Synthesis and Biological Evaluation of Salicylic Acid Analogues of Celecoxib as a New Class of Selective Cyclooxygenase-1 Inhibitor

Trifluoromethyl-β-dicarbonyls as Versatile Synthons in Synthesis of Heterocycles

Trifluoromethyl group relishes a privileged position in the realm of medicinal chemistry because its incorporation into organic molecules often enhances the bioactivity by altering pharmacological profile of molecule. Trifluoromethyl-β-dicarbonyls have emerged as pivotal building blocks in synthetic organic chemistry due to their facile accessibility, stability and remarkable versatility. Owing to presence of nucleophilic and electrophilic sites, they offer multifunctional sites for the reaction. This review covers a meticulous exploration of their multifaceted role, encompassing an in-depth analysis of mechanism, extensive scope, limitations and wide-ranging applications in diverse organic synthesis, covering the literature from the 21st century. This comprehensive review encapsulates the applications of trifluoromethyl-β-dicarbonyls and their synthetic equivalents as precursors of complex and diverse heterocyclic scaffolds, fused heterocycles and spirocyclic compounds having medicinal and material importance. Their potent synthetic utility in cyclocondensation reactions with binucleophiles, cycloaddition reactions, C-C bond formations, asymmetric multicomponent reactions using classical/solvent-free/catalytic synthesis have been presented. Influence of unsymmetrical trifluoromethyl-β-diketones on regioselectivity of transformation is also reviewed. This review will benefit the synthetic and pharmaceutical communities to explore trifluoromethyl-β-dicarbonyls as trifluoromethyl building blocks for fabrication of heterocyclic scaffolds having implementation into drug discovery programs in the imminent future.

SC-560 and mofezolac isosteres as new potent COX-1 selective inhibitors with antiplatelet effect

Selective cyclooxygenase (COX)-1 inhibitors can be employed as potential cardioprotective drugs. Moreover, COX-1 plays a key role in inflammatory processes and its activity is associated with some types of cancer. In this work, we designed and synthesized a set of compounds that structurally mimic the selective COX-1 inhibitors, SC-560 and mofezolac, the central cores of which were replaced either with triazole or benzene rings. The advantage of this approach is a relatively simple synthesis in comparison with the syntheses of parent compounds. The newly synthesized compounds exhibited remarkable activity and selectivity toward COX-1 in the enzymatic in vitro assay. The most potent compound, 10a (IC50  = 3 nM for COX-1 and 850 nM for COX-2), was as active as SC-560 (IC50  = 2.4 nM for COX-1 and 470 nM for COX-2) toward COX-1 and it was even more selective. The in vitro COX-1 enzymatic activity was further confirmed in the cell-based whole-blood antiplatelet assay, where three out of four selected compounds (10a,c,d, and 3b) exerted outstanding IC50 values in the nanomolar range (9-252 nM). Moreover, docking simulations were performed to reveal key interactions within the COX-1 binding pocket. Furthermore, the toxicity of the selected compounds was tested using the normal human kidney HK-2 cell line.

In Vitro and In Silico Investigation of Polyacetylenes from Launaea capitata (Spreng.) Dandy as Potential COX-2, 5-LOX, and BchE Inhibitors

Diverse secondary metabolites are biosynthesized by plants via various enzymatic cascades. These have the capacity to interact with various human receptors, particularly enzymes implicated in the etiology of several diseases. The n-hexane fraction of the whole plant extract of the wild edible plant, Launaea capitata (Spreng.) Dandy was purified by column chromatography. Five polyacetylene derivatives were identified, including (3S,8E)-deca-8-en-4,6-diyne-1,3-diol (1A), (3S)-deca-4,6,8-triyne-1,3-diol (1B), (3S)-(6E,12E)-tetradecadiene-8,10-diyne-1,3-diol (2), bidensyneoside (3), and (3S)-(6E,12E)-tetradecadiene-8,10-diyne-1-ol-3-O-β-D-glucopyranoside (4). These compounds were investigated for their in vitro inhibitory activity against enzymes involved in neuroinflammatory disorders, including cyclooxygenase-2 (COX-2), 5-lipoxygenase (5-LOX), and butyrylcholinesterase (BchE) enzymes. All isolates recorded weak-moderate activities against COX-2. However, the polyacetylene glycoside (4) showed dual inhibition against BchE (IC₅₀ 14.77 ± 1.55 μM) and 5-LOX (IC₅₀ 34.59 ± 4.26 μM). Molecular docking experiments were conducted to explain these results, which showed that compound 4 exhibited greater binding affinity to 5-LOX (-8.132 kcal/mol) compared to the cocrystallized ligand (-6.218 kcal/mol). Similarly, 4 showed a good binding affinity to BchE (-7.305 kcal/mol), which was comparable to the cocrystallized ligand (-8.049 kcal/mol). Simultaneous docking was used to study the combinatorial affinity of the unresolved mixture 1A/1B to the active sites of the tested enzymes. Generally, the individual molecules showed lower docking scores against all the investigated targets compared to their combination, which was consistent with the in vitro results. This study demonstrated that the presence of a sugar moiety (in 3 and 4) resulted in dual inhibition of 5-LOX and BchE enzymes compared to their free polyacetylenes analogs. Thus, polyacetylene glycosides could be suggested as potential leads for developing new inhibitors against the enzymes involved in neuroinflammation.

An Aspirin a Day: New Pharmacological Developments and Cancer Chemoprevention

Chemoprevention refers to the use of natural or synthetic agents to reverse, suppress, or prevent the progression or recurrence of cancer. A large body of preclinical and clinical data suggest the ability of aspirin to prevent precursor lesions and cancers, but much of the clinical data are inferential and based on descriptive epidemiology, case control, and cohort studies or studies designed to answer other questions (e.g., cardiovascular mortality). Multiple pharmacological, clinical, and epidemiologic studies suggest that aspirin can prevent certain cancers but may also cause other effects depending on the tissue or disease and organ site in question. The best-known biological targets of aspirin are cyclooxygenases, which drive a wide variety of functions, including hemostasis, inflammation, and immune modulation. Newly recognized molecular and cellular interactions suggest additional modifiable functional targets, and the existence of consensus molecular cancer subtypes suggests that aspirin may have differential effects based on tumor heterogeneity. This review focuses on new pharmacological developments and innovations in biopharmacology that clarify the potential role of aspirin in cancer chemoprevention.

Design and Synthesis of Novel 1,3,4-Oxadiazole and 1,2,4-Triazole Derivatives as Cyclooxygenase-2 Inhibitors with Anti-inflammatory and Antioxidant activity in LPS-stimulated RAW264.7 Macrophages

In an attempt to obtain new candidates with potential anti-inflammatory activity, two series of 1,3,4-oxadiazole based derivatives (8a-g) and 1,2,4-triazole based derivatives (10a,b and 11a-g) were synthesized and evaluated for their COX-1/COX-2 inhibitory activity. In vitro assays showed potent COX-2 inhibitory activity and selectivity of the novel designed compounds (IC50 = 0.04 - 0.16 μM, SI = 60.71 - 337.5) compared to celecoxib (IC50 = 0.045 μM, SI = 326.67). The anti-inflammatory and antioxidant activity of the synthesized compounds was investigated via testing their ability to inhibit pro-inflammatory [tumour necrosis factor (TNF-α) and interleukin-6 (IL-6)] and oxidative stress [nitric oxide (NO) and reactive oxygen species (ROS)] markers production in lipopolysaccharide (LPS)-activated RAW 264.7 macrophages. Most of the novel compounds exhibited potent anti-inflammatory and antioxidant activity. In particular, the novel compounds showed excellent IL-6 inhibitory activity (IC50 = 0.96 - 11.14 μM) when compared to celecoxib (IC50 = 13.04 μM) and diclofenac sodium (IC50 = 22.97 μM). Moreover, the most potent and selective COX-2 inhibitor 11c (IC50 = 0.04 μM, SI = 337.5) displayed significantly higher activity against NO and ROS production compared to celecoxib (IC50 = 2.60 and 3.01 μM vs. 16.47 and 14.30 μM, respectively). Molecular modelling studies of the novel designed molecules into COX-2 active sites analysed their binding affinity. In-silico simulation studies indicated their acceptable physicochemical properties and pharmacokinetic profiles. This study suggests that the novel synthesized COX-2 inhibitors exert potent anti-inflammatory and antioxidant activity, highlighting their potential as promising therapeutic agents for the treatment of inflammation and oxidative stress-related diseases.