Nitrobenzyl-Based Photosensitive Phosphoramide Mustards: Synthesis and Photochemical Properties of Potential Prodrugs for Cancer Therapy
作者:Robert Reinhard、Brigitte F. Schmidt
DOI:10.1021/jo961861m
日期:1998.4.1
their absorption spectra maximum compared to the parent nitrobenzyl moiety. As seen by UV and (31)P NMR spectroscopy, the phosphoramide mustard was quickly liberated upon irradiation with mercury arc lamps. Assaying the structurally different prodrugs on their alkylating activity showed that compounds 13b and 14, derived from secondary benzyl alcohols, are promising prodrug candidates. Their water
A novel method for phosphodiester and internucleotide bond synthesis
作者:M. Rubinstein、A. Patchornik
DOI:10.1016/0040-4020(75)80203-1
日期:1975.1
phosphate diesters from various alcohols and nucleosides is described, using the N-methylpyridinium salt of dichlorophosphoric acid (1) as a phosphorylating agent. Internucleotide bonds are formed by stepwise addition of two suitably protected nucleosides to 1. Side products, usually formed during oligonucleotide synthesis were not observed using this new method. In addition, a nucleoside 2′, 3′-cyclic
Catalytic Lewis acid phosphorylation with pyrophosphates
作者:Owen S. Fenton、Emily E. Allen、Kyle P. Pedretty、Sean D. Till、Joseph E. Todaro、Bianca R. Sculimbrene
DOI:10.1016/j.tet.2012.08.070
日期:2012.11
We report a method for the Lewis acid catalyzed phosphorylation of alcohols with pyrophosphates. Ti((OBu)-Bu-t)(4) was found to be the most effective catalyst in the phosphorylation of both primary and secondary alcohols with tetrabenzylpyrophosphate, providing conversions between 54% and >98% and isolated yields between 50% and 97%. Other pyrophosphates with orthogonal protecting groups were synthesized and screened to validate the generality of the approach. This study will describe how benzyl, methyl, ethyl, allyl, and o-nitrobenzyl pyrophosphates are all effective phosphorylating agents under Lewis acid catalysis. (C) 2012 Elsevier Ltd. All rights reserved.
Organelle-Specific Detection of Phosphatase Activities with Two-Photon Fluorogenic Probes in Cells and Tissues
作者:Lin Li、Jingyan Ge、Hao Wu、Qing-Hua Xu、Shao Q. Yao
DOI:10.1021/ja3036256
日期:2012.7.25
Two-photon fluorescence microscopy (TPFM) provides key advantages over conventional fluorescence imaging techniques, namely, increased penetration depth, lower tissue autofluorescence and self-absorption, and reduced photodamage and photobleaching and therefore is particularly useful for imaging deep tissues and animals. Enzyme-detecting, small molecule probes provide powerful alternatives over conventional fluorescent protein (FP) based methods in bioimaging, primarily due to their favorable photophysical properties, cell permeability, and chemical tractability. In this article, we report the first fluorogenic, small molecule reporter system (Y2/Y1) capable of imaging endogenous phosphatase activities in both live mammalian cells and Drosophila brains. The one and two photon excited photophysical properties of the system were thoroughly investigated, thus confirming the system was indeed a suitable Turn-ON fluorescence pair for TPFM. To our knowledge, this is the first enzyme reporting two-photon fluorescence bioimaging system which was designed exclusively from a centrosymmetric dye possessing desirable two-photon properties. By conjugation of our reporter system to different cell penetrating peptides (CPPs), we were able to achieve organelle- and tumor cell specific imaging of phosphatase activities with good spatial and temporal resolution. The diffusion problem typically associated with most small molecule imaging probes was effectively abrogated. We further demonstrated this novel two photon system could be used for imaging endogenous phosphatase activities in Drosophila brains with a detection depth of >100 mu m.