Antiinflammatory agents: new series of N-substituted amino acids with complex pyrimidine structures endowed with antiphlogistic activity

Opioid and Cannabinoid Systems in Pain: Emerging Molecular Mechanisms and Use in Clinical Practice, Health, and Fitness

Pain is an unpleasant sensory and emotional experience. Adequate pain control is often challenging, particularly in patients with chronic pain. Despite advances in pain management, drug addiction, overtreatment, or substance use disorders are not rare. Hence the need for further studies in the field. The substantial progress made over the last decade has revealed genes, signalling pathways, molecules, and neuronal networks in pain control thus opening new clinical perspectives in pain management. In this respect, data on the epigenetic modulation of opioid and cannabinoid receptors, key actors in the modulation of pain, offered new perspectives to preserve the activity of opioid and endocannabinoid systems to increase the analgesic efficacy of opioid- and cannabinoid-based drugs. Similarly, upcoming data on cannabidiol (CBD), a non-psychoactive cannabinoid in the marijuana plant Cannabis sativa, suggests analgesic, anti-inflammatory, antioxidant, anticonvulsivant and ansiolitic effects and supports its potential application in clinical contexts such as cancer, neurodegeneration, and autoimmune diseases but also in health and fitness with potential use in athletes. Hence, in this review article, we summarize the emerging epigenetic modifications of opioid and cannabinoid receptors and focus on CBD as an emerging non-psychoactive cannabinoid in pain management in clinical practice, health, and fitness.

Electrochemical synthesis and antimicrobial evaluation of some N-phenyl α-amino acids

In the present report, the authors describe a synthetic route for the generation of N-phenyl amino acid derivatives using CO2via a C-C coupling reaction in an undivided cell containing a combination of Mg-Pt electrodes. The reactions were completed in a short time without the formation of any other side product. The final products were purified via a simple recrystallization procedure. The structures of the newly prepared compounds were established using advanced spectroscopic techniques including 1H, 13C NMR, IR, and ESI-MS. All the prepared derivatives show good-to-excellent activity when tested against bacterial and fungal strains. Interestingly, it was observed that the presence of polar groups (capable of forming H-bonds) such as -OH (4d) and -NO2 (4e) at the para position of the phenyl ring show activity equivalent to the standard drugs.

Pyrazole, imidazole and triazole: In silico, docking and ADMET studies against SARS-CoV-2

The Coronavirus pandemic, Covid-19 and SARS-Cov-2 put multidisciplinary research by chemists, biologists, pharmacists and theorists necessary and primordial task to find new active biomolecules which will be beneficial for all humanity. The azoles drugs are electronic rich, they should be used with caution, and an understanding of their pharmacokinetic profile, safety, absorption, distribution, excretion, metabolism, toxicity, and drug-drug interaction profiles is important to provide effective and cure therapy. In these objectives and goals, twenty aromatic nitrogen heterocycle compounds were chosen for in silico, docking and AMET studies against SARS-CoV-2. In this paper with respect to the protein S of SARS-CoV-2 properties, the GAUSSIAN 09w program used in the semi-empirical method at the AM1 level with the optimization of the geometry of the structures. Then Toxicity and physicochemical properties were evaluated by AMET. Molecular docking investigations conducted; the binding affinities as well as interactions of the sieve compounds with the SRAS-CoV-2 protein Spike using PyRx software. In general, the preliminary results are fructuous and needs further in vitro testes.

Dietary supplementation of guanidinoacetic acid improves growth, biochemical parameters, antioxidant capacity and cytokine responses in Nile tilapia (Oreochromis niloticus)

A total of 180 unsexed Nile Tilapia fish (initial weight, 21 g) fed isonitrogenous (32%), isocaloric (3000 kcal/kg) diets containing different levels of guanidinoacetic acid (GAA) at levels of (GAA1, 0.06%, GAA2, 0.12%, GAA3, 0.18%); for 60 days. Results showed higher final body weight (FBW) and body weight gain (BWG) in groups supplemented with different levels of GAA. Specific growth rate (SGR) was the highest in groups supplemented with 0.12% and 0.18% GAA. Lipid % of whole-body composition was higher in all groups excluding GAA3 group. Serum creatine kinase (CK) activity, cholesterol, and creatinine levels showed a marked significant (P < 0.05) increase in all GAA supplemented groups compared to the control one. Triglycerides level demonstrated a higher elevation (P < 0.05) in both GAA2 and GAA3 supplemented groups. No significant observed in total protein, albumin, globulin, and A/G ratio. Lipid peroxidation marker (malondialdehyde/MDA) is markedly decreased along with a significant increase of superoxide dismutase (SOD), reduced glutathione (GSH), and nitric oxide (NO) levels in both GAA2 and GAA3 compared to other groups. Similarly, interleukin 1β (IL-1β) and tumor necrosis factor (TNF-α) gene expression levels were downregulated along with upregulation of transforming growth factor β1 (TGF-β1) at higher GAA levels, particularly at 0.18%. Our findings give important insights for the growth promoting, antioxidant and immunomodulatory effects of GAA supplemented diet particularly at level of 0.18%.

Direct enantioselective allylic substitution of 4-hydroxycoumarin derivatives with branched allylic alcohols via iridium catalysis

An iridium catalysed direct asymmetric allylic substitution reaction of 4-hydroxycoumarin derivatives with allylic alcohols with remarkably high yields and excellent enantioselectivities was realized.

Investigation of new 2-aryl substituted Benzothiopyrano[4,3-d]pyrimidines as kinase inhibitors targeting vascular endothelial growth factor receptor 2

Vascular Endothelial Growth Factor (VEGF) pathway has emerged as one of the most important positive modulators of Angiogenesis, a central process implicated in tumour growth and metastatic dissemination. This led to the design and development of anti-VEGF monoclonal antibodies and small-molecule ATP-competitive VEGFR-inhibitors. In this study, we describe the synthesis and the biological evaluation of novel 2-aryl substituted benzothiopyrano-fused pyrimidines 1a-i, 2a-i and 3a-i. The ability of the compounds to target the VEGF pathway was determined in vitro exploiting the compounds' antiproliferative efficacy against HUVEC cells. The VEGFR-2 inhibition was confirmed by enzymatic assays on recombinant human kinase insert domain receptor (KDR), by cell-based phospho-VEGFR-2 inhibition assays, and by ex vivo rat aortic ring tests. The selectivity profile of the best performing derivatives belonging to series 2 was further explored combining modeling studies and additional assays in a panel of human cell lines and other kinases.

Efficient PPA-SiO2-catalyzed synthesis of β-enaminones under solvent-free conditions

An efficient method has been developed for the synthesis of β-enaminones under solvent-free reaction conditions using PPA-SiO₂ as catalyst. The reaction yields were good to excellent (up to 90%). This methodology affords high selectivity and good tolerance of a variety of different functional groups present on both aromatic and aliphatic amines. In addition, the methodology is environmentally benign and cost-effective due to absence of solvent and easy work-up.

Six closely related 4,6-disubstituted 2-amino-5-formylpyrimidines: different ring conformations, polarized electronic structures, and hydrogen-bonded assembly in zero, one, two and three dimensions

In each of ethyl N-{2-amino-5-formyl-6-[methyl(phenyl)amino]pyrimidin-4-yl}glycinate, C(16)H(19)N(5)O(3), (I), N-{2-amino-5-formyl-6-[methyl(phenyl)amino]pyrimidin-4-yl}glycinamide, C(14)H(16)N(6)O(2), (II), and ethyl 3-amino-N-{2-amino-5-formyl-6-[methyl(phenyl)amino]pyrimidin-4-yl}propionate, C(17)H(21)N(5)O(3), (III), the pyrimidine ring is effectively planar, but in each of methyl N-{2-amino-6-[benzyl(methyl)amino]-5-formylpyrimidin-4-yl}glycinate, C(16)H(19)N(5)O(3), (IV), ethyl 3-amino-N-{2-amino-6-[benzyl(methyl)amino]-5-formylpyrimidin-4-yl}propionate, C(18)H(23)N(5)O(3), (V), and ethyl 3-amino-N-[2-amino-5-formyl-6-(piperidin-4-yl)pyrimidin-4-yl]propionate, C(15)H(23)N(5)O(3), (VI), the pyrimidine ring is folded into a boat conformation. The bond lengths in each of (I)-(VI) provide evidence for significant polarization of the electronic structure. The molecules of (I) are linked by paired N-H···N hydrogen bonds to form isolated dimeric aggregates, and those of (III) are linked by a combination of N-H···N and N-H···O hydrogen bonds into a chain of edge-fused rings. In the structure of (IV), molecules are linked into sheets by means of two hydrogen bonds, both of N-H···O type, in the structure of (V) by three hydrogen bonds, two of N-H···N type and one of C-H···O type, and in the structure of (VI) by four hydrogen bonds, all of N-H···O type. Molecules of (II) are linked into a three-dimensional framework structure by a combination of three N-H···O hydrogen bonds and one C-H···O hydrogen bond.

Synthesis of new 5,6-dihydrobenzo[h]quinazoline 2,4-diamino substituted and antiplatelet/antiphlogistic activities evaluation

In pursuing our research on some 2,4-diamino-benzopyranopyrimidines and 2-amino-5,6-dihydrobenzo[h]quinazolines, previously reported as antiplatelet and analgesic/anti-inflammatory agents respectively, we designed and synthesized a new series of 5,6-dihydrobenzo[h]quinazoline 2,4-diamino substituted. The insertion of amino substituents at positions 2 and 4 of the benzoquinazoline scaffold resulted in compounds endowed with a potent ASA-like antiplatelet activity, combined with an anti-inflammatory activity comparable, in some cases, to that of indomethacin, used as a reference drug.

Effect of creatine, creatinine, and creatine ethyl ester on TLR expression in macrophages

Despite the widespread availability and use of dietary supplements, minimal work has been performed to assess the potential dangers many of these supplements may have on the host's well-being, in particular the host's ability to respond to infection. One supplement extensively used by both adolescents and adults is creatine. Using Real-time PCR, we examined the impact of short-term exposure of a mouse macrophage cell line (RAW 264.7 cells) to two readily available forms of creatine used in supplements--creatine monohydrate (CR) and creatine ethyl ester (CEE) as well as the end product of creatine metabolism, creatinine (CRN), on expression of toll-like receptor-2 (TLR-2), TLR-3, TLR-4, and TLR-7. CR down-regulated TLR-2, TLR-3, TLR-4 and TLR-7 mRNA levels in RAW cells. Similar results were observed following exposure of RAW cells to CRN. Conversely CEE appears to possess immunostimulatory properties and increases expression of TLR-2, TLR-3, TLR-4, and TLR-7 in RAW cells. These data are supported by immunostaining using antibodies specific for the individual TLRs before and after exposure of RAW cells to CR, CRN, or CEE. To extend these findings, we isolated murine splenocytes and exposed the cells to CR, CEE, or CRN for 24 hours and performed immunofluorescent staining for TLR-2, TLR-3, TLR-4 and TLR-7. The results obtained from this study with primary splenocytes were consistent with the studies using RAW cells. Together, these data suggest that creatine and creatine derivatives may impact the ability of immune cells to sense a wide array of viral and bacterial pathogens. Of great interest, CRN--largely considered to be a waste product of the argenine biosynthesis pathway may also have immunosuppressive properties similar to those of CR.

Synthesis and Biological Evaluation of N-Pyrazolyl-N‘-alkyl/benzyl/phenylureas: a New Class of Potent Inhibitors of Interleukin 8-Induced Neutrophil Chemotaxis

Neutrophils chemotaxis is a complex multistep process that, if upregulated, causes acute inflammation and a number of autoimmune diseases. We report here the synthesis of a new N-(4-substituted)pyrazolyl-N'-alkyl/benzyl/phenylureas that are potent inhibitors of interleukin-8 (IL8)-induced neutrophil chemotaxis. The first series of compounds, obtained by functionalization with a urea moiety of the 5-amino-1-(2-hydroxy-2-phenylethyl)-1H-pyrazole-4-carboxylic acid ethyl ester 3, blocked the IL8-induced neutrophil chemotaxis, while they did not block N-formylmethionylleucylphenylalanine-mediated chemotaxis. The most active compounds, 3-benzyl- (4d), 3-(4-benzylpiperazinyl)- (4i), 3-phenyl- (4k) and 3-isopropylureido (4a) derivatives, showed an IC50 of 10, 14, 45, and 55 nM, respectively. Several different molecules were then synthesized to obtain more information for SAR study. Compounds 4a, 4d, and 4k were inactive in the binding assays on CXCR1 and CXCR2 (IL8 receptors), whereas they inhibited the phosphorylation of PTKs (protein tyrosine kinases) in the 50-70 kDa region. Moreover, in the presence of the same derivatives, we observed a complete block of F-actin rise and pseudopod formation.

Synthesis and biological evaluation of neutrophilic inflammation inhibitors

In several non-infectious human diseases, such as ulcerous colitis, rheumatoid arthritis, chronic obstructive pulmonary disease (COPD), the extravasal recruitment of neutrophils plays a crucial role in the development of tissue damage, which, when persistent, can lead to the irreversible organ dysfunction. The neutrophil activation is controlled by a number of intracellular pathways, particularly by a cAMP-dependent protein kinase A (PKA) which also acts on phosphodiesterase IV (PDE4) gene stimulating the synthesis of this enzyme, able to transform cAMP to inactive AMP. PDE4 inhibitors enhance intracellular cAMP and decrease inflammatory cell activation. Several 3-cyclopentyloxy-4-methoxybenzaldehyde and 3-cyclopentyloxy-4-methoxybenzoic acid derivatives were synthesized and studied by us to evaluate their ability to inhibit the superoxide anion production in human neutrophils. These compounds were found able to inhibit the neutrophil activation and some of them increased the cAMP level on tumor necrosis factor-alpha-stimulated neutrophils. Moreover, they also inhibited selectively the human PDE4 enzyme, although they are less potent than the reference compound Rolipram. We report here synthesis, biological studies and some SAR considerations concerning the above mentioned compounds.

New polycyclic pyrimidine derivatives with antiplatelet in vitro activity: synthesis and pharmacological screening

The preparation and the pharmacological screening of novel anti-aggregatory/antiphlogistic polycyclic pyrimidine derivatives are described. The compounds were developed starting from bioactive 2-aminobenzopyranopyrimidine derivatives in order to assess the importance of the benzopyrano[4,3-d]pyrimidine structure and the role of an amino basic moiety in position 2. Antiplatelet activity was assessed in vitro against ADP and arachidonic acid-induced aggregation in guinea-pig plasma. Anti-inflammatory/analgesic/antipyretic activities were studied in rat paw oedema, mouse writhing test and E. coli-induced rat fever. Ulcerogenic and gastroprotective effects were also investigated in vivo on rat gastric mucosa. Among the tested compounds, the 5-substituted benzopyranopyrimidine derivatives 3d and 4d proved to be the most active antiplatelet agents as potent as acetylsalicylic acid against arachidonic acid-stimulated aggregation. Furthermore the 2-methylthio derivative 4d was endowed with greater efficacy against ADP aggregation suggesting that additional non-TXA2 dependent mechanisms are involved in its biological activity. Orally administered at 100 mg kg(-1) in rats this latter compound displayed antiphlogistic acitivity comparable to indomethacin (10 mg kg(-1)) coupled with an unusual gastroprotective effect on ethanol-induced ulcers. In conclusion, these findings indicate that the 5-pyrrolidino-2-methylthiobenzopyrano[4,3-d]pyrimidine 4d fulfils the chemical requirements to exhibit antiplatelet activity associated with gastroprotective effect.