257-97-6Relevant articles and documents
Triplet Dynamic Nuclear Polarization of Guest Molecules through Induced Fit in a Flexible Metal–Organic Framework**
Fujiwara, Saiya,Kimizuka, Nobuo,Matsumoto, Naoto,Nishimura, Koki,Tateishi, Kenichiro,Uesaka, Tomohiro,Yanai, Nobuhiro
supporting information, (2022/01/19)
Dynamic nuclear polarization utilizing photoexcited triplet electrons (triplet-DNP) has great potential for room-temperature hyperpolarization of nuclear spins. However, the polarization transfer to molecules of interest remains a challenge due to the fast spin relaxation and weak interaction with target molecules at room temperature in conventional host materials. Here, we demonstrate the first example of DNP of guest molecules in a porous material at around room temperature by utilizing the induced-fit-type structural transformation of a crystalline yet flexible metal–organic framework (MOF). In contrast to the usual hosts, 1H spin-lattice relaxation time becomes longer by accommodating a pharmaceutical model target 5-fluorouracil as the flexible MOF changes its structure upon guest accommodation to maximize the host–guest interactions. Combined with triplet-DNP and cross-polarization (CP), this system realizes an enhanced 19F NMR signal of guest target molecules.
Potential chemopreventive agents based on the structure of the lead compound 2-bromo-1-hydroxyphenazine, isolated from streptomyces species, strain CNS284
Conda-Sheridan, Martin,Marler, Laura,Park, Eun-Jung,Kondratyuk, Tamara P.,Jermihov, Katherine,Mesecar, Andrew D.,Pezzuto, John M.,Asolkar, Ratnakar N.,Fenical, William,Cushman, Mark
experimental part, p. 8688 - 8699 (2011/02/28)
The isolation of 2-bromo-1-hydroxyphenazine from a marine Streptomyces species, strain CNS284, and its activity against NF-κB, suggested that a short and flexible route for the synthesis of this metabolite and a variety of phenazine analogues should be developed. Numerous phenazines were subsequently prepared and evaluated as inducers of quinone reductase 1 (QR1) and inhibitors of quinone reductase 2 (QR2), NF-κB, and inducible nitric oxide synthase (iNOS). Several of the active phenazine derivatives displayed IC50 values vs QR1 induction and QR2 inhibition in the nanomolar range, suggesting that they may find utility as cancer chemopreventive agents.
Solid-phase synthesis of 1,2-benzophenazine and some fused imidazole derivatives
Zefirov,Sereda,Volkov,Tkachenko,Zyk
, p. 577 - 579 (2007/10/03)
The solid-phase synthesis of 1,2-benzophenazine and various N-methylbenzimidazoles using o-diaminoarenes is very promising and permits the synthesis of 1-methyl-4,5-[b]naphtho-1H-imidazole, which could not be obtained by the condensation of o-diaminoarenes with paraformaldehyde using the standard liquid-phase method. 1996 Plenum Publishing Corporation.