heterocyclic monomers, was synthesized through the copolymeri- zation of methyl methacrylate (MMA) and butyl acrylate (BA) with functional monomers. The structures of the monomers and copolymers were validated by infrared (IR) and 1 H nuclear magnetic resonance (NMR) spectroscopies. The inhibitory activities of the copolymers on algae, bacteria, and barnacle larvae were measured, and the antifouling potencies against marine macrofouling organisms were investigated. The results showed that the grafted resin had significant inhibitory effects on the growth of three marine algae (Isochrysis galbana, Nannochloropsisoculata, and Chlorella pyrenoidosa), and three bacteria (Vibrio coralliilyticus, Staphylococcus aureus,and Vibrio parahaemolyticus). The target copolymers also showed excellent inhibition of the survival of barnacle larvae. Additionally, the release rate of the antifoulant and the results of the marine field tests indicated that the grafted copolymers had outstanding antifouling potency against the attachment of marine macrofouling organisms.

Synthesis, in vitro bioassays, and computational study of heteroaryl nitazoxanide analogs

Antiprotozoal drug nitazoxanide (NTZ) has shown diverse pharmacological properties and has appeared in several clinical trials. Herein we present the synthesis, characterization, in vitro biological investigation, and in silico study of four hetero aryl amide analogs of NTZ. Among the synthesized molecules, compound 2 and compound 4 exhibited promising antibacterial activity against Escherichia coli (E. coli), superior to that displayed by the parent drug nitazoxanide as revealed from the in vitro antibacterial assay. Compound 2 displayed zone of inhibition of 20 mm, twice as large as the parent drug NTZ (10 mm) in their least concentration (12.5 µg/ml). Compound 1 also showed antibacterial effect similar to that of nitazoxanide. The analogs were also tested for in vitro cytotoxic activity by employing cell counting kit-8 (CCK-8) assay technique in HeLa cell line, and compound 2 was identified as a potential anticancer agent having IC50 value of 172 µg which proves it to be more potent than nitazoxanide (IC50  = 428 µg). Furthermore, the compounds were subjected to molecular docking study against various bacterial and cancer signaling proteins. The in vitro test results corroborated with the in silico docking study as compound 2 and compound 4 had comparatively stronger binding affinity against the proteins and showed a higher docking score than nitazoxanide toward human mitogen-activated protein kinase (MAPK9) and fatty acid biosynthesis enzyme (FabH) of E. coli. Moreover, the docking study demonstrated dihydrofolate reductase (DHFR) and thymidylate synthase (TS) as probable new targets for nitazoxanide and its synthetic analogs. Overall, the study suggests that nitazoxanide and its analogs can be a potential lead compound in the drug development.

A Novel N-Tert-Butyl Derivatives of Pseudothiohydantoin as Potential Target in Anti-Cancer Therapy

Tumors are currently more and more common all over the world; hence, attempts are being made to explain the biochemical processes underlying their development. The search for new therapeutic pathways, with particular emphasis on enzymatic activity and its modulation regulating the level of glucocorticosteroids, may contribute to the development and implementation of new therapeutic options in the treatment process. Our research focuses on understanding the role of 11β-HSD1 and 11β-HSD2 as factors involved in the differentiation and proliferation of neoplastic cells. In this work, we obtained the 9 novel N-tert-butyl substituted 2-aminothiazol-4(5H)-one (pseudothiohydantoin) derivatives, differing in the substituents at C-5 of the thiazole ring. The inhibitory activity and selectivity of the obtained derivatives in relation to two isoforms of 11β-HSD were evaluated. The highest inhibitory activity for 11β-HSD1 showed compound 3h, containing the cyclohexane substituent at the 5-position of the thiazole ring in the spiro system (82.5% at a conc. 10 µM). On the other hand, the derivative 3f with the phenyl substituent at C-5 showed the highest inhibition of 11β-HSD2 (53.57% at a conc. of 10 µM). A low selectivity in the inhibition of 11β-HSD2 was observed but, unlike 18β-glycyrrhetinic acid, these compounds were found to inhibit the activity of 11β-HSD2 to a greater extent than 11β-HSD1, which makes them attractive for further research on their anti-cancer activity.

Novel 4-(piperazin-1-yl)quinolin-2(1H)-one bearing thiazoles with antiproliferative activity through VEGFR-2-TK inhibition

A new series of 2-(4-(2-oxo-1,2-dihydroquinolin-4-yl)piperazin-1-yl)-N-(4-phenylthiazol-2-yl)acetamide derivatives were synthesized and evaluated for anticancer activity. All target compounds showed anticancer activity higher than that of their 2-oxo-4-piperazinyl-1,2-dihydroquinolin-2(1H)-one precursors. Multidose testing of target compounds was performed against breast cancer T-47D cell line. Five compounds showed higher cytotoxic activity than Staurosporine. The dihalogenated derivative showed the best cytotoxic activity with IC₅₀ 2.73 ± 0.16 µM. In addition, the VEGFR-2 inhibitory activity of all synthetic compounds was evaluated. Two compounds of 6-fluoro-4-(piperazin-1-yl)quinolin-2(1H)-ones showed inhibitory activity comparable to sorafenib with IC₅₀ 46.83 ± 2.4, 51.09 ± 2.6 and 51.41 ± 2.3 nM, respectively. The cell cycle analysis of two compounds namely, 2-(4-(6-fluoro-2-oxo-1,2-dihydroquinolin-4-yl)piperazin-1-yl)-N-(4-phenylthiazol-2-yl)acetamide and N-(4-(4-chlorophenyl)thiazol-2-yl)-2-(4-(2-oxo-1-phenyl-1,2-dihydroquinolin-4-yl)piperazin-1-yl)acetamide revealed that the arrest of cell cycle occurred at S phase. In apoptosis assay, the same two compounds were able to induce significant levels of early and late apoptosis. In a similar manner to Sorafenib, docking of target compounds with VEGFR-2 protein 4ASD showed HB with Cys919 in hinge region of enzyme and HB with both Glu885 and Asp1046 in gate area. Using SwissADME, all target compounds were predicted to be highly absorbed from gastrointestinal tract with no BBB permeability. It is clear that the two compounds are promising antiproliferative candidates that require further optimization.

Thiazoline-related innate fear stimuli orchestrate hypothermia and anti-hypoxia via sensory TRPA1 activation

Thiazoline-related innate fear-eliciting compounds (tFOs) orchestrate hypothermia, hypometabolism, and anti-hypoxia, which enable survival in lethal hypoxic conditions. Here, we show that most of these effects are severely attenuated in transient receptor potential ankyrin 1 (Trpa1) knockout mice. TFO-induced hypothermia involves the Trpa1-mediated trigeminal/vagal pathways and non-Trpa1 olfactory pathway. TFOs activate Trpa1-positive sensory pathways projecting from trigeminal and vagal ganglia to the spinal trigeminal nucleus (Sp5) and nucleus of the solitary tract (NTS), and their artificial activation induces hypothermia. TFO presentation activates the NTS-Parabrachial nucleus pathway to induce hypothermia and hypometabolism; this activation was suppressed in Trpa1 knockout mice. TRPA1 activation is insufficient to trigger tFO-mediated anti-hypoxic effects; Sp5/NTS activation is also necessary. Accordingly, we find a novel molecule that enables mice to survive in a lethal hypoxic condition ten times longer than known tFOs. Combinations of appropriate tFOs and TRPA1 command intrinsic physiological responses relevant to survival fate.

Amino Acid Conjugates of Aminothiazole and Aminopyridine as Potential Anticancer Agents: Synthesis, Molecular Docking and in vitro Evaluation

PURPOSE

The development of resistance to available anticancer drugs is increasingly becoming a major challenge and new chemical entities could be unveiled to compensate this therapeutic failure. The current study demonstrated the synthesis of 2-aminothiazole [S3(a-d) and S5(a-d)] and 2-aminopyridine [S4(a-d) and S6(a-d)] derivatives that can target multiple cellular networks implicated in cancer development.

METHODS

Biological assays were performed to investigate the antioxidant and anticancer potential of synthesized compounds. Redox imbalance and oxidative stress are hallmarks of cancer, therefore, synthesized compounds were preliminarily screened for their antioxidant activity using DPPH assay, and further five derivatives S3b, S3c, S4c, S5b, and S6c, with significant antioxidant potential, were selected for investigation of in vitro anticancer potential. The cytotoxic activities were evaluated against the parent (A2780) and cisplatin-resistant (A2780CISR) ovarian cancer cell lines. Further, Molecular docking studies of active compounds were performed to determine binding affinities.

RESULTS

Results revealed that S3c, S5b, and S6c displayed promising inhibition in cisplatin-resistant cell lines in comparison to parent cells in terms of both resistance factor (RF) and IC50 values. Moreover, S3c proved to be most active compound in both parent and resistant cell lines with IC50 values 15.57 µM and 11.52 µM respectively. Our docking studies demonstrated that compounds S3c, S5b, and S6c exhibited significant binding affinity with multiple protein targets of the signaling cascade.

CONCLUSION

Anticancer activities of compounds S3c, S5b, and S6c in cisplatin-resistant cell lines suggested that these ligands may contribute as lead compounds for the development of new anticancer drugs.

Design, synthesis, fungicidal activities and structure-activity relationship studies of (-)-borneol derivatives containing 2-aryl-thiazole scaffold

A series of (-)-borneol derivatives containing 2-aryl-thiazole scaffold were designed, synthesized, and characterized by ¹H NMR, ¹³C NMR, and HRMS. The fungicidal activities of these novel compounds against Fusarium oxysporum, Magnaporthe grisea, Botrytis cinerea, and Penicillium digitatum were evaluated. The results indicated that (1S,2R,4S)-1,7,7-trimethylbicyclo[2.2.1]heptan-2-yl(Z)-4-oxo-4-(((2-phenylthiazol-4-yl)methyl)amino)but-2-enoate (6a) displayed potential fungicidal activities with broad spectrum. Especially, 6a exhibited an IC₅₀ value of 48.5 mg/L against P. digitatum, which has higher fungicidal activity than commercial products hymexazol and amicarthiazol. Moreover, (1S,2R,4S)-1,7,7-trimethylbicyclo[2.2.1]heptan-2-yl-4-oxo-4-(((2-phenylthiazol-4-yl)methyl)amino)butanoate (5a) possesses an IC₅₀ value of 24.3 mg/L against B. cinerea, comparable to hymexazol and far superior to amicarthiazol. Furthermore, the superficial structure-activity relationship was discussed, which might be helpful for discovering novel fungicides.

Co-Incubation with PPARβ/δ Agonists and Antagonists Modeled Using Computational Chemistry: Effect on LPS Induced Inflammatory Markers in Pulmonary Artery

Peroxisome proliferator activated receptor beta/delta (PPARβ/δ) is a nuclear receptor ubiquitously expressed in cells, whose signaling controls inflammation. There are large discrepancies in understanding the complex role of PPARβ/δ in disease, having both anti- and pro-effects on inflammation. After ligand activation, PPARβ/δ regulates genes by two different mechanisms; induction and transrepression, the effects of which are difficult to differentiate directly. We studied the PPARβ/δ-regulation of lipopolysaccharide (LPS) induced inflammation (indicated by release of nitrite and IL-6) of rat pulmonary artery, using different combinations of agonists (GW0742 or L-165402) and antagonists (GSK3787 or GSK0660). LPS induced release of NO and IL-6 is not significantly reduced by incubation with PPARβ/δ ligands (either agonist or antagonist), however, co-incubation with an agonist and antagonist significantly reduces LPS-induced nitrite production and Nos2 mRNA expression. In contrast, incubation with LPS and PPARβ/δ agonists leads to a significant increase in Pdk-4 and Angptl-4 mRNA expression, which is significantly decreased in the presence of PPARβ/δ antagonists. Docking using computational chemistry methods indicates that PPARβ/δ agonists form polar bonds with His287, His413 and Tyr437, while antagonists are more promiscuous about which amino acids they bind to, although they are very prone to bind Thr252 and Asn307. Dual binding in the PPARβ/δ binding pocket indicates the ligands retain similar binding energies, which suggests that co-incubation with both agonist and antagonist does not prevent the specific binding of each other to the large PPARβ/δ binding pocket. To our knowledge, this is the first time that the possibility of binding two ligands simultaneously into the PPARβ/δ binding pocket has been explored. Agonist binding followed by antagonist simultaneously switches the PPARβ/δ mode of action from induction to transrepression, which is linked with an increase in Nos2 mRNA expression and nitrite production.

Design, synthesis, and structure-activity relationship of programmed cell death-1/programmed cell death-ligand 1 interaction inhibitors bearing a benzo[d]isothiazole scaffold

Blockade of the programmed cell death-1 (PD-1)/programmed cell death-ligand 1 (PD-L1) pathway is an attractive strategy for immunotherapy. A novel series of compounds bearing a benzo[d]isothiazole scaffold were developed, among which CH20 exhibited promising activity, with an IC₅₀ value of 8.5 nM. Further cell-based PD-1/PD-L1 blockade bioassays indicated that CH20 can inhibit the PD-1/PD-L1 interaction at the cellular level, with an EC₅₀ value of 5.6 μM CH20 could have better potency in restoring the activity of effector cells, as the maximal luminescence values (RLU_max) of CH20 were equivalent to those of PD-L1 mAbs. The docking analysis of CH20 with the PD-L1 dimer complex (PDB ID: 6R3K) confirmed that CH20 is a promising lead compound for the development of inhibitors of the PD-1/PD-L1 interaction. The preliminary structure-activity relationship was investigated in this paper, with the aim of future drug development.

Magnetic cobalt oxide nanosheets: green synthesis and in vitro cytotoxicity

Cobalt oxide nanoparticles were prepared via green chemistry route and fully characterized by Field Emission Scanning Electron Microscope (FESEM), Energy-dispersive X-ray spectroscopy (EDAX), X-ray diffraction (XRD), High-resolution transmission electron microscopy (HRTEM) and Transmission electron microscopy (TEM) analyses; the CoO and Co₃O₄ nanoparticles, in sheet-shaped cobalt oxide form, ensued simultaneously in one step. The varying concentrations of NPs were analyzed via 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) test on the cancer cell line (U87) which revealed that with increasing concentration of cobalt oxide nanoparticles, the survival rate of U87 tumor cells decreases; IC₅₀ of nanoparticles being ~ 55 µg/ml^-1.

An Overview on Synthetic 2-Aminothiazole-Based Compounds Associated with Four Biological Activities

Amongst sulfur- and nitrogen-containing heterocyclic compounds, the 2-aminothiazole scaffold is one of the characteristic structures in drug development as this essential revelation has several biological activities abiding it to act as an anticancer, antioxidant, antimicrobial and anti-inflammatory agent, among other things. Additionally, various 2-aminothiazole-based derivatives as medical drugs have been broadly used to remedy different kinds of diseases with high therapeutic influence, which has led to their wide innovations. Owing to their wide scale of biological activities, their structural variations have produced attention amongst medicinal chemists. The present review highlights the recently synthesized 2-aminothiazole-containing compounds in the last thirteen years (2008-2020). The originality of this proposal is based on the synthetic strategies developed to access the novel 2-aminothiazole derivatives (N-substituted, 3-substituted, 4-substituted, multi-substituted, aryl/alkyl substituents or acyl/other substituents). The literature reports many synthetic pathways of these 2-aminothiazoles associated with four different biological activities (anticancer, antioxidant, antimicrobial and anti-inflammatory activities). It is wished that this review will be accommodating for new views in the expedition for rationalistic designs of 2-aminothiazole-based medical synthetic pathways.

Positron Emission Tomography Imaging for In Vivo Measuring of Myelin Content in the Lysolecithin Rat Model of Multiple Sclerosis

Multiple sclerosis (MS) is a neuroinflammatory disease with expanding axonal and neuronal degeneration and demyelination in the central nervous system, leading to motor dysfunctions, psychical disability, and cognitive impairment during MS progression. Positron emission tomography (PET) is an imaging technique able to quantify in vivo cellular and molecular alterations. Radiotracers with affinity to intact myelin can be used for in vivo imaging of myelin content changes over time. It is possible to detect either an increase or decrease in myelin content, what means this imaging technique can detect demyelination and remyelination processes of the central nervous system. In this protocol we demonstrate how to use PET imaging to detect myelin changes in the lysolecithin rat model, which is a model of focal demyelination lesion (induced by stereotactic injection) (i.e., a model of multiple sclerosis disease). 11C-PIB PET imaging was performed at baseline, and 1 week and 4 weeks after stereotaxic injection of lysolecithin 1% in the right striatum (4 µL) and corpus callosum (3 µL) of the rat brain, allowing quantification of focal demyelination (injection site after 1 week) and the remyelination process (injection site at 4 weeks). Myelin PET imaging is an interesting tool for monitoring in vivo changes in myelin content which could be useful for monitoring demyelinating disease progression and therapeutic response.

Evaluation of Fused Pyrrolothiazole Systems as Correctors of Mutant CFTR Protein

Cystic fibrosis (CF) is a genetic disease caused by mutations that impair the function of the CFTR chloride channel. The most frequent mutation, F508del, causes misfolding and premature degradation of CFTR protein. This defect can be overcome with pharmacological agents named “correctors”. So far, at least three different classes of correctors have been identified based on the additive/synergistic effects that are obtained when compounds of different classes are combined together. The development of class 2 correctors has lagged behind that of compounds belonging to the other classes. It was shown that the efficacy of the prototypical class 2 corrector, the bithiazole corr-4a, could be improved by generating conformationally-locked bithiazoles. In the present study, we investigated the effect of tricyclic pyrrolothiazoles as analogues of constrained bithiazoles. Thirty-five compounds were tested using the functional assay based on the halide-sensitive yellow fluorescent protein (HS-YFP) that measured CFTR activity. One compound, having a six atom carbocyle central ring in the tricyclic pyrrolothiazole system and bearing a pivalamide group at the thiazole moiety and a 5-chloro-2-methoxyphenyl carboxamide at the pyrrole ring, significantly increased F508del-CFTR activity. This compound could lead to the synthesis of a novel class of CFTR correctors.

Rapid and Selective Chemical Editing of Ribosomally Synthesized and Post-Translationally Modified Peptides (RiPPs) via CuII -Catalyzed β-Borylation of Dehydroamino Acids

We report the fast and selective chemical editing of ribosomally synthesized and post-translationally modified peptides (RiPPs) by β-borylation of dehydroalanine (Dha) residues. The thiopeptide thiostrepton was modified efficiently using CuII -catalysis under mild conditions and 1D/2D NMR of the purified product showed site-selective borylation of the terminal Dha residues. Using similar conditions, the thiopeptide nosiheptide, lanthipeptide nisin Z, and protein SUMO_G98Dha were also modified efficiently. Borylated thiostrepton showed an up to 84-fold increase in water solubility, and minimum inhibitory concentration (MIC) assays showed that antimicrobial activity was maintained in thiostrepton and nosiheptide. The introduced boronic-acid functionalities were shown to be valuable handles for chemical mutagenesis and in a reversible click reaction with triols for the pH-controlled labeling of RiPPs.

Multifunctional Isosteric Pyridine Analogs-Based 2-Aminothiazole: Design, Synthesis, and Potential Phosphodiesterase-5 Inhibitory Activity

The elaboration of new small molecules that target phosphodiesterase enzymes (PDEs), especially those of type 5 (PDE5), is an interesting and emerging topic nowadays. A new series of heterocycle-based aminothiazoles were designed and synthesized from the key intermediate, 3-oxo-N-(thiazol-2-yl)butanamide (a PDE5 inhibitor that retains its amidic function), as an essential pharmacophoric moiety. The PDE5 inhibitors prevent the degradation of cyclic guanosine monophosphate, thereby causing severe hypotension as a marked side effect. Hence, an in vivo testing of the target compounds was conducted to verify its relation with arterial blood pressure. Utilizing sildenafil as the reference drug, Compounds 5, 10a, and 11b achieved 100% inhibitions of PDE5 without significantly lowering the mean arterial blood pressures (115.95 ± 2.91, 110.3 ± 2.84, and 78.3 ± 2.57, respectively). The molecular docking study revealed that the tested compounds exhibited docking poses that were similar to that of sildenafil (exploiting the amide functionality that interacted with GLN:817:A). The molecular shape and electrostatic similarity revealed a comparable physically achievable electrostatic potential with the reference drug, sildenafil. Therefore, these concomitant results revealed that the tested compounds exerted sildenafil-like inhibitory effects (although without its known drawbacks) on blood circulation, thus suggesting that the tested compounds might represent a cornerstone of beneficial drug candidates for the safe treatment for erectile dysfunction.

In-Vitro Sorbent-Mediated Removal of Edoxaban from Human Plasma and Albumin Solution

BACKGROUND AND OBJECTIVE

Based on previous experience of sorbent-mediated ticagrelor, dabigatran, and radiocontrast agent removal, we set out in this study to test the effect of two sorbents on the removal of edoxaban, a factor Xa antagonist direct oral anticoagulant.

METHODS

We circulated 100 mL of edoxaban solution during six first-pass cycles through 40-mL sorbent columns (containing either CytoSorb in three passes or Porapak Q 50-80 mesh in the remaining three passes) during experiments using human plasma and 4% bovine serum albumin solution as drug vehicles. Drug concentration was measured by liquid chromatography-tandem mass spectrometry.

RESULTS

Edoxaban concentration in two experiments performed with human plasma dropped from 276.8 to 2.7 ng/mL and undetectable concentrations, respectively, with CytoSorb or Porapak Q 50-80 mesh (p = 0.0031). The average edoxaban concentration decreased from 407 ng/mL ± 216 ng/mL to 3.3 ng/mL ± 7 ng/mL (p = 0.017), for a removal rate of 99% across all six samples of human plasma (two samples) and bovine serum albumin solution (four samples). In four out of the six adsorbed samples, the drug concentrations were undetectable.

CONCLUSION

Sorbent-mediated technology may represent a viable pathway for edoxaban removal from human plasma or albumin solution.

Microwave-Assisted Rapid Green Synthesis of Gold Nanoparticles Using Seed Extract of Trachyspermum ammi: ROS Mediated Biofilm Inhibition and Anticancer Activity

Green synthesis of metal nanoparticles using plant extracts as capping and reducing agents for the biomedical applications has received considerable attention. Moreover, emergence and spread of multidrug resistance among bacterial pathogens has become a major health concern and lookout for novel alternative effective drugs has gained momentum. In current study, we synthesized gold nanoparticles using the seed extract of Trachyspermum ammi (TA-AuNPs), assessed its efficacy against drug resistant biofilms of Listeria monocytogenes and Serratia marcescens, and evaluated its anticancer potential against HepG2 cancer cell lines. Microwave-assisted green synthesis of gold nanoparticles was carried out and characterization was done using UV-vis spectroscopy, X-ray diffraction (XRD), transmission electron microscopy (TEM), and dynamic light scattering (DLS). Most nanoparticles were observed as spherical and spheroidal with few anisotropies with an average crystalline size of 16.63 nm. Synthesized TA-AuNPs demonstrated significant biofilm inhibitory activity against L. monocytogenes (73%) as well as S. marcescens (81%). Exopolysaccharide (EPS), motility, and CSH, key elements that facilitate the formation and maintenance of biofilm were also inhibited significantly at the tested sub-minimum inhibitory concentrations (sub-MICs). Further, TA-AuNPs effectively obliterated preformed mature biofilms of S. marcescens and L. monocytogenes by 64% and 58%, respectively. Induction of intracellular ROS production in TA-AuNPs treated bacterial cells could be the plausible mechanism for the reduced biofilm formation in test pathogens. Administration of TA-AuNPs resulted in the arrest of cellular proliferation in a concentration-dependent manner. TA-AuNPs decrease the intracellular GSH in HepG2 cancer cell lines, cells become more prone to ROS generation, hence induce apoptosis. Thus, this work proposes a new eco-friendly and rapid approach for fabricating NPs which can be exploited for multifarious biomedical applications.

Characterization and cytocompatibility of 3D porous biomimetic scaffold derived from rabbit nucleus pulposus tissue in vitro

Intervertebral disc (IVD) degeneration is one of the most important causes of lower back pain. Tissue engineering provides a new method for the experimental treatment of degenerative disc diseases. This study aims to develop a natural, acellular, 3D interconnected porous scaffold derived from the extracellular matrix (ECM) of nucleus pulposus. The nucleus pulposus (NP) was decellularized by sequential detergent-nuclease methods, including physical crushing, freeze-drying and cross-linking. These 3D porous scaffolds were fabricated with a high porosity of (81.28 ± 4.10)%, an ideal pore size with appropriate mechanical properties. Rabbit bone marrow mesenchymal stem cells (rBMSCs) were seeded and cultured on the scaffolds. And the mechanical tests showed the compressive elastic modulus of the scaffolds cultured for 4 weeks reached 0.12 MPa, which was better than that of the scaffolds cultured for 2 weeks (0.07 MPa) and that of the control group (0.04 MPa). Scanning electron microscopy (SEM), histological assays, molecular biology assays revealed that the scaffolds could provide an appropriate microstructure and environment for the adhesion, proliferation, migration and secretion of seeded cells in vitro. As assays like histology, immunohistochemistry and the real-time qRT-PCR showed, NP-like tissues were preliminarily formed. In conclusion, the 3D porous scaffold derived from NP ECM is a potential biomaterial for the regeneration of NP tissues. A natural, acellular, 3D interconnected porous scaffold derived from the extracellular matrix (ECM) of nucleus pulposus was developed by sequential detergent-nuclease and freeze-drying method, which can reduce the damage of protein activity to the minimum. It is very similar to the composition and internal environment of the natural nucleus pulposus, because it derived from the natural nucleus pulposus. Scanning electron microscopy (SEM), histological assays, molecular biology assays revealed that the scaffolds could provide an appropriate microstructure and environment for the adhesion, proliferation, migration, and secretion of seeded cells in vitro.

Synthesis, Antibacterial, and Antioxidant Evaluation of Novel Series of Condensed Thiazoloquinazoline with Pyrido, Pyrano, and Benzol Moieties as Five- and Six-Membered Heterocycle Derivatives

A novel synthesis of thiazolo[2,3-b]quinazolines 4(a–e), pyrido[2′,3′:4,5]thiazolo[2,3-b]quinazolines {5(a–e), 6(a–e), and 7(a–e)}, pyrano[2′,3′:4,5]thiazolo[2,3-b]quinazolines 8(a–e), and benzo[4,5]thiazolo[2,3-b]quinazoloine9(a–e) derivatives starting from 2-(Bis-methylsulfanyl-methylene)-5,5-dimethyl-cyclohexane-1,3-dione 2 as efficient α,α dioxoketen dithioacetal is reported and the synthetic approaches of these types of compounds will provide an innovative molecular framework to the designing of new active heterocyclic compounds. In our study, we also present optimization of the synthetic method along with a biological evaluation of these newly synthesized compounds as antioxidants and antibacterial agents against the bacterial strains, like S. aureus, E. coli, and P. aeruginosa. Among all the evaluated compounds, it was found that some showed significant antioxidant activity at 10 μg/mL while the others exhibited better antibacterial activity at 100 μg/mL. The results of this study showed that compound 6(c) possessed remarkable antibacterial activity, whereas compound 9(c) exhibited the highest efficacy as an antioxidant. The structures of the new synthetic compounds were elucidated by elemental analysis, IR, ¹H-NMR, and ¹³C-NMR.

Oxidovanadium(IV) Complex Disrupts Mitochondrial Membrane Potential and Induces Apoptosis in Pancreatic Cancer Cells

BACKGROUND

At the present time, there is a growing interest in metal-based anticancer agents. Metal complexes exhibit many valuable clinical properties, however, due to toxicity, only a few clinically useful complexes have been discovered. It has been demonstrated that synthetic vanadium complexes exhibit many biological activities, including anti-cancer properties, however, cellular and molecular mechanisms still are not fully understood.

OBJECTIVE

This investigation examined the potential effects of three newly synthesized oxidovanadium(IV) complexes with 2-amino-3-hydroxypyridine against pancreatic cancer cells.

METHODS

We measured cytotoxicity by using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, antiproliferative activity by bromodeoxyuridine assay and necrosis as well as late apoptosis by lactate dehydrogenase assay. Reactive oxygen species generation, apoptosis and mitochondrial membrane potential were determined by a flow cytometry technique. Cell morphology was evaluated by using a transmission electron microscope.

RESULTS

The results showed that oxidovanadium(IV) complexes were cytotoxic on pancreatic cancer cells (PANC-1 and MIA PaCa2) over the concentration range of 12.5-200μM, following 48h incubation. Additionally, the cellular mechanism of cytotoxic activity of [2-NH2-3-OH(py)H]4[V2O2(pmida)2]·6H2O (V3) complex was dependent on ROS generation, induction apoptosis with simultaneous disruption of mitochondrial membrane potential.

CONCLUSION

We have proven that oxidovanadium (IV) complexes show therapeutic potential in pancreatic cancer therapy. The results of our research will help to understand the cellular mechanisms of the cytotoxic activity of the vanadium complexes and will allow a more effective design structure of new vanadium-based compounds in the future.

Potent and Selective Mitogen-Activated Protein Kinase Kinase 1/2 (MEK1/2) Heterobifunctional Small-molecule Degraders

Previously, we reported a first-in-class von Hippel-Lindau (VHL)-recruiting mitogen-activated protein kinase kinases 1 and 2 (MEK1/2) degrader, MS432. To date, only two MEK1/2 degrader papers have been published and very limited structure-activity relationships (SAR) have been reported. Here, we describe our extensive SAR studies exploring both von Hippel-Lindau (VHL) and cereblon (CRBN) E3 ligase ligands and a variety of linkers, which resulted in two novel, improved VHL-recruiting MEK1/2 degraders, 24 (MS928) and 27 (MS934), and the first CRBN-recruiting MEK1/2 degrader 50 (MS910). These compounds potently and selectively degraded MEK1/2 by hijacking the ubiquitin-proteasome system, inhibited downstream signaling, and suppressed cancer cell proliferation. Furthermore, concurrent inhibition of BRAF or PI3K significantly potentiated the antitumor activity of degrader 27, suggesting that the combination of MEK1/2 degradation with BRAF or PI3K inhibition may provide potential therapeutic benefits. Finally, besides being more potent, degrader 27 displayed improved plasma exposure levels in mice, representing the best MEK1/2 degrader to date for in vivo studies.

Doping control analysis of GW1516 in equine plasma using liquid chromatography/electrospray ionization Q-Exactive high-resolution mass spectrometry

RATIONALE

GW1516 is a peroxisome proliferator-activated receptor-δ agonist in the class of hormones and metabolic modulators. The use of GW1516 is banned in both horseracing and equestrian competitions. To the best of our knowledge, this is the first metabolic study of GW1516 in horses.

METHODS

After protein precipitation of pre- and post-administration plasma GW1516 samples, the supernatants were analyzed using liquid chromatography/electrospray ionization Q-Exactive high-resolution mass spectrometry to detect GW1516 and its metabolites. Monoisotopic ions of GW1516 and its metabolites were monitored from the full-scan mass spectral data of pre- and post-administration samples. Quantification methods were developed and validated to establish the elimination profiles of GW1516, its sulfoxide, and its sulfone in equine plasma.

RESULTS

GW1516 and its four metabolites GW1516 sulfoxide, GW1516 sulfone, 5-(hydroxymethyl)-4-methyl-2-(4-trifluoromethylphenyl)thiazole (HMTT), and M1 were detected in post-administration plasma samples. GW1516 sulfoxide, GW1516 sulfone, and HMTT were identified by comparison with their respective reference standards whereas M1 was tentatively identified as 4-methyl-2-[4-(trifluoromethyl)phenyl]-1,3-thiazole-5-carboxylic acid by mass spectral interpretation. GW1516 had the longest detection time in post-administration plasma. The elimination profiles of GW1516, its sulfoxide, and its sulfone in plasma were established.

CONCLUSIONS

For the purpose of doping control, GW1516 is recommended as the target analyte to be monitored in equine plasma due to its long detection time (around 1 week) and the ready availability of its reference material.