Study of nonlinear optical responses of phytochemicals of Clitoria ternatea by quantum mechanical approach and investigation of their anti-Alzheimer activity with in silico approach.

Clitoria ternatea is a flowering plant with promising medicinal plants with a wide variety of active phytochemicals. The present study aimed at the computational investigation of the nonlinear optical (NLO) responses of the active phytochemicals of the Clitoria ternatea. The computational investigation of the NLO features was done by using the density functional theory (DFT) by B3LYP/6-311G + + (d, p) basis set. The structural parameters, mulliken charge distribution, and molecular electrostatic potential (MEP) surface clearly show the intramolecular charge transfer within Clitorin. The NLO properties were identified by computing the polarizability parameters. As the plant has high medicinal characteristics, the inhibiting properties of its phytochemicals were also investigated to combat Alzheimer disease (AD). The systematic in silico study identifies Clitorin as the most active and inhibiting phytochemicals of the plant. The results obtained from molecular dynamics (MD) simulation tell the stability of the complex and make it a fair selection as a drug-like molecule against AD. The cardio-toxicity analysis done for the Clitorin molecule verifies that it is harmless for the heart. Supplementary information: The online version contains supplementary material available at 10.1007/s11224-022-01981-5.

In Silico Investigation of Phytoconstituents of Medicinal Herb 'Piper Longum' Against SARS-CoV-2 by Molecular Docking and Molecular Dynamics Analysis.

Unavailability of treatment for the SARS-CoV-2 virus has raised concern among the population worldwide. This has led to many attempts to find alternative options to prevent the infection of the disease, including focusing on vaccines and drugs. The use of natural products and herbal extracts can be a better option in beating the virus and boosting up immunity. In the present paper, we have done a systematic in silico study of papain-like protease of COVID-19 virus with the chemical constituents of herbal plant Piper Longum. Screening of the pharmacokinetic properties is done with thirty-two phytoconstituents of Piper Longum which help us in selecting the most active components of the plant. After selection molecular docking is performed with Aristololactam (C17H11NO4), Fargesin (C21H22O6), l-asarinin (C20H18O6), Lignans Machilin F (C20H22O5), Piperundecalidine (C23H29NO3), and Pluviatilol (C20H20O6). Molecular dynamic (MD) is also performed with the inhibitor-receptor complex which suggest significant inhibition and a stable complex of I-Asarinin with PLpro. Docking scores and simulation results suggest that I-Asarinin can act as a potential drug like candidate against COVID-19.