Facile One Pot Synthesis of Acridinediones Using Caffeine Hydrogen Sulfate Catalyst and Their Antimicrobial Evaluation

A facile approach for the synthesis of bioactive acridinedione analogs using dimedone, aryl aldehydes, and ammonium acetate was developed using caffeine hydrogen sulfate catalyst in ethanol and water (2:1) solvent mixture at room temperature. The significant advantages of this procedure are efficient and simple method, ambient conditions, short reaction time (5–30 min), simple workup, easily recoverable catalyst, broad substrate scope and good yields (45–80%). Being water soluble, the catalyst was easily recovered by water and reused up to 4 runs. Moreover, the antimicrobial profile of synthesized derivatives was performed against different bacterial and fungal strains using broth microdilution method. Most of the synthesized derivatives exhibited significant activity against bacterial and fungal strains compared to standard. Compounds 4e (31.25 µg/mL and 31.25 µg/mL) and 4g (31.25 µg/mL and 62.5 µg/mL) were found the most active against E. coli. and S. aureus respectively with good MIC values. Compound 4f and 4j displayed the highest antifungal activity against A. niger with 31.25 µg/mL MIC value. </p

Antioxidant and Antimicrobial Assessment of Synthesized and Spectrally Characterized New Nitrophenothiazines and their Sulfone Analogues

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Structural elucidation of transmembrane domain zero (TMD0) of EcdL: A multidrug resistance-associated protein (MRP) family of ATP-binding cassette transporter protein revealed by atomistic simulation

<p>ATP-Binding cassette (ABC) transporters play an extensive role in the translocation of diverse sets of biologically important molecules across membrane. EchnocandinB (antifungal) and EcdL protein of <i>Aspergillus rugulosus</i> are encoded by the same cluster of genes. Co-expression of EcdL and echinocandinB reflects tightly linked biological functions. EcdL belongs to Multidrug Resistance associated Protein (MRP) subfamily of ABC transporters with an extra transmembrane domain zero (TMD0). Complete structure of MRP subfamily comprising of TMD0 domain, at atomic resolution is not known. We hypothesized that the transportation of echonocandinB is mediated via EcdL protein. Henceforth, it is pertinent to know the topological arrangement of TMD0, with other domains of protein and its possible role in transportation of echinocandinB. Absence of effective template for TMD0 domain lead us to model by I-TASSER, further structure has been refined by multiple template modelling using homologous templates of remaining domains (TMD1, NBD1, TMD2, NBD2). The modelled structure has been validated for packing, folding and stereochemical properties. MD simulation for 0.1 μs has been carried out in the biphasic environment for refinement of modelled protein. Non-redundant structures have been excavated by clustering of MD trajectory. The structural alignment of modelled structure has shown Z-score -37.9; 31.6, 31.5 with RMSD; 2.4, 4.2, 4.8 with ABC transporters; PDB ID 4F4C, 4M1 M, 4M2T, respectively, reflecting the correctness of structure. EchinocandinB has been docked to the modelled as well as to the clustered structures, which reveals interaction of echinocandinB with TMD0 and other TM helices in the translocation path build of TMDs.</p

Chemically Functionalized Gold Nanosphere-Blended Nematic Liquid Crystals for Photonic Applications

A demand for functional materials that are capable of tailoring light-emissive properties has apparently been rising nowadays substantially for their utilization in organic optoelectronic devices. Motivated by such promising characteristics, we present highly emissive as well as aggregation-induced emission (AIE) electroluminescent composite systems composed of a nematic liquid crystals (NLC) blended with polyethylene-functionalized gold nanospheres (GNSs). The major findings of this study include superior electro-optical properties such as threshold voltage reduction by around 24%. The fall time is reduced by 11.50, 30.33, 49.33, and 63.17% respectively, and rotational viscosity is reduced by 13.86, 32.77, 36.97, and 49.58% for 5.0 × 1011, 5.0 × 1012, 2.5 × 1013, and 5.0 × 1013 number of GNS-blended liquid crystal (LC) cells. The increased UV absorbance and greatly enhanced luminescence properties have been attributed to surface plasmon resonance near the surface of GNSs and AIE effect risen due to agglomeration of the capping agent with the NLC molecules respectively, and these characteristics make them suitable for new-age display applications