Publications by authors named "Nikitina L"

Here, we report a synthesis of fluoroquinolones carrying a monoterpene moiety at the C7 position of aromatic structure. The minimal inhibitory concentrations of fluoroquinolone fused with trans-3-hydroxy-cis-myrtanylamine 18 against Staphylococcus aureus (MSSA isolates) were two- to eightfold lower compared to moxifloxacin, although fourfold higher against MRSA isolates. The fluoroquinolone fused with (-)-nopylamine 16 was four- to eightfold less active on MSSA compared to moxifloxacin, while had similar activity on MRSA.

View Article and Find Full Text PDF

Motivational drivers and emotions that students experience play an important role in the process of learning a new language (L2). This has been recognised by researchers and educators, and extensive research has been conducted in recent decades to examine the psychological and emotional factors involved in L2 learning. However, two ubiquitous epistemic emotions, namely, boredom and curiosity, remain underexplored in the L2 research literature.

View Article and Find Full Text PDF

The design of fluorescent probes based on biocompatible luminophores for medical diagnostics is one of the rapidly developing areas worldwide. Here, we report the synthesis of a novel BODIPYs containing a propanoic acid residue at the α-position of one of the pyrrole rings conjugated to (+)-myrtenol or thiotherpenoid. Both conjugates are quite photostable (t ∼ 40 h) and exhibit high fluorescence efficiency (φ ∼ 77-90 %).

View Article and Find Full Text PDF
Article Synopsis
  • * This study investigates the effectiveness of two different drainage implants (digel and xenocollagen) used during combined cataract and glaucoma surgery on eye pressure and visual function.
  • * Over 24 months, both implant groups achieved similar intraocular pressure results, with Group 1 showing an average of 18.8 mm Hg and Group 2 at 18.5 mm Hg post-surgery.
View Article and Find Full Text PDF

Lead and cadmium are heavy metals widely distributed in the environment and contribute significantly to cardiovascular morbidity and mortality. Using Leadmium Green dye, we have shown that lead and cadmium enter cardiomyocytes, distributing throughout the cell. Using an motility assay, we have shown that sliding velocity of actin and native thin filaments over myosin decreases with increasing concentrations of Pb and Cd.

View Article and Find Full Text PDF

The disuse of skeletal limb muscles occurs in a variety of conditions, yet our comprehension of the molecular mechanisms involved in adaptation to disuse remains incomplete. We studied the mechanical characteristics of actin-myosin interaction using an in vitro motility assay and isoform composition of myosin heavy and light chains by dint of SDS-PAGE in soleus muscle of both control and hindlimb-unloaded rats. 14 days of hindlimb unloading led to the increased maximum sliding velocity of actin, reconstituted, and native thin filaments over rat soleus muscle myosin by 24 %, 19 %, and 20 %, respectively.

View Article and Find Full Text PDF

It has been reported that muscle functional unloading is accompanied by an increase in motoneuronal excitability despite the elimination of afferent input. Thus, we hypothesized that pharmacological potentiation of spontaneous contractile soleus muscle activity during hindlimb unloading could activate anabolic signaling pathways and prevent the loss of muscle mass and strength. To investigate these aspects and underlying molecular mechanisms, we used β-myosin allosteric effector Omecamtiv Mekarbil (OM).

View Article and Find Full Text PDF

In recent years, there has been a rise in research on sensorium in various academic disciplines. Olfaction is recognized as a sense that is most closely linked to cognition, memory and emotion. Due to this unique feature, studies on various aspects of human olfaction are steadily gaining prominence in the humanities and social sciences.

View Article and Find Full Text PDF

Cardiac myosin binding protein-C (cMyBP-C) located in the C-zone of myocyte sarcomere is involved in the regulation of myocardial contraction. Its N-terminal domains C0, C1, C2, and the m-motif between C1 and C2 can bind to the myosin head and actin of the thin filament and affect the characteristics of their interaction. Measurements using an optical trap showed that the C0-C2 fragment of cMyBP-C increases the interaction time of cardiac myosin with the actin filament, while in an in vitro motility assay, it dose-dependently reduces the sliding velocity of actin filaments.

View Article and Find Full Text PDF

Natural monoterpenes and their derivatives are widely considered the effective ingredients for the design and production of novel biologically active compounds. In this study, by using the molecular docking technique, we examined the effects of two series of "sulfide-sulfoxide-sulfone" thioterpenoids containing different (e.g.

View Article and Find Full Text PDF

In order to expand the arsenal of tools and areas for practical use of BODIPY dyes as bifunctional fluorescent theranostics, we studied the effect of the meso-substituents nature and medium properties on photo- and pH-stability, efficiency of singlet oxygen generation, and affinity to biostructures of terpene-BODIPY conjugates. The BODIPYs fused with myrtenol or thiotherpenoid via carboxylic acid residues exhibit high stability over a wide pH range and the presence of a bulky substituent at the meso-position of BODIPY conjugates increases their photostability two-fold compared to structurally related meso-unsubstituted analogues. Furthermore, the photodegradation rate of the conjugates directly depends on their ability to generate singlet oxygen and the course probability of the corresponding red-ox reactions involving reactive oxygen species.

View Article and Find Full Text PDF

Monoterpene thiols are one of the classes of natural flavors that impart the smell of citrus fruits, grape must and wine, black currants, and guava and are used as flavoring agents in the food and perfume industries. Synthetic monoterpene thiols have found an application in asymmetric synthesis as chiral auxiliaries, derivatizing agents, and ligands for metal complex catalysis and organocatalysts. Since monoterpenes and monoterpenoids are a renewable source, there are emerging trends to use monoterpene thiols as monomers for producing new types of green polymers.

View Article and Find Full Text PDF

The binding of calcium and magnesium ions to proteins is crucial for regulating heart contraction. However, other divalent cations, including xenobiotics, can accumulate in the myocardium and enter cardiomyocytes, where they can bind to proteins. In this article, we summarized the impact of these cations on myosin ATPase activity and EF-hand proteins, with special attention given to toxic cations.

View Article and Find Full Text PDF

Pulmonary arterial hypertension (PAH) leads to changes in the pump function of the heart and causes right-sided myocardial hypertrophy and heart failure. This study was the first to compare the contractile characteristics of the multicellular myocardial preparations of the right atrium (RA) and right ventricle (RV) of male rats from the control group (CON) and the group with monocrotaline (MCT)-induced hypertrophy at the molecular and multicellular levels. In both RA and RV in MCT-treated rats, the fraction of motile filaments and the maximum sliding velocity of actin and reconstituted thin filaments over myosin decreased, and the ratio of α-/β-myosin heavy chains (MHC) shifted towards β-MHC.

View Article and Find Full Text PDF

Available pyrrolylalkynones with tetrahydroindolyl, cycloalkanopyrrolyl, and dihydrobenzo[]indolyl moieties, acylethynylcycloalka[]pyrroles, are readily annulated with Δ-pyrrolines (MeCN/THF, 70 °C, 8 h) to afford a series of novel pyrrolo[1',2':2,3]imidazo[1,5-]indoles and cyclohepta[4,5]pyrrolo[1,2-]pyrrolo[1,2-]imidazoles functionalized with an acylethenyl group in up to an 81% yield. This original synthetic approach contributes to the arsenal of chemical methods promoting drug discovery. Photophysical studies show that some of the synthesized compounds, e.

View Article and Find Full Text PDF

Infectious diseases caused by various nosocomial microorganisms affect worldwide both immunocompromised and relatively healthy persons. Bacteria and fungi have different tools to evade antimicrobials, such as hydrolysis damaging the drug, efflux systems, and the formation of biofilm that significantly complicates the treatment of the infection. Here, we show that myrtenol potentiates the antimicrobial and biofilm-preventing activity of conventional drugs against and mono- and dual-species cultures.

View Article and Find Full Text PDF

The work aimed to investigate how the phosphorylation of the myosin essential light chain of fast skeletal myosin (LC1) affects the functional properties of the myosin molecule. Using mass-spectrometry, we revealed phosphorylated peptides of LC1 in myosin from different fast skeletal muscles. Mutations S193D and T65D that mimic natural phosphorylation of LC1 were produced, and their effects on functional properties of the entire myosin molecule and isolated myosin head (S1) were studied.

View Article and Find Full Text PDF

Natural monoterpenes and their derivatives are widely considered as effective ingredients for the design and production of new biologically active compounds with high antioxidant, antimicrobial and anti-protozoa properties. In this study, we synthesized two series of thiotherpenoids "sulfide-sulfoxide-sulfone", with different bicyclic monoterpene skeleton (bornane and pinane) structures. The effect of the obtained compounds on platelet aggregation was investigated by using the molecular docking technique.

View Article and Find Full Text PDF

A moderate degree of lead intoxication was observed in male rats after repeated intraperitoneal injections with two doses of lead acetate three times a week during 5 (12.5 mg of Pb per kg body mass) and 6 (6.01 mg of Pb per kg body mass) weeks.

View Article and Find Full Text PDF
Article Synopsis
  • The paper discusses the design and analysis of a BODIPY biomarker combined with a thioterpene fragment to improve its structural and biological properties.
  • It examines how this conjugate interacts with erythrocytes (red blood cells) and its potential use in bioimaging, confirming the molecular structure through various spectroscopic methods.
  • The results indicate that the conjugate has high photostability and fluorescence, effectively entering erythrocytes without causing toxicity, which enhances its application in biological contexts.
View Article and Find Full Text PDF

Exposure to lead is associated with an increased risk of cardiovascular diseases. Outbred white male rats were injected with lead acetate intraperitoneally three times a week and/or were forced to run at a speed of 25 m/min for 10 min 5 days a week. We performed noninvasive recording of arterial pressure, electrocardiogram and breathing parameters, and assessed some biochemical characteristics.

View Article and Find Full Text PDF

Fluorescent dyes absorbing and emitting in the visible and near-IR regions are promising for the development of fluorescent probes for labeling and bio-visualization of body cells. The ability to absorb and emit in the long-wavelength region increases the efficiency of recording the spectral signals of the probes due to the higher permeability of the skin layers. Compared to other fluorescent dyes, BODIPYs are attractive due to their excellent photophysical properties-narrow absorption and emission, intense fluorescence, simple signal modulation for the practical applications.

View Article and Find Full Text PDF

Platelet aggregation causes various diseases and therefore challenges the development of novel antiaggregatory drugs. In this study, we report the possible mechanism of platelet aggregation suppression by newly synthesized myrtenol-derived monoterpenoids carrying different heteroatoms (sulphur, oxygen, or nitrogen). Despite all tested compounds suppressed the platelet aggregation in vitro, the most significant effect was observed for the S-containing compounds.

View Article and Find Full Text PDF
Article Synopsis
  • The article discusses the design and biological properties of a fluorescent compound called BODIPYmyrt, which is made from a specific monoterpenoid and a fluorophore.
  • BODIPYmyrt has a high quantum yield (close to 100%) in the 515-518 nm range, indicating its effectiveness in fluorescence applications.
  • It can penetrate bacterial and fungal cell membranes, making it useful for studying various types of bacteria and fungi, and also shows potential for targeting subcellular structures like mitochondria in mammalian cells.
View Article and Find Full Text PDF
Article Synopsis
  • - This paper focuses on creating a fluorescent probe using meso-carboxysubstituted-BODIPY combined with a thioterpene fragment to examine the antiplatelet and anticoagulant effects of thioterpenoids.
  • - The researchers replaced a methoxy group in the BODIPY molecule with the thioterpene fragment to better understand the interactions of these compounds with membranes and receptors.
  • - The newly designed probe exhibits a high fluorescence quantum yield near 100% in the blue-green range (509-516 nm) and shows improved affinity to the platelet receptor P2Y through molecular docking studies.
View Article and Find Full Text PDF