Highly productive and scalable approach to synthesize ticlopidine: A potent thienopyridine anti-platelet aggregation drug

Interception and Synthetic Application of Diradical and Diene Forms of Dual-Nature Azabicyclic o-Quinodimethanes Generated by 6π-Azaelectrocyclization

We demonstrate that 2-alkenylarylaldimines and ketimines undergo thermal 6π-azaelectrocyclization to generate a wide range of azabicyclic o-quinodimethanes (o-QDMs). These o-QDMs exist as a hybrid of a diene and a benzylic diradical. The diradical nature was confirmed by their ability to undergo dimerization and react with H-atom donor, 2,2,6,6-tetramethylpiperidin-1-yl)oxyl (TEMPO) and O2. In addition, the interception of the diradicaloid o-QDMs by H-atom transfer was used to synthesize five tetrahydroisoquinoline alkaloids and related bioactive molecules. The diene form can undergo [4+2] cycloaddition reactions with different dienophiles to generate bridged azabicycles in high endo:exo selectivity. The azabicyclic o-QDMs can be generated for [4+2] cycloaddition from a wide range of electronically and sterically varied 2-alkenylarylimines, including mono, di, tri and tetrasubstituted alkenes, and imines derived from arylamine, alkylamine (1°, 2°, 3°), benzylamine, benzylsulfonamide and Boc-amine.

Ticlopidine induces embryonic development toxicity and hepatotoxicity in zebrafish by upregulating the oxidative stress signaling pathway

Ticlopidine exerts its anti-platelet effects mainly by antagonizing platelet p2y12 receptors. Previously, a few studies have shown that ticlopidine can induce liver injury, but the exact mechanism of hepatotoxicity remains unclear. Oxidative stress, metabolic disorders, hepatocyte apoptosis, lipid peroxidation, and inflammatory responses can all lead to hepatic liver damage, which can cause hepatotoxicity. In this study, in order to deeply explore the potential molecular mechanisms of ticlopidine -induced hepatotoxicity, we used zebrafish as a model organism to comprehensively evaluate the hepatotoxicity of ticlopidine and its associated mechanism. Three days post-fertilization, zebrafish larvae were exposed to varying concentrations (1.5, 1.75 and 2 μg/mL) of ticlopidine for 72 h, in contrast, adult zebrafish were exposed exposure to 4 μg/mL of ticlopidine for 28 days. Ticlopidine-exposed zebrafish larvae showed changes in liver morphology, shortened body length, and delayed development of the swim bladder development. Liver tissues of ticlopidine-exposed zebrafish larvae and adults stained with Hematoxylin & Eosin revealed vacuolization and increased cellular interstitial spaces in liver tissues. Furthermore, using Oil Red O and periodic acid-Schiff staining methods and evaluating different metabolic enzymes of ticlopidine-exposed zebrafish larvae and adults suggested abnormal liver metabolism and liver injury in both ticlopidine-exposed zebrafish larvae and adults. Ticlopidine also significantly elevated inflammation and oxidative stress and reduced hepatocyte proliferation. During the rescue intervention using N-acetylcysteine, we observed significant improvement in ticlopidine-induced morphological changes in the liver, shortened body length, delayed swim bladder development, and proliferation of liver tissues showed significant improvement. In conclusion, ticlopidine might inhibit normal development and liver proliferation in zebrafish by upregulation of oxidative stress levels, thus leading to embryonic developmental toxicity and hepatotoxicity. In this study, we used zebrafish as a model organism to elucidate the developmental toxicity and hepatotoxicity induced by ticlopidine upregulation of oxidative stress signaling pathway in zebrafish, providing a theoretical basis for clinical application.

Ticlopidine induces cardiotoxicity in zebrafish embryos through AHR-mediated oxidative stress signaling pathway

Ticlopidine has inhibitory effects on platelet aggregation via ADP (adenosine diphosphate), platelet release reaction and depolymerization. In clinical practice, it is commonly used to prevent heart, cerebrovascular and other thromboembolic diseases. However, ticlopidine has also been reported to have teratogenic effects on the heart, though its specific molecular mechanism remains unclear. In this study, zebrafish embryos were used as model organisms to examine the toxicity effect of ticlopidine. Zebrafish embryos exposed to 6, 7.5, and 9 mg/L ticlopidine solutions manifested several abnormalities, including body curvature, smaller eyes, slower absorption of the vitella sac, pericardial edema, slower heart rate, increased mortality, longer venous sinus - arterial ball (SV-BA) distance, and increased oxidative stress, which indicated developmental and cardiac toxicity. Abnormal expression of key genes related to heart development was observed, and the level of apoptotic gene expression was up-regulated. Further experiments revealed up-regulation of embryonic oxidative stress following ticlopidine exposure, leading to a decrease in cardiomyocyte proliferation. Conversely, the aromatic hydrocarbon receptor (AHR) inhibitor CH223191 protected embryos from the cardiotoxicity effect of ticlopidine, confirming further the role of up-regulated oxidative stress as the molecular mechanism of ticlopidine-induced cardiotoxicity in zebrafish. In conclusion, ticlopidine exposure leads to developmental and cardiotoxicity in zebrafish embryos. Therefore, further studies are warranted to ascertain such potential harms of ticlopidine in humans, which are vital in providing guidance in the safe use of drugs in clinical practice.