Fig 1.
Optimized chemical structures of alkaloids.
a) epiisopiloturine, b) epiisopilosine, c) isopilosine, d) pilosine, and e) macaubine.
Table 1.
Atomic charges (in atomic unit, a.u.) by the Mulliken, Chelpg, and NBO methods of the epiisopiloturine, epiisopilosine, isopilosine, pilosine and macaubine alkaloids using the theoretical model B3lyp/6-311++G(d,p).
Table 2.
Distances of the atomic bonds (Å), atomic angles, and dihedral angles (°) of the alkaloids epiisopiloturine, epiisopilosine, isopilosine, pilosine and macaubine using the theoretical model B3lyp/6-311++G(d,p).
Fig 2.
Relative energies in (kcal mol-1) of alkaloids isomers of EPI by theoretical models B3lyp/SDD (I), B3lyp/6-31+G(d,p) (II), and B3lyp/6-311++G(d,p) (III).
a) epiisopiloturine, b) epiisopilosine, c) isopilosine and d) pilosine.
Fig 3.
Graphic of the molecular orbitals HOMO and LUMO of the epiisopiloturine, epiisopilosine, isopilosine, pilosine and macaubine alkaloids using the theoretical model B3lyp/6-311++G(d,p).
Fig 4.
The molecular orbitals HOMO and LUMO of the epiisopiloturine, epiisopilosine, isopilosine, pilosine and macaubine alkaloids calculated using the theoretical model B3lyp/6-311++G(d,p) in the Swizard program.
Table 3.
Main assignments of the bands of the electronic spectrum of UV-Vis, energy, and types, calculated using the Swizard program for the molecular forms epiisopiloturine, epiisopilosine, isopilosine, pilosine and macaubine.
I = imidazole, D = dihydrofuran, B = benzene.
Fig 5.
UV-Vis spectrum of the epiisopiloturine, epiisopilosine, isopilosine, pilosine and macaubine alkaloids using the theoretical model B3lyp/6-311++G(d,p).
Fig 6.
Electronic density of alkaloids.
a) epiisopiloturine, b) epiisopilosine, c) isopilosine, d) pilosine, and e) macaubine, using the theoretical model B3lyp/6-311++G(d,p). The colors represent red (negative) and blue (positive).
Table 4.
ADMET predictions of the epiisopiloturine, epiisopilosine, isopilosine, pilosine and macaubine alkaloids.
Table 5.
Molecular affinity parameters of the epiisopiloturine, epiisopilosine, isopilosine, pilosine and macaubine alkaloids with S. mansoni enzymes by the autodock program.
Fig 7.
Molecular docking of the epiisipilosine alkaloid with the UP enzyme of S. mansoni.
a) 2D scheme showing the hydrogen bonds and hydrophobic interactions in the EPIIS-UP complex. b) 3D interactions by hydrogen bonds (Gln201, Met231 and Arg203) in EPIIS. c) 3D conformation of the active site of EPIIS binding in UP enzyme.
Fig 8.
Molecular docking showing the active site of the TGR enzyme with the alkaloids and their interactions by hydrogen bonds.
a) epiisopiloturine, b) epiisopilosine, c) isopilosine, d) pilosine, and e) macaubina.