Self-assembled Structures Formed by Fmoc modified aliphatic amino acids

Abstract

We report the self-assembled structures formed by Fmoc modified aliphatic uncharged single amino acids. The self-assembling properties of (((9H-fluoren-9-yl)methoxy)carbonyl)-L-alanine (Fmoc-Ala-OH), (((9H-fluoren-9-yl)methoxy)carbonyl)-L-leucine (Fmoc-Leu-OH), (((9H-fluoren-9-yl)methoxy)carbonyl)-L-isoleucine (Fmoc-Ile-OH), and (((9H-fluoren-9-yl)methoxy)carbonyl)-L-valine (Fmoc-Val-OH) were studied under varying conditions such as concentration and temperature. Fmoc-Ala-OH shows flower-like self-assembled structure at both low and high concentration under room temperature as well as on heating at 70ºC. We also studied self-assembly of the modified branched chain amino acids (BCAA) i.e. Fmoc-Leu-OH, Fmoc-Ile-OH, and Fmoc-Val-OH. Fmoc-Leu-OH forms flower-like morphology at both low and high concentration under room temperature which changes to small tube-like structure on heating. Fmoc-Ile-OH on the other hand shows fibres-like self-assembly at lower and higher concentration at room temperature. While, on heating at lower concentration they formed a tube like self-assembled structure and at higher concentration they formed a fibres-like morphology. In the case of Fmoc-Val-OH they form a flower-like morphology at lower concentration at room temperature and at higher concentration they formed fibres-like assembly at room temperature. On the other hand, on heating Fmoc-Val-OH shows a fibres-like assembly at lower and higher concentration. Once the self-assembled structure of all Fmoc single amino acid characterized through the optical microscopy then our future aims to characterized those self-assembled structure through sophisticated microscopy and spectroscopy techniques and understand the mechanisms of self-assembled structure. Hence, the modified amino acids may pave the way for the design of novel self-assembled architectures which can be controllable manipulated to impart desired function..