Thiophenyl-substituted triazolyl-thione l-alanine: asymmetric synthesis, aggregation and biological properties

In this work, we report the asymmetric synthesis and characterization of an artificial amino acid based on triazolyl-thione L-alanine, which was modified with a thiophenyl-substituted moiety, as well as in vitro studies of its nucleic acid-binding ability. We found, by dynamic light scattering studies, that the synthetic amino acid was able to form supramolecular aggregates having a hydrodynamic diameter higher than 200 nm. Furthermore, we demonstrated, by UV and CD experiments, that the heteroaromatic amino acid, whose enzymatic stability was demonstrated by HPLC analysis also after 24 h of incubation in human serum, was able to bind a RNA complex, which is a feature of biomedical interest in view of innovative antiviral strategies based on modulation of RNA-RNA molecular recognition

Spectroscopic and SEM evidences for G4-DNA binding by a synthetic alkyne-containing amino acid with anticancer activity

Herein, we present a spectroscopic (CD and UV) and SEM study of a phenylalanine derivative carrying a terminal alkyne moiety and indicated by us CF3IIIPhe, with particular attention to its interaction with Cu(II) cation and some biological macromolecules, aswell as a preliminary evaluation of its effect on cancerous cells. CD spectroscopy evidenced the ability of CF3IIIPhe to interact with tel26 and c-myc, two quadruplex DNA (G4 DNA) models explored in this study. Other CDandUV studies revealed the ability of the unnatural amino acid to form aggregates in aqueous solution, to bind Cu(II) cation, and to interact with bovine serum albumin (BSA). Cellular studies demonstrated CF3IIIPhe antiproliferative activity on PC3 cells. Its ability to bind telomeric DNA was verified with tel26 by CD investigation and SEM analysis, that revealed a noteworthy change in DNA morphology (mainly based on nanosphere structures) by CF3IIIPhe, confirming its G4-DNA binding ability already evidenced by spectroscopy