Computational quantum chemistry, molecular docking, and ADMET predictions of imidazole alkaloids of Pilocarpus microphyllus with schistosomicidal properties

PLoS One. 2018 Jun 26;13(6):e0198476. doi: 10.1371/journal.pone.0198476. eCollection 2018.

Abstract

Schistosomiasis affects million people and its control is widely dependent on a single drug, praziquantel. Computational chemistry has led to the development of new tools that predict molecular properties related to pharmacological potential. We conducted a theoretical study of the imizadole alkaloids of Pilocarpus microphyllus (Rutaceae) with schistosomicidal properties. The molecules of epiisopiloturine, epiisopilosine, isopilosine, pilosine, and macaubine were evaluated using theory models (B3lyp/SDD, B3lyp/6-31+G(d,p), B3lyp/6-311++G(d,p)). Absorption, distribution, metabolization, excretion, and toxicity (ADMET) predictions were used to determine the pharmacokinetic and pharmacodynamic properties of the alkaloids. After optimization, the molecules were submitted to molecular docking calculations with the purine nucleoside phosphorylase, thioredoxin glutathione reductase, methylthioadenosine phosphorylase, arginase, uridine phosphorylase, Cathepsin B1 and histone deacetylase 8 enzymes, which are possible targets of Schistosoma mansoni. The results showed that B3lyp/6-311++G(d,p) was the optimal model to describe the properties studied. Thermodynamic analysis showed that epiisopiloturine and epiisopilosine were the most stable isomers; however, the epiisopilosine ligand achieved a superior interaction with the enzymes studied in the molecular docking experiments, which corroborated the results of previous experimental studies on schistosomiasis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • 4-Butyrolactone / analogs & derivatives
  • 4-Butyrolactone / chemistry
  • 4-Butyrolactone / pharmacology
  • Alkaloids / chemistry
  • Alkaloids / pharmacology*
  • Animals
  • Anthelmintics / chemistry
  • Anthelmintics / pharmacology*
  • Imidazoles / chemistry
  • Imidazoles / pharmacology*
  • Models, Molecular
  • Molecular Docking Simulation
  • Pilocarpus / chemistry*
  • Plant Extracts / pharmacology
  • Quantum Theory
  • Schistosoma mansoni / drug effects
  • Thermodynamics

Substances

  • Alkaloids
  • Anthelmintics
  • Imidazoles
  • Plant Extracts
  • epiisopiloturine
  • pilosine
  • 4-Butyrolactone

Grants and funding

This work was supported by the Foundation for Scientific and Technological Research and Development of Maranhão - FAPEMA, and the State Government of Maranhão and Secretary of State for Science, Technology and Innovation - SECTI provided support with a scholarship (BD-02239/16). The Federal University of Maranhão - UFMA provided the incentive. The FAPESP 2016/22488-3 also supported this work.