Selective Complexation of S‐block Cations with Nanotubular Silk Type Cyclopeptides: A DFT Study

Abstract

Density functional theory (DFT) was used to study the interaction of alkali metal cations (Li + , Na + and K + ) with cyclic peptides constructed from silk type macrocycles (Silk1, Silk2, Silk3, Silk4, Silk5 and Silk6). The calculated binding energies were used as a base for investigating the selectivity of the cyclic peptides in biniding to considered metals ions. The highest cation selectivity for Li + compared to the other alkali metal ions was observed. The orbital nature of different interactions between the metal cations and the cyclic peptides was analyzed using NBO analysis. The main types of driving force for host-guest interactions was investigated and it was found that the electron-donating O offers lone pair electrons to the contacting LP* of alkali metal cations.

Investigation of inclusion complex of metformin into selective cyclic peptides as novel drug delivery system: Structure, electronic properties, AIM, and NBO study via DFT

“…In recent decades, many drug delivery systems have been designed by scientists, and cyclic peptides (CPs) are one of the most interesting ones. CPs have many applications in biology, materials science, and chemistry, such as application as surfactants, [1] extraction of different metal ions [2] , and so forth, so they are of interest today. [3][4][5] In CPs, polypeptide chains contain a circular sequence and flat conformation of the amino acids.…”