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A-234, [EtO-P([double bond, length as m-dash]O)(F)-N[double bond, length as m-dash]C(Me)-N(Et) 2 ], is the suspected A-type nerve agent used in the Skripal attack on the 4th of March 2018. Studies related to the structure and reactivity of this compound are limited. We, therefore, aimed at understanding the underlying hydrolysis mechanism of A-234 within the DFT framework. The attack of the water molecule can occur at the phosphinate and acetoamidine reactive centres. Our theoretical findings indicate that the hydrolysis at the acetoamidine centre is thermodynamically favoured compared to the hydrolysis at the phosphinate centre. The hydrolysis at the acetoamidine moiety may proceed via two pathways, depending on the nitrogen atom participating in the hydrolysis. The main pathway consists of four distinct channels to reach the final product, with the concerted 1,3-proton shift favoured kinetically and thermodynamically in the gas phase and water as solvent. The results are in good agreement with the literature, although some differences in the reaction mechanism were observed., Competing Interests: The authors declare no conflict of interest., (This journal is © The Royal Society of Chemistry.)

Correction for 'A colorimetric probe for the real-time naked eye detection of cyanide and hydroxide ions in tap water: experimental and theoretical studies' by Veikko Uahengo et al., Analyst, 2019, 144, 6422-6431.

Herein, a colorimetric sensor (L) based on a naphthyl derivative bearing hydrazone receptors was synthesized via a one-step reaction process, and its recognition properties towards biologically important anions in an acetonitrile-water mixture were investigated by naked-eye observation and UV-Vis and 1 H NMR spectroscopy. The molar addition of anions, such as TBAF - , TBAOH - , TBACN - and TBAAcO - , induced a significant red shift in the charge transfer band (Δλ = 73 nm, from 337 nm to 410 nm), in agreement with visible "naked eye" detectable colorimetric activities; in addition, soaked-in-L paper strips were prepared, which could significantly discriminate cyanide (KCN) and hydroxide (NaOH) ions dissolved in tap water via the litmus test method. This study was complemented by density functional theory computations to gain more insight into the interaction between L and anions.

Density functional theory and time-dependent density functional theory computations were used to understand the electronic and photophysical parameters of NIR β-thiophene-fused BF 2 -azadipyrromethene dyes. The computed data are in good agreement with those obtained experimentally and they provide insights into the origin of red shifted optical spectra compared to the parent aza-BODIPY, low Stokes shift, non-linear optical responses and quantitative description of the singlet-triplet energy gap. The resultant decrease in the HOMO - LUMO energy gap is responsible for the red shift. The possible use as non-linear optical materials is supported by large enhancement in the non-linear optical properties. On the basis of vertical triplet energies, their possible potential therapeutic use as a photosensitizer in photodynamic therapy is proposed. The singlet-triplet energetic gaps suggest that the β-thiophene-fused BF 2 -azadipyrromethene dyes can act as a sensitizer to produce an efficient generation of singlet oxygen. Their optimal use as an efficient singlet fission materials has been proposed on the basis of excitation energies in the ground, lowest singlet and triplet excited states.

2,4-Ditellurouracil exhibits keto-enol tautomerism via different pathways resulting in seven tautomers. These pathways were studied in the gas phase using density functional theory method. The functionals used were BLYP, B3LYP and BHLYP and the basis sets were 6-311++G(d,p) for all atoms except that LanL2DZ ECP was used for tellurium atom only. The results indicate that the diketo form is more stable as observed for uracil and its sulfur and selenium analogues. The effect of introducing fluorine at position 5 was also investigated and the energy difference between the diketo and dienol forms is reduced. 2,4-Ditellurouracil and its 5-fluoro analogue are expected to exist exclusively as the diketo form due to the high interconversion energy barrier. We extended the investigation to predict ADME parameters of the most stable diketo and dienol tautomers in view of understanding their biological properties. This research enlightens keto-enol tautomerism of 2,4-ditellurouracil and its 5-fluoro derivative with additional insights to biological functions., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

An efficient method for the synthesis of 5'-O-monomethoxytrityl-2',3'-dideoxy-2'-fluoro-3'-thioarabinothymidine [(5'MMT)araF-T(3'SH), (5)] and its 3'-phosphoramidite derivative (6) suitable for automated incorporation into oligonucleotides, is demonstrated. A key step in the synthesis involves reaction of 5'-O-MMT-2,3'-O-anhydrothymidine (4) (Eleuteri, A.; Reese, C.B.; Song, Q. J. Chem. Soc. Perkin Trans. 1 1996, 2237 pp.) with sodium thioacetate to give (5'-MMT)araF-T(3'SAc) (5) (Elzagheid, M.I.; Mattila, K.; Oivanen, M.; Jones, B.C.N.M.; Cosstick, Lönnberg, H. Eur. J. Org. Chem. 2000, 1987-1991). This nucleoside was then converted to its corresponding phosphoramidite derivative, 6, as described previously ((a) Sun, S.; Yoshida, A.; Piccirilli, J.A. RNA, 1997, 3, 1352-1363; (b) Matulic-Adamic, J.; Beigelman, L. Helvetica Chemica Acta 1999, 82, 2141-2150: (c) Fettes, K.J.; O'Neil, I.; Roberts, S.M.; Cosstick, R. Nucleosides, Nucleotides and Nucl. Acids 2001, 20, 1351-1354).

Interesting and very promising antisense properties of 2'-deoxy-2'-fluoroarabinonucleic acids ((a) Wilds, C.J.; Damha, M.J. 2'-Deoxy-2'-fluoroarabinonucleosides and oligonucleotides (2'F-ANA): synthesis and physicochemical studies. Nucl. Acids Res. 2000, 28, 3625-3635; (b) Viazovkina, E.; Mangos, M.; Elzagheid, M.I.; Damha, M.J. Current Protocols in Nucleic Acid Chemistry 2002, 4.15.1-4.15.21) (2'F-ANA) has encouraged our research group to optimize the synthetic procedures for 2'-deoxy-2'-fluoro-beta-D-arabinonucleosides (araF-N). The synthesis of araF-U, araF-T, araF-A and araF-C is straightforward, (Tann, C.H.; Brodfuehrer, P.R.; Brundidge, S.P.; Sapino, C., Jr. Howell H.G. Fluorocarbohydrates in synthesis. An efficient synthesis of 1-(2-deoxy-2-fluoro-beta-D-arabinofuranosyl)-5-iodouracil (beta-FIAU) and 1-(2-deoxy-2-fluoro-beta-D-arabinofuranosyl)thymine (beta-FMAU). J. Org. Chem. 1985, 50, 3644-3647; Howell, H.G.; Brodfuehrer, P.R.; Brundidge, S.P.; Benigni, D.A.; Sapino, C., Jr. Antiviral nucleosides. A stereospecific, total synthesis of 2'-fluoro-2'-deoxy-beta-D-arabinofuranosyl nucleosides. J. Org. Chem. 1988, 53, 85-88; Maruyama, T.; Takamatsu, S.; Kozai, S.; Satoh, Y.; Izana, K. Synthesis of 9-(2-deoxy-2-fluoro-beta-D-arabinofuranosyl)adenine bearing a selectively removable protecting group. Chem. Pharm. Bull. 1999, 47, 966-970) however, the synthesis of the guanine analogue is more complicated and affords poor to moderate yields of araF-G (4) ((a) Elzagheid, M.I.; Viazovkina, E.; Masad, M.J. Synthesis of protected 2'-deoxy-2'-fluoro-beta-D-arabinonucleosides. Synthesis of 2'-fluoroarabino nucleoside phosphoramidites and their use in the synthesis of 2'F-ANA. Current Protocols in Nucleic Acid Chemistry 2002, 1.7.1-1.7.19; (b) Tennila, T.; Azhayeva, E.; Vepsalainen, J.; Laatikainen, R.; Azhayev, A.; Mikhailopulo, I. Oligonucleotides containing 9-(2-deoxy-2-fluoro-beta-D-arabinofuranosyl)-adenine and -guanine: synthesis, hybridization and antisense properties. Nucleosides, Nucleotides and Nucl. Acids 2000, 19, 1861-1884). Here we describe an efficient synthesis of araF-G (4) that involves coupling of 2-deoxy-2-fluoro-3,5-di-O-benzoyl-alpha-D-arabinofuranosyl bromide (1) with 2-chlorohypoxanthine (2) to afford 2-chloro-beta-araF-I (3) in 52% yield. Nucleoside (3) was transformed into araF-G (4) by treatment with methanolic ammonia (150 degrees C, 6 h) in 67% yield.

The ability of modified antisense oligonucleotides (AONs) containing acyclic interresidue units to support RNase H-promoted cleavage of complementary RNA is described. Manipulation of the backbone and sugar geometries in these conformationally labile monomers shows great benefits in the enzymatic recognition of the nucleic acid hybrids, while highlighting the importance of local strand conformation on the hydrolytic efficiency of the enzyme more conclusively. Our results demonstrate that the duplexes support remarkably high levels of enzymatic degradation when treated with human RNase HII, making them efficient mimics of the native substrates. Furthermore, interesting linker-dependent modulation of enzymatic activity is observed during in vitro assays, suggesting a potential role for this AON class in an RNase H-dependent pathway of controlling RNA expression. Additionally, the butyl-modified 2'F-ANA AONs described in this work constitute the first examples of a nucleic acid species capable of eliciting high RNase H activity while possessing a highly flexible molecular architecture at predetermined sites along the AON.

This unit describes in detail the preparation of protected 2'-deoxy-2'-fluoroarabinonucleosides. These building blocks are required for the synthesis of 2'-deoxy-2'-fluoroarabinonucleic acid (2'F-ANA), an oligonucleotide analog exhibiting very promising antisense properties. The preparation of phosphoramidites from these building blocks and the synthesis of 2'F-ANA are described elsewhere in the manual.

This unit describes the chemical synthesis of 2'-deoxy-2'-fluoro-b-D-oligoarabinonucleotides (2'F-ANA), both with phosphodiester and phosphorothioate linkages. The protocols described herein include araF phosphoramidite preparation, assembly on DNA synthesizers, and final deprotection and purification of oligonucleotides.

The hydrolytic reactions of the dimethyl ester of 3'-deoxy-3'-thioinosine 3'-S-phosphorothiolate have been followed over a wide aciditiy range by HPLC. At pH > 3, only hydroxide ion catalyzed isomerization to the 2'-dimethylphosphate takes place, whereas under more acidic conditions hydrolysis to the 2'-monomethylphosphate and 3'-S-monomethylphosphorothiolate competes. The latter is the only product accumulating in very acidic solutions (1 M hydrochloric acid). Mechanisms of the reactions are discussed.

Bromophenol blue is a toxic triphenylmethane dye that is widely used in various industries. The dye-contaminated wastewater released from the industries results in substantial water pollution, causing several health problems and having severe negative consequences for the ecosystem. As a result, its toxic presence in environmental water is a cause for serious concern. Therefore, the removal of wastewater is vital to preserving environmental quality. The adsorption process stands out among several water treatment techniques due to its low cost, efficiency, simplicity, selectivity, and recyclability. Thus, several adsorbents have been applied for the treatment of bromophenol blue-contaminated water via the adsorption technique. This review presents the adsorption of bromophenol blue onto bio-based adsorbents such as biomass, activated carbon, and biochar as well as other potent materials like nanoparticles, polymers, and composite. The isotherm, kinetics, thermodynamics, and mechanism of the adsorption process were all discussed. We also considered the regeneration of the adsorbents and their reusability in the treatment process. Moreover, research gaps in many aspects were discovered, and future research proposals were offered. [ABSTRACT FROM AUTHOR]

Background: Plant pathogenic fungi pose a severe threat to crop yield and food security. This study aims to investigate the potential antifungal activity and mechanism of action of camphor-thiazole derivatives against six plant pathogenic fungi. A novel series of camphor-thiazole derivatives were designed, synthesized and evaluated for their antifungal effects against Rhizoctonia solani, Fusarium graminearum, Valsa mali, Alternaria solani, Colletotrichum orbiculare and Botryitis cinerea., Results: Most of the synthesized camphor-thiazole derivatives exhibited notable antifungal activity. Amongst them, compounds C5, C10 and C17 showed significant activity against R. solani with median effective concentrations (EC 50 ) values in the range 3-4 μg mL -1 , demonstrating superior antifungal efficacy to the control drug boscalid (EC 50  = 1.23 μg mL -1 ). Structure-activity relationship and density functional theory analysis emphasized the critical role of substituent selection in optimizing the biological activity of these compounds. Moreover, preliminary mechanistic studies revealed that compound C5 induced abnormal mycelial and cellular morphology in R. solani as observed using scanning and transmission electron microscopy, and triggered the production and accumulation of reactive oxygen species. Additionally, the increased concentration of C5 resulted in enhanced cell membrane permeability., Conclusion: In this study, the designed and optimized compound C5 emerged as a promising candidate for potent antifungal agents. The results demonstrate that synthesized camphor-thiazole derivatives possess potent antifungal activity and can serve as lead compounds for further optimization in antifungal agent development. © 2024 Society of Chemical Industry., (© 2024 Society of Chemical Industry.)

The impact of silver tungstate/reduced graphene oxide nanocomposites (Ag2WO4/rGO NCs) for improved photocatalytic degradation of organic dye pollution is examined in this study. A number of properties of the produced Ag2WO4/rGO NCs were identified, including their crystallinity, particle size, recombination of photogenerated charge carriers, energy gap, and surface morphologies. The presence of rGO in the composition improved the photocatalytic activity by diminishing the optical bandgap energy of Ag2WO4. Furthermore, the Ag2WO4/rGO NCs exhibited an outstanding photocatalytic efficiency of methylene blue (MB) degradation (97.14%) while pure Ag2WO4 and rGO showed 36.14% and 52.85%, respectively. The improved photocatalytic activity of the Ag2WO4/rGO NCs is ascribed to the rGO layers' strong electron transport abilities, which make it possible to separate electron–hole pairs effectively. According to the studies, Ag2WO4/rGO NCs is a powerful photocatalysts and may be utilized as the perfect material to stop water pollution in the future. [ABSTRACT FROM AUTHOR]

In this research, rice husk (RH) was utilized to prepare a magnetic adsorbent for adsorption of ascorbic acid (AA). The magnetic agent is iron(III) chloride (FeCl3). The impact of acid concentration in the range of 400–800 ppm, adsorbent dosage in the range of 0.5–1 g, and contact time in the range of 10–130 min were studied. The Langmuir model had the highest R2 of 0.9982, 0.9996, and 0.9985 at the temperature of 15, 25, and 35 °C, respectively, and the qmax values in these temperatures have been calculated at 19.157, 31.34, and 38.75 mg/g, respectively. The pseudo-second-order kinetic model had the best agreement with the experimental results. In this kinetic model, the values of q have been measured at 36.496, 45.248, and 49.019 mg/g at the acid concentration of 418, 600, and 718 ppm, respectively. The values of ΔHo and ΔSo were measured 31.972 kJ/mol and 120.253 kJ/mol K, respectively, which proves the endothermic and irregularity nature of the adsorption of AA. Besides, the optimum conditions of the design-expert software have been obtained 486.929 ppm of acid concentration, 0.875 g of the adsorbent dosage, and 105.397 min of the contact time, and the adsorption efficiency in these conditions was determined at 92.94%. The surface area of the RH and modified RH was determined of 98.17 and 120.23 m2/g, respectively, which confirms the high surface area of these two adsorbents. [ABSTRACT FROM AUTHOR]

Novichok agents have evolved as weapon of mass destruction. Its use has been reported in the previous decade mostly for providing detrimental effect on living organisms, surrounding ecosystem, and the environment. Novichok agents have a very high fatal effect due to its ability to bind with acetylcholinesterase, resulting in crippling of central nervous system. So, rapid and precise detection of novichok agents have become one of the promising aspects with much evident for the forensic perspective. Hence, this manuscript is aimed to emphasize on various novel detection techniques reported for novichok detection and the possible future aspect on the development of detection technology. [ABSTRACT FROM AUTHOR]

One of the most important types of chemical weapons is nerve agents. In recent years, a group of the newest, most unknown, and at the same time the most common nerve agents known as Novichok has been used in terrorist attacks. It is necessary to become more familiar with the basic and clinical chemical and pharmacologic features of this group of nerve agents for all the employees of the medical group. In this article, while reviewing the history of development and production, chemical structure, mechanism of action, toxicokinetic, and toxicology of these agents, the latest information regarding the methods of diagnosis and treatment of poisoning with these agents was also reviewed. Contrary to early information, it appears that Novichok poisoning is similar to other organophosphate agents and can be managed with prompt and appropriate treatment. Considering the existence of global threats in the field of terrorist incidents with these agents, the medical team must be familiar with these poisons to diagnose and treat the victims optimally. [ABSTRACT FROM AUTHOR]

In this study, firstly, bis(thiosemicarbazone) ligand [L: 2,2'-(2-(2-(4-methoxyphenyl)hydrazineylidene)cyclohexane-1,3-diylidene)bis(hydrazine-1-carbothioamide)] was synthesized by the condensation reaction of thiosemicarbazide and ketone compound (2-(2-(4-methoxyphenyl)hydrazone)cyclohexane-1,3-dione). The metal complexes were synthesized by the reaction of obtained ligand (L) with CuCl 2 ·2H 2 O, NiCl 2 ·6H 2 O, CoCl 2 ·6H 2 O, and MnCl 2 ·4H 2 O salts. The structures of synthesized ligand and their complexes were characterized using elemental analysis, IR, UV-Vis, 1 H-NMR spectra, 13 C-NMR spectra, magnetic susceptibility, mass spectra (LC-MS), thermogravimetry analysis-differential thermal analysis (TGA-DTA), and differential scanning calorimetry techniques. According to the results of the analysis, square plane geometry was suggested for Cu and Co complexes. However, the structures of Ni and Mn complexes were in agreement with octahedral geometry. Molecular docking analysis and pharmacological potential of the compound were evaluated to determine the inhibitory potential against acetylcholinesterase (AChE) and Glutathione-S-transferases (GST) enzymes. The compound exhibited strong binding/docking indices of - 5.708 and - 5.928 kcal/mol for the respective receptors. In addition, L-Ni(II) complex was found to be the most effective inhibitor for AChE enzyme with a K i value of 0.519. However, with a K i value of 1.119, L-Cu(II) complex was also found to be an effective inhibitor for the GST enzyme., (© 2024. The Author(s).)

This study was conducted to measure and compare the glycogen content in three Philippine mussels of the family Mytilidae -- Perna viridis, Mytella strigata, and Modiolus philippinarum. P. viridis, M. strigata, and M. philippinarum were collected from the provinces of Samar, Cavite, and Iloilo, respectively. P. viridis, locally known as "tahong," is cultured in the Philippines. M. strigata, known as "charru" or black mussel, has a distinct brown to black shell coloration that varies with age and is currently considered as an invasive species in the Philippines. Lastly, M. philippinarum mostly inhabits intertidal mudflats, that form extensive aggregates. These mussels are edible and are a well-known cheap source of animal protein. Extraction of glycogen involved mussel meat preparation, the addition of hydrolyzing agents, and precipitation. Results showed glycogen content varies in different species from 5.5-3.0% yield. This study is a contribution to the lack of recorded biological information regarding Philippine mussels in terms of biochemical content such as glycogen. This information can later be used to assess the mussels' health, biological, and habitat ecological status. [ABSTRACT FROM AUTHOR]

Multicobalt(II) two-dimensional layer coordination polymer {[Co(bitbu-OMe)2(NCS)2]·2MeOH}n (1) was synthesized using a bis-imidazole ligand having a steric hindrance, tert-butyl, and one methoxy group expressed by bitbu-OMe (bitbu-OMe = 1,1′-[(5-tert-butyl-2-methoxybenzene-1,3-diyl)dimethanediyl]bis(1H-imidazole). Since there are two methanol molecules trapped inside each void within 1, the investigation of small organic matter removal from organic wastewater was conducted in order to reveal its ability in the purification process. The research findings indicate that 1 has the ability to capture methanol, acetone, acetonitrile, and tetrahydrofuran in organic wastewater with removal ratios of 29.17%, 63.22%, 42.77%, and 21.24%, respectively. [ABSTRACT FROM AUTHOR]

The present study was intended to develop suitable methods for unambiguous identification and determination of ethyl (1-(diethylamino)ethylidene) phosphoramidofluoridate (known as A234-Novichok) biomarkers in urine and plasma samples. Multiple biomarkers were investigated for the first time, to verify intoxication by the A234-Novichok agent, using sensitive and accurate techniques including gas and liquid chromatography-tandem mass spectrometry (GC–MS/MS and LC–MS/MS). Like other nerve agents, in biological matrices, the A234-Novichok agent reacts with several proteins to form related adducts. Considering this, two different protein adduct biomarkers in blood samples were analyzed, and the regenerated A234 was determined. Two-dimensional chromatography and solid-phase extraction techniques were employed for blood sample preparation. Limits of detection for butyrylcholinesterase (BChE) adduct, the regenerated A234, and albumin covalent adduct were determined and reported as 1, 1, and 10 ng mL−1, while the related calibration curves were linear within the range of 2–100, 2–100, and 15–100 ng mL−1, respectively. The detection limit and linear range for the intact agent in the urine sample were determined as 0.1 and 1–100 ng mL−1, respectively. Since A234 and some other Novichok chemicals have been added to the Schedule 1 of the Chemical Weapons Convention (CWC), Annex on Chemicals, after UK incidents, the analytical methods developed in this work might be used for verification purposes, as well as OPCW Biomedical Proficiency Tests. [ABSTRACT FROM AUTHOR]

High toxicity and extensive accessibility of fluoride and cyanide ions in diverse environmental media encouraged attention for scheming well-organized probes for their detection. Keeping in mind we have designed and synthesized thiosemicarbazone-based chemosensors RB-1, RB-2 and RB-3 for the detection of fluoride and cyanide ions. The structural elucidation of the synthesized chemosensors is done by employing different analytical techniques including nuclear magnetic resonance and electronic absorption specrtoscopies. Admirable detection limit, binding constant and fast response time (2 s) to F− and CN− ions enlarged the applications of these chemosensors. Additional confirmation of the sensing ability of these chemosensors is derived from DFT and TDDFT calculations with M06/6-311G(d,p) method by performing FMO, UV–Vis, QTAIM and global reactivity parameters elucidation. Overall results point out that investigated chemosensors are suitable candidates for sensing the F− ions. These chemosensors were successfully applied to detect F− ions in a commercial toothpaste sample. [ABSTRACT FROM AUTHOR]

A fluorenyl-thioic-based dye (P) bearing a thioic ester moiety was designed, synthesized and spectroscopically characterized. The photophysical properties were studied via UV–Vis spectroscopy in acetonitrile (CH3CN) as a solvent of choice. Upon investigating and studying the photophysical properties, it was found that P could be an ideal colorimetric sensor for biologically important anions and cations. The chemosensing properties were studied through naked eye observable colour changes as well as UV–Vis titration method. The naked eye observations and UV–Vis titrations established that P is a colorimetric probe selective and sensitive to some cations (Ag+, Hg2+, Ni2+, Fe3+, Co2+, Cu2+ and Zn2+) and anions (F−, CN−, OH− and AcO−) in CH3CN. The nature of interaction with cations is via coordination by soft atoms (nitrogen and sulphur atoms), in the process inducing spectral red shift (375 to 475 nm), whereas interaction with anions was dominated by hydrogen bonding, leading to yet another red shift (375 to 453 nm). The cross-detection studies have indicated that M has more affinity towards Cu2+, followed by Zn2+, compared to all other cations used. The reversibility and reproducibility studies were carried out, and P was found to exhibit molecular logic behaviours, thereby displaying complementary IMP/INH logic functions, based on colour and spectral switching (ON/OFF). Hence, the probe can thus be utilized as a colorimetric molecular switch modulated by F−/Al3+. In addition, the experimental data were supplemented by computational calculations, where HOMO and LUMO levels at − 5.65 and − 2.51 eV (3.14 eV energy gap) for P were well in agreement with the absorption curve. [ABSTRACT FROM AUTHOR]

Thiophosphinoylation of N-methyl p-substituted benzohydroxamic acids using disulfanes (method A) or diphenylphosphinothioyl chloride (method B) provides only one conformer of the respective O-phosphothioyl derivative (X-ray and NMR analysis). Undergoing the P-transamidoxylation reaction is an evidence of the reversibility of thiophosphinoylation. Only those products containing strong EWG substituents in the aroyl residue or bulky substituents at the phosphorus atom possess E conformation. DFT calculations confirmed the energetic domination of each isomer. The Z-isomers are distorted amides having both high degree of nitrogen pyramidalization (38–55°) and amide twist (12–30°). In solution they exist in a defined conformation that is evidenced by the presence of a sharp signal of N-methyl protons at low temperature. They do not isomerize in solutions. Some of them slowly undergo the N-O bond scission above 100 °C. Both isomers are not as sensitive to neutral hydrolysis as twisted amides can be and are inert toward amines. The rate of alkaline hydrolysis can be correlated with pKa of hydroxamic acid. Because of their outstanding oxyphilicity, these compounds can be defined as nerve agent surrogates and safer alternatives of phosphorus fluorides for serine-active enzyme inhibition studies. [ABSTRACT FROM AUTHOR]

Brown seaweeds are rich in polysaccharides, such as fucoidan (FUC) which has shown beneficial effects in several medical conditions. The aim of the present study was to assess the antioxidant, anti-inflammatory, and hepatoprotective properties of Colpomenia sinuosa– and Sargassum prismaticum–isolated FUC in vitro and in vivo. The hot acid extraction method was used to isolate FUC from C. sinuosa (FCS) and S. prismaticum (FSP) species. The antioxidant, anticancer, as well as the effect on neurotransmitter-degrading enzyme and disaccharidase activities were measured using standard protocols. Moreover, the hepatoprotective effect of two FCS doses (100 and 200 mg/kg) on paracetamol-administered rats (one dose of 1 g/kg) were evaluated by measuring blood liver function markers, hepatic pro-oxidants as malondialdehyde (MDA) and nitric oxide (NO), antioxidants as glutathione (GSH) and glutathione peroxidase (GPx), proinflammatory markers as inducible nitric oxide synthase (iNOS), interleukin 1β (IL-1β), tumor necrosis factor-α (TNF-α), and liver histology. The crude fucoidan yield was 15.6% and 14.8% of C. sinuosa and S. prismaticum dry weights, respectively. The antioxidant effects and cytotoxic activity on hepatic cancer cell were higher for FCS than FSP. Moreover, in vivo data showed that FCS administration at both doses significantly improved liver functions and alleviated histological alterations, hepatic inflammation, and oxidative stress following paracetamol intake. In conclusion, fucoidan exerts anti-inflammatory, antidigestive enzyme activity, antioxidant, anticancer, and hepatoprotective effects. [ABSTRACT FROM AUTHOR]

In this study, a new chemosensor IDTTH for rapid detection of cyanide (CN─) based on 6,6,12,12-Tetrakis(4-hexylphenyl)-6,12-dihydrodithieno[2,3-d:2′,3′-d′]-s-indaceno[1,2-b:5,6-b′]di- thiophene-2,8-dicarboxaldehyde-hemicyanine conjugate has been developed. The 6,6,12,12-tetrakis(4-hexylphenyl)-6,12-dihydrodithi-eno[2,3-d:2′,3′-d′]-s-indaceno[1,2-b:5,6-b′]dithiophene was served as a signal unit and hemicyanine as a recognition unit. This probe shows high selectivity towards CN─ ions among tested anions. Addition of CN─ ions to probe IDTTH in semi-aqueous solution (acetonitrile/H2O = 1/1, V/V) could lead to a 195 nm blue shift of absorption band, together with colour changes from blue to yellow. The sensing mechanism is attributed to the nucleophilic addition between CN─ and the C=N bond of indolium group, which could be clearly clarified through the 1H NMR titration and MS spectral. Moreover, probe IDTTH could be used as the test strips with low cost to detect CN─ ions conveniently by naked eyes. [ABSTRACT FROM AUTHOR]

Is it possible to 'explore' metal's intrinsic property—a cohesive interaction—which naturally transform M0 into an aggregate or a particle or film for driving oxidative C–C bond formation? With this intention, reduction of [Ag(NH3)2]+ to Ag0 with concurrent oxidation of different phenols/naphthols to biphenyls was undertaken. The work is originated during careful observation of an undergraduate experiment—Tollens' test—where silver mirror film deposition takes place on the walls of borosilicate glass test tube. When the same reaction was carried out in polypropylene (plastic-Eppendorf) tube, we observed aggregation of Ag0 leading to floating Ag-particles but not silver film deposition. This prompted us to carry out challenging cross-coupling reaction by ONLY changing the surface of the reaction flask from glass to plastic to silicones. To our surprise, we observed good selective oxidative homo-coupling on Teflon surface while cross-coupling in Eppendorf vial. Thus, we propose that the formation of biphenyl is driven by the macroscopic growth of Ag0 into [Ag-particle] orchestrated by Ag...Ag cohesive interaction. To validate results, experiments were also performed on gram scale. More importantly, oxidation of β-naphthol carried out in quartz (chiral) tube which yielded slight enantioselective excess of BINOL. Details are discussed. [ABSTRACT FROM AUTHOR]

Background: Students, staff, and faculties are involved in activities that exposed them to a range of minor to severe or even fatal accidents in academic settings. Managing work environment risks is crucial to any safety and health prevention program. This study developed a risk assessment using combinations of hazards and risk factors to establish a scale of measures in a risk reduction action plan.Methods: This cross-sectional study was conducted in an Iranian medical sciences university in 2018. A structured method of risk assessment was developed, applying a three-step procedure to identify hazards, consequences, and risk evaluation. Data were collected through detailed health, safety, and environment checklist in 38 different sites. Finally, the risks quantified, prioritized, and control measures proposed accordingly. Chi-square and correlation tests assessed how environmental factors were associated with hazard consequences. The analysis results were evaluated at the significance level of 0.05.Results: The frequencies of moderate and high-risk levels were 22.7 and 2.9%, respectively. Thus, corrective measures should be considered as soon as possible and immediately for these risk groups. Facilities and functions within laboratories, library, and powerhouse were more vulnerable to serious risks. The type of hazard had associated with the sites and total risk score at the significance level of 0.05 (P-value = 0.017). Similarly, risk severity was significantly related to the sites (P-value = 0.003). Safety hazards had a statistically higher contribution to the total risk score when compared to health and environmental hazards.Conclusion: The study revealed complex risks and hazardous circumstances with significant variances in academic sites and activities. Universities should provide training in risk reduction programs to increase the awareness of students, staff, and faculties, which can improve life safety in a university environment. [ABSTRACT FROM AUTHOR]

Oligonucleotides (ONs) can interfere with biomolecules representing the entire extended central dogma. Antisense gapmer, steric block, splice-switching ONs, and short interfering RNA drugs have been successfully developed. Moreover, antagomirs (antimicroRNAs), microRNA mimics, aptamers, DNA decoys, DNAzymes, synthetic guide strands for CRISPR/Cas, and innate immunity-stimulating ONs are all in clinical trials. DNA-targeting, triplex-forming ONs and strand-invading ONs have made their mark on drug development research, but not yet as medicines. Both design and synthetic nucleic acid chemistry are crucial for achieving biologically active ONs. The dominating modifications are phosphorothioate linkages, base methylation, and numerous 2′-substitutions in the furanose ring, such as 2′-fluoro, O-methyl, or methoxyethyl. Locked nucleic acid and constrained ethyl, a related variant, are bridged forms where the 2′-oxygen connects to the 4′-carbon in the sugar. Phosphorodiamidate morpholino oligomers, carrying a modified heterocyclic backbone ring, have also been commercialized. Delivery remains a major obstacle, but systemic administration and intrathecal infusion are used for treatment of the liver and brain, respectively. [ABSTRACT FROM AUTHOR]

This study examines the influence of cellulose nanocrystal (CN) particles on the morphological, thermal, and thermo-mechanical properties of polylactide (PLA)/poly [(butylene succinate)-co-adipate] (PBSA) blend foams prepared by casting and particulate leaching method using fructose as porogen particles. The morphological analysis showed an interconnected open-cell structure, with porosity above 80%. The crystallinity of the prepared foams was disrupted by the inclusion of CN particles as observed from XRD analyses, which showed a decrease in PLA crystal peak intensity. With regards to neat blend foam, the onset thermal degradation increased with the addition of CN particles, which also increased the thermal stability at 50% weight loss. Furthermore, CN acted as a reinforcing agent in improving the stiffness of the prepared blend foam. Overall, completely environmentally friendly foams were successfully prepared, as a potential material that can replace the current existing foam materials that pose many environmental concerns. However, there is a need to develop an environmentally friendly processing technique. [ABSTRACT FROM AUTHOR]