Structure property relationship in two thiazole derivatives: Insights of crystal structure, Hirshfeld surface, DFT, QTAIM, NBO and molecular docking studies

Detailed structural and noncovalent interactions in two thiazole derivatives (N-(4-Bromophenyl)-2-(methylthio)thiazole-5-carboxamide and Ethyl-5-((4-bromophenyl)carbamoyl)thiazole-4-carboxylate) are investigated by single crystal X-ray diffraction study and computational approaches. The structure investigation revealed that various interactions like C-H…O, N-H…O, and N-H…N hydrogen bonds and Br…Br interactions are involved in constructing ring motifs to stabilize the crystal packing. Hirshfeld surface analysis and fingerprint plots were carried out to study the differences and similarities in the relative contribution of noncovalent interactions in both the molecules. The FMOs and other global reactive parameters are analyzed for thiazole derivatives. The strength and nature of weak interactions present in the molecule were characterized by RDG-based NCI and QTAIM analyses. Natural bond orbital (NBO) analysis unravels the importance of non-covalent and hyperconjugative interactions for the stability of the molecules in their solid state. Further, molecular docking of N-(4-Bromophenyl)-2-(methylthio)thiazole-5-carboxamide and Ethyl-5-((4-bromophenyl)carbamoyl)thiazole-4-carboxylate with SARS-Covid-19 have been carried out. © 2023 Taylor & Francis Group, LLC.

Vitamin K as a Simple but Efficient Add-on to the Current Treatment Regime of COVID-19: A Narrative Review

Background: Intravascular thrombosis and pulmonary fibrosis in COVID-19 patients with pneumonia are significantly associated with the severity of the disease. Vitamin K is known to balance the coagulation mechanisms and also prevent calcification and fibrosis of the extrahe-patic soft tissues. This narrative review focuses on the role of vitamin K as a linking factor for thrombotic as well as pulmonary complications of COVID-19. Materials and Methods: Article search was performed in databases of WHO, PubMed, Scopus and Clinical Trial Registry using appropriate keywords. Original articles included very few ob-servational studies which showed a reduced level of vitamin K as well as activated extrahepatic vitamin K Dependent Proteins (VKDP) in COVID-19 patients when compared to healthy con-trols. Chronic treatment with vitamin K Antagonists did not reduce the risk of in-hospital death. Docking study was performed using Swiss dock, and it demonstrated a significant interaction between menaquinone and SARS-CoV-2 main protease (SARS-CoV-2 Mpro). Results and Discussion: Deficiency of vitamin K in COVID-19 can be due to excessive use of antagonists or defective ingestion or absorption. This triggers an imbalance in the normal coagu-lation-anticoagulation mechanism by channeling the available vitamin K to the liver, thereby causing a deficiency of the same in extrahepatic tissues, thus finally leading to thrombosis. This also prevents carboxylation and activation of extrahepatic VKDP required to prevent the calcification of soft tissues, thus leading to lung fibrosis. Conclusion: Supplementation of vitamin K should be considered as a potentially modifiable risk factor in severe COVID-19. Randomized control trials are highly recommended to provide clear-er evidence on the same.

Per- and Polyfluoroalkyl Substances (PFAS) in Facemasks: Potential Source of Human Exposure to PFAS with Implications for Disposal to Landfills

Facemasks are important tools for fighting against disease spread, including Covid-19 and its variants, and some may be treated with per- and polyfluoroalkyl substances (PFAS). Nine facemasks over a range of prices were analyzed for total fluorine and PFAS. The PFAS compositions of the masks were then used to estimate exposure and the mass of PFAS discharged to landfill leachate. Fluorine from PFAS accounted only for a small fraction of total fluorine. Homologous series of linear perfluoroalkyl carboxylates and the 6:2 fluorotelomer alcohol indicated a fluorotelomer origin. Inhalation was estimated to be the dominant exposure route (40%-50%), followed by incidental ingestion (15%-40%) and dermal (11%-20%). Exposure and risk estimates were higher for children than adults, and high physical activity substantially increased inhalation exposure. These preliminary findings indicate that wearing masks treated with high levels of PFAS for extended periods of time can be a notable source of exposure and have the potential to pose a health risk. Despite modeled annual disposal of 29-91 billion masks, and an assuming 100% leaching of individual PFAS into landfill leachate, mask disposal would contribute only an additional 6% of annual PFAS mass loads and less than 11 kg of PFAS discharged to U.S. wastewater. © 2022 American Chemical Society.