Russian Journal of General Chemistry最新文献

Biological tests of hydrophosphoryl derivatives of the non-medical tetraene macrolide antibiotic tetramycin B were conducted. It was established that the prepared derivatives possess high fungicidal activity and moderate herbicidal activity. The prospects for their use in protecting plants from diseases and as growth-regulating compounds, which stimulates an increase in the yield of agricultural crops, are demonstrated.

The use of modern multifunctional biological agents as an alternative to chemicals contributes to increased soil biological activity and suppressiveness. This leads to a decrease in plant disease incidence, an improvement in the phytosanitary condition of agroecosystems, and an increase in yield. The research goal was to evaluate the efficacy of a new multirecycled granular preparation based on Trichoderma asperellum T-36 in protecting spring wheat from diseases and enhancing soil suppressiveness in West Siberia. The tasks were solved on the T-36-based granular biologic prototype developing; 2 years field trials data summarizing, evaluating and statistically processing on phytoregulatory activity and field efficacy of T-36-based granular biologic prototype in spring soft wheat cultivation in West Siberia; qualitative and quantitative indices characterizing of soil microbiota from spring soft wheat rhizosphere in West Siberia conditions; total and induced soil suppressive activity on natural and artificial infection backgrounds with T. asperellum T-36 introduction estimating. In 2 series field trials the T-36-based granular biologic prototype demonstrated phytoregulatory activity: biometric indices of wheat plants development (survival rate, length of shoots and roots, their number, plant height and biomass, leaf area, stand density and bushiness, ear length, number of grains in ear and spikelets, grain weight and yield) under the prototype influence reliably (p ≤ 0.05) 1.2–1.4 times exceeded the control ones. No significant differences in phytoregulatory activity were found in comparison with the registered biologic Sternyphage, WP (wettable powder) as a template reference. Biological efficacy against soil pathogens was 33–56, 41–59%; in the development of leaf-stem infections 25–50, 30–98% for Sternyphage, WP and T-36-based granular biologic prototype respectively. In the phases of crop development from tube emergence to milk ripeness, the highest soil activity in rhizosphere under the prototype influence was reliably (p ≤ 0.01) 2 times higher than the control one. Soil homeostasis indirect evidence in spring soft wheat rhizosphere was obtained, represented by total soil microbiota representatives stability and the saprotrophs trophic group abundance and number stability during all phases of the main crop development as well. High total soil suppressiveness, as well as forming and strengthening of induced suppressiveness by protective biologics (T-36-based granular biologic prototype and Sternyphage, WP) application in all phases of wheat plants development, caused by high antagonists abundance and significant phytopathogens abundance decrease were shown. Successions were revealed in various phases of spring soft wheat holobiont development from 0 day up to the vegetation end, caused by the absence of significant similarity in rhizosphere microbiota complexes in dynamics.

A method has been developed for isolating individual compounds from the mycelium of the entomopathogenic fungus Akanthomyces muscarius responsible for contact insecticidal activity against sap-sucking pests. The stereochemical structure of the main insecticidal metabolite of triterpenoid nature—(3β,5α,8α,22E)-5,8-epidioxy-ergosta-6,22-dien-3-ol—has been established using a combination of nuclear magnetic resonance (NMR) spectroscopy and X-ray diffraction (XRD) analysis.

The biological characteristics of promising Bacillus subtilis M-22 and B. subtilis I-5 strains— antagonists of phytopathogenic fungi and bacteria—were characterized in laboratory model and pot experiments. First- and second-generation clones of the original B. subtilis I-5 isolate, differing in the level of antagonistic activity, were obtained. For the first time, the composition of culture filtrates of strain B. subtilis M-22 and first- and second-generation clones of the psychrotolerant strain B. subtilis I-5 was studied using MIC-filtration based on mass ranges of chromatograms obtained by high-resolution HPLC-MS using an IT-TOF mass spectrometer. This approach allowed for the identification of components unique to each strain and the precise determination of their molecular masses, which, in turn, enabled the proposal of the most probable molecular formulas. By correlating the component composition of each filtrate with its biological activity, compounds most likely responsible for specific biological activities were identified.

1,3-Diaryl-7-chloroimidazo[4,5-b]pyridinium salts were readily prepared via chlorination of their 7-hydroxy precursors with POCl₃. Their utility as platforms for the synthesis of various decorated imidazo[4,5-b]pyridinium salts via nucleophilic substitution of the chlorine atom was demonstrated in the reaction with thiols. The obtained chloro- and sulfanyl-substituted compounds were employed as N-heterocyclic carbene (NHC) precursors for the preparation of novel M/NHC (M = Pd, Cu) complexes via C²–H bond metallation.

BODIPY bichromophores are of great interest due to their unique photophysical properties, which significantly distinguish them from BODIPY monomers and open up excellent prospects for their various applications. Thus, ethene/ethylene-bridged BODIPY dimers are usually may be concerned as intramolecular J-aggregates with significant exciton coupling and absorption in the NIR region. However, the synthesis of asymmetric α,α-ethene-bridged BODIPY dimers is limited by Stille cross-coupling reactions, without the possibility of obtaining α,α-ethene-bridged BODIPY dimers. Herein, we propose a novel approach to the synthesis of an asymmetric ethene-bridged α-α BODIPY dimer without cross-coupling reaction, which opens up the possibility of synthesis without the use of expensive cross-coupling reagents from readily available reagents.

Nitrile oxides are known in various reactions of 1,3-dipolar cycloaddition, where examples of the interaction of this dipole along exocyclic multiple carbon–carbon and carbon–heteroatom bonds are of particular interest. Such substrates can be used to create spiro-conjugated heterocyclic systems with high conformational rigidity, allowing achieving the required stereoelectronic properties in the resulting molecules. Herein, we propose a novel approach to the synthesis of spiro-oxadiazolidines by the reaction of nitrile oxides with 2-iminothiazolidines, which proceeds without isomerization of the starting heterocycles.

Previously undescribed nicotinonitrile–coumarin hybrids, namely 2-{[2-oxo-2-(2-oxo-2H-chromen-3-yl)ethyl]thio}pyridine-3-carbonitriles and -quinoline-3-carbonitriles, were synthesized via the reaction of 2-thioxo-1,2-dihydropyridine-3-carbonitriles with 3-(bromoacetyl)coumarin or 3-(bromoacetyl)benzo[f]coumarin in the presence of sodium propylate. Under laboratory conditions on sunflower seedlings, some of the prepared compounds exhibited a pronounced antidote effect against the herbicide 2,4-D, as well as moderate growth-stimulating activity.

A simple method was developed for the preparation of 7-hydroxyimidazo[4,5-b]pyridinium salts via the two-step reaction of readily available 4-amino-1,3-diarylimidazolium salts with 1,3-biselectrophiles in the presence of BF₃·Et₂O. The reactivity of the prepared bicyclic compounds was studied through alkylation with various reagents, leading to the synthesis of both O- and N-alkylated derivatives. The applicability of these bicyclic salts as N-heterocyclic carbene (NHC) precursors was demonstrated by their selective C²–H metallation, which afforded the corresponding Pd and Au complexes.

2-Iminothiazolidine-4,5-diones are prone to isomerization during the reaction of 1,3-dipolar cycloaddition with nitrile imines and aza-Wittig reactions, but the introduction of a polymethylene bridge between the nitrogen atoms fixes the structure of the starting heterocycle. In this work, the possibilities of various fragments using to fix the structure of 2-iminothiazolidines and their further aza-Wittig reactions to obtain diimines containing both endocyclic and exocyclic C=N bonds were investigated. It was shown that various 2-iminothiazoline-4,5-dione can be synthesized, depending on the reaction of oxalyl chloride and cyclic thiourea derivatives conditions, and these derivatives form the same diimines during the aza-Wittig reactions.