Synthesis Features Research Articles

Synthesis of 3α,6β‐Dihydroxyandrostan‐17‐one 3‐Glucuronides for the Detection of Testosterone Misuse

AbstractThe convenient synthesis of two 3‐glucuronide conjugates of 6β‐hydroxyandrosterone (6OH‐And‐3G 2) and 6β‐hydroxyetiocholanolone (6OH‐Etio‐3G 3) is reported. The conjugates are identified as long‐term markers of endogenous androgenic anabolic steroid abuse in doping control studies. Their resistance to enzymatic hydrolysis by E. coli β‐glucuronidase means they may be missed by conventional GC‐MS analysis protocols. One promising strategy to quantify these markers is by direct methods, which requires sufficient quantities of high purity reference materials. Our convergent synthesis features concurrent stereoselective introduction of 5α/5β hydrogen and 6β‐hydroxy groups on the steroid skeleton, and a mild Schmidt trichloroacetimidate glycosylation strategy.

Synthesis, characterization, linear and nonlinear optical features of novel organic compound Pyridylcarboxamide chalcone for nonlinear optical applications

This paper presents the synthesis, characterization, linear and third-order nonlinear optical (TNLO) features of a novel organic compound Pyridylcarboxamide chalcone (PCC) using aldol condensation and carboxamide formation method. The organic compound is characterized by 1H and 13C nuclear magnetic resonance (NMR) spectroscopy, mass spectroscopy and Fourier transform infrared (FT-IR) spectroscopy techniques and the title compound is optimized by DFT method. The solvent effect on linear and TNLO features of PCC is studied and significant changes are found in the linear and TNLO characteristics of the compound. The nonlinear refractive index (n2) and nonlinear absorption coefficient (β) of PCC is calculated to be the order of 10−7 cm2/W and 10−3 cm/W. The n2 of PCC is ascribed to negative nonlinearity due to self-defocusing effect and the β of PCC is attributed to the phenomenon of saturable and reverse saturable absorption (RSA) behaviors. The order of TNLO susceptibility (χ(3)) of PCC in polar solvents is calculated to be 10─6 esu. The effect of solvent characteristics such as solvent polarizability and dipole moment on the TNLO susceptibility of PCC is discussed. The results reveal that, the organic compound studied here is a novel material for future applications in nonlinear optics.

Oximes of fluoroalkyl-containing 1,3-diketones: specific features of synthesis, analysis, and thermal stability

Oximes of fluoroalkyl-containing 1,3-diketones: specific features of synthesis, analysis, and thermal stability

Optical properties, elastic moduli, and radiation shielding performance of some waste glass systems treated by bismuth oxide

This work reported on the optical properties, elastic moduli, and shielding performance, against charged particles and neutrons, of some waste glass systems, cathode-ray tubes (CRTs), described by (100-x) waste CRTs – xBi2O3 (where x = 0, 10, and 20 mol. %). The synthesis, chemical, and optical features of these glasses were experimentally determined. The well-known Makishima-Mackenzie Model (MMM) was applied to evaluate the elastic properties. The shielding performance of the studied glass specimens against charged particles is evaluated via two fundamental factors namely stopping power and particle range. Such factors are systematically calculated by employing SRIM, ESTAR, PSTAR, and ASTAR programs. Further, the shielding performance of the studied glass specimens against neutrons is evaluated via removal cross section. We found that all elastic moduli decrease as Bi2O3 replaces waste CRTs in the glass network. Moreover, The Σ_R of the glasses follows the trend: CRT-Bi0 (Σ_R=0.0891 cm−1) > CRT-Bi10 (Σ_R=0.0867 cm−1) > CRT-Bi20 (Σ_R=0.0850 cm−1). It is also clear that introducing Bi2O3 into the waste CRTs glass system may appear very beneficial for improving parameter-n, however, higher amounts in the dopant may cause conductive behavior in the glass network on the basis of parameter-M.

Ultrasensitive sensing of T4 PNK phosphatase activity through establishing a novel transcription-based signal amplification platform

Signal amplification plays a significant role in nucleic acid analysis, especially in trace nucleic acid detection. Transcription-based signal amplification is a very important component in the field of signal amplification, and has received extensive attention depending on outstanding cyclic transcription ability. However, the low efficiency of transcription caused by limited template length usually restricts their further applications significantly. Herein, we developed a transcription-based signal amplification method with high sensitivity and selectivity. The approach we proposed couples the advantageous features of long template synthesis from phosphorothioated-terminal hairpin formation and self-priming extension (PS-THSP) with self-amplification from cell-free transcription system. The results demonstrate that this approach can be applied to quantify T4 Polynucleotide Kinase (T4 PNK) phosphatase activity in a broad range from 0.00001 to 0.01 U/mL, with a detection limit of 8.1 × 10-6 U/mL. Moreover, this device can be further employed as a superior signal amplification platform for the detection of other analytical targets after moderate modifications.

A succinct synthesis of (25R)-cholesta-5,7-diene-3β,26-diol from ergosterol

An efficient seven-step procedure is described for the synthesis of (25R)-cholesta-5,7-diene-3β,26-diol from commercially available ergosterol in an overall yield of 25%. The synthesis features Julia-Kocienski olefination of the aldehyde with benzothiazole sulfone ester in presence of LiHMDS followed by reduction of the alkene.

Glycadelin in Obstetrical Practice: Past, Present, Practice

The article presents a review of the literature on one of the main proteins of the human reproductive system-glycodelin. The issues of the discovery of glycodelin, the features of synthesis, different names of the protein, its functions are covered. Depending on the place of origin, the same protein skeleton is glycosylated differently, giving rise to glycodelin isoforms with different biological effects. Glycodelin A (endometrial) and F (follicular fluid) inhibit the binding of spermatozoa and zona pellucida, thereby exhibiting contraceptive properties. In contrast, glycodelin C (cumulus) stimulates the binding of spermatozoa to the zona pellucida. Glycodelin S of seminal vesicles does not have a contraceptive effect, it affects the stability of the spermatozoa membrane, controls capacitation. The pronounced immunosuppressive activity of glycodelin A contributes to successful implantation and placentation, glycodelin S promotes the formation of antisperm immunity. The role of glycodelin in human reproductive function, the pathogenesis of reproductive losses (miscarriage, ectopic pregnancy, stillbirth), assessment of the functional state of the ovaries, fallopian tubes and endometrium, the maternal part of the placenta, and sperm fertility are shown. The review reflects both fundamental scientific data and the results of clinical studies of glycodelin content in menstrual blood, peripheral venous blood in women and semen in men, which made it possible to develop methods for diagnosing and predicting disorders of reproductive health and reproductive function in a married couple.

Synthesis, covalency parameters, energy calculations and crystal features of acylpyrazolone derived pentavalent Uranyl complex along with DFT and Hirshfeld analysis

A σ-donating acylpyrazolone DMBPMP (4-(3,5-dimethyl benzoyl) 1-phenyl 3-methyl 5-pyrazolone) ligand and its Uranyl acylpyrazolone complex [UO2(DMBPMP)2(EtOH)] were synthesized to analyze the nature of covalency, reactivity, and redox properties. The structure, pentavalent bipyramidal geometry, and complex composition are mainly scrutinized through their single-crystal x-ray crystal data, molar conductivity, gravimetric estimation, FTIR significant vibrations, δ-values of 1H NMR, 13C NMR and TG-DTA plots. The covalency of the Uranyl complex mainly depends on average bond length values on the pentagonal equatorial plane, Uranyl axial bond lengths, stretching frequency values, coordinated solvent on the fifth coordination site, and different aryl group substitution on the first position of the pyrazolone ring; and it can be confirmed through FTIR, single-crystal, and electronic UV–Vis spectral characterization methods. The UV–Vis data was also valuable for identifying n → π*, π → π*, and LMCT transitions and calculating Sinha’s covalency parameters, which shows that the complex can show maximum covalent character in DMSO solvent and covalency decreases in DMSO > DMF > Ethyl acetate > Ethanol > CHCl3 order. DFT calculations were performed to get an excellent correlation and comparison with all experimental values. This correlation and comparision is helpful to identify global index parameters to get an idea of the physical as well as chemical properties of such systems and to confirm the characteristics theoretically by HOMO-LUMO energy gap, theoretical vibrations, natural electronic configuration, and NBO charges. The Hirshfeld surface analysis was also carried out to identify the crystal strength through interaction energies and energy frameworks in the ligand and intermolecular non-covalent surface interactions with fingerprint plot details in both ligand and complex. Electro-chemical analysis in CV-DPV plots provides information on the redox properties of uranyl moiety.

Two-Stage Syntheses of Clionastatins A and B.

A concise and divergent synthesis of the polychlorinated marine steroids clionastatin A and B from inexpensive testosterone has been achieved through a unique two-stage chlorination-oxidation strategy. Key features of the two-stage synthesis include (1) conformationally controlled, highly stereoselective dichlorination at C1 and C2 and C4-OH-directed C19 oxygenation followed by a challenging neopentyl chlorination to install three chlorine atoms; (2) desaturation through one-pot photochemical dibromination-reductive debromination and anti-Markovnikov olefin oxidation by photoredox-metal dual catalysis to enhance the oxidation level of the backbone; and (3) Wharton transposition to furnish the D-ring enone. This synthesis proved that the introduction of the C19 chloride in the early stage of the synthesis secured the stability of the backbone against susceptibility to aromatization during the oxidation stage.

Rapid Synthesis of the epi-Biotin Sulfone via Tandem S,N-Carbonyl Migration/aza-Michael/Spirocyclization and Haller-Bauer Reaction.

A synthesis of 2-epi-biotin sulfone was accomplished from commercially available l-cysteine. The synthesis features an unprecedented tandem S,N-carbonyl migration/aza-Michael/spirocyclization reaction from an l-cysteine-derived enone with aq. ammonia, in which three new sigma bonds and two rings are formed. In addition, the synthesis includes a highly diastereoselective late-stage Haller–Bauer reaction of sulfone for direct introduction of the carbon side chain.

On an oxadiazole-pyridine derived diimine ligand and its Re complex: Synthesis, characterization and photophysical features

Recent development of optoelectronic functional films, photovoltaic devices, photocatalysts and display devices has attracted widespread attention on the design and synthesis of emitters and dyes with optoelectronic functions. Among these proposed emitters and dyes, polypyridine Re(I) carbonyl complexes are unique ones due to their simple molecular structure, which makes their chemical modification easy to perform. These Re(I) complexes could be explored as singlet oxygen (1O2) photosensitizer, which broadens their application. In this work, an electron-accepting diimine ligand with -CF3 group was incorporated into a Re(I) complex (denoted as Re-LCF3). This Re(I) complex was characterized by single crystal analysis, electronic structure analysis, photophysical property analysis, so that its phosphorescent nature was confirmed. Then Re-LCF3 was dispersed into nanofibers of polyvinylpyrrolidone by means of electro-spinning method, hoping to improve 1O2-producing performance of the resulting composite nanofibers (denoted as Re-LCF3@PVP). A full comparison between Re-LCF3 in solid state, in solution, in polymer fibers was performed, including their absorption, emission, quantum yield, lifetime and 1O2-producing performance. It was found that the photophysical performance of Re-LCF3@PVP was better than that of pure Re-LCF3 in solid state, showing emission blue shift, improved photostability, longer lifetime and better emission quantum yield. The 1O2-producing performance of Re-LCF3@PVP was better than that of pure Re-LCF3 in solid state.

Super‐Resolution Vibrational Imaging Using Expansion Stimulated Raman Scattering Microscopy

Stimulated Raman scattering (SRS) microscopy is an emerging technology that provides high chemical specificity for endogenous biomolecules and can circumvent common constraints of fluorescence microscopy including limited capabilities to probe small biomolecules and difficulty resolving many colors simultaneously. However, the resolution of SRS microscopy remains governed by the diffraction limit. To overcome this, a new technique called molecule anchorable gel‐enabled nanoscale Imaging of Fluorescence and stimulated Raman scattering microscopy (MAGNIFIERS) that integrates SRS microscopy with expansion microscopy (ExM) is described. MAGNIFIERS offers chemical‐specific nanoscale imaging with sub‐50 nm resolution and has scalable multiplexity when combined with multiplex Raman probes and fluorescent labels. MAGNIFIERS is used to visualize nanoscale features in a label‐free manner with C—H vibration of proteins, lipids, and DNA in a broad range of biological specimens, from mouse brain, liver, and kidney to human lung organoid. In addition, MAGNIFIERS is applied to track nanoscale features of protein synthesis in protein aggregates using metabolic labeling of small metabolites. Finally, MAGNIFIERS is used to demonstrate 8‐color nanoscale imaging in an expanded mouse brain section. Overall, MAGNIFIERS is a valuable platform for super‐resolution label‐free chemical imaging, high‐resolution metabolic imaging, and highly multiplexed nanoscale imaging, thus bringing SRS to nanoscopy.

Specific Features of Synthesis, Structure, Magnetometry, and NMR Spectroscopy of Different-Type Nanowires

Specific Features of Synthesis, Structure, Magnetometry, and NMR Spectroscopy of Different-Type Nanowires

Specific features of synthesis and luminescence for lithium–aluminum spinels doped with manganese ions

Ceramic samples of lithium aluminates doped with manganese ions have been synthesized by a solid-state reaction method. The ceramics sintered at temperatures of 1000, 1100, 1200 or 1300 °C for 4 h in air are identified as LiAl5O8 compounds belonging to a spinel-like crystal structure with the P4132 space group. Nonetheless, ceramic compositions obtained by annealing at temperatures 1000, 1100 or 1200 °C have larger lattice parameters than that of a LiAl5O8 single crystal and are considered as metastable LiAl5O8 phases having partial disorder for the occupation of two inequivalent octahedral sites by Li+ and Al3+ ions, i.e. possessing Li - Al inversion. Such Mn doped disordered compositions show typical Mn4+ red luminescence with an emission peak at ∼662 nm. The charge compensation of Mn4+ replacing Al3+ ions in octahedral sites is achieved by Li+ ions entering some adjacent Al3+ sites due to inversion. On the other hand, annealing at a higher temperature (1300 °C) or prolonged (170 h) annealing at a lower temperature (1100 °C) leads to complete ordering of Li+ and Al3+ in ratio 1:3 at different octahedral sites in the LiAl5O8 structure in which Mn4+ luminescence is not observed due to the lack of a charge compensation mechanism. Doping Mn ions in such an ordered structure are realized in di- and trivalent states causing green and far-red luminescence, respectively. Additional annealing of the mixtures of the Mn-doped ordered LiAl5O8 composition and Li2CO3 at 1300 °C in air results in the production of phosphors which again show intense Mn4+ red luminescence and have the spinel-like crystal structure with the Fd3‾m space group due to random occupation of cationic sites by Li+ and Al3+ ions.

Ecological and Economic Efforts in the Development of Molecular Sensors for the Optical Detection of Cyanide Ions

AbstractCyanide anions have wide use in industrial areas despite their high toxicity to the environment as waste; thus, numerous studies on the determination of this anion have been carried out. This review discusses recent progress in the colorimetric and fluorimetric detection of cyanide by nucleophilic addition or acid‐base reactions to different types of receptors by the chemodosimeter approach. Beyond sensor performance, we focus our analysis on the sustainable synthesis features of five representative families of probes based on small molecules. Some environmental and economic factors are considered (reaction mass efficiency, number of chemical changes, solvent greenness average, preliminary raw material cost, and energy implications), giving a complete picture of the current status of research in this detection field.

Current Developments in CuS Based Hybrid Nanocomposite for Electrochemical Biosensor Application: A Short Review

Development of rational synthesis methods for the hybrid metal chalcogenides is of great importance nowadays, due to their promising synergistic effect. The hybrid nanocomposites with well-defined nanostructures offers unique properties and fascinating applications. Recently, the CuS and its hybrid structures are largely adopted for the electrochemical sensor applications. In this review article, we have attempted to provide brief overview about synthesis and structural features of selected CuS and their composites. The review provide more detailed insights into their electrochemical sensor property with respect to selected biomolecule, such as glucose, tertazine, dopamine, hydrazine, Xanthine, and bisphenol A. In addition to the electrochemical sensing property of pure CuS, the importance of hybrid CuS with other nanomaterials, such as carbon fibers, and rGO, is also discussed in detail. Finally, this review provides summary and future scope of this work. This review would be very helpful for those who are working on copper sulfide based sensors to design their experiments and correlate their experimental results.

Features of the reactive oxygen species production by platelets and neutrophils in the formation of an insufficient response to acetylsalicylic acid in patients with coronary heart disease after coronary bypass surgery

Background. Aspirin resistance can lead to thrombosis. Platelets interact with neutrophils in the focus of atherosclerotic damage. The levels of synthesis of reactive oxygen species (ROS) characterize their functional potential. Platelet resistance to acetylsalicylic acid (ASA) can affect the synthesis of ROS.Objective. To reveal the features of ROS synthesis by platelets and neutrophils in patients with coronary heart disease (CHD) after coronary artery bypass grafting (CABG) depending on sensitivity to ASA and antiplatelet therapy.Design and methods. There were 104 patients with CHD and 36 healthy donors. Patients stopped receiving antiplatelet agents 5 days before CABG, ASA was prescribed after surgery, patients on dual antiplatelet therapy (DAT) clopidogrel were added to ASA for 2–3 days. Resistance to ASA was determined at a level of platelet aggregation with arachidonic acid ≥ 20 %. The ROS synthesis levels were examined by the chemiluminescent method (CL).Results. 31.7 % of patients were resistant to ASA (rASA). In ASA-sensitive patients (sASA), CL values were increased. In rASA on DAT, CL parameters were increased, but did not differ from sASA. In the sASA and rASA groups on ASA therapy, correlations between neutrophil and platelet CL parameters were revealed.Conclusion. The presence or absence of interaction between platelets and neutrophils at the level of receptors and/or microvesicles can lead to platelet resistance to ASA in patients with coronary artery disease. Sometimes, this effect could be compensated by DAT.

Catalytic, Asymmetric Total Synthesis of (+)-α-, (+)-β-, (+)-γ-, and (-)-δ-Lycorane.

The first collectively asymmetric total synthesis of all members of lycorane, including (+)-α, (+)-β, (+)-γ, and (-)-δ, in a catalytic manner has been achieved. The cornerstone of this synthesis features an asymmetric, stereodivergent Ir/amine dual catalytic α-allylation of 2-phthalimidoacetaldehyde.

4-Nitropyrazolin-5-ones as Readily Available Fungicides of the Novel Structural Type for Crop Protection: Atom-Efficient Scalable Synthesis and Key Structural Features Responsible for Activity.

The development of new types of fungicides for agriculture and medicine is highly desirable due to the uprising fungal resistance against commonly used compounds. Herein, 4-substituted-4-nitropyrazolin-5-ones (nitropyrazolones) were proposed as highly active fungicides of the novel structural type. The first scalable and practical method for the nitropyrazolone synthesis was proposed, which is atom-efficient, is applicable for the multigram scale synthesis, and allows for production of a wide variety of nitropyrazolones with high yields and purity. The synthesized compounds demonstrated high fungicidal activity against the broad spectrum of phytopathogenic fungi (Venturia inaequalis, Rhizoctonia solani, Fusarium oxysporum, Fusarium moniliforme, Bipolaris sorokiniana, and Sclerotinia sclerotiorum). Their mycelium growth inhibiting activity was comparable or superior to that of kresoxim-methyl. In vitro activity against Staphyloccocus aureus, Candida albicans, and Aspergillus niger revealed that nitropyrazolones are promising candidates against human pathogens. The key factors for the manifestation of high fungicidal activity were established to be an aromatic substituent on the N1 atom and small substituents, such as methyl, at the C3 and C4 positions of the pyrazolone ring.

Coaxial structures based on NiO/Ni@Carbon felt: Synthesis features, electrochemical behavior and application perspectives

• Coaxial structures of NiO/Ni@Carbon felt were produced by electrochemical template synthesis. • By varying the temperature conditions, materials with different electrochemical behavior were synthesized. • The best temperature conditions are proposed for the electrochemical template synthesis of NiO/Ni@Carbon felt. The coaxial structures of NiO/Ni@Carbon felt were synthesized via an electrochemical template approach followed by annealing at various temperatures and exposure. Comparison of synthesis conditions, morphology features, as well as the results of measurements of electrochemical performance, made it possible to classify the application of the material by the annealing degree of carbon template (R). At R < 0.05, the material shows electrocatalytic properties in reactions of water splitting (η HER = -230 mV and η OER = 175 mV at j = 20 mA·cm −2 ). At 0.05 < R < 0.7, the practical application of the material lies in the field of chemical current sources and supercapacitors as a precursor ( C m = 20–200F·g −1 ). Materials with higher values of R (R > 0.7) do not exhibit either electrocatalytic or capacitive properties and are the subject of further research and search for practical use.