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PurposeThis study examines the role of celebrity credibility in fostering loyalty and long-term commitment toward the financial service provider (banking services in this study) through the development of trust in the service provider. The relationship combines the commitment-trust theory, the source credibility, and the meaning transfer model.Design/methodology/approachThe proposed model uses online survey data from 855 participants. The data are analyzed using structural equation modeling. The relationship between celebrity credibility, commitment, and loyalty to the service provider is explored, with trust in the service provider acting as a mediator. The profession and gender of celebrities are considered moderators.FindingsTrust in service providers partially mediates the relationship between celebrity credibility, customer loyalty, and commitment. Moderation results across multiple groups show that male and sports celebrities are more persuasive in expertise, and customers find women and movie stars to be more effective endorsers in the attractiveness dimension.Research limitations/implicationsThis study focuses only on banking services with data collected from a single country to examine a celebrity’s role as a spokesperson.Practical implicationsConsidering the benefits of having a well-known celebrity as a spokesperson for financial services like banking is intriguing. Given the unique characteristics and significant perceived risk associated with financial services, marketers may consider hiring celebrity endorsers to increase tangibility and reduce risk.Originality/valueThe results of this study may provide a deeper understanding of the combined effect of celebrity credibility and trust in financial service providers, which provides tangibility and helps establish a strong customer relationship.

Leishmaniasis is a neglected tropical disease, and there is an emerging need for the development of effective drugs to treat it. To identify novel compounds with antileishmanial properties, a novel series of functionalized spiro[indoline-3,2′-pyrrolidin]-2-one/spiro[indoline-3,3′-pyrrolizin]-2-one 23a–f, 24a–f, and 25a–g were prepared from natural-product-inspired pharmaceutically privileged bioactive sub-structures, i.e., isatins 20a–h, various substituted chalcones 21a–f, and 22a–c amino acids, via 1,3-dipolar cycloaddition reactions in MeOH at 80 °C using a microwave-assisted approach. Compared to traditional methods, microwave-assisted synthesis produces higher yields and better quality, and it takes less time. We report here the in vitro antileishmanial activity against Leishmania donovani and SAR studies. The analogues 24a, 24e, 24f, and 25d were found to be the most active compounds of the series and showed IC50 values of 2.43 µM, 0.96 µM, 1.62 µM, and 3.55 µM, respectively, compared to the standard reference drug Amphotericin B (IC50 = 0.060 µM). All compounds were assessed for Leishmania DNA topoisomerase type IB inhibition activity using the standard drug Camptothecin, and 24a, 24e, 24f, and 25d showed potential results. In order to further validate the experimental results and gain a deeper understanding of the binding manner of such compounds, molecular docking studies were also performed. The stereochemistry of the novel functionalized spirooxindole derivatives was confirmed by single-crystal X-ray crystallography studies.

Heterocycles are very important scaffolds since many of them exhibit building blocks properties and good biological activities. Various chemical methods have been utilized for their synthesis and out of them, the environmentally benign approaches are highly demanding in view of the importance of green chemistry. There are vast pieces of literature available on sustainable and multi-component synthetic approaches, but it is difficult for a researcher to keep up with research. Therefore, a review article in sustainable and multi-component synthesis of heterocycle was highly required. Herein, we have compiled the work of literatures related to multi-component reaction under solvent free condition, ultrasound assisted, water or ionic liquid mediated conditions.

An efficient iodine-mediated method is developed for the synthesis of functionalized 2-(methylthio)-4H-chromen-4-ones by intramolecular cyclization of easily accessible 1-(2-benzyloxy-aryl)-3,3-bis-methylsulfanyl-propenones. The synthesized chromen-4-ones turn out to be a key precursor for various kinds of chemical reactions. Mechanistically, we observed that iodine-mediated intramolecular cyclization of ketene dithioacetal proceeded through a radical pathway. 3-Halo-2-(methylthio)-4H-chromen-4-ones were achieved via various two- or one-pot halogenation approaches.

A mild and efficient route for the synthesis of conjugated trienes via nitroethane-mediated ring contraction of 2-oxobenzo[h]chromenes/2H-pyran-2-ones followed by decarboxylative rearrangement of the obtained spirobutenolides and butenolides is described. The (E)-isomer of trienes was obtained by step-wise and one-pot approaches from 2-oxobenzo[h]chromenes. Butenolides 4a–l as new substrates have been developed for the construction of trienes. The mixture of the (E)- and (Z)-isomers of spirobutenolides undergoes decarboxylative rearrangement in the presence of sodium ethoxide as a base to yield the (E)-isomer of trienes, while the (E)-isomer of butenolides reacts to give a mixture of (2E,4E)- and (2E,4Z)-isomers of trienes in an almost steady ratio of 45 : 55 or 1 : 1.2. The structure and geometry of the obtained butenolides and trienes were confirmed by single-crystal X-ray analysis.

Excited state intramolecular proton transfer (ESIPT) based functionalized thieno[3,2-c]pyran P was designed and synthesized as a fluorescent turn-on chemosensor for the selective recognition of Zn2+ ion with a low detection limit (0.67 μM). Fourier transform infrared spectroscopy (FTIR), NMR, and Job plot studies were used to investigate the binding phenomenon of P and Zn2+, which was achieved via deprotonation of the hydroxyl group. Zn2+ ions undergo interaction with thieno[3,2-c]pyran to afford the complex P–Zn2+, which enhances the weak emissive properties of the chemosensor P up to λem 484 nm via geometrical alteration and termination of the keto to enol oscillation. In addition, thieno[3,2-c]pyran P also showed higher fluorescence in a solution of 60% water in THF owing to the aggregation-induced emission phenomenon. All of these photophysical properties of chemosensor P and complex P–Zn2+ are supported by quantum chemical density functional theory (DFT) calculations. The structure of P was also confirmed using single X-ray crystallography.

A new type of ketene dithioacetal, 2-(3,3-bis-methylsulfanyl-1-arylallylidene)malononitriles containing 1,4 and 1,6-Michael acceptors, were synthesized to study their reactivity for the synthesis of a new molecular entity. We report a [5 + 1] annulation strategy for the construction of multifunctional biaryls and p-teraryls by the selection of a suitable nucleophilic source. The reaction of p-nitrotoluene with 2-(3,3-bis-methylsulfanyl-1-aryl-allylidene)malononitriles under basic conditions produces p-teraryls in good yields, while the use of nitroethane as the nucleophile source provides functionalized biaryls through cyclization, followed by denitration. This reaction requires mild conditions and exhibits good functional group tolerance.

We have developed two novel chemosensors 6-morpholino-8-(thiophen-2-yl)-1,2,3,4-tetrahydroquinoline-5-carbonitrile (L1) and 6-(methylthio)-8-(thiophen-2-yl)-1,2,3,4-tetrahydroquinoline-5-carbonitrile (L2) for selective identification of highly toxic Pd2+ ions. The selectivity of L1 and L2 was examined with a series of metal ions, among which Pd2+ ions were recognized selectively with fluorescence turn-off performances in methanol with very low limits of detection (nM). Another compound L3 was synthesized and studied to understand the role of the thienyl ring during complex L1 + Pd2+ and L2 + Pd2+ formation. The fluorescence changes after addition of Pd2+ were also observed through the “naked-eye” (under a 365 nm UV lamp). Quantum chemical (DFT) calculations have been carried out to acquire information about the stability of the chemosensors and their complexes with Pd2+ (L1 + Pd2+ and L2 + Pd2+), which suggested that complex L2 + Pd2+ is more stable than L1, L2 and complex L1:Pd2+. A number of studies comprising Job plots, Stern–Volmer plots and detection limits illustrate the notable sensing abilities of the chemosensors with Pd2+ ions, in which probe L2 was found to be more applicable than L1.

We explored the antibacterial potential (alone and combination) against multidrug resistant (MDR) Pseudomonas aeruginosa isolates KG-P2 using synthesized thieno[3,2-c]pyran-2-ones in combination with different antibiotics. Out of 14 compounds, two compounds (3g and 3l) abridged the MIC of tetracycline (TET) by 16 folds. Compounds was killing the KG-P2 cells, in time dependent manner, lengthened post-antibiotic effect (PAE) of TET and found decreased the mutant prevention concentration (MPC) of TET. In ethidium bromide efflux experiment, two compounds repressed the drug transporter (efflux pumps) which is further supported by molecular docking of these compounds with efflux complex MexAB-OprM. In another study, these compounds inhibited the synthesis of biofilm.

An efficient iodine-mediated method is developed for the synthesis of functionalized 2-(methylthio)-4

The amination of aryl sulfides and sulfoxides with azaarylamines is investigated using a palladium-N-heterocyclic carbene (NHC) complex. Because azaarylamines are less nucleophilic than anilines, more reactive diaryl sulfides and sulfoxides are found to be suitable coupling partners that liberate better leaving arenethiolate or arenesulfenate anions, instead of aryl methyl sulfides as reported previously.

A mild and efficient route for the synthesis of conjugated trienes via nitroethane-mediated ring contraction of 2-oxobenzo[h]chromenes/2H-pyran-2-ones followed by decarboxylative rearrangement of the obtained spirobutenolides and butenolides is described. The (E)-isomer of trienes was obtained by step-wise and one-pot approaches from 2-oxobenzo[h]chromenes. Butenolides 4a-l as new substrates have been developed for the construction of trienes. The mixture of the (E)- and (Z)-isomers of spirobutenolides undergoes decarboxylative rearrangement in the presence of sodium ethoxide as a base to yield the (E)-isomer of trienes, while the (E)-isomer of butenolides reacts to give a mixture of (2E,4E)- and (2E,4Z)-isomers of trienes in an almost steady ratio of 45 : 55 or 1 : 1.2. The structure and geometry of the obtained butenolides and trienes were confirmed by single-crystal X-ray analysis.

A simple, efficient, and transition metal-free approach to synthesize functionalized 2-(alkynyl)benzonitriles has been developed using suitably functionalized 2H-pyran-2-ones and 4-phenyl/trimethylsilanyl-but-3-yn-2-ones as precursors. The reaction proceeds in the presence of a base at room temperature to yield internal as well as terminal alkynes. The structure of the synthesized compound was confirmed by single-crystal X-ray analysis. The molecular docking study was performed to evaluate the binding mode of action of newly synthesized alkyne derivatives with known human breast cancer target receptor aromatase (PDB ID: 3EQM).

Tetrahydroquinoline and isoquinoline scaffolds are important class of heterocyclic compounds, which is implied for the development of new drugs and diagnostic for therapeutic function. Naturally occurring as well as synthetic tetrahydroquinolines/isoquinolines possess many different biological activities and have been testified as remarkable cytotoxic and potency in human cancer cell lines. Tetrahydroquinoline/isoquinoline based compounds displayed a key role in the development of anticancer drugs or lead molecules and acting through various mechanisms such as cell proliferation, apoptosis, DNA fragmentation, inhibition of tubulin polymerization, induced cell cycle arrest, interruption of cell migration, and modulation. The number of tetrahydroquinoline/isoquinoline derivatives has been reported as potent anticancer agents. Due to promising anticancer activities and wideranging properties of these molecules, we have compiled the literature for the synthesis and anticancer properties of various tetrahydroquinolines and isoquinolines. We have reported the synthesis of potent tetrahydroquinoline/isoquinoline molecules of the last 10 years with their anticancer properties in various cancer cell lines and stated their half-maximal inhibitory concentration (IC50). In addition, we also considered the discussion of molecular docking and structural activity relationship wherever provided to understand the possible mode of activity a target involved and structural feature responsible for the better activity, so the reader can directly find the detail for designing new anticancer agents.

A simple, efficient and transition metal-free strategy was established for the synthesis of highly functionalized, sterically hindered allylarenes (6, 7 & 8) by base-mediated ring transformation of 2-oxo-6-aryl-4-(methylthio/sec-amino)-2H-pyran-3-carbonitriles (3/4) with 5-hexene-2-one (5). This provides a method for the synthesis of allylarenes functionalized with different electron donating and withdrawing groups in one pot. The structures of isolated products 6c and 7a were ascertained by spectroscopic and single crystal X-ray diffraction analyses. In addition, we have performed a molecular docking study to predict the biological activity of the synthesized molecules for binding to estrogen receptor alpha (ERα) and estrogen receptor beta (ERβ).

Alkynes are a very important class of compounds and used as precursors for the assembly of a variety of carbocycles and heterocycles. Alkynes are classified into two classes: terminal alkynes and internal alkynes. Terminal alkynes were used as one of the precursors for the synthesis of internal alkynes. Besides, various elimination reactions were conducted to obtain alkynes. Various applications of alkynes are known but no compiled review is reported so far regarding their synthesis. Therefore, we have compiled the literature available for the synthesis of various functionalized alkynes from non-alkyne sources in this review. We have not discussed the synthesis of internal alkynes from terminal alkynes. Based on the available literature, the synthesis of alkynes can be classified into three major types of reactions: (a) synthesis of alkynes through α,β-elimination, (b) synthesis of alkynes through carbene rearrangement and (c) synthesis of alkynes via miscellaneous approaches. In this review, we have focused on the different methods available for these transformations including their scope, limitations and recent developments. We have also discussed the mechanism involved during the reaction.

Bifunctional chelate EDTA-bis amide (N,N'-bis (tyramide)ethylenediamine-N,N'-diacetic acid) that has ability to mimic natural amino acids was synthesized and analyzed by various spectroscopic techniques. The physicochemical studies were performed to calculate the various thermodynamic and kinetic parameters for the synthesized poly-amino carboxylate ligand. The two protonation constant (pka's = 3.460 and 6.722) of the prepared ligand and stability constants (log K

Background Genome sequencing and genetic polymorphism analysis of clinical isolates of M. tuberculosis is carried out to gain further insight into molecular pathogenesis and host-pathogen interaction. Therefore the functional evaluation of the effect of single nucleotide variation (SNV) is essential. At the same time, the identification of invariant sequences unique to M. tuberculosis contributes to infection detection by sensitive methods. In the present study, genome analysis is accompanied by evaluation of the functional implication of the SNVs in a MDR clinical isolate VPCI591. Result By sequencing and comparative analysis of VPCI591 genome with 1553 global clinical isolates of M. tuberculosis (GMTV and tbVar databases), we identified 141 unique strain specific SNVs. A novel intergenic variation in VPCI591 in the putative promoter/regulatory region mapping between embC (Rv3793) and embA (Rv3794) genes was found to enhance the expression of embAB, which correlates with the high resistance of the VPCI591 to ethambutol. Similarly, the unique combination of three genic SNVs in RNA polymerase β gene (rpoB) in VPCI591 was evaluated for its effect on rifampicin resistance through molecular docking analysis. The comparative genomics also showed that along with variations, there are genes that remain invariant. 173 such genes were identified in our analysis. Conclusion The genetic variation in M. tuberculosis clinical isolate VPCI591 is found in almost all functional classes of genes. We have shown that SNV in rpoB gene mapping outside the drug binding site along with two SNVs in the binding site can contribute to quantitative change in MIC for rifampicin. Our results show the collective effect of SNVs on the structure of the protein, impacting the interaction between the target protein and the drug molecule in rpoB as an example. The study shows that intergenic variations bring about quantitative changes in transcription in embAB and in turn can lead to drug resistance.

Additional file 4. Intergenic Variations identified in VPCI591 (Type II).

Additional file 5. Invariant genes in global clinical isolates (including VPCI591).

Additional file 6. Unique genic variations in VPCI591.

Additional file 7. Inter-genic variations unique to VPCI591.

Additional file 3. Intergenic Variations in VPCI591 (Type I).

A facile, efficient and atom-economic synthesis of highly substituted benzo[h]qninolines was established by reaction of 2-methyl-5-nitrobenzonitrile with suitably functionalized 2H-pyran-2-ones under basic conditions. We observed that the presence of a thiomethyl group at the C-4 position of pyran provides 6-aryl-4-(2-cyano-4-nitrobenzyl)-2-oxo-2H-pyran-3-carbonitrile exclusively without any trace of benzo[h]quinolines. Depending on the nature of the functional group at C-4 of the pyran ring, different products were achieved. To probe the mechanism, we performed control experiments and isolated 3-(1-amino-7-nitro-3-thiophen-2-yl-naphthalen-2-yl)-3-piperidin-1-yl-acrylonitrile, which, on further treatment with base, provided the benzo[h]quinolines. The structure of one the products was characterized by single-crystal X-ray diffraction.