Search

In this study, a new triplex hairpin oligosensor was developed for the determination of a breast cancer biomarker using silicon quantum dots (Si QD) (λ ex  = 370 nm, λ em  = 482 nm) as donor and gold nanoparticles (GNP) as an acceptor in a FRET (fluorescence resonance energy transfer) mechanism. In the triplex hairpin oligosensor, a triplex-forming oligonucleotide (TFO) labeled with Si QD and a single-strand DNA labeled with GNP form a hairpin shape with a triplex structure at the hairpin stem. In a turn-on mechanism, the triplex hairpin stem is opened in the presence of sequence-specific miRNA-155 which leads to the release of the Si QD-labeled TFO probe and recovery of the fluorescence signal. About 80 % of the fluorescence intensity of the Si QD-TFO is quenched in the triplex hairpin structure of the oligosensor and in the presence of 800 pM miRNA-155, the fluorescence signal recovered to 57.7 % of its initial value. The LOD of about 10 pM was obtained. The designed triplex-based biosensor can discriminate concentrations of breast cancer biomarkers with high selectivity., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

The combination of heterocycles offers a new opportunity to create novel multicyclic compounds having improved biological activity. Coumarins are ubiquitous natural heterocycle widely adopted in the design of various biologically active compounds. Fusing different heterocycles with coumarin ring is one of the interesting approaches to generating novel hybrid molecules having highlighted biological activities. In the efforts to develop heterocyclic-fused coumarins, a wide range of 3,4-heterocycle-fused coumarins have been introduced bearing outstanding biological activity. The effect of heterocycles annulation at 3,4-positions of coumarin ring on the biological activity of the target structures were discussed. This review focuses on the important progress of 3,4-heterocycle-fused coumarins providing better insight for medicinal chemists on the design and preparation of biologically active heterocycle-fused coumarins with a significant therapeutic effect in the future., Competing Interests: Declaration of competing interest We wish to confirm that there are no known conflicts of interest associated with this publication and there has been no significant financial support for this work that could have influenced its outcome., (Copyright © 2020 Elsevier Masson SAS. All rights reserved.)

Diabetes mellitus is a metabolic disorder with several psychological problems such as anxiety, depression, and pain sense. This study aimed to evaluate the effect of Schiff base on the modulation of anxiety, depression, and pain behaviors in diabetic rats. Anxiety, depression, and pain behaviors were evaluated by elevated plus maze (EPM), forced swim test (FST), and hot-plate test, respectively. The results indicated that induction of diabetes decreased time spent in open arms (OAT) in the EPM whereas injection of insulin (1 ml/kg), glibenclamide (5 mg/kg), and Schiff base II (100 mg/kg) increased OAT in the EPM. So, induction of diabetes in rats caused an anxiogenic effect that this effect reversed by drug treatment. Interestingly, co-treatment of insulin and glibenclamide along with an ineffective dose of Schiff base II potentiated anxiolytic behavior in diabetic rats. Furthermore, induction of diabetes increased immobility time in the FST but administration of insulin (1 ml/kg), glibenclamide (5 mg/kg), and Schiff base II (25, 50, and 100 mg/kg) decreased immobility time in the FST which indicated depressant effect in diabetic rats without drug-treatment and antidepressant effect in diabetic rats with drug-treatment. Additionally, induction of diabetes decreased latency in the hot-plate test while injection of insulin (1 ml/kg), glibenclamide (5 mg/kg), Schiff base I (50 mg/kg), and Schiff base II (25, 50, and 100 mg/kg) enhanced latency in the hot-plate test which revealed hyperalgesic effect in diabetic rats without drug-treatment and analgesic effect in diabetic rats with drug-treatment. Consequently, induction of diabetes-induced anxiogenic, depressant, and hyperalgesia effects that administration of insulin, glibenclamide, Schiff bases I, and II reversed these effects., Competing Interests: Conflict of interestNo financial or other conflicts of interest are declared., (© Springer Nature Switzerland AG 2021.)

Direct functionalization of C-H bonds has attracted great attention in recent years from the perspectives of atom and step economy. In this context, a variety of processes have been developed for the construction of synthetically and biologically important organic azides through the oxidative C-H bonds azidation. In this review, we have summarized recent progress in the direct azidation of C(sp 2 )-H bonds. The review is divided into three major sections: (i) direct azidation of aromatic C-H bonds; (ii) direct azidation of olefinic C-H bonds; and (iii) direct azidation of aldehydic C-H bonds. Mechanistic aspects of the reactions are considered and discussed in detail., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)