Potassium Salt Research Articles

Synthesis, characterization, and biological target prediction of novel 1,3-dithiolo[4,5-b]quinoxaline and thiazolo[4,5-b]quinoxaline derivatives

Abstract Quinoxalines are a family of nitrogen-based heterocyclic compounds that have garnered much interest because of their wide range of applications. 2,3-Dichloroquinoxaline is an aromatic molecule that frequently serves as a synthetic intermediate in materials science, pharmaceuticals, and organic chemistry. 1,3-Dithiolo[4,5-b]quinoxaline derivatives 8a–c and thiazolo[4,5-b]quinoxaline derivatives 11a,b were synthesized by the reaction of 2,3-dichloro-6-sulfonyl quinoxaline derivative 5 with 1,3-binucleophiles. Moreover, 1,3-dithiolo[4,5-b]quinoxalin2-ylidene derivatives 8a–c were obtained by treating 2,3-dichloro-6-sulfonyl quinoxaline derivative 5 with potassium salts of hydrazonodithioates 7a–c at room temperature. Additionally, 2,3-dichloroquinoxaline derivative 5 was reacted with thioureas 9a,b in 1,4-dioxane to yield 6-(pyrrolidin-1-yl sulfonyl)thiazolo[4,5-b]quinoxalin-2(3H)-imines 11a,b rather than thiazolo[5,4-b]quinoxaline 10. Elemental analysis, infrared spectroscopy, 1H NMR, 13C NMR, and mass spectroscopy were used to confirm the structures of the newly synthesized compounds. Finally, we used artificial intelligence to perform biological evaluation via predicting the possible molecular targets and antimicrobial activity of the designed derivative. The results showed good bacterial activity, weak fungal potency, and potential biological targets.

Regulating the Thermal Behavior of Nitrocellulose by Stable Incorporation of a Green Supramolecular Salt

Commonly used inorganic potassium salts present challenges in nitrocellulose (NC)-based propellants due to poor dispersion, destabilization, and toxic byproduct formation. Environmental concerns drive interest in green flame suppressants. Here, we report a green supramolecular salt, carboxymethyl-cyclodextrin potassium (CM-CD-K) through alkalinization and etherification reaction. Molecular dynamic simulations reveal stronger interactions between CM-CD-K and NC. The loading of CM-CD-K within NC forms a stable structure with resistance to migration and defense against crystalline precipitation. Remarkably, static combustion tests show reduced flame areas and harmful gas concentrations compared to traditional potassium salt-doped NC. Kinetic analysis reveals a shift from order to Kamal-Sourour reaction with CM-CD-K addition. CD-based hybrid organic salts hold potential as eco-friendly propellant alternatives.

Allelochemical root-growth inhibitors in low-molecular-weight cress-seed exudate.

Cress seeds release allelochemicals that over-stimulate the elongation of hypocotyls of neighbouring (potentially competing) seedlings and inhibit their root growth. The hypocotyl promoter is potassium, but the root inhibitor was unidentified; its nature is investigated here. Low-molecular-weight cress-seed exudate (LCSE) from imbibed Lepidium sativum seeds was fractionated by phase partitioning, paper chromatography, high-voltage electrophoresis and gel-permeation chromatography (on Bio-Gel P-2). Fractions, compared with pure potassium salts, were bioassayed for effects on Amaranthus caudatus seedling growth in the dark for 4 days. The LCSE robustly promoted amaranth hypocotyl elongation and inhibited root growth. The hypocotyl inhibitor was non-volatile, hot acid stable, hydrophilic and resistant to incineration, as expected for K+. The root inhibitor(s) had similar properties but were organic (activity lost on incineration). The root inhibitor(s) remained in the aqueous phase (at pH 2.0, 6.5 and 9.0) when partitioned against butan-1-ol or toluene, and were thus hydrophilic. Activity was diminished after electrophoresis, but the remaining root inhibitors were neutral. They became undetectable after paper chromatography; therefore, they probably comprised multiple compounds, which separated from each other, in part, during fractionation. On gel-permeation chromatography, the root inhibitor co-eluted with hexoses. Cress-seed allelochemicals inhibiting root growth are different from the agent (K+) that over-stimulates hypocotyl elongation and the former probably comprise a mixture of small, non-volatile, hydrophilic, organic substances. Abundant components identified chromatographically and by electrophoresis in cress-seed exudate fitting this description include glucose, fructose, sucrose and galacturonic acid. However, none of these sugars co-chromatographed and co-electrophoresed with the root-inhibitory principle of LCSE, and none of them (in pure form at naturally occurring concentrations) inhibited root growth. We conclude that the root-inhibiting allelochemicals of cress-seed exudate remain unidentified.

Stability of Highly Soluble Ferrocyanides at Neutral pH for Energy Dense Flow Batteries

Ferro- and ferricyanides are among the most employed positive electrolyte materials in aqueous flow battery research but the limited solubility of commonly available sodium and potassium salts is a critical factor limiting application at scale. We systematically study the cation dependent solubility of these materials and, importantly, the cation dependent stability of the anion in aqueous solution. For Li4Fe(CN)6 we report a maximum solubility of 2.3 M and show stable cycling of a 2 M symmetric cell (54 Ah L−1) over 200 days, and also demonstrate solubilities of 1.6 M for ammonium and calcium salts. Importantly, we observe cation dependent electrolyte stability in long-term experiments and investigate the pronounced anion decomposition observed in presence of ammonium cations.[1] While achieving high solubilities leads to increased energy densities, concentrated electrolytes present many challenges such as high osmotic strength and high viscosity. This is particularly pronounced in electrolytes that employ ions with high charge states such as ferrocyanide. Furthermore, the selected cation needs to be compatible with the membrane in the cell.[2] We thus outline several often neglected design aspects that must be considered when developing new active materials for aqueous flow batteries. [1] Reber, D., Thurston, J.R., Becker, M., Marshak, M.P., Stability of highly soluble ferrocyanides at neutral pH for energy dense flow batteries, Cell. Rep. Phys. Sci. 2022, 4, 101215 [2] Waters, S.E., Thurston, J.R., Armstrong, R.W., Robb, B.H., Marshak, M.P., Reber, D., Holistic design principles for flow batteries: Cation dependent membrane resistance and active species solubility J. Power Sources 2022, 520, 230877

Toxicity of some inorganic potassium salts towards duckweed (Lemna minor L.)

The toxicity of six potassium inorganic salts: potassium carbonate (K2CO3), potassium hydrogen carbonate (KHCO3), potassium sulfate (K2SO4), dipotassium hydrogen orthophosphate (K2HPO4), monopotassium phosphate (KH2PO4) and potassium aluminum sulfate (KAl(SO4)2.12H2O) towards duckweed (Lemna minor L.) was studied. The results showed that all tested chemicals were with low toxicity but similar salts as potassium carbonate and potassium hydrogen carbonate or dipotassium hydrogen orthophosphate and monopotassium phosphate can express different toxic action towards the tested object. Potassium aluminum sulfate, was toxic to duckweed at very narrow ranges: up to 0.8 % concentration but the salt did not cause any damage to the plants. At 1 % concentration, the first phytotoxic symptoms appeared and at 1.44% concentration LC50 was established and LC90 was reached at concentration of 1.65%. The most toxic chemical was potassium carbonate due to the higher pH of its solutions, but KH2PO4 was found to be more toxic than K2HPO4 although its solutions were with neutral pH, while a pH of solution of K2HPO4 over 1 % concentration was slightly alkaline. Keywords: Lemna minor L., potassium carbonate, potassium hydrogen carbonate, potassium sulfate, dipotassium hydrogen orthophosphate, monopotassium phosphate, potassium aluminum sulfate

Synthesis of (thio)alkyloxy-substituted perfluorinated terphenyl derivatives: Optical properties, molecular docking and antioxidant activity

Nucleophilic aromatic substitution (SNAr) has been known to be a strongly para-selective reaction for various multifunctional perfluoroaryls. In the current study, we report the application of SNAr chemistry to synthesize different derivatives of optically active symmetrical and asymmetrical perfluorinated fluoroterphenyl analogues. The synthesis procedures include a Cu-assisted decarboxylation of perfluorinated fluorobenzoate derivatives and SNAr reaction to produce (thio)alkyloxy-substituted perfluorinated fluoroterphenyls in respectable yield and superb purity starting from the potassium salt of perfluorobenzoate and aryl iodide. The synthesized adducts were inspected by FT-IR and 1H/13C/19F NMR spectroscopy. The optical properties of the synthesized perfluorinated adducts were explored. The absorption and fluorescence spectra showed solvatochromic properties. The DPPH procedure was utilized to inspect the synthesized perfluoroterphenyl analogues for their antioxidant activity. The results demonstrated that the perfluoroterphenyl adducts with asymmetrical hydrocarbon chain exhibited maximum efficiency over an IC50 =10.25±0.24 µg/mL. Moreover, the perfluoroterphenyl adducts were employed in molecular docking using (PDB: 5IKQ) protein.

Enhanced Charging/Discharging Process in Perovskite Active Light Source for High‐Speed Visible‐Light Communication

AbstractMetal halide perovskites are promising light source materials for visible light communication (VLC) due to their excellent photoelectric properties and small resistance‐capacitance time constant. However, previous reports mainly used perovskites as the passive light sources, which not only makes it susceptible to posterior excitation light sources, but also complex in the integration process. Herein, the quasi‐2D PEA2Csn‐1PbnBr3n+1 perovskite light–emitting diodes (PeLEDs) as an active light source in VLC link is demonstrated. It is found that the charging/discharging process of PeLEDs is an important factor governing the ‐3 dB bandwidth (f‐3 dB) of the VLC. To improve this, 3‐sulfopropyl methacrylate potassium salt (SMPS) molecules are introduced into perovskite to simultaneously passivate deep and shallow energy level defects at grain boundaries. Additionally, the multiple quantum wells structures of PEA2Csn‐1PbnBr3n+1 are modified to be flat. At the optimal SMPS concentration, the maximum external quantum efficiency of PeLEDs reaches 21.5%. Meanwhile, the VLC achieves 3.2 MHz f‐3 dB with data transmission of 18.6 Mbps, which is the highest f‐3 dB in PeLEDs with the same active area. Hence, it provides a versatile method to improve the performance of VLC links based on active light sources and advances toward the goal of high‐speed, energy‐efficient and secure free communication.

Screening of Auxin-like Substances among Synthetic Compounds, Derivatives of Pyridine and Pyrimidine

The effect of known synthetic compounds Ivin (N-oxide-2,6-dimethylpyridine), Methyur (sodium salt of 6-methyl-2-mercapto-4-hydroxypyrimidine), Kamethur (potassium salt of 6-methyl-2-mercapto-4-hydroxypyrimidine) and new synthetic compounds, derivatives of pyrimidine (No. 1 - 7) on the rooting of isolated stem cuttings of haricot bean (Phaseolus vulgaris L.) variety Bilozernaya was studied. The growth regulatory activity of synthetic compounds Ivin, Methyur, Kamethur, and synthetic compounds, derivatives of pyrimidine (No. 1 - 7) was compared with the activity of auxins IAA (1H-indol-3-yl)acetic acid) and NAA (1-naphthylacetic acid). The conducted studies showed that the regulatory effect of synthetic compounds Ivin, Methyur, Kamethur, and synthetic compounds, derivatives of pyridine (No. 1 - 7) on the rooting of isolated stem cuttings of haricot bean was similar to the auxins IAA and NAA. The synthetic compounds Ivin, Methyur, and Kamethur, and synthetic compounds, derivatives of pyrimidine (No. 1, 4, 5, and 7) showed the highest auxin-like activity. The indicators of the total number of roots (pcs) and total length of roots (cm) obtained on isolated stem cuttings of haricot bean immersed in a water solution of synthetic compounds Ivin, Methyur, Kamethur and synthetic compounds, derivatives of pyridine (No. 1, 4, 5 and 7), used at a concentration of 10-7 M, statistically significantly exceeded similar indicators obtained on control isolated stem cuttings of haricot bean immersed in distilled water. The practical use of synthetic compounds Ivin, Methyur, Kamethur, and synthetic compounds, derivatives of pyrimidine (No. 1, 4, 5 and 7) is proposed to improve the vegetative propagation of haricot bean plants (Phaseolus vulgaris L.) and other plant species of the family Fabaceae by stem cuttings.

Glyphosate-Based Herbicide Formulations and Their Relevant Active Ingredients Affect Soil Springtails Even Five Months after Application

Glyphosate is the most widely used active ingredient (AI) in glyphosate-based herbicides (GBHs) worldwide and is also known to affect a variety of soil organisms. However, we know little about how the effects of glyphosate AIs differ from those of GBHs that also contain so-called inert co-formulants. We conducted a greenhouse experiment using the model cover crop white mustard (Sinapis alba) to investigate the effects of three GBHs (Roundup PowerFlex, Roundup LB Plus, and Touchdown Quattro) and their respective glyphosate AIs (glyphosate potassium, isopropylamine, and diammonium salt) on epedaphic springtails (Sminthurinus niger; Collembola) activity in soils with low (3.0%) or high (4.1%) organic matter content (SOM). Springtail activity was assessed using pitfall traps. Most GBHs and AIs reduced springtail activity compared to mechanical removal of mustard in the short-term and even up to 5 months after application. GBHs and AIs differed considerably in their effects on springtail activity, and effects were modified by SOM content. Our results highlight the need to (i) distinguish between the effects of glyphosate AIs and commercial GBH formulations, (ii) disclose all ingredients of GBHs, as co-formulants also affect non-target organisms, and (iii) include soil properties in ecotoxicological risk assessments for soil organisms to better characterize the situation in the field.

Biobanking in the hospital of a multidisciplinary research medical center as a potential for a wide research range. Part I. Organizational and methodological aspects

Aim. To develop an algorithm and manage total biobanking of samples of whole blood, serum and plasma of patients in the hospital of the National Medical Research Center for Therapy and Preventive Medicine in order to create a detailed biosample collection through the integration of electronic medical records and a biobank database.Material and methods. The study includes all patients admitted to the hospital of the National Medical Research Center for Therapy and Preventive Medicine in various departments who signed informed consent for biobanking. Clinical information is collected as part of patient examination and stored in electronic medical records in the Medialog medical information system. Biobanking of blood and related products is carried out in accordance with standard operating procedures. From each patient, 12 aliquots of serum and blood plasma are stored, as well as 1 tube of whole blood with ethylenediaminetetraacetic acid potassium salt. Information about biospecimens, patient identification numbers and storage location coordinates are contained in the biobank database.Results. An algorithm for total biobanking of biomaterial and data from inpatients has been developed and put into practice. This collection is associated with large biomedical data stored in a medical information system, laboratory information system and biobank. The combined databases make it possible to search for samples in the collection according to specified criteria.Conclusion. The collection developed can be used for a wide range of studies by forming patient samples according to the necessary criteria. The developed algorithm for total biobanking in a hospital can be used in various medical centers equipped with biobanks.

Impact of alkyl chains, electron donor substituents and acidic group on aggregation-induced emission of carboxylic acid functionalized quinoxalines

We report an optical study of quinoxaline-based luminogens derived from 2,3-bis(aryl)-quinoxaline-6-carboxylic acid (1a, 1b, and 2) in solution and solid state. These compounds were fluorescent in solid films and in solutions with emission bands ranging from blue to green (445–517 nm). They showed a positive solvatochromism in the PL spectra, indicative of intramolecular charge transfer (ICT) in the excited state. 1a, 1b, and 2 exhibited Aggregation-Induced Enhanced Emission (AIEE) characteristics with a drastic change in properties by increasing alkyl chains and donor alkoxy groups. Their carboxylate potassium salts had a blueshift emission compared to the acid carboxylic form and a significant quenching in PL intensity in protic polar solvents. The salt of 1a presented an Aggregation-Induced Emission (AIE) profile, its weak fluorescence in water had an expressive enhancement by adding THF. Theoretical calculations were also carried out considering implicit solvent effects. The optimized structures of compounds and their simulated UV–vis absorption spectra showed no significant differences in water and acetonitrile. These results are in good agreement with the solvatochromism experiments. The calculated HOMO-LUMO energy gaps were 3.47 eV in both solvents, and the energy levels for HOMO and LUMO are slightly lower in water.

КАЛЛУСООБРАЗОВАНИЕ КАК ФИЗИОЛОГИЧЕСКИЙ ПРИЗНАК НЕДОСТАТКА АУКСИНА В СОСТАВЕ СТИМУЛЯТОРА РИЗОГЕНЕЗА (НА ПРИМЕРЕ УКОРЕНЕНИЯ IN VIVО ЧЕРЕНКОВ ХВОЙНЫХ КУЛЬТУР)

Characteristics of the effectiveness of rooting of coniferous crops are the percentage of rooting, the number of roots formed and their length. Callus formation often accompanies the rooting process, but research data on the relationship of this process with the effectiveness of rooting is contradictory. In the conditions of film cuttings equipped with heated substrate, studies were carried out on the relationship between the rooting of cuttings of coniferous crops and callus formation. To stimulate the rooting of semi-lignified cuttings of Juniperus scopulorum S. cultivar Skyrocket, growth powders Chrysatop and Rizapon 1% containing indolyl-3-butyric acid (IBA) in different concentrations were used. In the control treatment without a stimulant, all cuttings formed callus without rooting; when the bases of the cuttings were dusted with Chrysatop containing 0.25% IBA, callus formation decreased by 3.8 times, and the survival rate was 76%. In the variant with Rizapon powder containing 1% IMC, no callus formation was observed at all, the survival rate reached 81.4%. To stimulate the rooting of green cuttings of Juniperus scopulorum S. variety Blue Arrow, aqueous solutions of potassium salt IMC (IMC-K) were used in the concentration range from 0 to 150 mg/l when the bases of the cuttings were soaked for 16 hours. In the concentration range from 0 to 100 mg/l, an increase in survival rate by 1.89 and 3.87 times was observed, respectively, callus formation decreased by 3.38 times. To stimulate the rooting of semi-lignified cuttings of Thuja occidentalis L. variety Smaragd, Juníperus sabina L. species form and green cuttings of Thuja occidentalis L. variety Brabant, Kornevin growth powder containing 0.5% IBA was used. To obtain a concentration gradient, the powder was diluted with talc. Against the background of high survival rate of cuttings of Thuja occidentalis L. of both varieties – 82.85–96.9%, callus formation decreased from 92.9% in the control variant to 6.3% in the variant with pure Kornevin in cuttings of the Smaragd variety and from 71.88% in the control variant to 19.1% in variant Kornevin:talc 1:1 in cuttings of the Brabant variety. When rooting cuttings of Juniperus sabina L. with an increase in the concentration of IBA in the powder from 0 to 0.25% IBA, the survival rate increased from 10.71 to 89.29%, and the formation of callus on the cuttings decreased from 44.59 to 0%. The data obtained indicate that calus formation can serve as a sign of a lack of exogenous auxin in the rooting stimulator and, accordingly, an increase in the auxin content, all other things being equal, within the effective range is one of the ways to increase the percentage of survival of cuttings of coniferous crops.

Herbicide potassium glyphosate 660 g/L as weed control in hybrid corn (Zea mays L.) cultivation under no-tillage system ​

Weed management during land preparation is a pivotal concern in agriculture. A viable alternative for weed control in the context of corn cultivation involves employing herbicides within the no-tillage system. Potassium salts formulated with the active ingredient glyphosate allow more effective absorption of glyphosate into the leaves This study aimed to determine the effectiveness and obtain a dose of Potassium Glyphosate 660 g/L herbicide in controlling weeds in corn cultivation with the no-tillage system. The research was conducted from January to May 2023 at the Experimental Garden of the Faculty of Agriculture, University of Padjadjaran, West Java, Indonesia. The experiment used a randomized block design (RBD) with 6 treatments and 4 replications. The treatment consisted of no-tillage with a dose of herbicide with the active ingredient Potassium Glyphosate 660 g/L dose of 1.0 L/ha, 1.5 L/ha, 2.0 L/ha, 2.5 L/ha, 3.0 L/ha, and a control (Perfect Tillage). The application of herbicide with the active ingredient Potassium Glyphosate 660 g/L was carried out once, namely 14 days before corn planting. The experimental results showed that the herbicide with the active ingredient Potassium Glyphosate 660 g/L starting at a dose of 2.0 L/ha – 3.0 L/ha was effective in controlling weeds Imperata cylindrica, Bidens pilosa, Alternanthera sessilis, Ageratum conyzoides, and Borreria alata and other weeds (Mimosa invisa, Cyperus rotundus, Synedrella nodiflora, Axonopus compressus) up to 4 weeks after planting without causing a phytotoxic effect on corn planting and preparation for planting corn and increasing the growth and yield of corn plants.

Особенности образования и использования твердых отходов в Республике Беларусь

The purpose of the work is to justify the priority of processing municipal solid waste over other solid waste. The methodology chosen is the analysis of statistical data characterizing the generation and use of solid waste in Belarus. It has been established that over 60% of solid waste in the Republic is generated as a result of the activities of OJSC Belaruskali, which specializes in the extraction of potassium salt and the production of mineral fertilizers. These production wastes are characterized by a low level of danger and are sent for temporary storage. Only 1.6% of all production waste generated is subject to burial, which in world practice is recognized as the least desirable method of disposal. Municipal solid waste accounts for about 6% of the mass fraction of all generated solid waste. However, the municipal solid waste segment accounts for 86% of all waste disposed of in landfills. There is a trend towards an increase in the share of municipal solid waste use from 9% in 2010 to 30% in 2021, which means a general decrease in the volume of waste disposal in Belarus. The growth in the use of municipal solid waste is hampered by its complex morphological composition, therefore, before using waste, it is advisable to sort it or separate collection. To improve monitoring of waste generation and use in Belarus, some additions to the existing statistical system of environmental indicators are also proposed.

Colloidal SERS measurement of enrofloxacin with petaloid nanostructure clusters formed by terminal deoxynucleotidyl transferase catalyzed cytosine-constituted ssDNA.

We developed petal-like plasmonic nanoparticle (PLNP) clusters-based colloidal SERS method for enrofloxacin (EnFX) detection. PLNPs were synthesized by the regulation of single-stranded DNA composed of homo-cytosine deoxynucleotides (hC) catalyzed by terminal deoxynucleotidyl transferase. SERS hot spots were created via the agglomeration process of PLNPs by adding an inorganic salt potassium iodide solution, in which EnFX molecules were attached to the negatively charged PLNPs surface by electrostatic interactions. This approach enabled direct in situ detection of antibiotic residues, achieving a limit of detection (LOD) of 1.15μg/kg for EnFX. The spiked recoveries of the SERS method were approximately 92.7% to 107.2% and the RSDs ranged from 1.05% to 7.8%, indicating that the method can be applied to actual sample detection. This colloidal SERS measurement platform would be very promising in various applications, especially in real-time and on-site food safety screening owing to its rapidness, simplicity, and sensitivity.

Isolation of embelin from embeliaribes berries for the development of topical anti–inflammatory preparation

Purpose: Embelin is a natural benzoquinone compound, isolated from Embeliaribes berries, known extensively for its anti-inflammatory properties. Due to its hydrophobic nature, it was less explored for topical preparation. Therefore, the purpose of this study was to explore the potential of embelin as an anti-inflammatory agent for topical preparations as well as assess its potential to replace synthetic drugs, which can be resistant to bacterial strains. A topical preparation with embelin would be potentially more effective as well as safer than synthetic drugs. Method: Embelin has been converted into its potassium salt, and a cream was developed, which was then subjected to physiochemical evaluation. The isolated Embelin and Embelin Potassium salts were characterised by various spectral analysis. The in vitro anti-inflammatory activity was determined by the heat-induced hemolysis and albumin denaturation. Docking scores of embelin and diclofenac were compared and the drug content per gram of cream was estimated. Result: The UV spectral absorption peak of Embelin was determined to be at 274 nm, while that of the potassium salt of Embelin was at 515 nm.. The IR bands were found at 1328.951cm-1,361.74 cm-1, 1616.35 cm -1,1616.35 cm -1 ,1452.4 cm -1, 748.28 cm -1 and 2947.23 cm -1 respectively due to phenolic OH bending, C=O stretching, aromatic ring bending, methylene bending and methyl stretching . The IR spectra of Embelin potassium salt exhibited similar pattern as that of Embelin but with shifted band due to presence of potassium salt. Heat-induced hemolysis using diclofenac as standard and embelin potassium salt as test showed 98.01% inhibition and 92% inhibition, respectively, at50µg/ml. The binding affinity of diclofenac was determined to be -4.9, while the binding affinity of embelin was -5.7, indicating a higher affinity for embelin. Lastly, the drug content per gram of cream was found to be 95%, indicating the amount of active drug (embelin or embelin potassium salt) present in the cream formulation. Conclusion: Embelin was isolated from Embeliaribes berries and formulated into a herbal cream. The in-vitro studies conducted on the cream showed that it has a significant effect on inflammation . However, in–vivo studies are required for the prepared topical cream to confirm its effectiveness.

Hydroboration of aldehydes with pinacolborane catalyzed by bulky 2‐iminopyrrolyl copper(I) triphenylphosphine complexes

Eight new copper(I) triphenylphosphine complexes of bulky 5‐substituted‐2‐iminopyrrolyl ligands [Cu{κ2N,N′‐5‐R‐NC4H2–2‐C(H) = N(2,6‐iPr2C6H3)}(PPh3)n] (for n = 2: R = 2,6‐Me2C6H3 (1), 3,5‐(CF3)2C6H3 (2); for n = 1: R = 2,4,6‐iPr3C6H2 (3), CPh3 (4), 2,6‐(OMe)2C6H3 (5), 2,4,6‐Ph3C6H2 (6), 2,6‐Me2C6H3 (7), 3,5‐(CF3)2C6H3 (8)) are presently reported. The complexes were prepared in good yields by: (1) the reaction of the previously reported binuclear complexes [Cu{κN,κN'‐5‐R‐NC4H2‐2‐C(H) = N(2,6‐iPr2C6H3)}]2 (D1–D6) with triphenylphosphine (PPh3); (2) the reaction of the respective 5‐R‐2‐iminopyrrolyl potassium salts (KL1–KL3 and KL5) and [Cu(NCMe)2(PPh3)2]BF4; or (3) the abstraction of one PPh3 ligand present in complexes 1 and 2 with one equivalent of tris(pentafluorophenyl)borane (only for complexes 7 and 8, respectively). All complexes were characterized by NMR spectroscopy, elemental analysis and, in selected cases, by single crystal X‐ray diffraction. The single crystal X‐ray diffraction structures of 1, 3, and 5–7 displayed tetrahedral (for 1) and trigonal planar (for 3 and 5–7) coordination geometries. All complexes catalyzed the 1,4‐hydroboration of some α,β‐unsaturated (E)‐2‐enals with pinacolborane (HBPin), with 1,4:1,2‐addition selectivities as high as 29:1, the maximum turnover frequencies being equal to 9.9 min−1, and the 1,4‐hydroboration selectivity being favored by increasing steric protection of the 5‐substituted‐2‐iminopyrrolyl scaffold. Additionally, these complexes also catalyzed the hydroboration of an array of other aldehydes, reaching TOFs as high as 9.9 min−1. A combination of control experiments suggests that the catalyst system operates via a non‐classical copper‐hydride outer sphere route.

Growth and Yield of Grain Cowpea (Vigna unguiculata sub sp. cylindrica) in Response to Foliar Nutrition and Graded Levels of Phosphorus and Potassium

Aim: To assess the growth and yield of grain cowpea in response to varied doses of phosphorus (P) and potassium (K) supplemented with foliar application of nano diammonium phosphate (DAP) and potassium salt of active phosphorus (PSAP).
 Study Design: The field experiment was a factorial experiment, laid out in randomised block design with two levels of P, three levels of K and two sources of foliar nutrition, compared against a control, with three replications.
 Place and Duration of Study: The study was conducted at the Integrated Farming System Research Station, Karamana, Nedumcaud, Thiruvananthapuram, Kerala, India, during the period from December 2022 to February 2023.
 Methods: The study utilized PGCP-6 cowpea variety and adopted fertilizer recommendations as per KAU POP (Package of Practices Recommendations of the Kerala Agricultural University). The entire dose of FYM, P and K and half dose of nitrogen (N) were applied as basal dose. The remaining half dose of N was applied at 15 days after sowing (DAS). Additionally, foliar application of nano DAP and PSAP (each @ 0.4 %) was done at 20 DAS and 40 DAS.
 Results: The results of the study revealed that the treatment combination, p2k1f2 and p2k1f1 had comparable leaf area per plant and leaf area index (LAI) (at 60 DAS). The highest seed yield (1642 kg ha-1) was recorded with p2k1f2. Higher dose of P and K along with foliar application of nano DAP (0.4 % at 20 DAS and 40 DAS) had significant effect on the total DMP and haulm yield.
 Conclusion: Combined application full dose of N, half dose of P, full dose of K and foliar application of PSAP (0.4 %) at 20 DAS and 40 DAS could be recommended as the best treatment combination for yield enhancement in grain cowpea.

Gravity fields at accident sites in mines at the Upper Kama potassium salt deposit

Gravity fields at accident sites in mines at the Upper Kama potassium salt deposit

In vivo comprehensive metabolite profiling of esculetin and esculin derived from chicory in hyperuricemia rats using ultra-high-performance liquid chromatography coupled with quadrupole-orbitrap high-resolution mass spectrometry.

Chicory, renowned for its multifaceted benefits, houses two vital coumarins, esculetin and esculin, both instrumental in reducing uric acid. This study emphasizes the metabolic pathways of esculetin and esculin under both standard and hyperuricemia conditions. Hyperuricemia was induced in Sprague-Dawley rats using oxonic acid potassium salt (300mg·kg-1 ) and a 10% fructose water regimen over 21 days. Leveraging the ultra-high-performance liquid chromatography-Q Exactive hybrid quadrupole-orbitrap high resolution mass spectrometry, we analyzed the fragmentation behaviors of esculetin and esculin in rat bio-samples. Post oral-intake of esculetin or esculin, a notable dip in serum uric acid levels was observed in hyperuricemia rats. The investigation unveiled 24 esculetin metabolites and 14 for esculin. The metabolic pathways of both compounds were hydrolysis, hydroxylation, hydrogenation, dehydroxylation, glucuronidation, sulfation, and methylation. Interestingly, certain metabolites presented variations between standard and hyperuricemia rats, indicating that elevated levels of uric acid may affect enzyme activity linked to these metabolic reactions. This is the first systematic study on comparison of metabolic profiles of esculetin and esculin in both normal and hyperuricemia states, which was helpful to enrich our understanding of the complicated structure-activity relationships between esculin and esculetin and shed light to their action mechanism.