232597-42-1Relevant articles and documents
Near-Infrared Photoactivatable Nitric Oxide Donors with Integrated Photoacoustic Monitoring
Zhou, Effie Y.,Knox, Hailey J.,Reinhardt, Christopher J.,Partipilo, Gina,Nilges, Mark J.,Chan, Jefferson
, p. 11686 - 11697 (2018)
Photoacoustic (PA) tomography is a noninvasive technology that utilizes near-infrared (NIR) excitation and ultrasonic detection to image biological tissue at centimeter depths. While several activatable small-molecule PA sensors have been developed for various analytes, the use of PA molecules for deep-tissue analyte delivery and monitoring remains an underexplored area of research. Herein, we describe the synthesis, characterization, and in vivo validation of photoNOD-1 and photoNOD-2, the first organic, NIR-photocontrolled nitric oxide (NO) donors that incorporate a PA readout of analyte release. These molecules consist of an aza-BODIPY dye appended with an aryl N-nitrosamine NO-donating moiety. The photoNODs exhibit chemostability to various biological stimuli, including redox-active metals and CYP450 enzymes, and demonstrate negligible cytotoxicity in the absence of irradiation. Upon single-photon NIR irradiation, photoNOD-1 and photoNOD-2 release NO as well as rNOD-1 or rNOD-2, PA-active products that enable ratiometric monitoring of NO release. Our in vitro studies show that, upon irradiation, photoNOD-1 and photoNOD-2 exhibit 46.6-fold and 21.5-fold ratiometric turn-ons, respectively. Moreover, unlike existing NIR NO donors, the photoNODs do not require encapsulation or multiphoton activation for use in live animals. In this study, we use PA tomography to monitor the local, irradiation-dependent release of NO from photoNOD-1 and photoNOD-2 in mice after subcutaneous treatment. In addition, we use a murine model for breast cancer to show that photoNOD-1 can selectively affect tumor growth rates in the presence of NIR light stimulation following systemic administration.
11C Radiolabeling of anle253b: a Putative PET Tracer for Parkinson's Disease That Binds to α-Synuclein Fibrils in vitro and Crosses the Blood-Brain Barrier
Bender, Dirk,Buss, Sabrina,Giese, Armin,Griesinger, Christian,Herfert, Kristina,Kuebler, Laura,Leonov, Andrei,Linder, Ruth,Maurer, Andreas,Pichler, Bernd J.,Ryazanov, Sergey,Schmidt, Felix,Weckbecker, Daniel
, (2020)
There is an urgent clinical need for imaging of α-synuclein (αSyn) fibrils, the hallmark biomarker for Parkinson's disease, in neurodegenerative disorders. Despite immense efforts, promising tracer candidates for nuclear imaging of αSyn are rare. Diphenyl pyrazoles are known modulators of αSyn aggregation and thus bear potential for non-invasive detection of this biomarker in vivo. Here we demonstrate high-affinity binding of the family member anle253b to fibrillar αSyn and present a high-yielding site-selective radiosynthesis route for 11C radiolabeling using in-situ generated [11C]formaldehyde and reductive methylation. Radio-HPLC of the tracer after incubation with rat serum in vitro shows excellent stability of the molecule. Positron emission tomography in healthy animals is used to assess the pharmacokinetics and biodistribution of the tracer, showing good penetration of the blood–brain barrier and low background binding to the non-pathological brain.
Synthesis and Configuration of a p-Aminoacetophenonic Acid Isolated from Endophyte of the Mangrove Plant Kandel candel
Liu, Bo,Wu, Yikang,Xiong, Xin
, (2020/07/31)
Two diastereomers of the title compound were synthesized through an enantioselective route, with the stereogenic center at the C-2 derived from a commercially available reagent and the one at the C-4 installed via Evans asymmetric aldol condensation. By comparison of 1H and 13C NMR spectra as well as optical rotation, the configuration of the natural product was as assigned as (-2R,4R). Some interesting issues such as suppression of the undesired yet dominating formation of cyclic ethers associated with deprotection of a TBS protected terminal hydroxyl group and the previously unknown differences in 1H NMR and IR between the end product separated by normal phase chromatography and that by reverse phase chromatography are also presented.
A Greener Approach for the Chemoselective Boc Protection of Amines Using Sulfonated Reduced Graphene Oxide as a Catalyst in Metal- And Solvent-Free Conditions
Awasthi, Satish K.,Mishra, Anupam,Mittal, Rupali
, p. 591 - 601 (2020/02/13)
Sulfonated reduced graphene oxide (SrGO) has displayed great potential as a solid acid catalyst due to its efficiency, cost-effectiveness, and reliability. In this study, SrGO was synthesized by the introduction of sulfonic acid-containing aryl radicals onto chemically reduced graphene oxide using ultrasonication. The SrGO catalyst was characterized by Fourier Transform Infrared (FTIR) spectroscopy, Raman spectroscopy, powder X-ray diffraction (PXRD), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and transmission electron microscopy (TEM). Further, SrGO was effectively utilized as a metal-free and reusable solid acid catalyst for the chemoselective N - t -Boc protection of various aromatic and aliphatic amines under solvent-free conditions. The N - t -Boc protection of amines was easily achieved under ambient conditions affording high yields (84-95percent) in very short reaction times (5 min-2 h). The authenticity of the approach was confirmed by a crystal structure. The catalyst could be easily recovered and was reused up to seven consecutive catalytic cycles without any substantial loss in its activity.
