4-Benzothiazole-7-hydroxyindolinyl diaryl ureas are potent P2Y1 antagonists with favorable pharmacokinetics: low clearance and small volume of distribution

Potential antiplatelet aggregation metabolites from the discarded sorghum (Sorghum bicolor L.) root

Sorghum (Sorghum bicolor L.) is the fifth largest crop in the world and has potential health benefits, but vast quantities of sorghum roots are discarded after harvest. Based on the previous antiplatelet aggregation for this species, two new multi-substituted 3H-indole alkaloids sorghumine A (1) and sorghumine B (2), together with 14 known compounds (3-16), were found from the water extract of sorghum roots. Compounds 1-2 were identified by analyzing their spectroscopic data and physic and chemical properties, and the absolute configuration was further determined by electronic circular dichroism (ECD) analysis and calculations. 1-2, 4, 6-8 and 13-15 showed significant inhibition of platelet aggregation induced by adenosine diphosphate. 2-4, 6-9 and 11 showed significant inhibition of platelet aggregation induced by collagen. 4-6, 8, 10-11 and 16 showed significant inhibition on platelet aggregation induced by thrombin. Furthermore, molecular docking showed that active compounds can bind to P2Y12 and COX-1 receptors in platelet.

Diarylureas: Repositioning from Antitumor to Antimicrobials or Multi-Target Agents against New Pandemics

Antimicrobials have allowed medical advancements over several decades. However, the continuous emergence of antimicrobial resistance restricts efficacy in treating infectious diseases. In this context, the drug repositioning of already known biological active compounds to antimicrobials could represent a useful strategy. In 2002 and 2003, the SARS-CoV pandemic immobilized the Far East regions. However, the drug discovery attempts to study the virus have stopped after the crisis declined. Today’s COVID-19 pandemic could probably have been avoided if those efforts against SARS-CoV had continued. Recently, a new coronavirus variant was identified in the UK. Because of this, the search for safe and potent antimicrobials and antivirals is urgent. Apart from antiviral treatment for severe cases of COVID-19, many patients with mild disease without pneumonia or moderate disease with pneumonia have received different classes of antibiotics. Diarylureas are tyrosine kinase inhibitors well known in the art as anticancer agents, which might be useful tools for a reposition as antimicrobials. The first to come onto the market as anticancer was sorafenib, followed by some other active molecules. For this interesting class of organic compounds antimicrobial, antiviral, antithrombotic, antimalarial, and anti-inflammatory properties have been reported in the literature. These numerous properties make these compounds interesting for a new possible pandemic considering that, as well as for other viral infections also for CoVID-19, a multitarget therapeutic strategy could be favorable. This review is meant to be an overview on diarylureas, focusing on their biological activities, not dwelling on the already known antitumor activity. Quite a lot of papers present in the literature underline and highlight the importance of these molecules as versatile scaffolds for the development of new and promising antimicrobials and multitarget agents against new pandemic events.

Purinergic Signaling: Impact of GPCR Structures on Rational Drug Design

The purinergic signaling system includes membrane-bound receptors for extracellular purines and pyrimidines, and enzymes/transporters that regulate receptor activation by endogenous agonists. Receptors include: adenosine (A1 , A2A , A2B, and A3 ) and P2Y (P2Y1 , P2Y2 , P2Y4 , P2Y6 , P2Y11 , P2Y12 , P2Y13 , and P2Y14 ) receptors (all GPCRs), as well as P2X receptors (ion channels). Receptor activation, especially accompanying physiological stress or damage, creates a temporal sequence of signaling to counteract this stress and either mobilize (P2Rs) or suppress (ARs) immune responses. Thus, modulation of this large signaling family has broad potential for treating chronic diseases. Experimentally determined structures represent each of the three receptor families. We focus on selective purinergic agonists (A1 , A3 ), antagonists (A3 , P2Y14 ), and allosteric modulators (P2Y1 , A3 ). Examples of applying structure-based design, including the rational modification of known ligands, are presented for antithrombotic P2Y1 R antagonists and anti-inflammatory P2Y14 R antagonists and A3 AR agonists. A3 AR agonists are a potential, nonaddictive treatment for chronic neuropathic pain.

Antiplatelet aggregation and antithrombotic benefits of terpenes and flavones from hawthorn leaf extract isolated using the activity-guided method

Hawthorn is a well-known functional food; at present, increasing attention has been given to hawthorn leaf due to its numerous functional and nutritional properties. In this study, the antithrombotic properties of hawthorn leaves were evaluated using the activity-guided isolation process and high-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (HPLC-QTOF-MS). A crude extract prepared in 75% ethanol was fractionated using macroporous resin D101 and polyamide chromatography to obtain three active fractions (Fr.C, Fr.C-1 and Fr.C-2). Thereafter, the inhibitory activities of these fractions were examined by platelet aggregation and antithrombus assays using a zebrafish model. Using the HPLC-QTOF-MS technique, we identified 25 compounds in the active fraction (Fr.C). The structures of these compounds were identified by comparing the retention time (tR) and mass spectral data from the previous reports and 19 reference compounds. Based on the analysis, 21 peaks were detected in the mass spectrum of Fr.C-1 and 8 peaks were detected in Fr.C-2, we found that 11 compounds in Fr.C-1 exhibited potent inhibitory effects on platelet aggregation, including nine monoterpenoids, one diterpenoid and one flavanone. Accordingly, monoterpenoids are suggested as the main anti-platelet aggregation constituents from hawthorn leaves. Particularly, compounds 10 and 24 inhibited ADP-induced platelet aggregation and delayed FeCl3-induced thrombus in zebrafish. Furthermore, interactions between compounds 10 and 24 with two ADP receptors P2Y1 and P2Y12, serving as the target for key regulators of antiplatelet aggregative activity, were investigated via molecular modeling. In addition, five flavones were obtained from the active fraction (Fr.C-2). These results indicated that monoterpenoid glycosides and some flavones were responsible for the antithrombotic activity of hawthorn leaves. Moreover, this study shows that the activity-guided isolation is a fast, efficient and systematic separation method for the identification of active compounds in natural products.

Natural terpenoid glycosides with in vitro/vivo antithrombotic profiles from the leaves of Crataegus pinnatifida

Two norditerpenoids (1–2) with unique carbon skeletons, four sesquiterpenoids (3–6) and nine nor-sesquiterpenoids (7–15) were isolated from the leaves of Crataegus pinnatifida and evaluated as possessing antithrombotic activities in vitro/vivo.

Drug-like Antagonists of P2Y Receptors-From Lead Identification to Drug Development

P2Y receptors are expressed in virtually all cells and tissue types and mediate an astonishing array of biological functions, including platelet aggregation, smooth muscle cell proliferation, and immune regulation. The P2Y receptors belong to the G protein-coupled receptor superfamily and are composed of eight members encoded by distinct genes that can be subdivided into two groups on the basis of their coupling to specific G-proteins. Extensive research has been undertaken to find modulators of P2Y receptors, although to date only a limited number of small-molecule P2Y receptor antagonists have been approved by drug/medicines agencies. This Perspective reviews the known P2Y receptor antagonists, highlighting oral drug-like receptor antagonists, and considers future opportunities for the development of small molecules for clinical evaluation.