Anticoagulant rodenticide exposure in common buzzards: Impact of new rules for rodenticide use.

Rodenticides are a key component of rodent management strategies, but birds of prey are susceptible to non-target exposure. New rules on sale and use of rodenticide products were introduced across the UK in 2016 in an industry-led stewardship scheme, with the aim of reducing this risk. To determine if this intervention has achieved its aim, exposure to second generation anticoagulant rodenticides (SGARs) was measured in buzzards. Liver samples from 790 buzzards collected between 2005 and 2022 (excluding 2016 and 2017 samples) were analyzed and the percentage presence and concentrations of SGARs from pre-stewardship and post-stewardship samples were compared. There was no statistically significant decrease in the percentage of buzzards exposed to bromadiolone, difenacoum or combined SGAR residues after the introduction of stewardship. The percentage of buzzards exposed to brodifacoum increased significantly post-stewardship, from 8 % to 27 %. There were no significant decreases in the concentrations of individual SGARs post-stewardship but concentration of combined SGARs increased significantly post-stewardship. Individual buzzards were significantly more likely to be exposed to multiple SGARs post-stewardship. Rodenticide poisoning was recorded as the cause of death for 5 % of pre- and post-stewardship buzzards with detectable levels of SGARs, and 90 % of these had combined SGAR residues >0.1 mg/kg. These findings suggest that the industry-led stewardship scheme has not yet had the intended impact of reducing SGAR exposure in non-target wildlife. The study highlights a substantial increase in exposure of buzzards to brodifacoum and to multiple SGARs post-stewardship, indicating that further changes to the stewardship scheme may be necessary.

Anticoagulant rodenticide toxicity in dogs: A retrospective study of 349 confirmed cases in Saskatchewan.

Objective: To evaluate the signalment and clinical, laboratory, treatment, and outcome features of dogs diagnosed with anticoagulant rodenticide (AR) intoxication in Saskatchewan. Animals: We studied 349 dogs. Procedure: Medical records from the Veterinary Medical Centre (Saskatoon, Saskatchewan) between 1999 and 2022 were reviewed. Cases were included if they met at least 1 of the following criteria: owner witnessed the dog ingesting an AR; AR was seen in the vomitus when emesis was induced; the dog had clinical signs of coagulopathy, with elevation of PT ± aPTT that normalized after vitamin K1 therapy, in the presence of appropriate clinical and paraclinical data and the absence of other causes of hypocoagulable state determined by the primary clinician. Results: Fifty-three percent of cases were seen between July and October. Most dogs (61%) came from an urban setting. Ninety-two percent of dogs ingested a 2nd-generation AR and the most frequent toxin was bromadiolone. Clinical signs were reported in 30% of AR intoxications and included lethargy (86%), dyspnea (55%), and evidence of external hemorrhage (44%). The most common site of hemorrhage was the pleural space, accounting for 43% of hemorrhage sites. Consumptive thrombocytopenia was reported in 24% of dogs with evidence of AR-induced hemorrhage, with moderate (platelet count < 60 K/µL) and marked (< 30 K/µL) thrombocytopenia in 7/12 and 2/12 dogs, respectively. Blood products were administered to 84% of dogs with AR-induced hemorrhage; the most common product administered was fresh frozen plasma (56% of cases). Among dogs with AR-induced hemorrhage, those that received blood products were more likely to survive to discharge (81%) compared to those that did not (19%) (P = 0.017). Eighty-six percent of dogs with AR-induced hemorrhage survived to discharge. Conclusion and clinical relevance: The pleural space was the most common site of hemorrhage. Moderate thrombocytopenia was a common finding. Eighty-six percent of dogs with AR-induced hemorrhage survived to discharge.

Toxicité des rodenticides anticoagulants chez les chiens : étude rétrospective de 349 cas confirmés en Saskatchewan. Objectif: Évaluer le signalement et les caractéristiques cliniques, de laboratoire, de traitement et de résultats des chiens diagnostiqués avec une intoxication par un rodenticide anticoagulant (AR) en Saskatchewan. Animaux: Nous avons étudié 349 chiens. Procédure: Les dossiers médicaux du Veterinary Medical Centre (Saskatoon, Saskatchewan) entre 1999 et 2022 ont été examinés. Les cas ont été inclus s'ils répondaient à au moins 1 des critères suivants : le propriétaire a vu le chien ingérer un AR; de l'AR a été observée dans les vomissures lorsque des vomissements ont été provoqués; le chien présentait des signes cliniques de coagulopathie, avec une élévation du PT ± aPTT qui s'est normalisée après un traitement par la vitamine K1, en présence de données cliniques et paracliniques appropriées et en l'absence d'autres causes d'état hypocoagulable déterminées par le clinicien initial. Résultats: Cinquante-trois pour cent des cas ont été observés entre juillet et octobre. La plupart des chiens (61 %) venaient d'un milieu urbain. Quatre-vingt-douze pour cent des chiens ont ingéré un AR de 2e génération et la toxine la plus fréquente était la bromadiolone. Des signes cliniques ont été rapportés dans 30 % des intoxications par AR et incluaient de la léthargie (86 %), de la dyspnée (55 %) et des signes d'hémorragie externe (44 %). Le site d'hémorragie le plus fréquent était l'espace pleural, représentant 43 % des sites d'hémorragie. Une thrombocytopénie de consommation a été rapportée chez 24 % des chiens présentant des signes d'hémorragie induite par l'AR, avec une thrombocytopénie modérée (nombre de plaquettes < 60 K/µL) et marquée (< 30 K/µL) chez 7 chiens sur 12 et 2 chiens sur 12, respectivement. Des produits sanguins ont été administrés à 84 % des chiens présentant une hémorragie induite par l'AR; le produit le plus fréquemment administré était le plasma frais congelé (56 % des cas). Parmi les chiens présentant une hémorragie induite par l'AR, ceux qui ont reçu des produits sanguins étaient plus susceptibles de survivre jusqu'à leur congé (81 %) que ceux qui n'en ont pas reçu (19 %) (P = 0,017). Quatre-vingt-six pour cent des chiens présentant une hémorragie induite par l'AR ont survécu jusqu'à leur sortie. Conclusion et pertinence clinique: L'espace pleural était le site d'hémorragie le plus fréquent. Une thrombocytopénie modérée était fréquente. Quatre-vingt-six pour cent des chiens présentant une hémorragie induite par l'AR ont survécu jusqu'à leur sortie.(Traduit par Dr Serge Messier).

Design, synthesis and bioactivity evaluation of 4-hydroxycoumarin derivatives as potential anti-inflammatory agents against acute lung injury and colitis.

Acute lung injury (ALI) and inflammatory bowel disease (IBD) are common inflammatory illnesses that seriously affect people's health. Herein, a series of 4-hydroxylcoumarin (4-HC) derivatives were designed and synthesized. The inhibitory effects of these compounds on LPS-induced interleukin-6 (IL-6) release from J774A.1 cells were then screened via ELISA assay, compound B8 showed 3 times more active than the lead compound 4-HC. The most active compound B8 had the IC50 values of 4.57 µM and 6.51 µM for IL-6 release on mouse cells J774A.1 and human cells THP-1, respectively. Furthermore, we also found that B8 could act on the MAPK pathway. Based on the target prediction results of computer virtual docking, kinase inhibitory assay was carried out, and it revealed that targeting IRAK1 was a key mechanism for B8 to exert anti-inflammatory activity. Moreover, B8 exerted a good therapeutic effect on the dextran sulfate sodium (DSS)-induced colitis model and liposaccharide (LPS)-induced ALI mouse models. The acute toxicity experiments indicated that high-dose B8 caused no adverse reactions in mice, confirming its safety in vivo. Additionally, the preliminary pharmacokinetic (PK) parameters of B8 in SD rats were also examined, revealing a bioavailability (F) of 28.72 %. In conclusion, B8 is a potential candidate of drug for the treatment of ALI and colitis.

Identification of a murder caused by brodifacoum poisoning based on clinical examinations and LC-MS/MS results.

Brodifacoum exerts its antagonistic effect against the metabolism of vitamin K, an essential component in the synthesis of blood coagulation factors. This effect ultimately hinders the blood's capacity to clot effectively, rendering it a commonly employed rodenticide. Instances of lethal poisonings are exceedingly rare owing to expeditious medical intervention and treatment. Within this report, we present a case of brodifacoum-induced homicide, wherein the patient exhibited distinct clinical examinations and symptoms. Moreover, the patient's blood sample exhibited a noteworthy brodifacoum concentration of 0.681 µg/mL even after a period of 43 days following the incident of poisoning. Although an autopsy was not conducted due to religious restrictions, we endeavor to reasonably deduce the cause of death and furnish corroborative evidence for clinical diagnosis, treatment, and forensic examination in instances involving brodifacoum poisoning.

Fishing antioxidant 4-hydroxycoumarin derivatives: synthesis, characterization, and in vitro assessments.

Coumarins represent a diverse class of natural compounds whose importance in pharmaceutical and agri-food sectors has motivated multiple novel synthetic derivatives with broad applicability. The phenolic moiety in 4-hydroxycoumarins underscores their potential to modulate the equilibrium between free radicals and antioxidant species within biological systems. The aim of this work was to assess the antioxidant activity of 18 4-hydroxycoumarin coumarin derivatives, six of which are commercially available and the other 12 were synthesized and chemically characterized and described herein. The 4-hydroxycoumarins were prepared by a two steps synthetic strategy with satisfactory yields. Their antioxidant potential was evaluated through three in vitro methods, two free radical-scavenging assays (DPPH• and ABTS•+) and a metal chelating activity assay. Six synthetic coumarins (4a, 4g, 4h, 4i, 4k, 4l) had a scavenging capacity of DPPH• higher than butylated hydroxytoluene (BHT) (IC50 = 0.58 mmol/L) and compound 4a (4-hydroxy-6-methoxy-2 H-chromen-2-one) with an IC50 = 0.05 mmol/L outperformed both BHT and ascorbic acid (IC50 = 0.06 mmol/L). Nine hydroxycoumarins had a scavenging capacity against ABTS•+ greater (C3, 4a, 4c) or comparable (C1, C2, C4, C6, 4g, 4l) to Trolox (IC50 = 34.34 µmol/L). Meanwhile, the set had a modest ferrous chelation capacity, but most of them (C2, C5, C6, 4a, 4b, 4h, 4i, 4j, 4k, 4l) reached up to more than 20% chelating ability percentage. Collectively, this research work provides valuable structural insights that may determine the scavenging and metal chelating activity of 4-hydroxycoumarins. Notably, substitutions at the C6 position appeared to enhance scavenging potential, while the introduction of electron-withdrawing groups showed promise in augmenting chelation efficiency.

Anticoagulant Rodenticide Toxicity in Terrestrial Raptors: Tools to Estimate the Impact on Populations in North America and Globally.

Anticoagulant rodenticides (ARs) have caused widespread contamination and poisoning of predators and scavengers. The diagnosis of toxicity proceeds from evidence of hemorrhage, and subsequent detection of residues in liver. Many factors confound the assessment of AR poisoning, particularly exposure dose, timing and frequency of exposure, and individual and taxon-specific variables. There is a need, therefore, for better AR toxicity criteria. To respond, we compiled a database of second-generation anticoagulant rodenticide (SGAR) residues in liver and postmortem evaluations of 951 terrestrial raptor carcasses from Canada and the United States, 1989 to 2021. We developed mixed-effects logistic regression models to produce specific probability curves of the toxicity of ∑SGARs at the taxonomic level of the family, and separately for three SGARs registered in North America, brodifacoum, bromadiolone, and difethialone. The ∑SGAR threshold concentrations for diagnosis of coagulopathy at 0.20 probability of risk were highest for strigid owls (15 ng g-1) lower and relatively similar for accipitrid hawks and eagles (8.2 ng g-1) and falcons (7.9 ng g-1), and much lower for tytonid barn owls (0.32 ng g-1). These values are lower than those we found previously, due to compilation and use of a larger database with a mix of species and source locations, and also to refinements in the statistical methods. Our presentation of results on the family taxonomic level should aid in the global applicability of the numbers. We also collated a subset of 440 single-compound exposure events and determined the probability of SGAR-poisoning symptoms as a function of SGAR concentration, which we then used to estimate relative SGAR toxicity and toxic equivalence factors: difethialone, 1, brodifacoum, 0.8, and bromadiolone, 0.5. Environ Toxicol Chem 2024;43:988-998. © 2024 His Majesty the King in Right of Canada and The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC Reproduced with the permission of the Minister of Environment and Climate Change Canada.

Radiological findings in poisoning by synthetic cannabinoids adulterated with brodifacoum.

OBJECTIVES: Severe coagulopathy due to consumption of synthetic cannabinoids adulterated with brodifacoum, a long-acting anticoagulant, is an emerging worldwide hazard. Here, we review the spectrum of imaging findings in adulterated cannabinoid poisoning. MATERIALS AND METHODS: In this retrospective study, we used the Israeli Poison Information Center database to identify patients with cannabinoid-associated coagulopathy who presented to the Rambam Health Care Campus, where most patients were treated during an outbreak in northern Israel between September 2021 and June 2022. All relevant imaging studies for these patients were reviewed. We estimated the sensitivity of findings for cannabinoid-associated coagulopathy. Associations between a continuous variable and a dichotomous outcome were assessed with the Mann-Whitney U test. RESULTS: We identified 48 patients (mean age 40 years ± 9 [SD], 43 males) with 54 hospitalizations due to cannabinoid-associated coagulopathy. Symptomatic hemorrhage was documented in 50 (93%) cases at presentation, most of whom (78%) had hemorrhage from multiple systems. The most common bleeding site was the genitourinary collecting system, with a characteristic sign of suburothelial bleeding in 16/18 of performed abdominal CTs (sensitivity 89% [CI 65-99%] for cannabinoid-associated coagulopathy). Intramural bowel hematomas were noted in 70% (7/10) of CTs of patients with gastrointestinal bleeding. Incidental bleeding sites were identified on imaging in 24% of patients. An increased number of bleeding sites was associated with need for vasopressors (difference in bleeding sites 3.00 [95% CI 0.99-4.00], p = 0.026). CONCLUSION: CT plays a key role in the diagnosis and work-up of adulterated cannabinoid-associated coagulopathy. Characteristic signs include suburothelial hemorrhage and intramural bowel hematomas. CLINICAL RELEVANCE STATEMENT: Recognition of radiological signs of adulterated synthetic cannabinoid-associated coagulopathy is critical for optimizing outbreak control on the public health level and ensuring timely treatment on the individual patient level. KEY POINTS: • Severe coagulopathy due to consumption of synthetic cannabinoids adulterated with brodifacoum, a long-acting anticoagulant, is an emerging worldwide threat. • Characteristic imaging signs include suburothelial bleeding, intramural bowel hematomas, and rare incidental bleeding sites. • Imaging has a pivotal role in optimizing outbreak control and ensuring timely and appropriate treatment.

[One case of bromadiolone poisoning leading to intestinal necrosis and severe coagulopathy].

Bromadiolone is still often used in life as a poisonous rodent agent. Bromadiolone poisoning is often manifested as coagulation dysfunction, resulting in organ bleeding, including cerebral hemorrhage, intestinal bleeding, abdominal hemorrhage, etc. At present, no case of intestinal necrosis caused by bromadiolone poisoning have been reported. This article reviewed one case of intestinal necrosis and severe coagulation dysfunction, and finally confirmed bromadiolone poisoning by poison detection. The patient recovered and was discharged after surgery, vitamin K injection, plasma transfusion and other treatment methods.

In Silico and In Vitro Studies of 4-Hydroxycoumarin-Based Heterocyclic Enamines as Potential Anti-Tumor Agents.

The present study reports the one-step synthesis of several 3-formyl-4-hydroxycouramin-derived enamines (4a-4i) in good yields (65-94%). The characterization of the synthesized compounds was carried out via advanced analytical and spectroscopic techniques, such as melting point, electron impact mass spectrometry (EI-MS), 1H-NMR, 13C-NMR, elemental analysis, FTIR, and UV-Visible spectroscopy. The reaction conditions were optimized, and the maximum yield was obtained at 3-4 h of reflux of the reactants, using 2-butanol as a solvent. The potato disc tumor assay was used to assess Agrobacterium tumefaciens-induced tumors to evaluate the anti-tumor activities of compounds (4a-4i), using Vinblastine as a standard drug. The compound 4g showed the lowest IC50 value (1.12 ± 0.2), which is even better than standard Vinblastine (IC50 7.5 ± 0.6). For further insight into their drug actions, an in silico docking of the compounds was also carried out against the CDK-8 protein. The binding energy values of compounds were found to agree with the experimental results. The compounds 4g and 4h showed the best affinities toward protein, with a binding energy value of -6.8 kcal/mol.

New 5-methyl-4-hydroxycoumarin polyketide derivatives from Gerbera delavayi with anti-inflammatory activity.

Five new 5-methyl-4-hydroxycoumarin polyketide derivatives (MPDs), delavayicoumarins A-E (1-5), were isolated from the whole plants of Gerbera delavayi. Among them, compounds 1-3 are the common monoterpene polyketide coumarins (MPCs), while 4 is a modified MPC with both the lactone ring contracted to a five-membered furan ring and a carboxyl at C-3, and 5 is a pair of unusual phenylpropanoid polyketide coumarin enantiomers (5a and 5b), featuring a phenylpropanoid unit at C-3. The planar structures were elucidated by spectroscopic methods and biosynthetic arguments, and the absolute configurations of 1-3, 5a and 5b were confirmed by calculated electronic circular dichroism (ECD) experiment. Furthermore, compounds 1-3, (+)-5 and (-)-5 were tested for the nitric oxide (NO) inhibitory activity by using lipopolysaccharide (LPS)-induced RAW 264.7 cells in vitro. The results showed that compounds 1-3, (+)-5 and (-)-5 remarkably inhibited NO production at the concentration of 10.0 µM, exhibiting that they have significant anti-inflammatory activity.

Isoform selectivities of novel 4-hydroxycoumarin imines as inhibitors of myosin II.

Muscle myosin inhibition could be used to treat many medical conditions involving hypercontractile states, including muscle spasticity, chronic musculoskeletal pain, and hypertrophic cardiomyopathy. A series of 13 advanced analogs of 3-(N-butylethanimidoyl)ethyl)-4-hydroxy-2H-chromen-2-one (BHC) were synthesized to explore extended imine nitrogen side chains and compare aldimines vs. ketimines. None of the new analogs inhibit nonmuscle myosin in a cytokinesis assay. ATPase structure-activity relationships reveal that selectivity for cardiac vs. skeletal myosin can be tuned with subtle structural changes. None of the compounds inhibited smooth muscle myosin II. Docking the compounds to homology models of cardiac and skeletal myosin II gave rationales for the effects of side arm length on inhibition selectivity and for cardiac vs. skeletal myosin. Properties including solubility, stability and toxicity, suggest that certain BHC analogs may be useful as candidates for preclinical studies or as lead compounds for advanced candidates for drugs with cardiac or skeletal muscle myosin selectivity.

[Managing Superwarfarin Poisoning: A Challenging Case]. / Relato de caso de intoxicación con superwarfarinas: un desafío terapéutico.

Human intoxication by long-acting anticoagulant rodenticides, known as superwarfarins, causes coagulopathy that is difficult to manage. We present the case of a 42-year-old man who ingested a toxic dose of rodenticide in a suicide attempt, evolving with epistaxis, INR of 11.6, and needing hospitalization. For seven days, serial controls of coagulation tests were carried out, with optimization of different doses of Vitamin K supplementation. The case highlights this type of anticoagulant's potency and prolonged half-life (approximately six weeks), which requires regular clinical control and satisfactory treatment adherence.

Synthesis of coumarin derivatives and investigation of their inhibitory effects on lung cancer cell motility.

Based on the pharmaceutical potentials of coumarins, which have antitumor activity, we synthesized new coumarin derivatives and evaluated their biological activities. The new coumarin derivatives were chemically synthesized from 4-hydroxycoumarin, and their structures were confirmed by nuclear magnetic resonance data. Ten of the synthesized compounds were investigated for antimetastatic activity against lung carcinoma cells. Several of the tested compounds showed good to mild inhibitory effects on lung cancer cell motility. There were no cytotoxic effects related to the use of these compounds. 4-Hydroxycoumarin derivatives, 4h and 4i, elicited the significant inhibitory effect on lung cancer cell motility by suppressing expression of the epithelial-mesenchymal transition markers N-cadherin, Snail, and Twist.

Brønsted acidic ionic liquid-catalyzed tandem reaction: an efficient and sustainable approach towards the regioselective synthesis and molecular docking studies of 4-hydroxycoumarin-substituted indoles bearing lower E-factors.

1-Butane sulfonic acid-3-methylimidazolium tosylate, [BSMIM]OTs, is a remarkable catalyst for the cascade synthesis of coumarin-functionalized indole derivatives via a tandem cyclization reaction of aniline and phenylglyoxal monohydrate. This reaction possibly proceeds through imine formation/nucleophilic addition/cyclization. In addition, this method shows lower E-factors. A clean reaction, easily accessible reactants, metal-free and environmentally friendly reaction conditions, and reusability of the catalyst are the notable advantages of this procedure. In addition, molecular docking studies show the theoretical possibility of binding these types of synthesized compounds to key proteins in tumorigenesis.

[A case of bromadiolone poisoning leading to digestive tract, abdominal hemorrhage and secondary paralytic ileus].

Bromadiolone, commonly known as super warfarin, is a long-acting coumarin dicoumarin rodenticide. The mechanism of bromadiolone is mainly to inhibit vitamin K1 epoxide reductase and affect the synthesis of coagulation factors Ⅱ, Ⅶ, Ⅸ and Ⅹ, which causes blood coagulation dysfunction and systemic multiple organ hemorrhage. Here, we report of a case of bromadiolone poisoning patient who had digestive tract, abdominal hemorrhage, as well as secondary paralytic ileus. After blood product transfusion and vitamin K1 supplementation, the patient was discharged after the physical condition was improved. It's suggestied that clinicians should pay attention to rare complications to prevent missed diagnosis when treating other bromadiolone poisoning.

Anticoagulant rodenticide blood-clotting dose-responses and resistance factors for Tyrosine139Cysteine (Y139C) heterozygous- and homozygous-resistant house mice (Mus musculus).

BACKGROUND: The house mouse (Mus musculus) is a globally distributed rodent pest species against which anticoagulant rodenticides are widely used for the protection of human and animal health and the conservation of threatened wildlife. Anticoagulant-resistant house mice have been known for more than half a century. A house mouse strain was developed in the laboratory that was homozygous resistant for the single nucleotide polymorphism (SNP) Tyrosine139Cysteine (Y139C) and, subsequently, heterozygous resistant animals were produced from this strain by crossing with the homozygous susceptible strain. RESULTS: Using blood clotting response tests, resistance factors at the ED50 level in the homozygous resistant strain for the first-generation anticoagulants warfarin, chlorophacinone, diphacinone and coumatetralyl were in the range 31.5 to 628.0 for males (M) and 21.6 to 628.0 for females (F), thus indicating that Y139C house mice are substantially resistant to all these substances. Resistance factors at the ED50 level for the homozygous strain generated against the second-generation compounds were: brodifacoum (M, 1.7; F, 1.9), bromadiolone (M, 16.6; F, 21.0), difenacoum (M, 1.2; F, 2.7), difethialone (M, 1.5; F, 1.5), and flocoumafen (M, 0.9; F, 1.2). Equivalent values for the heterozygous strain were: brodifacoum (M, 1.6; F, 1.4), bromadiolone (M, 5.6; F, 6.5), difenacoum (M, 1.0; F, 1.3), difethialone (M, 1.1; F, 1.1), flocoumafen (M, 0.9; F, 1.1). CONCLUSION: Y139C SNP homozygous resistant mice are more resistant to anticoagulants than heterozygous resistant animals. All first-generation anticoagulants are highly resisted and, among the second-generation compounds, Y139C mice are resistant to bromadiolone and sometimes to difenacoum. © 2022 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Synthesis of 4-Hydroxycoumarin-Based Triazoles/Oxadiazoles as Novel Anticancer Agents.

A series of novel 3-substituted-4-hydroxycoumarins 7 and 8 containing (5-aryl-1,3,4-oxadiazol-2-yl)thio or (4-amino-5-aryl-4H-1,2,4-triazol-3-yl)thio moieties have been synthesized and evaluated as anticancer agents. The in vitro MTT assay of compounds against hepatocellular carcinoma (HepG2), breast cancer (MCF7) cells, and a human colorectal adenocarcinoma cell line with epithelial morphology (HT29) indicated that the HepG2 cells had more susceptibility to the tested compounds. Indeed, all compounds (with the exception of 7b, 7c, 7g, and 8g) were more potent than the standard drug doxorubicin against HepG2 cells (IC50 values=1.65-3.83 µM). Although, the better result was obtained with the oxadiazole analog 7h against HepG2 (IC50 =1.65 µM), the N-amino-triazole derivatives 8c, 8e, 8f and, 8h with IC50 values of 1.78-6.34 µM showed potent activity against all tested cell lines. The good drug-like properties and in vitro potency and selectivity of 4-hydroxycoumarins 8 make them as good leads for the development of new anticancer agents.

Facile Synthesis of 2-Methylenebenzothiazoles from Benzothiazole Salts and 4-Hydroxycoumarins by Ball Milling.

A simple and practical method for the synthesis of 2-methylenebenzothiazoles via the coupling of a benzothiazole salts and 4-hydroxycoumarins have been described herein. The reaction showed a good substrate range and functional compatibility under mechanochemical conditions, and proceeded without catalysts or solvents. The 2-methylenebenzothiazoles products were achieved via the formation of a C=C double bond and exhibited strong luminescence and typical aggregation-induced emission (AIE) properties, indicating their potential for use as fluorescent materials.

Construction of spirocyclic oxindole derivatives by copper-catalyzed enantioselective Michael/hemiketalization in aqueous media.

An asymmetric Michael/hemiketalization reaction between isatin-derived ß,γ-unsaturated α-ketoesters and 4-hydroxycoumarins was developed in aqueous media. A series of chiral spirooxindole derivatives with an all-carbon quaternary stereogenic center were obtained in high yields (up to 93%) and excellent enantioselectivities (up to 98%).