39713-14-9Relevant academic research and scientific papers
Bio-proton coupled semiconductor/metal-complex hybrid photoelectrocatalytic interface for efficient CO2 reduction
Liu, Jibo,Guo, Chenyan,Hu, Xiaojun,Zhao, Guohua
, p. 339 - 348 (2019/01/30)
Aimed at high-efficiency biomimetic CO2 photoelectrochemical conversion, a bio-proton coupling metal-complex/semiconductor hybrid photoelectrocatalytic interface (Ru-BNAH/TiO2/Cu2O) was constructed by covalently modifying an in situ proton-transfer functionized molecular catalyst (Ru-BNAH) on the surface of a TiO2/Cu2O composite semiconductor substrate electrode. Due to the excellent proton coupling of the bio-proton carrier, the light current density in a CO2 atmosphere of the prepared Ru-BNAH/TiO2/Cu2O photoelectrocatalytic interface was twice as high as that without a proton carrier under the same conditions. Simultaneously, based on the excellent photosensitivity of the metal oxide substrate, the photogenerated electrons could rapidly transfer to the molecular catalyst for efficient CO2 reduction in a water medium. After 8 h irradiation at -0.9 V potential, the Ru-BNAH/TiO2/Cu2O photoelectrocatalytic interface produced 409.5 μmol formic acid, which was 2.44 times more than that without a proton transfer carrier. In addition, the in situ UV-visible absorption spectra and in situ Raman spectra indicated that the proton transport carrier supplied protons during CO2 reduction. Moreover, the generation of HCOO- in CO2-saturated D2O medium confirmed the proton (H) originated from the proton transfer carrier rather than the solvent (D2O).
Mimicking nature: Synthetic nicotinamide cofactors for C=C bioreduction using enoate reductases
Paul, Caroline E.,Gargiulo, Serena,Opperman, Diederik J.,Lavandera, Iván,Gotor-Fernández, Vicente,Gotor, Vicente,Taglieber, Andreas,Arends, Isabel W. C. E.,Hollmann, Frank
supporting information, p. 180 - 183 (2013/04/24)
A series of synthetic nicotinamide cofactors were synthesized to replace natural nicotinamide cofactors and promote enoate reductase (ER) catalyzed reactions without compromising the activity or stereoselectivity of the bioreduction process. Conversions and enantioselectivities of >99% were obtained for C=C bioreductions, and the process was successfully upscaled. Furthermore, high chemoselectivity was observed when employing these nicotinamide cofactor mimics (mNADs) with crude extracts in ER-catalyzed reactions.
Synthesis, in vitro and in vivo Evaluation of a Delivery System for Targeting Anticancer Drugs to the Brain
El-Sherbeny, Magda A.,Al-Salem, Huda S.,Sultan, Maha A.,Radwan, Mahasen A.,Farag, Hassan A.,El-Subbagh, Hussein I.
, p. 445 - 455 (2007/10/03)
A 1,4-dihydropyridine ? pyridinium salt type redox system is described as a general and flexible method for site-specific and sustained delivery of drugs to the brain. This concept was used in the present investigation as a model to deliver an alkylating antitumor agent into the brain. A bis-(chloroethyl)amine drug was hooked to 1,4-dihy-dropyridine chemical delivery system (CDS) through an amide linkage. Five new target compounds (23-27) of the 1,4-dihydropyridine CDS type were synthesized through the reduction of five new pyridinium quaternary intermediates (18-22). The synthesized 1,4-dihydropyridines were subjected to various chemical and biological investigations to evaluate their ability to cross the blood-brain barrier (BBB), and to be oxidized biologically into their corresponding quaternary compounds. The in vitro oxidation studies showed that 1-benzyl-3-{N-[2-bis(2-chloroethyl)aminoethyl]-carbamoyl}-1,4-dihydropyridine (23) and 1-(4-nitrobenzyl)-3-{N-[2-bis(2-chloroethyl)aminoethyl]carbamoyl}-1, 4-dihydropyridine (27) could be oxidized into their corresponding quaternary compounds 18 and 22, respectively, at an adequate rate, which ensure the release of the carried anticancer drug. The in vivo studies showed that compound 23 was able to cross the BBB at detectable concentrations. On the other hand, the in vitro alkylation activity studies revealed that 1-(4-nitrobenzyl)-3-{N-[2-bis(2-chloroethyl)aminoethyl]carbamoyl}pyridinium bromide (22) is an alkylating agent with activity comparable to the known drug chlorambucil.
