HPLC-DAD identification of compounds in corrosion inhibitor Salix alba bark extract and the hydrolate

The compounds present in Salix alba bark (SAB) extract and its hydrolate were identified using high performance liquid chromatography with diode array detection (HPLC-DAD). SAB extract and its hydrolate were obtained by evaporating a macerate of dried, ground white willow bark and hot distilled water. A total of 19 standard polyphenolic compounds were used for the HPLC analysis. Results indicate that only 4-hydroxybenzoic acid (4-HBA) was detected in the SAB hydrolate. In contrast, both gallic acid and caffeic acid were present in the SAB extract. The presence of 4-HBA indicates the potential possibility of using SAB hydrolate as a starting component for the synthesis of parabens and other 4-HBA derivatives. Additionally, the identification of gallic and caffeic acids in the SAB extract further confirms the effect as a cathodic inhibitor of copper corrosion in chloride environments, because both acids are proven cathodic inhibitors of copper in different corrosion environments

Quantum Theory of Atoms In Molecules Analysis of NH/O Hydrogen Bonds of Glycine Complexes with a Water Molecule

Quantum Theory of Atoms In Molecules (QTAIM) analysis was performed for NH/O hydrogen bonds of various glycine transition metal complexes. The dependencies of the CCSD(T)/CBS interaction energy values and hydrogen bond distances on QTAIM parameters at the corresponding bond critical point were analyzed. Values of electron densities ρ(rb) range from 0.0224 to 0.0344 au, Laplacians of electron densities ∇2ρ(rb) are all positive, total energy densities H(rb) are approximately zero, and the ratios of kinetic and potential energy densities [-G(rb)/V(rb)] are close to 1.0. For complexes with the same charge, hydrogen bonds with stronger interaction energies have higher ρ(rb) and ∇2ρ(rb), and lower H(rb) and [-G(rb)/V(rb)]. Almost all charged complexes have negative H(rb) values, which was shown to be a indicator of covalent character of the hydrogen bond. Linear regressions between hydrogen bond distances and any of the QTAIM parameters have very high correlation coefficient: 0.994, 0.993, 0.968, and 0.995 for ρ(rb), ∇2ρ(rb), H(rb), and [-G(rb)/V(rb)], respectively

Fast and selective protein modification with iron-substituted polyoxometalates via a radical pathway

Oxidative modifications of proteins are crucial post-translational modifications that profoundly impact their structure, function, and turnover. Developing chemical methods that selectively induce oxidative protein modifications and cleavage would significantly facilitate elucidation of these oxidative processes, benefiting our understanding of disease mechanisms, identifying novel therapeutic targets, and advancing biotechnological applications. In this work, we demonstrate that all-inorganic discrete polyoxometalate (POM) clusters stabilize redox active metal centers such as Fe(III) and Mn(III) under physiological pH and temperature (pH = 7.5, 37 °C), enabling the generation of reactive oxygen species (ROS) under mild aqueous conditions. Specifically, we show that catalytic amounts of the iron-substituted POM K7[FeIII(α2-P2W17O61)(H2O)] (FeIIIWD), in the presence of ascorbate (Asc), rapidly induce selective oxidation and cleavage of hen egg-white lysozyme (HEWL) in four narrow regions of the protein sequence. The protein cleavage sites are all located near the interaction sites of MIIIWD (M = Mn or Fe) catalysts with the protein surface. In contrast, the manganese-substituted POM K7[MnIII(α2-P2W17O61)(H2O)] (MnIIIWD) shows no similar catalytic activity, pointing towards a different radical mechanism. These findings highlight the potential of well-tailored inorganic clusters to facilitate selective catalytic processes, enabling iron to target specific regions of a protein sequence without relying on coordination sites on the protein surface, while offering flexibility in reaction conditions

Liquid chromatography in determination of pharmacokinetic properties of compounds in drug discovery process

Liquid chromatography plays a pivotal role in the determination of pharmacokinetic properties during drug discovery, particularly through the evaluation of lipophilicity. This parameter is essential in drug development, significantly influencing pharmacokinetic and pharmacodynamic behavior of potential drugs. It affects membrane permeability, solubility, distribution, and interaction with biological targets, making it a central focus in the early stages of drug design. Poor lipophilicity-related characteristics are often associated with drug failures, inefficacy, toxicity, and increased development costs. Experimental and computational methods, such as chromatographic techniques and theoretical calculations, are vital for accurately determining lipophilicity. These approaches enable the simulation of biological processes, providing insights into how lipophilicity impacts ADME (absorption, distribution, metabolism, and excretion) properties and supporting the optimization of drug candidates. In silico tools further enhance the efficiency of ADME evaluations, reducing the risk of pharmacokinetic-related failures and streamlining the drug discovery process

Comprehensive analysis of 44 elements in the lung cancer tissues of smokers: A comparative study with control lung tissues

Lung cancer remains one of the leading causes of morbidity and mortality worldwide, yet the baseline status of trace elements in healthy/control lung tissues is largely unresolved, with no comprehensive elemental profile established for lung cancer. This study aimed to characterize baseline concentrations of 44 elements in healthy lung tissues (n = 92) and investigate changes in elemental composition in cancerous lung tissues (n = 92). The second aim was to observe possible differences in elemental concentrations in healthy and cancerous lung tissues based on age and sex. Additionally, this study aimed to identify trace elements potentially involved in lung cancer pathophysiology. Through detailed elemental analysis, this study revealed significant differences between healthy and cancerous lung tissues. Specifically, concentrations of Mn, Co, Ni, Cd, and U were significantly higher in healthy lung tissues, while Cu, Tl, Pb, Rh, Pd, and Bi were significantly higher in cancerous lung tissues. Age-related analysis of the control tissue group showed that healthy lung tissue from older individuals (above 64 years) had lower concentrations of elements Mn, Zn, Be, Al, Sb, Ba, Tl, Ga, Rb, Y, Re, Eu, Tb, Dy, Ho, Er, Yb, La, and Bi than healthy tissues from younger individuals (below 64 years). In cancerous lung tissues, those from females (n = 40) exhibited significantly lower concentrations of Cr, Cu, As, and Pb but higher Pt concentrations than cancerous lung tissues from males (n = 52). Furthermore, in cancerous lung tissues, those from younger patients displayed lower concentrations of As, Sb, and Au compared to equivalent tissues from older individuals. These findings offer valuable insights into the elemental composition of lung cancer tissue, enhancing the understanding of how trace elements could influence lung cancer pathophysiology

Biomarker composition and origin of Miocene pale lignites in China and Serbia | 中国−塞尔维亚中新世浅色褐煤生物标志化合物组成及其成因

Pale lignites are widely distributed in Cenozoic lignite basins around the world, but their origin is still controversial. Identifying their organic matter composition and formation mechanism is of great significance for reconstructing paleoclimate changes and clean and low-carbon utilization of lignite resources. Taking the Miocene pale lignite from Kolubara Basin in Serbia and Mile Basin in Yunnan, China as the research objects, organic geochemical methods, such as Soxhlet extraction, column chromatography separation and gas chromatography-mass spectrometry, were used to qualitatively and quantitatively analyze biomarker compounds in aliphatic and aromatic hydrocarbons to explore the differences in vegetation composition, microbial degradation and sedimentary environment during the coalification process of light and dark lignites. The results show that the pale lignite in Mile Basin has a high content of long-chain n-alkanes (up to 82.5%), showing a significant contribution from leaf waxes of terrestrial higher plants (mainly angiosperms), accompanied by a lower aquatic plant indicator value (Paq of 0.16) and a higher plant leaf wax index (Pwax of 0.86), indicating that its coal-forming environment was relatively dry and accompanied by strong microbial degradation; while the dark lignite has an increased proportion of medium-chain and short-chain n-alkanes, indicating that the input of aquatic plants and lower organisms was enhanced during the sedimentation process in Mile Basin. Both the pale and dark lignite in Kolubara are mainly contributed by gymnosperms. Content of diterpenoids in their aliphatic hydrocarbons is extremely high (87.3% for pale and 82.5% for dark), and the relative mass fraction ratio of diterpenoids to diterpenoids + triterpenoids is close to 1, reflecting the predominance of conifers in the peatland. At the same time, the higher relative mass fraction ratio of C31(R)hopane to total hopane and C30 hop-17(21)-ene to C30αβhopane reveal that Kolubara lignites were formed under relatively oxidative, acidic and low thermal evolution conditions. In addition, perylene and higher CWDI values indicate that pale lignite in two basins was subjected to stronger degradation, which is consistent with the higher content of hopane. By comparing the differences between Cenozoic pale and dark lignite, it is clarified that the sedimentary environment is the main controlling color change of lignite

Enzimska i hemijska sinteza auronolignana

Kotinignani A i B su jedini do sada izolovani auronolignani, a izolovani su iz srži stabla biljke Cotinus coggygria. Spadaju u grupu flavonolignana i sastoje se iz auronskog i lignanskog dela. Značajna citotoksičnost i selektivnost kotinignana A na K562 ćelijskim linijama leukemije utvrđena u ranijim istraživanjima je bila motiv za sintezu auronolignana. U tu svrhu odabrane su sinteza iz aurona sulfuretina i sinapil alkohola katalizovana enzimom lakazom i hemijskom sintezom uz pomoć srebro-karbonata. Cilj ovog rada bio je sineza auronolignana tipa izokotinignana i ispitivanje njihove citotoksičnosti. Sintetisana su i okarakterisana dva izokotinignana, cis-izokotinignan A (1) i trans-izokotinignan A (2), i ispitana je njihova citotoksičnost

Metal Complexes with Hydroxyflavones: A Study of Anticancer and Antimicrobial Activities

Metal chelation to bioactive small molecules is a well-established strategy to enhance thebiological activity of the resulting complexes. Among the widely explored structural motifs,the combination of prominent metal centers with naturally inspired derivatives has attractedconsiderable attention. One such promising platform is the flavone scaffold, derivedfrom flavonoids and studied since ancient times. Flavones are plant-derived compoundsknown for their diverse biological activities and health benefits. They exhibit significantstructural variability, primarily through backbone modifications such as hydroxylation.Importantly, coordination of metal ions to hydroxylated flavone cores often improvestheir natural bioactivities, including anticancer and antimicrobial effects. In this review,we summarize transition metal complexes incorporating hydroxyflavone (OH–F) ligandsreported over the past 15 years. We provide a concise overview of synthetic approachesand structural characterization, with a particular emphasis on coordination modes (e.g.,maltol-type, acetylacetonate-type, catechol-type, and others). Furthermore, we discussbiological evaluation results, especially anticancer and antimicrobial studies, to highlightthe therapeutic potential of these complexes. Finally, we suggest directions for the futuredevelopment of metal-based agents bearing hydroxyflavone moieties through several criticalpoints in terms of the accuracy, reproducibility, and relevance of biological studiesinvolving metal-based compounds

The influence of environmental pollution on the allergenic potential of grass pollen

Grass pollen is the most common cause of pollen allergies in Europe. However, growing evidence suggests that air pollution and climate change may contribute to the rising number of allergic cases and worsening symptoms. This narrative review article aims to summarize the impacts of increased health complications based on pollution research in recent years, obtained from ecological, molecular and clinical studies to provide a new perspective on the impact of pollutants on the environment and human health. Our detailed literature review includes studies on pollution and its effect on pollen allergens, which cause allergy symptoms, but only in the case of three grass species: Dactylis glomerata, Lolium perenne and Phleum pratense

Liquid chromatography in determination of pharmacokinetic properties of compounds in drug discovery process

Liquid chromatography plays a pivotal role in the determination of pharmacokinetic properties during drug discovery, particularly through the evaluation of lipophilicity. This parameter is essential in drug development, significantly influencing pharmacokinetic and pharmacodynamic behavior of potential drugs. It affects membrane permeability, solubility, distribution, and interaction with biological targets, making it a central focus in the early stages of drug design. Poor lipophilicity-related characteristics are often associated with drug failures, inefficacy, toxicity, and increased development costs. Experimental and computational methods, such as chromatographic techniques and theoretical calculations, are vital for accurately determining lipophilicity. These approaches enable the simulation of biological processes, providing insights into how lipophilicity impacts ADME (absorption, distribution, metabolism, and excretion) properties and supporting the optimization of drug candidates. In silico tools further enhance the efficiency of ADME evaluations, reducing the risk of pharmacokineticrelated failures and streamlining the drug discovery process