Micrometer‐Sized Hexagonal Tubes Self‐Assembled by a Cyclic Peptide in a Liquid Crystal

Generally, the self-assembly process occurs insolution,isoftentriggeredbyachangeinsolubilityofthepeptideinorganicsolvents,andresultsincrystalsorganizedbynanotubes.Herein,wereportontheobservationofself-assembledstructuresofacyclicpeptideinanematicliquidcrystal(LC).Hexagonalhollowtubesthathavediametersintheorderofmicrometersandreachingseveralmillimetresinlengthwereobserved.Strongexperimentalevidencesuggeststheoccurrenceofahierarchicalandself-similar-structuredself-assembly of the cyclic peptide. That is, individualmoleculesofhexagonalconformationstackupintohexagonalnanotubes,whichthenself-organizeintolargeraggregateswith the same appearance. Each molecule provides bothintra-andintertubeHbondingthatensurethemolecularstackingwithinandthepackingofnanotubes.Tothebestofourknowledge,thisisthefirstworkexploringtheuseofliquidcrystalsfortheself-assemblyofcyclicpeptides,andtheresultsshowthesurprisingimpactoftheliquidcrystallinemedium.Previousworkshowedthatthelipophilicmacrolactamcyclo-(NHCH