Synthesis and Characterization of Photoactivatable Doxycycline Analogues Bearing Two-Photon-Sensitive Photoremovable Groups Suitable for Light-Induced Gene Expression
Photolabile caged versions of 9‐aminodoxycycline that photolyse after visible light irradiation or 740 nm two‐photon excitation are reported. 9‐Aminodoxycycline is a tetracycline analogue that can be efficiently coupled to photoremovable protecting groups by carbamoylation, leading to new caged doxycycline derivatives that can be used in combination with the TetOn system for photoactivated gene expression
作者:Hitesh K. Agarwal、Radoslav Janicek、San-Hui Chi、Joseph W. Perry、Ernst Niggli、Graham C. R. Ellis-Davies
DOI:10.1021/jacs.5b11606
日期:2016.3.23
We have designed a nitroaromatic photochemical protecting group that absorbs visible light in the violet-blue range. The chromophore is a dinitro derivative of bisstyrylthiophene (or BIST) that absorbs light very effectively (epsilon(440) = 66,000 M-1 cm(-1) and two-photon cross section of 350 GM at 775 nm). We developed a "caged calcium" molecule by conjugation of BIST to a Ca2+ chelator that upon laser flash photolysis rapidly releases Ca2+ in <0.2 ms. Using the patch clamp method the optical probe, loaded with Ca2+ was delivered into acutely isolated mouse cardiac myocytes, where either one- and two-photon uncaging of Ca2+ induced highly local or cell-wide physiological Ca2+ signaling events.
Aryl-Substituted Sulfonium Betaines: Preparation and Use in the Epoxidation of Aldehydes
作者:David C. Forbes、Sejal R. Amin、Christie J. Bean、Michael C. Standen
DOI:10.1021/jo061370u
日期:2006.10.1
Thermally induced decarboxylation of carboxymethylsulfonium betaines results in formation of the corresponding sulfur ylides in situ. Decarboxylation rates for a range of arylcarboxymethylsulfonium betaine salts have been determined using NMR spectroscopy, and the efficiency of ylide generation and trapping has been evaluated via methylidene transfer to a range of aldehydes to form epoxides.