Synthesis, Photophysical Properties, and Complexation Behavior of Three New Luminescent Tetraaza-tetraoxamacrobicyclic Receptors

Abstract

Three luminescent receptors 1−3 have been synthesized by linking photo-active groups to a tetraaza-tetraoxamacrobicyclic subunit. These multicomponent species constitute a homogeneous series with identical binding subunits, where changes are made to the chromophore and to the spacers. The new compounds exhibit absorption spectra and luminescence properties in acetonitrile dominated by the photo-active components, perturbed by the presence of the nitrogens of the azacrown subunits. Although structurally similar, compounds 1−3 exhibit three qualitatively different photophysical properties: 2 emits from a pure π−π* ( 1 L a ) level, 3 from both a charge-transfer (CT) level and from an excimeric spe- [a]

Synthesis and Structure–Activity Relationship Studies of N-Terminal Analogues of the Antimicrobial Peptide Tridecaptin A1

“…The possibility of carbamate deprotection being responsible for bactericidal effects could therefore not be ruled out. To further probe this hypothesis, 3-anthracenylpropanoic acid was prepared and used in the synthesis of Apa-TriA 1 ( 19 ). , In contrast to the Fpa analogue 18 , anthracene analogue 19 retained comparable activity to the natural peptide. This suggests that carbamate deprotection is not responsible for the observed activity but does not explain the reduced activity of 18 .…”

“…Oct-TriA 1 displayed excellent antimicrobial activity against the Gram-negative strains but was predictably less active against the Gram-positive C. dif f icile strain. To further assess the potential clinical applications of Oct-TriA 1 , cytotoxicity data were (7) 0.8 Oct-TriA 1 (10) 4.7 Laur-TriA 1 (14) 82.2 Fmoc-TriA 1 (17) 100.0 obtained using an MTT assay. The synthetic analogue was 2fold more toxic (MIC = 100 μg/mL) against HEK 293 cells than tridecaptin A 1 (MIC = 200 μg/mL).…”

New Building Blocks Based on Truxene Cores: Synthesis of Functionalized syn‐Tri‐ and ‐Hexasubstituted Derivatives

“…and addition of RX, but yields were lower by this method. Alkylation with 9‐(3‐bromopropyl)anthracene17 failed to provide the corresponding hexasubstituted derivative, and instead gave 9‐(prop‐1‐enyl)anthracene and a mixture of unidentified truxenes.…”