NUCLEOPHILIC SUBSTITUTION OF NITRO GROUP IN 1-METHYL- 5-NITRO-1,2,4-TRIAZOLE BY DIAMINOGLYOXIME

Изучен процесс взаимодействия 1-метил-5-нитро-1,2,4-триазола с многоцентровым бифункциональным О-нуклеофилом – диаминоглиоксимом. Показано, что исходный субстрат вступает в реакцию SNipso-замещения нитрогруппы с гидроксильными группами О-нуклеофила с образованием биологически активного соединения, объединяющего в единой молекуле фармакофорные фрагменты различного типа – 1,2,4-триазоловые гетероциклы и NH2-группы. Процесс сопровождается конкурентными реакциями образования триазолона и продукта его дальнейшего взаимодействия с исходным субстратом. С помощью веб-ресурса PASS Online осуществлен компьютерный скрининг, показано, что исходный субстрат и продукты реакции могут выступать потенциальными фармацевтическими субстанциями. The reaction between 1-methyl-5-nitro-1,2,4-triazome and a concerted bifunctional О-nucleophile – diaminoglyoxime was explored herein. The starting substrate was shown to engage into the SNipso-substitution of the nitro group by the О-nucleophile hydroxyls to furnish a bioactive compound whose single molecule combines different-type pharmacophoric moieties – 1,2,4-triazole heterocycles and NH2groups. The process came amid competitive reactions to form triazolone and a product from its subsequent reaction with the starting substrate. The PASS Online web-resource was used to perform computer-aided screening, demonstrating that the starting substrate and the reaction products can serve as potential pharmaceutical substances.

Kinetic compartmentalization by unnatural reaction for itaconate production

Physical compartmentalization of metabolisms using membranous organelles in eukaryotes is helpful for chemical biosynthesis to ensure the availability of substrates from competitive metabolic reactions. Bacterial hosts lack such a membranous system, which is one of the major limitations for efficient metabolic engineering. Here, we introduced kinetic compartmentalization as an alternative strategy to enable substrate availability from competitive reactions. This method utilizes a non-natural biochemical reaction performed by an engineered enzyme to kinetically isolate the metabolic pathways and ensure substrate availability for the desired reaction. As a proof of concept, we could successfully demonstrate kinetic separation for efficient itaconate production from acetate in Escherichia coli, mimicking the native mitochondrial membrane system in Aspergillus species. Despite the utilization of the non-preferred carbon source, kinetic compartmentalization could lead to substantial increases of itaconate in both yield and titer, suggesting enough potential of our strategy for broad applications in diverse engineering.

Connecting Gas-Phase Computational Chemistry to Condensed Phase Kinetic Modeling: The State-of-the-Art

In recent decades, quantum chemical calculations (QCC) have increased in accuracy, not only providing the ranking of chemical reactivities and energy barriers (e.g., for optimal selectivities) but also delivering more reliable equilibrium and (intrinsic/chemical) rate coefficients. This increased reliability of kinetic parameters is relevant to support the predictive character of kinetic modeling studies that are addressing actual concentration changes during chemical processes, taking into account competitive reactions and mixing heterogeneities. In the present contribution, guidelines are formulated on how to bridge the fields of computational chemistry and chemical kinetics. It is explained how condensed phase systems can be described based on conventional gas phase computational chemistry calculations. Case studies are included on polymerization kinetics, considering free and controlled radical polymerization, ionic polymerization, and polymer degradation. It is also illustrated how QCC can be directly linked to material properties.

Inhibiting Effect of Moroccan Medicinal Plants on Crystallization of Oxalo-calcic Calculations in vitro

Abstract- The aim of this work is to study the inhibitory effect of some Moroccan medicinal plants: parsley, nettle, oregano and corn beard on the crystallization of oxalocalcium urinary stones under experimental conditions which simu l a t e t h e u ri n a r y e n v ir o nme n t (physiological concentrations in calcium and oxalate, temperature and pH). The experimental tests were followed by the turbidimetric method using UV-Visible Model SP8-400 spectrophotometry, the response of which restores the concentration of calcium oxalate. The results showed that the potassium and magnesium ions which constitute the main elements of these plants compete with the calcium ions in order to combine with the oxalate ions. All the competitive reactions reflecting the affinities of the different ions towards each other contribute to the observed overall inhibition of the crystallization of calcium oxalate. Keywords: Crystallization, Urinary Calculus, Calcium oxalate, Inhibition, Moroccan Medicinal Plants

Discerning Torquoselectivity of Non-Competitive and Competitive Ring-Opening Reactions Using QTAIM and Stress Tensor

Within this study, four thermal ring-opening reactions, Reactions (1-4), were selected in order to investigate the phenomenon of torquoselectivity as well as predicting non-competitive or competitive reactions in QTAIM and stress tensor frameworks rather than using conventional methods. The theoretical analysis for these reactions exhibits differently for non-competitive and competitive reactions as well as for the conrotatory preferences either TSOC or TSIC directions by presenting degeneracy or non-degeneracy in their results. The concordant results of stress tensor and QTAIM scalar and vectors with experimental results provide a better understanding of all reactions mechanism. Examination the (rb), ε, H(rb), ℙσ, 3, BPL, and H indicate that Reaction 1 is a competitive and Reactions (2-4) are non-competitive reactions with TSOC, TSOC, and TSIC preference directions respectively.

Mode-Selective Chemistry through Polaritonic Vibrational Strong Coupling

Recent experiments have demonstrated remarkable mode-selective reactivities by coupling molecular vibrations with vacuum fluctuations inside an optical cavity. The fundamental mechanism behind such effects, on the other hand, remains elusive. In this work, we theoretically demonstrate the basic principle of how cavity photon frequency can be tuned to achieve mode-selective reactivities. We find that the non-Markovian nature of the radiation mode leads to a cavity frequency-dependent dynamical caging effect of a reaction coordinate, resulting in a suppression of the rate constant. In the presence of multiple competitive reactions, it is possible to preferentially cage a reaction coordinate when the barrier frequencies for competing reaction paths are different. Our theoretical results illustrate the cavity-induced mode-selective chemistry through polaritonic vibrational-strong couplings, revealing the fundamental mechanism for changing chemical selectivities through cavity quantum electrodynamics.

Mode-Selective Chemistry through Polaritonic Vibrational Strong Coupling

Recent experiments have demonstrated remarkable mode-selective reactivities by coupling molecular vibrations with vacuum fluctuations inside an optical cavity. The fundamental mechanism behind such effects, on the other hand, remains elusive. In this work, we theoretically demonstrate the basic principle of how cavity photon frequency can be tuned to achieve mode-selective reactivities. We find that the non-Markovian nature of the radiation mode leads to a cavity frequency-dependent dynamical caging effect of a reaction coordinate, resulting in a suppression of the rate constant. In the presence of multiple competitive reactions, it is possible to preferentially cage a reaction coordinate when the barrier frequencies for competing reaction paths are different. Our theoretical results illustrate the cavity-induced mode-selective chemistry through polaritonic vibrational-strong couplings, revealing the fundamental mechanism for changing chemical selectivities through cavity quantum electrodynamics.