Synthesis and Antiplatelet Potential Evaluation of 1,3,4-Oxadiazoles Derivatives

2019 ◽  
Vol 233 (12) ◽  
pp. 1741-1759
Author(s):  
Ayesha Ramzan ◽  
Areesha Nazeer ◽  
Ahmad Irfan ◽  
Abdullah G. Al-Sehemi ◽  
Francis Verpoort ◽  
...  

AbstractA novel series of 2-(3-methyl-1,6-diphenyl-1H-pyrazolo[3,4-b]pyridin-4-yl)-5-aryl-1,3,4-oxadiazoles (4a–4h) has been synthesized from corresponding hydrazones (3a–3h) and evaluated their antiplatelet aggregation effect induced by arachidonic acid and collagen. Spectral data and elemental evaluation were used to confirm the structure of the compounds while molecular docking against cyclooxygenase 1 and 2 (COX1 & COX2) and quantitative structure-activity relationship (QSAR) were performed in describing their antiplatelet potential. All synthesized compound exhibited more than 50% platelet aggregation inhibition against both arachidonic acid and collagen. Antiplatelet activities results showed that 4b and 4f compounds have highest % inhibition against arachidonic acid. High Egap and ionization potential values showed that the compound 4d, 4e and 4f were supposed to be more active and good electron donor while 4b, 4c, 4d, 4e, 4g and 4h might be more active due to more electrophilic sites. Interaction with more than one residues in the binding pocket of COX-1 in comparison with aspirin and ligand efficacy (LE) consequences showed that compounds have excellent action potential for COX-1. Computational evaluations are in good agreement with antiplatelet activities of the compounds. All compounds might be promising antiplatelet agents especially 4b, 4f and helpful in the synthesis of new drugs for the treatment of cardiovascular diseases (CVDs).

2021 ◽  
Vol 22 (13) ◽  
pp. 6846
Author(s):  
Hla Nu Swe ◽  
Boonchoo Sritularak ◽  
Ponlapat Rojnuckarin ◽  
Rataya Luechapudiporn

Lusianthridin is a phenanthrene derivative isolated from Dendrobium venustum. Some phenanthrene compounds have antiplatelet aggregation activities via undefined pathways. This study aims to determine the inhibitory effects and potential mechanisms of lusianthridin on platelet aggregation. The results indicated that lusianthridin inhibited arachidonic acid, collagen, and adenosine diphosphate (ADP)-stimulated platelet aggregation (IC50 of 0.02 ± 0.001 mM, 0.14 ± 0.018 mM, and 0.22 ± 0.046 mM, respectively). Lusianthridin also increased the delaying time of arachidonic acid-stimulated and the lag time of collagen-stimulated and showed a more selective effect on the secondary wave of ADP-stimulated aggregations. Molecular docking studies revealed that lusianthridin bound to the entrance site of the cyclooxygenase-1 (COX-1) enzyme and probably the active region of the cyclooxygenase-2 (COX-2) enzyme. In addition, lusianthridin showed inhibitory effects on both COX-1 and COX-2 enzymatic activities (IC50 value of 10.81 ± 1.12 µM and 0.17 ± 1.62 µM, respectively). Furthermore, lusianthridin significantly inhibited ADP-induced suppression of cAMP formation in platelets at 0.4 mM concentration (p < 0.05). These findings suggested that possible mechanisms of lusianthridin on the antiplatelet effects might act via arachidonic acid-thromboxane and adenylate cyclase pathways.


2018 ◽  
Vol 11 (4) ◽  
pp. 101 ◽  
Author(s):  
Alessandra Pannunzio ◽  
Mauro Coluccia

Prostaglandins and thromboxane are lipid signaling molecules deriving from arachidonic acid by the action of the cyclooxygenase isoenzymes COX-1 and COX-2. The role of cyclooxygenases (particularly COX-2) and prostaglandins (particularly PGE2) in cancer-related inflammation has been extensively investigated. In contrast, COX-1 has received less attention, although its expression increases in several human cancers and a pathogenetic role emerges from experimental models. COX-1 and COX-2 isoforms seem to operate in a coordinate manner in cancer pathophysiology, especially in the tumorigenesis process. However, in some cases, exemplified by the serous ovarian carcinoma, COX-1 plays a pivotal role, suggesting that other histopathological and molecular subtypes of cancer disease could share this feature. Importantly, the analysis of functional implications of COX-1-signaling, as well as of pharmacological action of COX-1-selective inhibitors, should not be restricted to the COX pathway and to the effects of prostaglandins already known for their ability of affecting the tumor phenotype. A knowledge-based choice of the most appropriate tumor cell models, and a major effort in investigating the COX-1 issue in the more general context of arachidonic acid metabolic network by using the systems biology approaches, should be strongly encouraged.


2007 ◽  
Vol 282 (38) ◽  
pp. 28096-28105 ◽  
Author(s):  
Christine A. Harman ◽  
Melissa V. Turman ◽  
Kevin R. Kozak ◽  
Lawrence J. Marnett ◽  
William L. Smith ◽  
...  

The modification of the nonselective nonsteroidal anti-inflammatory drug, indomethacin, by amidation presents a promising strategy for designing novel cyclooxygenase (COX)-2-selective inhibitors. A series of α-substituted indomethacin ethanolamides, which exist as R/S-enantiomeric pairs, provides a means to study the impact of stereochemistry on COX inhibition. Comparative studies revealed that the R- and S-enantiomers of the α-substituted analogs inhibit COX-2 with almost equal efficacy, whereas COX-1 is selectively inhibited by the S-enantiomers. Mutagenesis studies have not been able to identify residues that manifest the enantioselectivity in COX-1. In an effort to understand the structural impact of chirality on COX-1 selectivity, the crystal structures of ovine COX-1 in complexes with an enantiomeric pair of these indomethacin ethanolamides were determined at resolutions between 2.75 and 2.85Å. These structures reveal unique, enantiomer-selective interactions within the COX-1 side pocket region that stabilize drug binding and account for the chiral selectivity observed with the (S)-α-substituted indomethacin ethanolamides. Kinetic analysis of binding demonstrates that both inhibitors bind quickly utilizing a two-step mechanism. However, the second binding step is readily reversible for the R-enantiomer, whereas for the S-enantiomer, it is not. These studies establish for the first time the structural and kinetic basis of high affinity binding of a neutral inhibitor to COX-1 and demonstrate that the side pocket of COX-1, previously thought to be sterically inaccessible, can serve as a binding pocket for inhibitor association.


Molecules ◽  
2021 ◽  
Vol 26 (10) ◽  
pp. 3036
Author(s):  
Cristina Zaragozá ◽  
Francisco Zaragozá ◽  
Irene Gayo-Abeleira ◽  
Lucinda Villaescusa

Atherosclerotic cardiovascular disease is the leading cause of death in developed countries. Therefore, there is an increasing interest in developing new potent and safe antiplatelet agents. Coumarins are a family of polyphenolic compounds with several pharmacological activities, including platelet aggregation inhibition. However, their antiplatelet mechanism of action needs to be further elucidated. The aim of this study is to provide insight into the biochemical mechanisms involved in this activity, as well as to establish a structure–activity relationship for these compounds. With this purpose, the antiplatelet aggregation activities of coumarin, esculetin and esculin were determined in vitro in human whole blood and platelet-rich plasma, to set the potential interference with the arachidonic acid cascade. Here, the platelet COX activity was evaluated from 0.75 mM to 6.5 mM concentration by measuring the levels of metabolites derived from its activity (MDA and TXB2), together with colorimetric assays performed with the pure recombinant enzyme. Our results evidenced that the coumarin aglycones present the greatest antiplatelet activity at 5 mM and 6.5 mM on aggregometry experiments and inhibiting MDA levels.


2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Maria L. Garcia Cruz ◽  
M. Alejandro Jimenez-Chobillon ◽  
Luis M. Teran

Rhinosinusitis is a feature of aspirin-exacerbated respiratory disease (AERD), which in the initial phase is manifested as nasal congestion, mostly affecting females at the age of around 30 years on average. Subsequently, nasal inflammation progresses to chronic eosinophilic rhinosinusitis, asthma, nasal polyposis, and intolerance to aspirin and to other NSAIDs. While it has been long established that NSAIDs cause inhibition of cyclooxygenase-1 (COX-1), leading to excessive metabolism of arachidonic acid (AA) to cysteinyl-leukotrienes (cys-LTs), there is now evidence that both cytokines and staphylococcus superantigens amplify the inflammatory process exacerbating the disease. This paper gives a brief overview of the development of chronic rhinosinusitis (CRS) in sensitive patients, and we share our experience in the diagnosis and management of CRS in AERD.


2013 ◽  
Vol 13 (3) ◽  
pp. 283-286 ◽  
Author(s):  
Muhammad Radifar ◽  
Nunung Yuniarti ◽  
Enade Perdana Istyastono

Identification of Protein-Ligand Interaction Fingerprints (PLIF) has been performed as the rescoring strategy to identify the best pose for the docked poses of indomethacin-(R)-α-ethyl-etanolamide (IMM) in the binding site of cyclooxygenase-1 (COX-1) from simulations using PLANTS molecular docking software version 1.2 (PLANTS1.2). Instead of using the scoring functions included in the docking software, the strategy presented in this article used external software called PyPLIF that could identify the interactions of the ligand to the amino acid residues in the binding pocket and presents them as binary bitstrings, which subsequently were compared to the interaction bitstrings of the co-crystal ligand pose. The results show that PyPLIF-assisted redocking strategy could select the correct pose much better compared to the pose selection without rescoring. Out of 1000 iterative attempts, PyPLIF-assisted redocking simulations could identify 971 correct poses (more than 95%), while the redocking simulations without PyPLIF could only identify 500 correct poses (50%).These works have also provided us with the initial step of the construction of a valid Structure-Based Virtual Screening (SBVS) protocol to identify COX-1 inhibitors.


2018 ◽  
Vol 18 (3) ◽  
pp. 219-232 ◽  
Author(s):  
Riccardo Concu ◽  
M. Natalia D.S. Cordeiro

Epidermal Growth Factor Receptor (EGFR) is still the main target of the Head and Neck Squamous Cell Cancer (HNSCC) because its overexpression has been detected in more than 90% of this type of cancer. This overexpression is usually linked with more aggressive disease, increased resistance to chemotherapy and radiotherapy, increased metastasis, inhibition of apoptosis, promotion of neoplastic angiogenesis, and, finally, poor prognosis and decreased survival. Due to this reason, the main target in the search of new drugs and inhibitors candidates is to downturn this overexpression. Quantitative Structure-Activity Relationship (QSAR) is one of the most widely used approaches while looking for new and more active inhibitors drugs. In this contest, a lot of authors used this technique, combined with others, to find new drugs or enhance the activity of well-known inhibitors. In this paper, on one hand, we will review the most important QSAR approaches developed in the last fifteen years, spacing from classical 1D approaches until more sophisticated 3D; the first paper is dated 2003 while the last one is from 2017. On the other hand, we will present a completely new QSAR approach aimed at the prediction of new EGFR inhibitors drugs. The model presented here has been developed over a dataset consisting of more than 1000 compounds using various molecular descriptors calculated with the DRAGON 7.0© software.


2009 ◽  
Vol 102 (08) ◽  
pp. 336-346 ◽  
Author(s):  
Marilena Crescente ◽  
Gisela Jessen ◽  
Stefania Momi ◽  
Hans-Dieter Höltje ◽  
Paolo Gresele ◽  
...  

SummaryWhile resveratrol and quercetin possess antiplatelet activity, little is known on the effect of gallic acid on platelets.We studied the interactions of these three different polyphenols among themselves and with aspirin, at the level of platelet cyclooxygenase-1 (COX-1). Both functional (in vitro and in vivo) and molecular modelling approaches were used. All three polyphenols showed comparable antioxidant activity (arachidonic acid [AA]-induced intraplatelet ROS production); however, resveratrol and quercetin, but not gallic acid, inhibited AA-induced platelet aggregation. Gallic acid, similarly to salicylic acid, the major aspirin metabolite, prevented inhibition of AA-induced platelet function by aspirin but, at variance with salicylic acid, also prevented inhibition by the other two polyphenols. Molecular modelling studies, performed by in silico docking the polyphenols into the crystal structure of COX-1, suggested that all compounds form stable complexes into the COX-1 channel, with slightly different but functionally relevant interaction geometries. Experiments in mice showed that gallic acid administered before aspirin, resveratrol or quercetin fully prevented their inhibitory effect on serum TxB2. Finally, a mixture of resveratrol, quercetin and gallic acid, at relative concentrations similar to those contained in most red wines, did not inhibit platelet aggregation, but potentiated sub-inhibitory concentrations of aspirin. Gallic acid interactions with other polyphenols or aspirin at the level of platelet COX-1 might partly explain the complex,and possibly contrasting, effects of wine and other components of the Mediterranean diet on platelets and on the pharmacologic effect of lowdose aspirin.


2006 ◽  
Vol 191 (1) ◽  
pp. 263-274 ◽  
Author(s):  
Simone Odau ◽  
Christoph Gabler ◽  
Christoph Holder ◽  
Ralf Einspanier

The aim of the present study was to investigate the enzymes for the local prostaglandin (PG) biosynthesis present in the bovine oviduct during the estrous cycle to influence early reproductive events. Bovine oviducts were classified into four phases: pre-ovulatory, post-ovulatory, early-to-mid luteal, and late luteal phase, subdivided further into ipsi- or contralateral site and separated into ampulla or isthmus. Oviductal cells were gained by flushing the oviductal regions. Quantitative real-time reverse transcriptase-PCR was performed for the secretory and cytosolic phospholipases A2 (sPLA2IB, cPLA2α, and cPLA2β) and cyclooxygenases (COX-1 and COX-2) as the first step enzymes of PG synthesis. COX-1 and cPLA2β showed significant highest mRNA expression around and before ovulation compared with the luteal phase respectively. sPLA2IB and cPLA2α mRNA expression was unregulated during the estrous cycle. Regional differences in mRNA content were found for sPLA2IB with higher mRNA expression in the ampulla than in the isthmus. Western blot analysis revealed the highest COX-1 protein content in the early-to-mid luteal phase. Immunohistochemistry demonstrated that COX-1 was localized in epithelial and smooth muscle cells, whereas COX-2 was only localized in epithelial cells. COX-2 showed a differential distribution within the epithelial cell layer suggesting a regulation on a cellular level, although the COX-2 mRNA and protein amounts did not vary throughout the estrous cycle. A COX activity assay of oviductal cells revealed that COX activity originated predominantly from COX-1 than from COX-2. Treatment of primary oviductal cells with 10 pg/ml 17β-estradiol or 10 ng/ml progesterone resulted in a higher expression of COX-2 and cPLA2α, but not of the other enzymes. The expression pattern of these enzymes suggests that an estrous-cycle dependent and region-specific PG synthesis in the bovine oviduct may be required for a successful reproduction.


2008 ◽  
Vol 100 (07) ◽  
pp. 70-75 ◽  
Author(s):  
Martijn G. H. van Oijen ◽  
Santosh Sundaresan ◽  
Marc A. Brouwer ◽  
Rene H. M. te Morsche ◽  
Wessel Keuper ◽  
...  

SummaryAspirin prevents thrombotic events by inhibiting platelet cyclooxygenase-1 (COX-1), thus reducing thromboxane A2 formation and platelet aggregation. The C50T polymorphism of COX-1 is associated with an impaired inhibition of both thromboxane production and in-vitro platelet aggregation by aspirin. We studied whether this polymorphism is also associated with the risk of clinical thrombotic events in patients using aspirin. We included 496 patients admitted to our Coronary Care Unit for various indications treated with aspirin 80 mg daily. Genotyping for the C50T polymorphism demonstrated that 86.7% of the patients had the common genotype, and 13.3% had the variant (12.5% heterozygous, 0.8% homozygous). Baseline variables were well balanced, except that patients with the common genotype more frequently used aspirin prior to admission compared to those patients with the variant genotype. The composite primary endpoint of myocardial infarction, stroke, and/or cardiovascular death occurred in 98 patients (19.8%). Myocardial infarction occurred in 9.6% of patients, stroke in 1.6%, and cardiovascular death in 12.1%.The unadjusted hazard ratio (95% CI) for the primary endpoint for patients with the variant versus the common genotype was 1.07 (0.62–1.85), p=0.8.The adjusted hazard ratio was 0.86 (0.49–1.50), p=0.6. In prior laboratory studies the COX-1 C50T polymorphism was associated with an impaired inhibitory effect of aspirin on thromboxane production and platelet function. However, in this cohort of patients using low-dose aspirin for secondary prevention the polymorphism was not associated with a higher risk of atherothrombotic events.


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