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In this manuscript, a pyridyl containing porphyrin, C46H36N8O4 (denoted as Tris@NTPP) and its derived polyoxometalate-porphyrin hybrid, [C4H9)4N]3[C41H26N7NHCO(NH)C(OCH2)3MnMo6 O18(OCH2)3C(NH)CONHN7 H26C41] (denoted as NTPP@POM) in which two pyridyl containing porphyrin moieties hanged onto one Anderson polyoxometalate, have been successfully synthesized and thoroughly characterized. Fluorescence quenching was observed in NTPP@POM as compared with its precursor Tris@NTPP inferring the transfer of electron/energy from porphyrin moiety to POM moiety. NTPP@POM showed notably enhanced nonlinear absorption (β = 2.32 × 10–5 esu) than Tris@NTPP (β = 0.73 × 10–5 esu). These NLO responses were associated with fluorescence decay mechanism which oriented the singlet excited(*S) states and triplet excited(*T) states of Tris@NTPP and NTPP@POM. Life time decay studies revealed that NTPP@POM (τ2 = 5.32 ns) were stayed for shorter time in excited triplet state than Tris@NTPP (τ2 = 10 ns), implying shorter life time led towards higher NLO responses. [ABSTRACT FROM AUTHOR]

Using biomolecule-rich plant extracts, the conversion of metal ions to metal oxide nanoparticles via abiogenic approach is highly intriguing, environmentally friendly, and quick. The inherent inclination of plant extracts function as capping agents in the insitu synthesis. In this study, biogenic zinc oxide nanoparticles (ZnO−NPs) were synthesized using an aqueous leaf extract from Moringaoleifera. The ZnO−NPs were then mixed with carboxylated carbon nanotubes (CNTs) to create a carboxylated CNTs/biogenic ZnO composite using asol–gel method. The CNTs/ZnO composite displayed 18 mm, 16 mm, and 17 mm zones of inhibition (ZOI) against Bacillus cereus, Pseudomonas aeruginosa, and Escherichia coli, respectively. In contrast with ZnO−NPs, the produced carboxylated CNTs/ZnO composite demonstrated a 13 percent elevation in ZOI as antibacterial activity against Bacillus cereus ATCC 19659, Escherichia coli ATCC 25922, and Pseudomonas aeruginosa ATCC 27853. The characterization of ZnO−NPs and the carboxylated CNTs/ZnO composite were performed via FTIR, UV/Vis spectroscopy, SEM, and XRD. The XRD pattern depicted a nano−sized crystalline structure (Wurtzite) of ZnO−NPs and a carboxylated CNTs/ZnO composite. The current work comprehends a valuable green technique for killing pathogenic bacteria, and gives fresh insights into the manufacture of metal oxide composites for future research. [ABSTRACT FROM AUTHOR]

Functionalised multi‐walled carbon nanotubes (MWCNTs) are exclusively used in antibacterial activity due to their high aspect ratio and surface penetration characteristics. This study reports the synthesis of piperazine and dopamine functionalised MWCNTs to investigate antibacterial activity against strains like Staphylococcus aureus and Micrococcus luteus. MWCNTs were activated through acid oxidation and then refluxed at 75°C for 10 and 8 h in the presence of piperazine and dopamine, respectively. The functionalised MWCNTs were characterised by scanning electron microscopy, Fourier‐transform infrared spectroscopy, X‐ray diffraction and Raman spectroscopy. Moreover, functionalised MWCNTs were subjected to zone inhibition assay on agar plates. Results revealed the significant antibacterial activity against various bacteria up to 50%. Similarly, it was observed that the effect of different solvents, such as dimethyl formamide (DMF) and dimethyl sulfoxide (DMSO) was non‐prevalent to the bacterial zone of inhibition. Such facile nano‐modifications provide passage to nano‐antibacterials for advanced studies. [ABSTRACT FROM AUTHOR]

A novel series of (1,2-benzothiazin-4-yl)acetic acid enantiomers was prepared by chiral resolution, and their absolute configurations were determined using the PGME method. The biological evaluation of the racemate and single enantiomers has shown a remarkable difference for the aldose reductase inhibitory activity and selectivity. The (R)-(−)-enantiomer exhibited the strongest aldose reductase activity with an IC50value of 0.120 μM, which was 35 times more active than the S-(+)-enantiomer. Thus, the stereocenter at the C4 position of this scaffold was shown to have a major impact on the activity and selectivity. [ABSTRACT FROM AUTHOR]

A novel series of polyphosphazene-graft-polystyrene (PP- g-PS) copolymers were successfully prepared by atom transfer radical polymerization (ATRP) of styrene monomers and brominated poly(bis(4-methylphenoxy)phosphazene) macroinitiator. The graft density and the graft length could be regulated by changing the bromination degree of the macroinitiator and the ATRP reaction time, respectively. The PP- g-PS copolymers readily underwent a regioselective sulfonation reaction, which occurred preferentially at the polystyrene sites, producing the sulfonated PP- g-PS copolymers with a range of ion exchange capacities. The resulting sulfonated PP- g-PS membranes prepared by solution casting showed high water uptake, low water swelling and considerable proton conductivity. They also exhibited good oxidative stability and high resistance to methanol crossover. Morphological studies of the membranes by transmission electron microscopy showed clear nanophase-separated structures resulted from hydrophobic polyphosphazene backbone and hydrophilic polystyrene sulfonic acid segments, indicating the formation of proton transferring tunnels. Therefore, these sulfonated copolymers may be candidate materials for proton exchange membranes in direct methanol fuel cell (DMFC) applications. [ABSTRACT FROM AUTHOR]

Polyphosphazenes containing perfluoroalkyl sulfonic acids (PSA-P) were synthesized by the copper-catalyzed coupling reaction of poly[(4-bromophenoxy)(phenoxy)phosphazene] with potassium 1,1,2,2-tetrafluoro-2-(1,1,2,2-tetrafluoro-2-iodoethoxy) ethanesulfonate. Two synthetic protocols have been developed to obtain the polymers and 1, 10-phenanthroline was found benefit for improving the efficiency of the coupling reaction. ThePSA-Pmembranes prepared by solution casting showed excellent thermal stability, oxidative stability and low swelling ratios. In addition, compared with the sulfonated poly[bis(phenoxy)phosphazene] membrane with similar IEC, thePSA-Pmembrane displayed significant superiority in proton conductivity, water resistance, oxidative and thermal stability, indicating that it is a good candidate for proton exchange membranes. [ABSTRACT FROM PUBLISHER]

Dimorphamides A-C (-, resp.), three new polyphenolic amides, have been isolated from the BuOH-soluble fraction of the whole plant of Atriplex dimorphostagia, along with two known compounds, thymidine and N-[( E)-feruloyl]tyramine. Their structures have been determined on the basis of spectral studies. [ABSTRACT FROM AUTHOR]