This work focuses on the synthesis of undoped and doped lanthanum oxide nanoparticles (La 2 O 3 NPs) by a simple co-precipitation method for the catalytic reduction of 4-nitrophenol (4-NP) using NaBH 4 as a reducing agent. Their optical properties, morphologies, structure, chemical compositions and electronic properties were carefully characterized by XRD, FTIR, SEM, TEM, PL and UV–visible absorption spectroscopy. The SEM and TEM images showed various shape morphologies and sizes of the particles. The XRD pattern revealed a polycrystalline nature with the hexagonal structure of the La 2 O 3 NPs. The synthesized undoped and doped La 2 O 3 NPs were also employed as catalysts for the reduction of 4-nitrophenol, it shows that the doped (Sm 3+ , Gd 3+ and Hf 3+ ) La 2 O 3 NPs provided better catalytic activity than the undoped La 2 O 3 NPs. Moreover, Hf 3+ doped La 2 O 3 NPs exhibited an enhanced catalytic activity for the reduction of 4-nitrophenol to 4-aminophenol in 90 min. The catalytic conversion was studied by UV–vis spectroscopy with high reduction rate (k = 2.048 min −1 ). The applications of the present study may utilize in the removal of toxic pollutants in a cleaning of environmental pollution as well as in industrial applications.

A convenient synthesis of novel prototypes containing the two pharmacophores of chromene and 1,2,3-triazole in a single molecular backbone, were evaluated againstMycobacterium tuberculosisH37Rv strain.

As part of an ongoing effort to develop new antitubercular and antimicrobial agents, a series of substituted xanthenone derivatives () were synthesized. Xanthenone derivatives () were prepared a one-pot three-component thermal cyclization reaction of β-naphthol (), substituted 1-aryl-1-[1,2,3]triazole-4-carbaldehydes (), and cyclic-1,3-diones (, ) in the presence of a catalytic amount of iodine. The newly synthesized compounds were characterized by IR, NMR, mass spectral data, and elemental analysis. These compounds ( and ) were screened for antitubercular activity against the HRv (ATCC 27294) strain, for antibacterial activity against Gram-positive and Gram-negative strains, and for antifungal activity against a pathogenic strain of fungi. Among the compounds tested, most of them showed good to excellent antimicrobial and antitubercular activity. The active compounds displaying good potency in the MTB were further examined for toxicity in a HEK cell line. In addition, the structure and antitubercular activity relationship were further supported by molecular-docking studies of the active compounds against the pantothenate synthetase (PS) enzyme of.

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