A simple and straightforward strategy for expedient access to benzoxazoles using chemically engineered 2D magnetic graphene oxide nanosheets as an eco-compatible catalyst.

Two-dimensional (2D) graphene oxide nanosheets serve as an excellent support material for immobilizing metal complexes to deal with the drawbacks of homogeneous catalysis. In this work, we report a magnetically retrievable graphene oxide (MGO) based copper nanocatalytic system that has been efficiently exploited for obtaining a series of pharmaceutically and biologically active benzoxazole scaffolds. The nanocatalyst was designed by covalent immobilization of dehydroacetic acid (DHA) onto a magnetic amino-silanized graphene oxide nanosupport which was accompanied by its metallation with copper acetate. The structure of the synthesized MGO hybrid material (Cu@DHA@APTES@MGO) was characterized by numerous physico-chemical techniques such as transmission electron microscopy (TEM), field emission scanning electron microscopy (FE-SEM), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), vibrating sample magnetometry (VSM), elemental mapping, atomic absorption spectroscopy (AAS), thermogravimetric analysis (TGA), Brunauer-Emmett-Teller (BET) surface area analysis and energy-dispersive X-ray fluorescence spectroscopy (ED-XRF). The fabricated architectures exhibited high efficiency for cyclization of 2-aminophenols and ß-diketones with wide substrate scope, excellent functional group tolerance, a higher conversion percentage (>98%) and a high turnover number (TON). The exceptional catalytic activity could be attributed to the 2D architecture of graphene oxide which provides space for trapping of reactants between 2D graphitic overlayers and metal surfaces and the reaction proceeds to afford benzoxazole products with moderate to excellent conversion percentages. Notably, this nanocomposite could be recovered easily through an external magnetic force and reused for multiple runs without any appreciable loss in its catalytic efficacy.

Preparation and characterization of the h-BN/Fe3O4/APTES-AMF/CuII nanocomposite as a new and efficient catalyst for the one-pot three-component synthesis of 2-amino-4-aryl(or heteroaryl)-7,7-dimethyl-5-oxo-5,6,7,8-tetrahydro-4H-chromene-3-carbonitriles.

The intriguing features of surface-engineered hexagonal two-dimensional boron nitride (h-BN) nanostructures have captivated the immense interest of researchers working in the arena of materials science. Inspired by striking attributes exhibited by h-BN nanosheets as the support material, we devoted our efforts towards synthesizing a novel magnetically retrievable h-BN/Fe3O4/APTES-AMF/CuII catalytic system, which was then comprehensively characterized using various techniques including SEM, TEM, EDX, SEM-based elemental mapping, ED-XRF, AAS, XRD, FT-IR, VSM, XPS, TGA, and BET. Further, the catalytic potential of h-BN/Fe3O4/APTES-AMF/CuII nanocomposites was investigated in the one-pot multicomponent coupling reaction to gain access to a library of biologically active 2-amino-4-aryl(or heteroaryl)-7,7-dimethyl-5-oxo-5,6,7,8-tetrahydro-4H-chromene-3-carbonitriles under ambient conditions. In addition, the use of green solvent, facile magnetic recoverability, and reusability of up to six successive runs made this protocol environmentally benign and economical. This work throws light on the development of covalently functionalized 2D-BN nanostructure-based copper catalysts and establishes its significance in furnishing industrially demanding products that would pave the way towards sustainable chemistry.

An Earth-abundant cobalt based photocatalyst: visible light induced direct (het)arene C-H arylation and CO2 capture.

In this work, we have reported a noble metal free heterogeneous photocatalyst to carry out direct (het)arene C-H arylation and solvent-free CO2 capture via single-electron transfer processes at room temperature and under pressure. The catalytic system comprises a cobalt(III) complex grafted over the silica coated magnetic support for the efficient recovery of the photocatalytic moiety without hampering its light-harvesting capability. The novel Earth-abundant cobalt(III) based photocatalyst possesses various fascinating properties such as high surface area to volume ratios, large pore volume, crystalline behaviour, high metal loading, excellent stability and reusability. The general efficacy of the highly abundant and low-cost cobalt based heterogeneous nanocatalyst was checked for the selective conversion of aryldiazonium salts into synthetically and pharmaceutically significant biaryl motifs under ambient conditions upon irradiation with visible light. The highly efficient photocatalytic conversion of carbon dioxide (CO2) to a value-added chemical was accomplished under mild reaction conditions with high selectivity, showing the added benefit of operational simplicity.

Increase in the risk of type 2 diabetes during lockdown for the COVID19 pandemic in India: A cohort analysis.

Lockdown due to the Coronavirus disease 2019 (COVID 19) pandemic may cause weight gain and enhance the risk of type 2 diabetes mellitus (T2DM). We aimed to determine this risk in apparently non-diabetic individuals. MATERIAL METHODS: Baseline demographic and clinical data from 100 apparently non-diabetic household members (related or unrelated) of patients with type 2 diabetes mellitus were collected until 49 days of lockdown and analyzed using the XL-STAT statistical software. A two-pronged analytical strategy was employed. First, the metabolic risk profile related to age, sex, weight, family history, and exercise pattern was analyzed. This was followed by an assessment of the risk of developing type 2 diabetes using an established risk assessment engine. RESULTS: There was a trend towards weight gain seen in 40% of the cohort, with 16% of the population experiencing a 2.1-5 kg weight increment. When all the risk parameters were analyzed together using the ADA risk engine, there was an increase in the ADA diabetes risk score in 7% of the population, with 6.66% in the high-risk group. There was a further increase in weight among 3% of the population who were already obese at baseline. CONCLUSION: We show an increased risk of T2MD consequent to weight gain during 49 days of lockdown in India.

Effects of nationwide lockdown during COVID-19 epidemic on lifestyle and other medical issues of patients with type 2 diabetes in north India.

BACKGROUND AND AIMS: During the current pandemic of COVID-19, India is under lockdown which could cause disruption in diet and lifestyle in patients with type 2 diabetes (T2DM). We aimed to study lifestyle changes and other common issues related to treatment in our previously seen and treated patients with T2DM. METHODS: Patients (n, 150) who were regularly following up before lockdown were interviewed telephonically (after 45 days of start of lockdown) regarding lifestyle changes, stress and other diabetes-related questions. RESULT: Carbohydrate consumption and frequency of snacking increased in 21% and 23% patients, respectively. Interestingly, 27% patients reported an increase in consumption of fruits. Exercise duration was reduced in 42% and weight gain occurred in 19% patients. Frequency of doing self-monitoring of blood glucose (SMBG) was decreased in 23% patients. 'Mental stress' of any kind was reported in 87% patients. Availability of medicines and insulin was uninterrupted in 91% patients. Knowledge about telemedicine was present in 69% and majority (92%) of these patients preferred video consultation. CONCLUSION: During 45 days of lockdown increase in carbohydrate intake, decrease in exercise, decreased SMBG and widespread mental stress in patients with T2DM was recorded, factors which may destabilize or exacerbate hyperglycemia and hypertension. Some positive changes (e.g. increased intake of fruits) were also observed.

Dipeptidyl peptidase 4 inhibitors linked bullous pemphigoid in patients with type 2 diabetes mellitus: A series of 13 cases.

BACKGROUND: Dipeptidyl peptidase 4 (DPP4) inhibitors have increasingly been linked to bullous pemphigoid, but there is paucity of data from India where about 1.85 million patients have been estimated to use these drugs. METHODS: In 30,000 patients with T2DM seen by us in two tertiary care centres since 2015, we detected 13 cases of bullous pemphigoid linked to DPP4 inhibitors. We used WHO-UMC (World Health Organisation-Uppsala Monitoring Centre) causality assessment system for assessment. RESULTS: Lesions of bullous pemphigoid appeared at varied intervals (within 1 weeks-2 years) after start of DPP4 inhibitors. Implicated drugs were Linagliptin (n, 8), Vildagliptin (n, 4) and Sitagliptin (n, 1). Mostly, lesions were seen after 60 years age, and over trunk and extremities. Skin biopsy was compatible with bullous pemphigoid in two patients. Lesions regressed within a month of stopping DPP4 inhibitors in 9 patients while delayed regression up to 6 months in 4 patients. Overall, skin lesions remitted in all patients and did not recur. CONCLUSION: Any new bullous lesion appearing while patient is on DPP4 inhibitors should be considered as bullous pemphigoid and should necessitate prompt withdrawal of the drug.

Design and Exploration of Catalytic Activity of Two-Dimensional Surface-Engineered Graphene Oxide Nanosheets in the Transannulation of N-Heterocyclic Aldehydes or Ketones with Alkylamines.

In this work, pharmaceutically and biologically important compounds containing imidazo[1,5-a]pyridine nuclei have been synthesized via transannulation of N-heteroaryl aldehydes or ketones with alkylamines using a graphene oxide-supported copper catalyst. The nanocatalyst was fabricated by the covalent immobilization of 4-aminoantipyrine onto an amine-functionalized graphene oxide nanosupport followed by its metallation with copper acetate. Structural analysis by transmission electron microscopy, scanning electron microscopy, X-ray photoelectron spectroscopy (XPS), and X-ray diffraction demonstrates that the two-dimensional sheet-like structure of graphene oxide is maintained even after the chemical modifications, whereas XPS revealed crucial information related to elemental composition and surface electronic states of the metal present in the catalyst. Apart from this, Fourier transform infrared spectroscopy helped in identifying the degree of oxidation and the presence of oxygenated groups in graphene oxide nanocomposites. As a heterogeneous catalyst, this graphene oxide-supported copper complex showed moderate to good catalytic activity in the C(sp3)-H bond activation/amination of a variety of substrates. This superior catalytic performance originated from the unique 2-dimensional structure of graphene oxide-based material which provided space between graphitic overlayers due to appropriate positioning of metal on their basal planes, decreasing the diffusion resistances of reactant surfaces, thus making it function as a nanoreactor. More importantly, this nanomaterial could be recovered easily and reused repeatedly by simple washing without chemical treatment with no appreciable loss in its catalytic activity, showing good potential for increasing the overall turnover number of this synthetically useful catalyst.