ABSTRACT
We report a selective ruthenium catalyzed reduction of tertiary amides on the side chain of Fmoc-Gln-OtBu derivatives, leading to innovative unnatural α,ß or γ-amino acids functionalized with tertiary amines. Rapid and scalable, this process allowed us to build a library of basic unnatural amino acids at the gram-scale and directly usable for liquid- or solid-phase peptide synthesis. The diversity of available tertiary amines allows us to modulate the physicochemical properties of the resulting amino acids, such as basicity or hydrophobicity.
Subject(s)
Amines/chemistry , Amino Acids/chemical synthesis , Arginine/analogs & derivatives , Lysine/analogs & derivatives , Ornithine/analogs & derivatives , Solid-Phase Synthesis Techniques/methods , Amides/chemistry , Amines/chemical synthesis , Amino Acids/chemistry , Arginine/chemical synthesis , Catalysis , Lysine/chemical synthesis , Ornithine/chemical synthesis , Oxidation-Reduction , Ruthenium/chemistry , Solid-Phase Synthesis Techniques/economicsABSTRACT
Two-photon photodynamic therapy is a promising therapeutic method which requires the development of sensitizers with efficient two-photon absorption and singlet-oxygen generation. Reported here are two new diketopyrrolopyrrole-porphyrin conjugates as robust two-photon absorbing dyes with high two-photon absorption cross-sections within the therapeutic window. Furthermore, for the first time the singlet-oxygen generation efficiency of diketopyrrolopyrrole-containing systems is investigated. A preliminary study on cell culture showed efficient two-photon induced phototoxicity.
Subject(s)
Coloring Agents/chemistry , Photosensitizing Agents/chemistry , Porphyrins/chemistry , Pyrroles/chemistry , Singlet Oxygen/chemistry , Cell Survival/drug effects , Coloring Agents/pharmacology , HEK293 Cells , HeLa Cells , Humans , Photochemotherapy , Photons , Photosensitizing Agents/pharmacology , Porphyrins/pharmacology , Pyrroles/pharmacologyABSTRACT
Two-photon excited microscopy has evolved as a routine technique for long-term cellular and in vivo imaging and is now available in most optical microscopy facilities. Classical dyes and fluorescent proteins, developed for epifluorescence or confocal microscopy, are used but unfortunately present a low efficiency upon two-photon excitation inducing the need of high excitation power (over 20 mW). To reduce this excitation power, new dyes need to be developed, allowing really low two-photon excitation power in the milliwatt or sub-milliwatt range. We report here the conception, synthesis, and physicochemical and photophysical properties of new functionalized diketopyrrolopyrrole (DPP) derivatives acting as fluorescent tags for biomolecules. They present high two-photon absorption cross-sections and bright luminescence around 600 nm. These two-photon optimized fluorophores were bioconjugated to HIV-I Tat (44-61), and their cellular localization was observed by two-photon excited microscopy using sub-milliwatt laser excitation power.
