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Research Publications (Applied Sciences)

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    Larvicidal Activities of 2-Aryl-2,3-Dihydroquinazolin-4-ones against Malaria Vector Anopheles arabiensis, in Silico ADMET prediction and molecular target investigation
    (MDPI, 2020-03-02) Venugopala, Katharigatta Narayanaswamy; Ramachandra, Pushpalatha; Tratrat, Christophe; Gleiser, Raquel M.; Bhandary, Subhrajyoti; Chopra, Deepak; Morsy, Mohamed A.; Aldhubiab, Bandar E.; Attimarad, Mahesh; Nair, Anroop B.; Sreeharsha, Nagaraja; Venugopala, Rashmi; Deb, Pran Kishore; Chandrashekharappa, Sandeep; Khalil, Hany Ezzat; Alwassil, Osama I.; Abed, Sara Nidal; Bataineh, Yazan A.; Palenge, Ramachandra; Haroun, Michelyne; Pottathil, Shinu; Girish, Meravanige B.; Akrawi, Sabah H.; Mohanlall, Viresh
    Malaria, affecting all continents, remains one of the life-threatening diseases introduced by parasites that are transmitted to humans through the bites of infected Anopheles mosquitoes. Although insecticides are currently used to reduce malaria transmission, their safety concern for living systems, as well as the environment, is a growing problem. Therefore, the discovery of novel, less toxic, and environmentally safe molecules to effectively combat the control of these vectors is in high demand. In order to identify new potential larvicidal agents, a series of 2-aryl-1,2-dihydroquinazolin-4-one derivatives were synthesized and evaluated for their larvicidal activity against Anopheles arabiensis. The in silico absorption, distribution, metabolism, excretion, and toxicity (ADMET) properties of the compounds were also investigated and most of the derivatives possessed a favorable ADMET profile. Computational modeling studies of the title compounds demonstrated a favorable binding interaction against the acetylcholinesterase enzyme molecular target. Thus, 2-aryl-1,2-dihydroquinazolin-4-ones were identified as a novel class of Anopheles arabiensis insecticides which can be used as lead molecules for the further development of more potent and safer larvicidal agents for treating malaria.
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    Crystallography, in silico studies, and In vitro antifungal studies of 2,4,5 trisubstituted 1,2,3-triazole analogues
    (MDPI AG, 2020-06-20) Venugopala, Katharigatta N.; Khedr, Mohammed A.; Girish, Yarabahally R.; Bhandary, Subhrajyoti; Chopra, Deepak; Morsy, Mohamed A.; Aldhubiab, Bandar E.; Deb, Pran Kishore; Attimarad, Mahesh; Nair, Anroop B.; Sreeharsha, Nagaraja; V, Rashmi; Kandeel, Mahmoud; Akrawi, Sabah H.; Reddy M B, Madhusudana; Shashikanth, Sheena; Alwassil, Osama I.; Mohanlall, Viresh
    A series of 2,4,5 trisubstituted-1,2,3-triazole analogues have been screened for their antifungal activity against five fungal strains, Candida parapsilosis, Candida albicans, Candida tropicalis, Aspergillus niger, and Trichophyton rubrum, via a 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) microdilution assay. Compounds GKV10, GKV11, and GKV15 emerged as promising antifungal agents against all the fungal strains used in the current study. One of the highly active antifungal compounds, GKV10, was selected for a single-crystal X-ray diffraction analysis to unequivocally establish its molecular structure, conformation, and to understand the presence of different intermolecular interactions in its crystal lattice. A cooperative synergy of the C-H···O, C-H···N, C-H···S, C-H···π, and π···π intermolecular interactions was present in the crystal structure, which contributed towards the overall stabilization of the lattice. A molecular docking study was conducted for all the test compounds against Candida albicans lanosterol-14α-demethylase (pdb = 5 tzl). The binding stability of the highly promising antifungal test compound, GKV15, from the series was then evaluated by molecular dynamics studies.
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    Quantitative analysis of intermolecular interactions in 7-hydroxy-4-methyl-2H-chromen-2-one and Its hydrate
    (The National Academy of Sciences, 2014-03-09) Venugopala, Katharigatta Narayanaswamy; Panini, Piyush; Odhav, Bharti; Chopra, Deepak
    The determination of the crystal and molecular structure of organic compounds has contributed immensely towards the area of crystal engineering. This contributes towards the understanding of the molecular geometry and the different intermolecular interactions which control crystal packing. An approach which quantifies the energetics associated with the formation of different “molecular pairs” is of importance to recognize the hierarchy of intermolecular interactions present in the crystal. We intend to explore different computational tools which contribute towards the field of crystal engineering. In this regard, the crystal structure of 7-hydroxy-4-methyl-2H-chromen-2-one and its hydrate were re-determined and their crystal packing were analyzed in terms of the interaction energy of different intermolecular interactions, calculated by PIXEL method, contributing towards the stabilization of the crystal packing. The system is so chosen such that it allows the analysis of weak interactions like C–H···O, C–H···π, π···π, lp···π etc. in the presence of strong O–H···O hydrogen bonds and also allows for a systematic exploration of the effect of solvent (water in the present case) on the crystal packing. The calculation of the lattice energy reveals that the anhydrous form is 7 kcal/mol more stable than the corresponding hydrate. The major stabilization towards the crystal packing were observed to come from strong O–H···O=C hydrogen bonds (9 kcal/mol) in case of the anhydrous form while in case of its hydrate, water acts as both an acceptor and a donor of the hydrogen bonds, the interaction energy ranging from 5 to 9 kcal/mol. The weak C–H···O hydrogen bond were found to be the second highest contributor (I.E = 3.5–5.5 kcal/mol) towards the stabilization of the packing in both the crystal structures. The main differences in the crystal packing were observed in the presence of weaker interactions in their crystal packing. The weak C–H···π, O(lp)···C=O interactions were observed in the crystal packing of the anhydrous form while the π···π, O(lp)···π interactions stabilize the crystal packing in case of its hydrate. This phenomenon were further well supported by the analysis of the Hirshfeld surfaces mapped with different properties, 2D-fingerprint plots, electrostatic potential mapped on the Hirshfeld surface and electron density isosurface (calculated by ab initio calculation at DFT-D3/B97-D) at both solid state and optimized geometry.