Synthesis and in vitro evaluation of diverse heterocyclic diphenolic compounds as inhibitors of DYRK1A

Dual-specificity tyrosine phosphorylation-related kinase 1A (DYRK1A) is a dual-specificity protein kinase that catalyses phosphorylation and autophosphorylation. Higher DYRK1A expression correlates with cancer, in particular glioblastoma present within the brain. We report here the synthesis and biological evaluation of new heterocyclic diphenolic derivatives designed as novel DYRK1A inhibitors. The generation of these heterocycles such as benzimidazole, imidazole, naphthyridine, pyrazole-pyridines, bipyridine, and triazolopyrazines was made based on the structural modification of the lead DANDY and tested for their ability to inhibit DYRK1A. None of these derivatives showed significant DYRK1A inhibition but provide valuable knowledge around the importance of the 7-azaindole moiety. These data will be of use for developing further structure-activity relationship studies to improve the selective inhibition of DYRK1A.     

Design,synthesis and biological evaluation of novel 7-azaspiro[3.5]nonane derivatives as GPR119 agonists

The design and synthesis of a novel class of 7-azaspiro[3.5]nonane GPR119 agonists are described. In this series, optimization of the right piperidine N-capping group (R²) and the left aryl group (R³) led to the identification of compound 54g as a potent GPR119 agonist. Compound 54g showed a desirable PK profile in Sprague-Dawley (SD) rats and a favorable glucose lowering effect in diabetic rats.     

Expedient synthesis and biological evaluation of alkenyl acyclic nucleoside phosphonate prodrugs

The importance of phosphonoamidate prodrugs (ProTides) of acyclic nucleoside phosphonate (ANPs) is highlighted by the approval of Tenofovir Alafenamide Fumarate for the treatment of HIV and HBV infections. In the present paper we are reporting an expedient, one-pot, two-steps synthesis of allyl phosphonoamidates and diamidates that offers a time saving strategy when compared to literature methods. The use of these substrates in the cross metathesis reactions with alkenyl functionalised thymine and uracil nucleobases is reported. ANPs prodrugs synthesized via this methodology were evaluated for their antiviral activities against DNA and RNA viruses. It is anticipated that the use of 5,6,7,8-tetrahydro-1-napthyl as aryloxy moiety is capable to confer antiviral activity among a series of otherwise inactive uracil ProTides.     

Synthesis and biological activity of structurally diverse phthalazine derivatives: A systematic review

Phthalazine, a structurally and pharmacologically versatile nitrogen-containing heterocycle, has gained more attention from medicinal chemists in the design and synthesis of novel drugs owing to its pharmacological potential. In particular, phthalazine scaffold appeared as a pharmacophoric feature numerous drugs exhibiting pharmacological activities, in particular, antidiabetic, anticancer, antihypertensive, antithrombotic, anti-inflammatory, analgesic, antidepressant and antimicrobial activities. This review presents a summary of updated and detailed information on phthalazine as illustrated in both patented and non-patented literature. The reported literature have described the optimal pharmacological characteristics of phthalazine derivatives and highlighted the applicability of phthalazine, as potent scaffold in drug discovery.     

Synthesis and evaluation of camphor and cytisine-based cyanopyrrolidines as DPP-IV inhibitors for the treatment of type 2 diabetes mellitus

In this study, bornyl- and cytisine-based cyanopyrrolidines as potent dipeptidyl peptidase-IV (DPP-IV) inhibitors were synthesised. The in vitro inhibiting activities of bornyl- and cytisine derivatives towards DPP-IV were evaluated. Bornyl-based cyanopyrrolidines were shown to have moderate inhibitory activity with regard to DPP-IV (1.27–15.78?µM). A docking study was performed to elucidate the structure-activity relationship of the obtained compounds. The in vivo hypoglycemic activities of the same compounds were evaluated with the oral glucose tolerance test (OGTT) in mice. Bornyl-based cyanopyrrolidines were shown to have good hypoglycemic activity.     

Design,synthesis and evaluation against Chikungunya virus of novel small-molecule antiviral agents

Chikungunya virus is a re-emerging arbovirus transmitted to humans by mosquitoes, responsible for an acute flu-like illness associated with debilitating arthralgia, which can persist for several months or become chronic. In recent years, this viral infection has spread worldwide with a previously unknown virulence. To date, no specific antivirals treatments nor vaccines are available against this important pathogen. Starting from the structures of two antiviral hits previously identified in our research group with in silico techniques, this work describes the design and preparation of 31 novel structural analogues, with which different pharmacophoric features of the two hits have been explored and correlated with the inhibition of Chikungunya virus replication in cells. Structure-activity relationships were elucidated for the original scaffolds, and different novel antiviral compounds with EC₅₀ values in the low micromolar range were identified. This work provides the foundation for further investigation of these promising novel structures as antiviral agents against Chikungunya virus.     

Synthesis and biological evaluation of novel N-substituted nipecotic acid derivatives with a cis-alkene spacer as GABA uptake inhibitors

To discover new, potent, and selective inhibitors for the murine gamma-aminobutyric acid transporter 4 (mGAT4), the structure-activity relationship (SAR) study of a new cis-alkene analog family based on DDPM-1457 [(S)-2], which previously showed promising inhibitory potency at and subtype selectivity for mGAT4, was conducted. To uncover the importance of the differences between the trans- and the cis-alkene moiety in the spacer, the present publication describes the synthesis of the new compounds via catalytic hydrogenation with Lindlar’s catalyst. The biological results collected by the SAR study revealed that analog rac-7j characterized by a four-instead of a three-carbon atom spacer with a cis double bond applying to the majority of the studied compounds displays a surprisingly high potency at mGAT1 (pIC₅₀?=?6.00?±?0.04) and at the same time a reasonable potency at mGAT4 (pIC₅₀?=?4.82).     

Synthesis and biological evaluation of a trisaccharide repeating unit derivative of Streptococcus pneumoniae 19A capsular polysaccharide

Streptococcus pneumoniae (SP) is a common human pathogen associated with a broad spectrum of diseases and it is still a leading cause of mortality and morbidity worldwide, especially in children. Moreover, SP is increasingly associated with drug resistance. Vaccination against the pathogen may thus represent an important strategy to overcome its threats to human health. In this context, revealing the molecular determinants of SP immunoreactivity may be relevant for the development of novel molecules with therapeutic perspectives as vaccine components. Serogroup 19 comprises the immune-cross reactive types 19F, 19A, 19B and 19C and it accounts for a high percentage of invasive pneumococcal diseases, mainly caused by serotypes 19F and 19A. Herein, we report the synthesis and biological evaluation of an aminopropyl derivative of the trisaccharide repeating unit of SP 19A. We compare two different synthetic strategies, based on different disconnections between the three monosaccharides which make up the final trisaccharide, to define the best approach for the preparation of the trisaccharide. Synthetic accessibility to the trisaccharide repeating unit lays the basis for the development of more complex biopolymer as well as saccharide conjugates. We also evaluate the binding affinity of the trisaccharide for anti-19A and anti-19F sera and discuss the relationship between the chemical properties of the trisaccharide unit and biological activity.     

Development of a novel NURR1/NOT agonist from hit to lead and candidate for the potential treatment of Parkinson's disease

In the course of a programme aimed at identifying Nurr1/NOT agonists for potential treatment of Parkinson’s disease, a few hits from high throughput screening were identified and characterized. A combined optimization pointed to a very narrow and stringent structure activity relationship. A comprehensive program of optimization led to a potent and safe candidate drug displaying neuroprotective and anti-inflammatory activity in several in vitro and in vivo models.     

Design,synthesis and biological evaluation of novel spiro-pentacylamides as acetyl-CoA carboxylase inhibitors

Acetyl-CoA carboxylase (ACC) catalyzes the rate-determining step in de novo lipogenesis and plays an important role in the regulation of fatty acid oxidation. Therefore, ACC inhibition offers a promising option for intervention in nonalcoholic fatty liver disease (NAFLD), type 2 diabetes (T2DM) and cancer. In this paper, a series of spiropentacylamide derivatives were synthesized and evaluated for their ACC1/2 inhibitory activities and anti-proliferation effects on A549, H1975, HCT116, SW620 and Caco-2 cell lines in vitro. Compound 6o displayed potent ACC1/2 inhibitory activity (ACC1 IC₅₀?=?0.527?μM, ACC2 IC₅₀?=?0.397?μM) and the most potent anti-proliferation activities against A549, H1975, HCT116, SW620 and Caco-2 cell lines, with IC₅₀ values of 1.92?μM, 0.38?μM, 1.22?μM, 2.05?μM and 5.42?μM respectively. Further molecular docking studies revealed that compound 6o maintained hydrogen bonds between the two carbonyls and protein backbone NHs (Glu-B2026 and Gly-B1958). These results indicate that compound 6o is a promising ACC1/2 inhibitor for the potent treatment of cancer.     

Fungal communities associated with species of Fraxinus tolerant to ash dieback,and their potential for biological control

Ash dieback, caused by the fungus Hymenoscyphus fraxineus, has threatened ash trees in Europe for more than two decades. However, little is known of how endophytic communities affect the pathogen, and no effective disease management tools are available. While European ash (Fraxinus excelsior) is severely affected by the disease, other more distantly related ash species do not seem to be affected. We hypothesise that fungal endophytic communities of tolerant ash species can protect the species against ash dieback, and that selected endophytes have potential as biocontrol agents. These hypotheses were tested by isolating members of the fungal communities of five tolerant ash species, and identifying them using ITS regions. Candidate endophytes were tested by an in vitro antagonistic assay with H.fraxineus. From a total of 196 isolates we identified 9 fungal orders, 15 families, and 40 species. Fungi in orders Pleosporales, such as Boeremia exigua and Diaporthe spp., and Hypocreales (e.g., Fusarium sp.), were recovered in most communities, suggesting they are common taxa. The in vitro antagonistic assay revealed five species with high antagonistic activity against H. fraxineus. These endophytes were identified based on ITS region as Sclerostagonospora sp., Setomelanomma holmii, Epicoccum nigrum, B. exigua and Fusarium sp. Three of these taxa have been described previously as antagonists of plant pathogenic microbes, and are of interest for future studies of their potential as biological control agents against ash dieback, especially for valuable ash trees in parks and urban areas.     

Development of a stereoselective and scalable process for the preparation of a methylcyclobutanol-pyridyl ether

The evolution of a scalable process for the preparation of methylcyclobutanol-pyridyl ether 1 is described. Key aspects of this development including careful control of the stereochemistry, elimination of chromatography, and application to kilogram-scale synthesis are addressed.     

State of the Art Technology for Bone Tissue Engineering and Drug Delivery

BackgroundCritical size bone defect and fracture unable to regenerate itself, inspire the origination and technological advancement in the field of bone tissue engineering (BTE). The strategies of bone tissue engineering are often classified into three groups: First, is a direct injection of cells into the tissue of interest; second is grafting of cell-scaffold constructs; and third is scaffold-based signaling molecules, drug delivery or both. Much research was available on the first two categories, still finding the structure and property of scaffold close towards the natural tissue is yet to achieve.Aim of the ReviewThe proposed mini review focus on ceramic biomaterials uses for bone regeneration and drug delivery. It covers the fabrication process of scaffold including conventional and non-conventional i.e. rapid prototyping approach along with it advantage. The use of scaffold for drug delivery and signaling molecules such as growth factor is an emerging field of research in tissue engineering.ConclusionThe biodegradable beads used as a local drug delivery system are ubiquitous in surgery to treat post-operative infections but does not play any role in tissue regeneration. The use of this clinically accepted drug delivery technique in bone regeneration is an alternative way for the treatment on several bone infections (especially osteomyelitis and arthritis associated with tuberculosis). It is predicted to be the future of organ replacement and treatment.     

A review of salvinorin analogs and their kappa-opioid receptor activity

The plant metabolite salvinorin A potently and selectively agonizes the human kappa-opioid receptor, an emerging target for next-generation analgesics. Here we review analogs of the salvinorin chemotype and their effects on selectivity, affinity and potency. Extensive peripheral modifications using isolated salvinorin A have delivered a trove of SAR information. More deep-seated changes are now possible by advances in chemical synthesis.     

An apparatus for safe and convenient handling of anhydrous, liquid hydrogen fluoride at controlled temperatures and reaction times. Application to the generation of oligosaccharides from polysaccharides

β-d-Gal-(1 → 4)-β-d-GlcNAc-OC₆H₄NO₂-p (p-nitrophenyl N-acetyl-β-lactosaminide) and β-d-Gal-(1 → 6)-β-d-GlcNAc-OC₆H₄NO₂-p (p-nitrophenyl N-acetyl-β-isolactosaminide) were regioselectively synthesized from lactose and p-nitrophenyl 2-acetamido-2-deoxy-glucopyranoside, employing transglycosylation by the β-d-galactosidase from Bacillus circulans and by controlling the concentration of organic solvent in the reaction system. The (1 → 4)-linked disaccharide was formed exclusively when the concentration of organic solvent was high, whereas the (1 → 6)-linked isomer was produced with a low concentration. Further utilization of the transglycosylation by the enzyme led to the regioselective formation of β-d-Gal-(1 → 4)-d-GalNAc and β-d-Gal-(1 → 4)-β-d-GalNAc-OC₆H₄NO₂-p. With the enzyme, β-d-galactosyl transfer occurred preferentially at the O-4 position of GlcNAc and GalNAc, regardless of the configuration of the hydroxyl group.     

Design,synthesis and molecular modelling of new bulky Fananserin derivatives with altered pharmacological profile as potential antidepressants

It is now known that many neurotransmitter systems are responsible for diseases of the central nervous system (CNS). One of the most common CNS disease is depression. Considering that in the treatment and the genesis of depression, the most important are the serotonin receptors from 5-HT_1A, 5-HT_2A, 5-HT₆ and 5-HT₇ groups, and dopamine D₂R this article describes searching for group of new ligands for mentioned receptors. In the searching for potentially useful compound, we decided to start from the structure of well-known Fananserin. We tried to developed new derivatives, with changed profile of activity compared to Fananserin. Literature analysis and virtual screening emerged group of halogenated long-chain arylpiperazines derivatives of 1,8 naphthosultam/lactam with hexyl carbon chain to synthesis. The compounds obtaining method was developed with a microwave assisted synthesis. Reactions were carried out in acetonitrile, water or in solvent-free conditions. The obtained compounds were tested for their affinity for the serotonin receptors mentioned above. The work managed to obtain compounds acting on selected serotonin receptors, including multifunctional 5-HT_1A/5-HT₇/D₂ ligand 5k, dual 5-HT_1A/D₂ ligand 5j and selective 5-HT_1A ligands 5r and 5c. The SAR analysis showed a visible dependence of affinity for the 5-HT₆ receptors from structure of ligands. This relationship was discussed using molecular docking methods. A conformal analysis was also performed for selected ligands and the Fukui indexes were calculated using the DFT (B3LYP/6-311+G (d,p) level of theory) methods. The conducted research and analysis using molecular docking methods allows for selecting further pathways of structural modifications in the design of new ligands for serotonin receptors belonging to the group mentioned. What is more, conducted research show the potential using of Fukui indices to predict the biological activity of new molecules.     

A Distribution-Moment Approximation for Coupled Dynamics of the Airway Wall and Airway Smooth Muscle

Asthma is fundamentally a disease of airway constriction. Due to a variety of experimental challenges, the dynamics of airways are poorly understood. Of specific interest is the narrowing of the airway due to forces produced by the airway smooth muscle wrapped around each airway. The interaction between the muscle and the airway wall is crucial for the airway constriction that occurs during an asthma attack. Although cross-bridge theory is a well-studied representation of complex smooth muscle dynamics, and these dynamics can be coupled to the airway wall, this comes at significant computational cost—even for isolated airways. Because many phenomena of interest in pulmonary physiology cannot be adequately understood by studying isolated airways, this presents a significant limitation. We present a distribution-moment approximation of this coupled system and study the validity of the approximation throughout the physiological range. We show that the distribution-moment approximation is valid in most conditions, and we explore the region of breakdown. These results show that in many situations, the distribution-moment approximation is a viable option that provides an orders-of-magnitude reduction in computational complexity; not only is this valuable for isolated airway studies, but it moreover offers the prospect that rich ASM dynamics might be incorporated into interacting airway models where previously this was precluded by computational cost.     

Synthesis and biological evaluation of isoxazolyl-sulfonamides: A non-cytotoxic scaffold active against Trypanosoma cruzi, Leishmania amazonensis and Herpes Simplex Virus

In this study we report the synthesis, characterization, biological evaluation, and druglikeness assessment of a series of 20 novel isoxazolyl-sulfonamides, obtained by a four-step synthetic route. The compounds had their activity against Trypanosoma cruzi, Leishmania amazonensis, Herpes Simplex Virus type 1 and cytotoxicity evaluated in phenotypic assays. All compounds have drug-like properties, showed low cytotoxicity and were promising regarding all other biological activities reported herein, especially the inhibitory activity against T. cruzi. The compounds 8 and 16 showed significant potency and selectivity against T. cruzi (GI₅₀?=?14.3?µM, SI?>?34.8 and GI₅₀?=?11.6?µM, SI?=?29.1, respectively). These values, close to the values of the reference drug benznidazole (GI₅₀?=?10.2?µM), suggest that compounds 8 and 16 represent promising candidates for further pre-clinical development targeting Chagas disease.