2874-33-1Relevant articles and documents
Synthesis and biological evaluation of novel isoxazole derivatives from acridone
Aarjane, Mohammed,Slassi, Siham,Tazi, Bouchra,Amine, Amina
, (2020/12/07)
The present study was carried out in an?attempt to synthesize a new class of potential antibacterial agents. In this context, novel isoxazoles were synthesized and evaluated for their potential antibacterial behavior against four pathogenic bacterial strains. The synthesized compounds exhibited moderate-to-good antibacterial activity against these strains. The highest antibacterial activity was observed against the Escherichia coli strains, particularly for compounds 4a and 4e with phenyl and para-nitrophenyl groups on the isoxazole–acridone skeleton;?they showed promising minimum inhibitory concentration values of 16.88 and 19.01 μg/ml, respectively, compared with the standard drug chloramphenicol (22.41 μg/ml). The synthesized compounds were subjected to in silico docking studies to understand the mode of their interactions with the DNA topoisomerase complex (PDB ID: 3FV5) of E. coli. The molecular docking results showed that compounds 4a–l occupy the active site of DNA topoisomerase (PDB ID: 3FV5), stabilized via hydrogen bonding and hydrophobic interactions, which may be the reason behind their interesting in vitro antibacterial activity.
Potassium Poly(Heptazine Imide): Transition Metal-Free Solid-State Triplet Sensitizer in Cascade Energy Transfer and [3+2]-cycloadditions
Antonietti, Markus,Guldi, Dirk M.,Hussain, Tanveer,Karton, Amir,Markushyna, Yevheniia,Mazzanti, Stefano,Oschatz, Martin,Sánchez Vadillo, José Manuel,Savateev, Aleksandr,Strauss, Volker,Tarakina, Nadezda V.,Tyutyunnik, Alexander P.,Walczak, Ralf,ten Brummelhuis, Katharina
supporting information, p. 15061 - 15068 (2020/06/17)
Polymeric carbon nitride materials have been used in numerous light-to-energy conversion applications ranging from photocatalysis to optoelectronics. For a new application and modelling, we first refined the crystal structure of potassium poly(heptazine imide) (K-PHI)—a benchmark carbon nitride material in photocatalysis—by means of X-ray powder diffraction and transmission electron microscopy. Using the crystal structure of K-PHI, periodic DFT calculations were performed to calculate the density-of-states (DOS) and localize intra band states (IBS). IBS were found to be responsible for the enhanced K-PHI absorption in the near IR region, to serve as electron traps, and to be useful in energy transfer reactions. Once excited with visible light, carbon nitrides, in addition to the direct recombination, can also undergo singlet–triplet intersystem crossing. We utilized the K-PHI centered triplet excited states to trigger a cascade of energy transfer reactions and, in turn, to sensitize, for example, singlet oxygen (1O2) as a starting point to synthesis up to 25 different N-rich heterocycles.
Synthesis of nitrogenated lignin-derived compounds and reactivity with laccases. Study of their application in mild chemoenzymatic oxidative processes
Albarrán-Velo, Jesús,López-Iglesias, María,Gotor, Vicente,Gotor-Fernández, Vicente,Lavandera, Iván
, p. 50459 - 50471 (2017/11/10)
The chemical synthesis of a series of lignin-derived nitrogenated compounds was performed in high yields (73-99%) through simple conventional chemical transformations starting from natural monomers such as vanillin, syringaldehyde or 3,4-dihydroxybenzaldehyde. The study of the vanillin-derived compounds as substrates for commercially available laccases from Trametes versicolor and Myceliophthora thermophila in oxidative transformations, generally led to the isolation of several dimeric species in high to excellent conversions (>70%), while for hydrazone derivatives a more rapidly oxidative coupling was evidenced by the formation of oligomers and/or polymers. Remarkably, vanillin was obtained due to the hydrolysis of some of the nitrogenated functional groups, such as the hydrazone or the hydrazono tetrazole. The three families of lignin-derived compounds can provide a great source of new laccase-mediator systems (LMS), the possibility of employing them for lignin modification being particularly attractive. Preliminary experiments showed promising levels of activity towards the oxidation of a monomer (veratryl alcohol, up to 70% conversion) and a dimer (adlerol, up to 22% conversion) lignin models, higher than those achieved with the natural vanillin and syringaldehyde (up to 7% conversion with veratryl alcohol and almost negligible conversion with adlerol), these processes being also highly influenced by the pH of the reaction medium.
