Revolutionizing fuel production through biologically synthesized zero-dimensional nanoparticles.

The sustainable management of wastewater and the production of clean fuel with a reduced carbon footprint require innovative methods, including photocatalytic degradation of pollutants and hydrogen generation. To achieve this, biosynthesized photocatalysts are necessary, with carbon quantum dots (CQDs) being a promising candidate for achieving this goal. In this study, CQDs were prepared from water caltrop peels and a composite of greenly synthesized CQDs with copper selenide (CuSe) was used for the photocatalytic degradation of pollutants and production of fuel. Thymol blue (TB) and Congo red (CR) were chosen as model dyes for degradation studies, with optimized reaction conditions being determined by varying the dose, pH, intensity, and concentration of dyes. The composite (CuSe@CQDs) showed a degradation rate of 99.4% and 97.8% for TB and CR, respectively, within 60 minutes, with a corresponding hydrogen production rate of 2360 and 1875 µmol g-1 h-1. The yield of hydrogen production using the composite was 35.7 and 29 times greater than that of CuSe alone for TB and CR, respectively. Spectroscopic techniques such as XRD, UV-Vis, FESEM, HRTEM, XPS, FTIR, BET, and TGA were used to characterize the composite, and the results revealed that the composite had superior degradation rates compared to CuSe alone, with the degradation rate being enhanced by about three times. GCMS analysis was used to investigate the intermediate and possible degradation pathways. Overall, this study highlights the potential of biosynthesized CQDs as effective photocatalysts for the sustainable management of wastewater and production of fuel.

Catalyst- and Solvent-Free Coupling of 2-Methyl Quinazolinones and Isatins: An Environmentally Benign Access of Diastereoselective Schizocommunin Analogues.

An environmentally benign highly atom-economic protocol for the construction of the C-C bond has been developed under catalyst- and solvent-free conditions. This protocol involves the efficient coupling of 2-methyl quinazolinones with isatin for the highly diastereoselective access of schizocommunin derivatives in excellent yields (up to 97%). Furthermore, the preliminary cytotoxicity screening of selected schizocommunin analogues displayed promising anticancer activity against human cancer cell lines, and the cytotoxic potential of active compound 12ac was also validated by in silico molecular docking simulation studies.

Synthesis and characterization of polyaniline-drug conjugates as effective antituberculosis agents.

Polyaniline (PANI) and its drug composites with some drugs like Neomycin (NM), Trimethoprim (TMP) and Streptomycin (ST) have been prepared by oxidative polymerization of aniline using hydrochloric acid (HA) and ammonium persulfate (APS) as a dopant and as an oxidant, respectively. The structures of PANI and PANI-drug composites were elucidated by FTIR and NMR spectroscopy, which confirmed the presence of benzenoid and quinoid rings in the synthesized compound. Molecular weight and thermal stability were determined by gel permeation chromatography (GPC) and thermogarvimetric analysis, respectively. From the GPC, PDI values of PANI-NM, PANI-TMP and PANI-ST were found to be 1.37, 1.23 and 1.56, respectively. For the study of antibacterial behavior of the synthesized PANI and PANI-drug composites, different micro-organisms, namely, four Gram positive (S. aureus MTCC 96, B. subtilis MTCC 441, S. pyogenes MTCC 442 and S. mutans MTCC 890) and four Gram negative (S. typhi MTCC 98, KL. pneumoniae MTCC 109, E. coli MTCC 443 and P. aeruginosa MTCC 1688) bacteria were selected due to their pharmacological importance. Some of the PANI-drug composites were found to show excellent results as compared to components polyaniline and drugs used for composite formation. Antituberculosis activity of the PANI and its drug composites against Mycobacterium tuberculosisH37RV (acid fast Bacilli) was determined. MIC values for PANI-NM and PANI-TMP were found to be 0.12 and 0.20 µg/mL, respectively. Results suggested that some of the drug composites may be tried as potential candidates for use as an antituberculoid agent to reduce TB transmission.

An Environmentally-Benign Synthesis of Spiro-benzo[1,4]diazepines Using Multi Phase Nano-titania as a Highly Efficient Catalyst via MAOS Technique.

AIM AND OBJECTIVE: Benzodiazepines and indole fused heterocycles are pharmacologically significant scaffolds. Trivial work on indole fused benzodiazepine compounds is reported in the literature. Hence, it is imperative to explore the synthesis of indole-fused benzodiazepines that may act as a template for biological studies in the future. Hence, in the present work, the synthesis of indole fused benzodiazepine derivatives was undertaken using multi-phase nano-titania as catalyst under microwave irradiation. MATERIALS AND METHODS: MAOS technique was used to carry out the synthesis of spiro-benzo [1,4]diazepine derivatives in the presence of multiphase nano-titania as a catalyst. Nano-titania was prepared by sol-gel method and characterized by XRD, FT-IR, FESEM, EDS and thermogravimetric techniques. The synthesized spiro-benzo [1,4] diazepine derivatives were identified by physical and spectral methods. RESULTS: Synthesized compounds were obtained in excellent yields in a short span of time. The synthesis was also carried out in the presence of conventional catalysts in addition to nano-titania. Among all the catalysts, the best result was obtained with nano-titania. The amount of nano-titania was optimized to be 0.05g giving 93- 95% yield of products. The study of reusability of nano-titania revealed that it could be reused up to four times with a negligible change in efficiency. CONCLUSION: The paper reports an efficient, cost-effective and environmentally benign approach for the synthesis of spiro-benzo [1,4] diazepine derivatives in the presence of multiphase nano-titania catalyst under microwave irradiation.

Spectral and thermal characterization of halogen-bonded novel crystalline oligo(p-bromoacetophenone formaldehyde).

A novel oligomer p-bromoacetophenone-formaldehyde (OPBAF) was prepared by condensation polymerization in the presence of an acid as catalyst. It was characterized by FT-IR, NMR, pyrolysis GC/MS, XRD, GPC, and TG-DTG. The crystallographic parameters and space group for hexagonal OPBAF were a = b = 2.0810 Å and c = 9.2340 Å and P3̅m1, respectively. The degradation activation energy of the oligomer was studied by the Kissinger method. The kinetic parameters were also obtained. Halogen bonding interactions in the crystalline oligomers are identified between halogen···carbonyl and halogen···halogen. Little correlation was found in the halogen bonding motifs exhibited as a function of bromine present in this oligomer, and a unique bifurcated Br···Br/Br···O═C halogen bonding synthon was identified. This newly developed oligomer may be used as an interesting material for the development of 3D-designed structural products.