Applications of p-hydroxyphenacyl (pHP) and coumarin-4-ylmethyl photoremovable protecting groups

Abstract

Most applications of photoremovable protecting groups have used o-nitrobenzyl compounds and their (often commercially available) derivatives that, however, have several disadvantages. The focus of this review is on applications of the more recently developed title compounds, which are especially well suited for time-resolved biochemical and physiological investigations, because they release the caged substrates in high yield within a few nanoseconds or less. Together, these two chromophores cover the action spectrum for photorelease from >700 nm to 250 nm.

Design and Synthesis of a Caged Carboxylic Acid with a Donor−π–Donor Coumarin Structure: One-photon and Two-photon Uncaging Reactions Using Visible and Near-Infrared Lights

“…This has been achieved by the introduction of electron-donating and/or withdrawing substituents at the C5-C8 positions. [10][11][12] Two-photon (TP) excitation processes using light in the near-infrared (NIR) region, 650-1050 nm, are advantageous for physiological studies, because deep penetration and a high spatial resolution can be achieved. [13][14][15][16] The development of new NIR-TP-responsive chromophores is currently a state-ofthe-art challenge.…”

Von Ein‐ zu Zwei‐Photonen‐Sonden: photoaktivierbare Reagentien, Aktuatoren und Photoschalter

“…Bromhydroxycumarine [44] Die ersten photoaktivierbaren Reagentien mit einem Wirkungsquerschnitt der Zwei-Photonen-Freisetzung d u ! 1 GM waren 6-Brom-7-hydroxycumarin-4-ylmethyl(Bhc)-Derivate (Abbildung 10).…”

Switchable Materials Containing Polyzwitterion Moieties

“…Despite the advantages of using photolytic transformation, further studies should be directed towards the employment of a photolabile group (i.e., coumarine type ester) with a non-toxic site product of photolysis [63] and satisfy the two photon absorption properties for improved biomedical applications [64]. (18) and irreversible switch to poly(19) (b) schematic application of poly (18) in the complexation with negatively charged BSA to form self-assembly polyionic complex that improve the protection of the protein against denaturation, shields the negative charge of the protein and penetration to the tumor cell due to the enhanced and permeability and retention (EPR) effect and by UV light irradiation accelerated the release of bovine serum albumin (BSA).…”

“…Despite the advantages of using photolytic transformation, further studies should be directed towards the employment of a photolabile group (i.e., coumarine type ester) with a non-toxic site product of photolysis [63] and satisfy the two photon absorption properties for improved biomedical applications [64].…”