Synthesis and Gelling Performances of 4-Biphenylcarboxy Protected Dipeptide

Abstract

In this paper, we have designed and synthesized a terminally protected dipeptide Ala-Phe 2 with 4-biphenylcarboxy protecting group at the N-terminus and methyl ester protecting group at C-terminus. Interestingly, the dipeptide formed organogel in different aromatic solvents such as benzene, toluene, xylene, chlorobenzene and 1,2-dichlorobenzene. However, the dipeptide fails to form gel in hexane, EtOAc, DCM, acetonitrile, MeOH, EtOH, diesel and kerosene under same condition. From X-ray crystallography, the peptide 1, 4-biphenylcarboxy protected alanine self-assembled through intermolecular hydrogen bonding and [Formula: see text]–[Formula: see text] stacking interactions to parallel sheet like structure however that fails to form organogel under same condition. The minimum gelation concentration (MGC) of the terminally protected dipeptide for toluene is 8[Formula: see text]mg/mL. From rheology study, the storage modulus of the organogel was approximately an order of magnitude larger than the loss modulus, which indicates the elastic nature of the gel. FE-SEM images of the xerogel exhibit twisted fiber morphology and a danse fiber network that entangled and encapsulated solvents to form orgenogel.