Browsing by Author "Roy, N."

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Catalytic Synthesis of Xanthene and Unprecedented Evolution of Naphthopyrans Using Heteropoly Acid-Tantalum(V) Oxide Hybrid Composite as Promoter
(John Wiley and Sons Inc, 2025) Mahapatra, J.; Dastidar, S.G.; Jagankar, D.; Roy, N.; Sharma, J.; Mukherjee, A.; Maity, C.; Panda, T.K.; Mal, S.S.
Xanthene derivatives are prepared by using tantalum(V) oxide (Ta2O5)-supported heteropoly acid (HPA), Keggin 12-phosphotungstic acid (PTA)-based heterogeneous catalyst PTA@Ta2O5 under neat conditions. The composite is prepared by the wetness impregnation method and is characterized by various techniques. Under optimized conditions, xanthenes are synthesized with prominent yields in remarkably short reaction times. The green chemistry metrics are appraised for the xanthene reaction. Surprisingly, a few novel naphthopyran derivatives are isolated instead of the conventional xanthene derivatives when cinnamaldehyde analogous are introduced under the same reaction protocol. Unprecedented naphtho[2,1-b]pyran-type derivatives of 3m, 3n, and 3o are isolated, depending on the specific substituted cinnamaldehyde used, and interestingly, the nature of the substituent in cinnamaldehyde decides the different reaction pathways leading to the formation of respective pyrans. Diverse possible mechanisms are encountered with the PTA@Ta2O5 catalyst based on the respective transformations. The solid-state structures of xanthenes and naphthopyrans are thoroughly investigated. Furthermore, some derivatives are studied in vitro to assess their antimicrobial activity, and the findings are compared with those of reference standard antibiotics. © 2025 Wiley-VCH GmbH.
Juglans regia seeds have effects on platelets and peripheral fat deposition in the aorta and heart of C57BL/6J mice fed with normal and high fat simple carbohydrate diet
(2016) Prabhu, S.G.; Karkala, S.; Roy, N.; D Souza, S.; Abraham, A.
Background: Consumption of nuts particularly walnuts has been widely recommended for lowering the risk of coronary heart disease; however, very few studies have evaluated the potential unfavourable effects that Walnut seeds might have in vivo. Objective: To investigate the long-term effects of Juglans regia seed supplementation in specially formulated feed when fed to developed mice model. Method: C57BL/6J male mice were divided into four groups, labelled, C (control), T (High Fat Simple Carbohydrate-HFSC), Cw (control + walnut) and Tw (HFSC+ walnut) based on diet. Four mice from each group were sacrificed at the end of the first and fifth month respectively. Blood samples were collected every month. Bleeding time, blood platelet number and morphology were studied. Histopathological analysis of heart and aorta were also performed. Results: Groups Cw and Tw showed a significant increase in platelet count; however, platelet activation was not detected. There was a trend to an increase in bleeding time in group Cw. Expanded lumen diameter of the aorta was observed in Cw and Tw mice initially, however, it was found to constrict by the end of the study. A large amount of peripheral fat deposition in the aortas of Cw and Tw was observed, which increased through the course of the experiment. Conclusion: Kashmiri walnut seed supplementation was found to reduce the signs in shape change of platelets as well as increase platelet number with a trend to an increased bleeding time. This observation could be of medical interest. Histopathological analysis of heart and aorta showed lipid sequestration which merits further investigations. 2016 Bentham Science Publishers.
Juglans regia seeds have effects on platelets and peripheral fat deposition in the aorta and heart of C57BL/6J mice fed with normal and high fat simple carbohydrate diet
(Bentham Science Publishers B.V. P.O. Box 294 Bussum 1400 AG, 2016) Prabhu, S.G.; Karkala, S.; Roy, N.; D'Souza, S.; Abraham, A.
Background: Consumption of nuts particularly walnuts has been widely recommended for lowering the risk of coronary heart disease; however, very few studies have evaluated the potential unfavourable effects that Walnut seeds might have in vivo. Objective: To investigate the long-term effects of Juglans regia seed supplementation in specially formulated feed when fed to developed mice model. Method: C57BL/6J male mice were divided into four groups, labelled, C (control), T (High Fat Simple Carbohydrate-HFSC), Cw (control + walnut) and Tw (HFSC+ walnut) based on diet. Four mice from each group were sacrificed at the end of the first and fifth month respectively. Blood samples were collected every month. Bleeding time, blood platelet number and morphology were studied. Histopathological analysis of heart and aorta were also performed. Results: Groups Cw and Tw showed a significant increase in platelet count; however, platelet activation was not detected. There was a trend to an increase in bleeding time in group Cw. Expanded lumen diameter of the aorta was observed in Cw and Tw mice initially, however, it was found to constrict by the end of the study. A large amount of peripheral fat deposition in the aortas of Cw and Tw was observed, which increased through the course of the experiment. Conclusion: Kashmiri walnut seed supplementation was found to reduce the signs in shape change of platelets as well as increase platelet number with a trend to an increased bleeding time. This observation could be of medical interest. Histopathological analysis of heart and aorta showed lipid sequestration which merits further investigations. © 2016 Bentham Science Publishers.