Browsing by Author "Singh, A.K."

Now showing 1 - 3 of 3

Identification of Compounds from Curcuma longa with in Silico Binding Potential against SARS-CoV-2 and Human Host Proteins Involve in Virus Entry and Pathogenesis
(Indian Pharmaceutical Association, 2021-12-07T00:00:00) Kumar, S.; Singh, A.K.; Kushwaha, P.P.; Prajapati, Kumari Sunita; Senapati, S.; Mohd, S.; Gupta, S.
Severe acute respiratory syndrome coronavirus 2 and associated coronavirus disease 2019 is a newly identified human coronavirus has imposed a serious threat to global health. The rapid transmission of severe acute respiratory syndrome coronavirus 2 and its ability to spread in humans have prompted the development of new approaches for its treatment. Severe acute respiratory syndrome coronavirus 2 requires RNA-dependent RNA polymerases for life cycle propagation and Spike (S)-protein for attachment to the host cell surface receptors. The virus enters the human body with the assistance of a key functional host receptor dipeptidyl peptidase-4 primed by transmembrane serine protease 2 which are putative targets for drug development. We performed screening of 267 compounds from Curcuma longa L. (Zingiberaceae family) against the viral S-protein and RNA-dependent RNA polymerases and host receptor proteins dipeptidyl peptidase-4 and transmembrane serine protease 2 using in silico molecular docking. Compounds C1, ((4Z,6E)-1,5-dihydroxy-1,7-bis(4-hydroxy-3-methoxyphenyl)hepta-4,6-dien- 3-one) and C6 ((4Z,6E)-1,5-dihydroxy-1-(4-hydroxy-3-methoxyphenyl)-7-(4-hydroxyphenyl)hepta-4,6- dien-3-one) exhibited tight binding to the S1 domain of the Spike protein than VE607 and with RNAdependent RNA polymerase protein more effectively than ribavirin and remdesivir. These compounds also interacted with the human host proteins dipeptidyl peptidase-4 and transmembrane serine protease 2 with higher efficiency than standard inhibitors sitagliptin and camostat mesylate. The lead compounds showed favorable free binding energy for all the studied protein-ligand complexes in Molecular mechanics/ Generalized born model and solvent accessibility analysis. Besides, other Curcuma longa compounds C14 and C23 exhibited almost similar potential against these target proteins. The structure based optimization and molecular docking studies have provided information on some lead Curcuma longa compounds with probability for advancement in preclinical research. � 2021 Indian Pharmaceutical Association. All rights reserved.
Late Quaternary evolution of Tista River terraces in Darjeeling-Sikkim-Tibet wedge: Implications to climate and tectonics
(Elsevier Ltd, 2017) Singh, A.K.; Pattanaik, J.K.; Gagan, Jaiswal, M.K.
Terraces in the Himalayas are important geomorphic archives which preserve the signature of tectonics and past environment. Terraces in eastern part of the Himalayan fold and thrust belt have not received much attention of the geologists. A geochemical approach using luminescence dating has been applied to understand the evolution of paired and deformed terraces between major thrust boundaries of the eastern Himalayas, on the either banks of the Tista River in Darjeeling-Sikkim-Tibet wedge. These terraces are located at the confluence of Tum Thang khola and the Tista River. Three levels of terraces are present in general and also in the study area. The terrace T3 was formed during last interglacial period and the T2 terrace during last glacial maximum (LGM) and in the humid phases after LGM. The top section of T2 terrace (?2.5 m thick) was formed in the transition phase (arid to humid) after Younger Dryas event. The region has experienced several deformational events, (i) one after 45 ka which raised the T3 terrace to its present level, (ii) another one after 11.9 ka which raised the T2 to its present level and this event is also associated with the shifting of the Tum Thang khola, and (iii) the region is still tectonically active as shown by the warping of the T1 and T0 surfaces, which are of recent origin. These terraces have complex input of sediments from Higher Himalayan Crystalline (HHC) rocks and from locally present Lingtse granites. ? 2016 Elsevier Ltd and INQUA
Luminescence chronology of alluvial fan in North Bengal, India: Implications to tectonics and climate
(Walter de Gruyter GmbH, 2016) Singh, A.K.; Jaiswal, M.K.; Pattanaik, J.K.; Dev, M.
Alluvial fans are important geomorphic archives because of its strategic location at mountain front which can provide clues to the past climate and tectonics. In general, they provide information about optimum climate condition suitable for fan formation. We provide a detailed luminescence chronology of alluvial fan in north West Bengal, India. The regional fan surface (T44) has been dissected by E-W trending Himalayan thrusts known as Matiali and Chalsa thrusts and have various terraces named as T3, T2 and youngest one as T1. Luminescence ages suggest that the formation of the alluvial fan (regional surface) started before 171 ka and continued till 72 ka covering a time span of nearly 100 ky; suggesting of weaker monsoon at 72 ka. Matiali fault activated after 171 ky. Chalsa fault is suggested to be active during 48-41 ka. The last aggradational phase was around 6 ka which led to the formation of T1a terrace. The study suggests that climatic fluctuation during the period were shaping the morphology of the alluvial fan, along with tectonic activities on the two faults. ? 2015 A. K. Singh et al.