Conformation Analysis and Stereodynamics of Symmetrically -Disubstituted Carvacrol Derivatives.

The design and synthesis of analogs of natural products can be a valuable source of medicinal preparations for the pharmaceutical industry. In the present study, the structural elucidation of eleven derivatives of 2,4-dihalogeno substituted synthetic analogues of the natural compound carvacrol was carried out by means of NMR experiments, and of another thirteen by DFT calculations. By selective NOE experiments and the irradiation of CH signals of the isopropyl group, individual conformers were assigned as and .

Soil Fungi in Sustainable Agriculture.

It is widely accepted that the continuously growing human population needs rapid solutions to respond to the increased global demand for high agricultural productivity [...

A Small Change in Structure, a Big Change in Flexibility.

Studies of the rotational barrier energy of the amide bond using quantum computing and nuclear magnetic resonance (NMR) are focused mainly on its use as a model of the peptide bond. The results of these studies are valuable not only in terms of the fundamental conformational properties of amide bonds, but also in the design of molecular machines, which have recently attracted interest. We investigate the fluxionality of the amide and enamide bonds of compound 3-[()-(dimethylamino)methylidene]-1,1-dimethylurea using advanced dynamic NMR experiments and a theoretical evaluation of the density functional theory (DFT) calculation.

Design, Synthesis, In Silico Studies and In Vitro Evaluation of New Indole- and/or Donepezil-like Hybrids as Multitarget-Directed Agents for Alzheimer's Disease.

Alzheimer's disease (AD) is considered a complex neurodegenerative condition which warrants the development of multitargeted drugs to tackle the key pathogenetic mechanisms of the disease. In this study, two novel series of melatonin- and donepezil-based hybrid molecules with hydrazone () or sulfonyl hydrazone () fragments were designed, synthesized, and evaluated as multifunctional ligands against AD-related neurodegenerative mechanisms. Two lead compounds ( and ) exhibited a well-balanced multifunctional profile, demonstrating intriguing acetylcholinesterase (AChE) inhibition, promising antioxidant activity assessed by DPPH, ABTS, and FRAP methods, as well as the inhibition of lipid peroxidation in the linoleic acid system.

The Combined Applications of Microbial Inoculants and Organic Fertilizer Improve Plant Growth under Unfavorable Soil Conditions.

The performance of two bio-inoculants either in single or in combined applications with organic fertilizer was tested to determine their effect on plant growth and yield under normal and unfavorable field conditions such as low pH value and low content of P. Arbuscular Mycorrhiza Fungi (AMF; three species of ) and the plant-growth-promoting bacterial strain were applied to barley in a two-year field experiment with different soil pH levels and available nutrients. Grain yield; contents of P, N, K, and Mg; and soil microbial parameters were measured.

Synthesis and Biological Study of 4-Aminopyridine-Peptide Derivatives Designed for the Treatment of Neurodegenerative Disorders.

Background: Alzheimer's disease (AD) and Multiple sclerosis (MS) lead to neurodegenerative processes negatively affecting millions of people worldwide. Their treatment is still difficult and practically incomplete. One of the most commonly used drugs against these neurodegenerative diseases is 4-aminopyridine.

Effect of the Mode of Fermentation on the Behavior of in Conditions of Abiotic Stress.

The ability of a strain to support acid production and simultaneously solubilize inorganic sources of phosphate in conditions of submerged, solid-state fermentation (SSF) and immobilized cell system was examined in this study. Abiotic stress factors such as NaCl and different values of pH were introduced into the different fermentation process schemes to measure the fungal response. The results showed a higher tolerance of when the fermentation process was carried out in solid-state and immobilized-cell conditions, which mimics the natural state of the soil microorganisms.

Novel Arylsulfonylhydrazones as Breast Anticancer Agents Discovered by Quantitative Structure-Activity Relationships.

Breast cancer (BC) is the second leading cause of cancer death in women, with more than 600,000 deaths annually. Despite the progress that has been made in early diagnosis and treatment of this disease, there is still a significant need for more effective drugs with fewer side effects. In the present study, we derive QSAR models with good predictive ability based on data from the literature and reveal the relationships between the chemical structures of a set of arylsulfonylhydrazones and their anticancer activity on human ER+ breast adenocarcinoma and triple-negative breast (TNBC) adenocarcinoma.

Structure and Conformational Mobility of OLED-Relevant 1,3,5-Triazine Derivatives.

A series of OLED-relevant compounds, consisting of 1,3,5-triazine core linked to various aromatic arms by amino group, has been synthesized and characterized. The studied compounds exist in solution as a mixture of two conformers, a symmetric propeller and asymmetric conformer, in which one of the aromatic arms is rotated around the C-N bond. At temperatures below -40 °C, the VT NMR spectra in DMF-d7 are in a slow exchange regime, and the signals of two conformers can be elucidated.

Favipiravir-Tautomeric and Complexation Properties in Solution.

The tautomeric properties of favipiravir were investigated experimentally for the first time by using molecular spectroscopy (UV-Vis absorption, fluorescence and NMR), as well as DFT quantum-chemical calculations. According to the obtained results, the enol tautomer is substantially more stable in most of the organic solvents. In the presence of water, a keto form appears to be favored due to the specific solute-solvent interactions.

Fungi, P-Solubilization, and Plant Nutrition.

The application of plant beneficial microorganisms is widely accepted as an efficient alternative to chemical fertilizers and pesticides. It was shown that annually, mycorrhizal fungi and nitrogen-fixing bacteria are responsible for 5 to 80% of all nitrogen, and up to 75% of P plant acquisition. However, while bacteria are the most studied soil microorganisms and most frequently reported in the scientific literature, the role of fungi is relatively understudied, although they are the primary organic matter decomposers and govern soil carbon and other elements, including P-cycling.

Development of New Antimycobacterial Sulfonyl Hydrazones and 4-Methyl-1,2,3-thiadiazole-Based Hydrazone Derivatives.

Fifteen 4-methyl-1,2,3-thiadiazole-based hydrazone derivatives - and sulfonyl hydrazones - were synthesized. They were characterized by H-NMR, C NMR, and HRMS. strain H37Rv was used to assess their antimycobacterial activity.

Synthesis and biological study of new galanthamine-peptide derivatives designed for prevention and treatment of Alzheimers disease.

The Alzheimer's disease leads to neurodegenerative processes and affecting negatively million people worldwide. The treatment of the disease is still difficult and incomplete in practice. Galanthamine is one of the most commonly used drugs against the illness.

Neuroprotective evaluation of novel substituted 1,3,4-oxadiazole and aroylhydrazone derivatives.

The paper reports on the facile and convenient synthesis of a series of novel 2,5-substituted 1,3,4-oxadiazoles 3a-f and that of aroylhydrazone-based molecular hybrids 5a-g from readily available starting materials. The structure of the compounds was confirmed by IR, H NMR, C NMR and HRESI-MS spectral data. The toxicological potential of the compounds was evaluated by monitoring the synaptosomal viability and the levels of reduced glutathione in rat brain synaptosomes, isolated by Percoll gradient.

Special Issue: Microorganisms and Plant Nutrition.

Plant-beneficial microorganisms affect plant nutrition and health, as a key part of prebiotic-, probiotic-, and symbiotic-based interactions [...

Fermentation Strategies to Improve Soil Bio-Inoculant Production and Quality.

The application of plant beneficial microorganisms has been widely accepted as an efficient alternative to chemical fertilizers and pesticides. Isolation and selection of efficient microorganisms, their characterization and testing in soil-plant systems are well studied. However, the production stage and formulation of the final products are not in the focus of the research, which affects the achievement of stable and consistent results in the field.

A single isomer rotary switch demonstrating anti-Kasha behaviour: Does acidity function matter?

A novel rotary switch, overcoming the disadvantages of hydrazone based switches with competitive proton acceptor sub-rotors, has been designed. The new compound contains a pyridyl ring and a COOH group as sub-rotors, which provides engagement of the pyridyl nitrogen atom and leads to the existence of a single isomer in the ground state. The availability of acidic functionality in the rotor creates conditions for excited state intramolecular proton transfer (ESIPT), which exhibits anti-Kasha behavior.

: From Soil to Industry and Back.

is an important saprophytic filamentous fungus that can be found in soils. Like many other soil microorganisms, demonstrates multiple functions and offers various important metabolites, which can be used in different fields of human activity. The first application of on an industrial level is the production of itaconic acid, which is now considered as one of the most important bioproducts in the Green Chemistry field.

An H NMR- and MS-Based Study of Metabolites Profiling of Garden Snail Mucus.

Metabolic profiling based on H nuclear magnetic resonance (NMR) spectroscopy was applied with the aim to investigate the functional role of the metabolites in lyophilized mucus from the garden snail . Twenty metabolites were unambiguously identified by H, 1D TOCSY, 2D J-resolved, 2D COSY, and 2D HSQC NMR spectra with water suppression. The metabolic profiles of two fractions with low molecular weight (Mw < 1 kDa and Mw < 3 kDa) are very similar.

Thiol-ene coupling reaction achievement and monitoring by "" UV irradiation NMR spectroscopy.

In this study, the possibilities of a new "" LED UV illumination NMR spectroscopic technique for performing an initiator-free thiol-ene "click" coupling reaction of an allyl-functionalized poly(allyl glycidyl ether) (PAGE) prepolymer with a number of mono- and di-oligo polyethylene glycol (PEG) thiols is demonstrated. The state-of-the-art setup constructed with LEDs as UV light sources that illuminate through optical fibers directly into an NMR testing tube at a fixed wavelength of 365 nm is appropriate for various polymeric materials and biologically active substances. The selected experimental protocol uses a series of periods of irradiation and dark periods, thus providing opportunities to conduct an effective thiol-ene "click" reaction and simultaneously study the kinetics of the photochemical reaction with the exposure time, as well as macromolecular association directly in a solution applying the whole types of NMR methods: from conventional H or C NMR to diffusion NMR spectroscopy (DOSY).

Formulation of Microbial Inoculants by Encapsulation in Natural Polysaccharides: Focus on Beneficial Properties of Carrier Additives and Derivatives.

In the last 10-15 years, the wide application of bioformulated plant beneficial microorganisms is accepted as an effective alternative of chemical agro-products. Two main problems can be distinguished in their production and application: (a) economical competiveness based on the overall up-stream and down-stream operational costs, and (b) development of commercial products with a high soil-plant colonization potential in controlled conditions but not able to effectively mobilize soil nutrients and/or combat plant pathogens in the field. To solve the above problems, microbe-based formulations produced by immobilization methods are gaining attention as they demonstrate a large number of advantages compared to other solid and liquid formulations.

Synthesis of New Galanthamine-Peptide Derivatives Designed for Prevention and Treatment of Alzheimer's Disease.

Background: Although no effective treatment for the Alzheimer's disease currently exist, some drugs acting as Acetylcholinesterase inhibitors, like galanthamine have positively affected such patients. β- and/or γ-secretase inhibitors are another type of potential drugs. Here we report synthesis of new peptide-galanthamine derivatives, with expected inhibitory activity against both Acetylcholinesterase and β-secretase.