On the mechanisms of ion adsorption to aqueous interfaces: air-water vs. oil-water.

The adsorption of ions to water-hydrophobe interfaces influences a wide range of phenomena, including chemical reaction rates, ion transport across biological membranes, and electrochemical and many catalytic processes; hence, developing a detailed understanding of the behavior of ions at water-hydrophobe interfaces is of central interest. Here, we characterize the adsorption of the chaotropic thiocyanate anion (SCN-) to two prototypical liquid hydrophobic surfaces, water-toluene and water-decane, by surface-sensitive nonlinear spectroscopy and compare the results against our previous studies of SCN- adsorption to the air-water interface. For these systems, we observe no spectral shift in the charge transfer to solvent spectrum of SCN-, and the Gibb's free energies of adsorption for these three different interfaces all agree within error. We employed molecular dynamics simulations to develop a molecular-level understanding of the adsorption mechanism and found that the adsorption for SCN- to both water-toluene and water-decane interfaces is driven by an increase in entropy, with very little enthalpic contribution. This is a qualitatively different mechanism than reported for SCN- adsorption to the air-water and graphene-water interfaces, wherein a favorable enthalpy change was the main driving force, against an unfavorable entropy change.

Self-assembly of new cobalt complexes based on [Co (SCN)4], synthesis, empirical, antioxidant activity, and quantum theory investigations.

The cobalt (II) complexes have been synthesized from the reaction of the cationic entities (3,4-dimethylaniline (1) and histamine (2)) with metallic salt CoCl2⋅6H2O and thiocyanate ion (SCN-) as a ligand in H2O/ethanolic solution and processing by the evaporation crystal growth method at room temperature to get crystals. The synthesized complex has been fully characterized by single-crystal X-ray diffraction. UV-Visible, FTIR spectroscopy, TGA analysis, and DFT circulations were also performed. The crystal structural analysis reveals that the solid (1) {[Co(SCN)4] (C8H12N)3}·Cl crystallizes in the monoclinic system with the space group P21/n and the solid (2) {[Co(SCN)4](C5H11N3)2}·2Cl crystallizes in the monoclinic space group P21/m. Metal cations are joined into corrugated chains parallel to the b-axis direction in (1) and (2) by four thiocyanate anions. The crystal structures of (1) and (2) were calculated using XRPD data, indicating that they are closely connected to the DRX mono-crystal results. Different interactions pack the system into a ring formed by N-H⋯Cl and N-H⋯S hydrogen bonds. C-H⋯π and the π⋯π stacking of anilinuim ring for (1) and N-H⋯S intermolecular interactions for (1) and (2) increase the crystals' robustness. Hirshfeld surface analysis cum 2D fingerprint plots visualize the main intermolecular interactions with their contributions in the solid-state phase. The molecular geometries of both complexes obtained from the crystal structure were used for quantum chemical calculation. Here, frontier orbital analysis and electrostatic potential illustrate the chemical reactivities of metal-organic complexes. QTAIM and NCI analysis reveal the strength of interactions at the electronic level.

NDTP Mediated Direct Rapid Amide and Peptide Synthesis without Epimerization.

Herein, we explored an unprecedented mild, nonirritating, conveniently available, and recyclable coupling reagent NDTP, which could activate the carboxylic acids via acyl thiocyanide and enable the rapid amide and peptide synthesis at very mild conditions. In addition, the methodology was compatible with Fmoc-SPPS, which may provide an alternative to peptide manufacturing.

Cavitas electrochemical sensors for the direct determination of salivary thiocyanate levels.

Noninvasive diagnosis using salivary samples to detect thiocyanate provides vital information on individual health. This article demonstrates the first example of a wearable sensing device to noninvasively assess thiocyanate levels. The customized screen-printed electrode system is integrated into a form of a mouthguard squarewave-voltammetric sensor toward the convenient and fast detection of the salivary biomarker within 15 s. The sensor with a protective film to mitigate the effect of biofouling offers high sensitivity and selectivity toward the detection of thiocyanate ions. Partial least square regression is applied to analyze the high-order squarewave-voltammetric data over the applied potential range of 0-1.75 V vs Ag/AgCl and quantify the thiocyanate concentration in a complex matrix. The mouthguard sensor operating under physiological conditions can monitor a wide range of thiocyanate (up to 11 mM) with a low detection limit of 30 µM. The demonstration introduces a unique approach, that obviates the requirement for blood sampling, to study thiocyanate levels of healthy people, cigarette smokers, or people with other health conditions. It is envisioned that the new cavitas device possesses a substantial promise for diverse biomedical diagnosis applications.

Lepidium graminifolium L.: Glucosinolate Profile and Antiproliferative Potential of Volatile Isolates.

Glucosinolates (GSLs) from Lepidium graminifolium L. were analyzed qualitatively and quantitatively by their desulfo-counterparts using UHPLC-DAD-MS/MS technique and by their volatile breakdown products-isothiocyanates (ITCs) using GC-MS analysis. Thirteen GSLs were identified with arylaliphatic as the major ones in the following order: 3-hydroxybenzyl GSL (glucolepigramin, 7), benzyl GSL (glucotropaeolin, 9), 3,4,5-trimethoxybenzyl GSL (11), 3-methoxybenzyl GSL (glucolimnanthin, 12), 4-hydroxy-3,5-dimethoxybenzyl GSL (3,5-dimethoxysinalbin, 8), 4-hydroxybenzyl GSL (glucosinalbin, 6), 3,4-dimethoxybenzyl GSL (10) and 2-phenylethyl GSL (gluconasturtiin, 13). GSL breakdown products obtained by hydrodistillation (HD) and CH2Cl2 extraction after hydrolysis by myrosinase for 24 h (EXT) as well as benzyl ITC were tested for their cytotoxic activity using MTT assay. Generally, EXT showed noticeable antiproliferative activity against human bladder cancer cell line UM-UC-3 and human glioblastoma cell line LN229, and can be considered as moderately active, while IC50 of benzyl ITC was 12.3 µg/mL, which can be considered as highly active.

A convenient synthesis of branched-chain nucleoside isothiocyanates via aza-Claisen rearrangement.

Stereocontrolled introduction of a nitrogen atom at either C-2' or C-3' positions of nucleosides derived from uridine, 4-N-benzoylcytidine and adenosine was investigated. An efficient and rapid procedure was employed for creating new chiral centers at C-2' and C-3' positions using [3,3]-sigmatropic aza-Claisen rearrangement of allyl thiocyanates under conventional and microwave conditions. Structure of isothiocyanate products was confirmed by 1-D and 2-D NMR spectral analyses including selective 1H 1-D-NOE experiments.

Synergistic Interaction between 5-FU and an Analog of Sulforaphane-2-Oxohexyl Isothiocyanate-In an In Vitro Colon Cancer Model.

Combination therapy is based on the beneficial effects of pharmacodynamic interaction (synergistic or additive) between combined drugs or substances. A considerable group of candidates for combined treatments are natural compounds (e.g., isothiocyanates) and their analogs, which are tested in combination with anticancer drugs. We tested the anticancer effect of the combined treatment of isothiocyanate 2-oxohexyl isothiocyanate and 5-fluorouracil in colon and prostate cancer cell lines. The type of interaction was described using the Chou-Talalay method. The cytostatic and cytotoxic activities of the most promising combined treatments were investigated. In conclusion, we showed that combined treatment with 5-fluorouracil and 2-oxohexyl isothiocyanate acted synergistically in colon cancer. This activity is dependent on the cytostatic properties of the tested compounds and leads to the intensification of their individual cytotoxic activity. The apoptotic process is considered to be the main mechanism of cytotoxicity in this combined treatment.

Site-Specific Conversion of Cysteine in a Protein to Dehydroalanine Using 2-Nitro-5-thiocyanatobenzoic Acid.

Dehydroalanine exists natively in certain proteins and can also be chemically made from the protein cysteine. As a strong Michael acceptor, dehydroalanine in proteins has been explored to undergo reactions with different thiolate reagents for making close analogues of post-translational modifications (PTMs), including a variety of lysine PTMs. The chemical reagent 2-nitro-5-thiocyanatobenzoic acid (NTCB) selectively modifies cysteine to form S-cyano-cysteine, in which the S-Cß bond is highly polarized. We explored the labile nature of this bond for triggering E2 elimination to generate dehydroalanine. Our results indicated that when cysteine is at the flexible C-terminal end of a protein, the dehydroalanine formation is highly effective. We produced ubiquitin and ubiquitin-like proteins with a C-terminal dehydroalanine residue with high yields. When cysteine is located at an internal region of a protein, the efficiency of the reaction varies with mainly hydrolysis products observed. Dehydroalanine in proteins such as ubiquitin and ubiquitin-like proteins can serve as probes for studying pathways involving ubiquitin and ubiquitin-like proteins and it is also a starting point to generate proteins with many PTM analogues; therefore, we believe that this NTCB-triggered dehydroalanine formation method will find broad applications in studying ubiquitin and ubiquitin-like protein pathways and the functional annotation of many PTMs in proteins such as histones.

Feasibility of Phosphoproteomics on Leftover Samples After RNA Extraction With Guanidinium Thiocyanate.

In daily practice, different types of biomolecules are usually extracted for large-scale "omics" analysis with tailored protocols. However, when sample material is limited, an all-in-one strategy is preferable. Although lysis of cells and tissues with urea is widely used for phosphoproteomic applications, DNA, RNA, and proteins can be simultaneously extracted from small samples using acid guanidinium thiocyanate-phenol-chloroform (AGPC). Use of AGPC for mass spectrometry-based phosphoproteomics was reported but has not yet been thoroughly evaluated against a classical phosphoproteomic protocol. Here we compared urea- with AGPC-based protein extraction, profiling phosphorylations in the DNA damage response pathway after ionizing irradiation of U2OS cells as proof of principle. On average we identified circa 9000 phosphosites per sample with both extraction methods. Moreover, we observed high similarity of phosphosite characteristics (e.g., 94% shared class 1 identifications) and deduced kinase activities (e.g., ATM, ATR, CHEK1/2, PRKDC). We furthermore extended our comparison to murine and human tissue samples yielding similar and highly correlated results for both extraction protocols. AGPC-based sample extraction can thus replace common cell lysates for phosphoproteomic workflows and may thus be an attractive way to obtain input material for multiple omics workflows, yielding several data types from a single sample.

Antioxidant activity of two edible isothiocyanates: Sulforaphane and erucin is due to their thermal decomposition to sulfenic acids and methylsulfinyl radicals.

Sulforaphane(SFN) and erucin(ERN) are isothiocyanates (ITCs) bearing, respectively, methylsulfinyl and methylsulfanyl groups. Their chemopreventive and anticancer activity is attributed to ability to modulate cellular redox status due to induction of Phase 2 cytoprotective enzymes (indirect antioxidant action) but many attempts to connect the bioactivity of ITCs with their radical trapping activity failed. Both ITCs are evolved from their glucosinolates during food processing of Cruciferous vegetables, therefore, we studied antioxidant behaviour of SFN/ERN at elevated temperature in two lipid systems. Neither ERN nor SFN inhibit the oxidation of bulk linolenic acid (below 100  °C) but both ITCs increase oxidative stability of soy lecithin (above 150 °C). On the basis of GC-MS analysis we verified our preliminary hypothesis (Antioxidants2020, 9, 1090) about participation of sulfenic acids and methylsulfinyl radicals as radical trapping agents responsible for the antioxidant effect of edible ITCs during thermal oxidation of lipids at elevated temperatures (above 140 °C).

Degradation of thiocyanate by electrochemical oxidation process in coke oven wastewater: Role of operative parameters and mechanistic study.

This study presents the removal of thiocyanate (SCN-) from coke oven wastewater by the electrooxidation (EO) process. Initially, the performances boron-doped diamond (BDD) and different DSA (Dimensionally stable anode) electrodes including Ti/IrO2, Ti/IrO2-RuO2, and Ti/IrO2-RuO2-TiO2 in SCN- removal were compared. BDD anode outperformed the Ti-based mixed metal oxide (MMO) anodes achieving 96.51% SCN- removal efficiency. The most favorable conditions for the removal of SCN- using BDD anode were determined as follows: pH = 9, current density = 43.10 A m-2, and the electrolyte concentration (Na2SO4) = 2.5 g L-1. The strong role of ⦁OH in the removal of SCN- was confirmed by the addition of radical quenching agents. The evolution of the intermediates as a result of the EO of SCN- was determined. Under the determined conditions, the EO process could remove 84.13% of SCN- and 94.67% of phenol from a real coke oven wastewater, which was comparable to that of the simulated solution. The electrical energy consumption cost of the process to remove 1 kg of SCN- was calculated as 0.208 US $. Overall, the study showed the EO using BDD anode is a cost-effective method for the removal of SCN- from a coke oven wastewater.

Characterization of the simplest sulfenyl thiocyanate: isomers, spectroscopy and implications of astrophysical and biological relevance.

Sulfenyl thiocyanate compounds, RSSCN, are involved in the human immune system biochemical processes. They are also the routes for the synthesis of complex S-containing species such as polypeptides, or symmetrical (RSSR) and unsymmetrical disulfides (RSSR'). At present, we have characterized the stable forms of the simplest sulfenyl thiocyanate compound, HSSCN, at the coupled cluster level. We found twenty-three isomers, for which we determined a set of structural parameters, anharmonic frequencies and reaction energies for the formation of the corresponding diatomic + triatomic and atomic + tetratomic fragments. We also discussed the implications of the present findings for biological entities containing a disulfide bridge, where we identified three isomers that may serve as prototypes. Similarities and differences with other S/N hybrid bioactive molecules are also discussed. From an astrophysical point of view, we expect HSSCN isomers to be present in astrophysical media, since several of their molecular fragments have already been detected. In sum, the present set of data can be used for the identification of HSSCN compounds and understanding the physical chemistry of sulfur containing molecules in vivo, in the laboratory and in astrophysical media.

COVID-19 Molecular Testing in Korea: Practical Essentials and Answers From Experts Based on Experiences of Emergency Use Authorization Assays.

Coronavirus disease 2019 (COVID-19) is a respiratory disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Early detection of COVID-19 and immediate isolation of infected patients from the naive population are important to prevent further pandemic spread of the infection. Real-time reverse transcription (RT)-PCR to detect SARS-CoV-2 RNA is currently the most reliable diagnostic method for confirming COVID-19 worldwide. Guidelines for clinical laboratories on the COVID-19 diagnosis have been recently published by Korean Society for Laboratory Medicine and the Korea Centers for Disease Control and Prevention. However, these formal guidelines do not address common practical laboratory issues related to COVID-19 real-time RT-PCR testing and their solutions. Therefore, this guideline is intended as a practical and technical supplement to the "Guidelines for Laboratory Diagnosis of COVID-19 in Korea".

Ruthenium Bipyridyl Dithiocyanate Complex Exerted Adjuvant Activity on the Activated Mammalian Macrophages in vitro.

A cell's function can be regulated through its mechanism, and there has been a growing body of literature on how immune cells' metabolism shapes its overall immune response. Manipulation of the cells metabolic activity through a biocompatible material would present new venues to the field of medicine. These agents are known as immunomodulatory and immunostimulatory reagents. They can either stimulate the immune response in a disease case where the immune response is lacking the strength or they can determine the nature and strength of the immune response as an immunomodulator according to our needs to cope with certain disorders. In our recent studies, we have been examining different kinds of materials on the macrophages in order to delineate their immunostimulatory or immunomodulatory potentials. Ruthenium-based materials have gathered our attention due to their ability to get involved into the electron mobility processes in the solar cells. In line with our expectations, probably by interfering the electron transport processes of the macrophages, ruthenium bipyridyl dithiocyanate complex had a stark immunomodulatory function on the LPS-activated mammalian macrophages in vitro. Our results support that it can be utilized as an adjuvant in the new generation vaccines.

Following local light-induced structure changes and dynamics of the photoreceptor PYP with the thiocyanate IR label.

Photoactive Yellow Protein (PYP) is a bacterial blue light receptor that enters a photocycle after excitation. The intermediate states are formed on time scales ranging from femtoseconds up to hundreds of milliseconds, after which the signaling state with a lifetime of about 1 s is reached. To investigate structural changes and dynamics, we incorporated the SCN IR label at distinct positions of the photoreceptor via cysteine mutation and cyanylation. FT-IR measurements of the SCN label at different sites of the well-established dark state structure of PYP characterized the spectral response of the label to differences in the environment. Under constant blue light irradiation, we observed the formation of the signaling state with significant changes of wavenumber and lineshape of the SCN bands. Thereby we deduced light-induced structural changes in the local environment of the labels. These results were supported by molecular dynamics simulations on PYP providing the solvent accessible surface area (SASA) at the different positions. To follow protein dynamics via the SCN label during the photocycle, we performed step-scan FT-IR measurements with a time resolution of 10 µs. Global analysis yielded similar time constants of τ1 = 70 µs, τ2 = 640 µs, and τ3 > 20 ms for the wild type and τ1 = 36 µs, τ2 = 530 µs, and τ3 > 20 ms for the SCN-labeled mutant PYP-A44C*, a mutant which provided a sufficiently large SCN difference signal to measure step-scan FT-IR spectra. In comparison to the protein (amide, E46) and chromophore bands the dynamics of the SCN label show a different behavior. This result indicates that the local kinetics sensed by the label are different from the global protein kinetics.

Functional Annotation and Analysis of Dual Oxidase 1 (DUOX1): a Potential Anti-pyocyanin Immune Component.

Dual Oxidase 1 (DUOX1) is a prominent immune system component primarily expressed in esophagus, lungs, skin, and urinary bladder including others. DUOX1 is involved in lactoperoxidase-mediated innate immunity at mucosal surfaces by generation of antimicrobial hypothiocyanite at the apical surface of epithelial lining. Upon detection of bacterial pathogens mainly Pseudomonas aeruginosa, DUOX1 is activated in bronchial epithelial cells. Both the host and pathogen enter a redox dual with DUOX1 and hypothiocyanite from host and Pyocyanin (PCN) as a redox active virulence factor from P. aeruginosa. The synergy of the both enzymes permanently oxidizes PCN and thus holds the potential to prevent PCN-induced virulence, which otherwise paves the way for establishment of persistent chronic infection. In this study, we structurally and functionally annotated the DUOX1, predicted its 3d structure, physio-chemical properties, post-translational modifications, and genetic polymorphism analysis with subsequent disease-associated single-nucleotide variations and their impact on DUOX1 functionality by employing in silico approaches. DUOX1 holds greater homology with gorilla and chimpanzee than other primates. The localization signal peptide was present at the beginning of the peptide with cleavage site at 22 aa position. Three distinct functional domains were observed based on homology: An_peroxidase, FRQ1, and oxido-reductase domains. Polymorphism analysis revealed > 60 SNPs associated with different cancers with probable damaging effects. No cancer-associated methylated island was observed for DUOX1. Three-dimensional structure was developed via homology modeling strategy. The proper annotation will help in characterization of DUOX1 and enhance our knowledge of its functionality and biological roles.

Absorption and metabolism of isothiocyanates formed from broccoli glucosinolates: effects of BMI and daily consumption in a randomised clinical trial.

Sulphoraphane originates from glucoraphanin in broccoli and is associated with anti-cancer effects. A preclinical study suggested that daily consumption of broccoli may increase the production of sulphoraphane and sulphoraphane metabolites available for absorption. The objective of this study was to determine whether daily broccoli consumption alters the absorption and metabolism of isothiocyanates derived from broccoli glucosinolates. We conducted a randomised cross-over human study (n 18) balanced for BMI and glutathione S-transferase µ 1 (GSTM1) genotype in which subjects consumed a control diet with no broccoli (NB) for 16 d or the same diet with 200 g of cooked broccoli and 20 g of raw daikon radish daily for 15 d (daily broccoli, DB) and 100 g of broccoli and 10 g of daikon radish on day 16. On day 17, all subjects consumed a meal of 200 g of broccoli and 20 g of daikon radish. Plasma and urine were collected for 24 h and analysed for sulphoraphane and metabolites of sulphoraphane and erucin by triple quadrupole tandem MS. For subjects with BMI >26 kg/m2 (median), plasma AUC and urinary excretion rates of total metabolites were higher on the NB diet than on the DB diet, whereas for subjects with BMI <26 kg/m2, plasma AUC and urinary excretion rates were higher on the DB diet than on the NB diet. Daily consumption of broccoli interacted with BMI but not GSTM1 genotype to affect plasma concentrations and urinary excretion of glucosinolate-derived compounds believed to confer protection against cancer. This trial was registered as NCT02346812.

Structural Mapping of Anion Inhibitors to ß-Carbonic Anhydrase psCA3 from Pseudomonas aeruginosa.

Pseudomonas aeruginosa is a Gram-negative facultative anaerobe belonging to the Pseudomonadaceae family. It is a multidrug-resistant opportunistic human pathogen, a common cause of life-threatening nosocomial infections, and a key bacterial agent in cystic fibrosis and endocarditis. The bacterium exhibits intrinsic resistance to most antibacterial agents, including aminoglycosides and quinolones. Hence, the identification of new drug targets for P. aeruginosa is ongoing. PsCA3 is a ß-class carbonic anhydrase (ß-CA) that catalyzes the reversible hydration of carbon dioxide to bicarbonate and represents a new class of antimicrobial target. Previously, inhibitor screening studies of psCA3 have shown that a series of small anions including sulfamide (SFN), imidazole (IMD), and 4-methylimidazole (4MI), and thiocyanate (SCN) inhibit the enzyme with efficiencies in the micro- to millimolar range. Herein the X-ray crystal structures of these inhibitors in complex with psCA3 are presented and compared with human CA II. This structural survey into the binding modes of small anions forms the foundation for the development of inhibitors against ß-CAs and more selective inhibitors against P. aeruginosa.

Determination of thiocyanate in exhaled breath condensate.

Thiocyanate is a heme peroxidase substrate that scavenges oxidants produced during inflammation and regulates host defense. In cystic fibrosis (CF) patients, increased airway thiocyanate levels are associated with improved lung function. Research on airway thiocyanate is limited, however, because convenient non-invasive airway sampling methods, such as exhaled breath condensate (EBC), yield low concentrations that are difficult to detect with available assays. In the present study, we developed a method for the determination of thiocyanate in dilute samples using isotope dilution headspace gas chromatography-coupled high-resolution, accurate-mass mass spectrometry (GC-HRMS). The method reliably quantified as little as 4 pmol thiocyanate in EBC and could detect even lower amounts. We successfully measured thiocyanate in EBC from seven healthy donors, with a mean ±â€¯SD of 27 ±â€¯16 nM and a median inter-assay coefficient of variation of 10.4% over six months. The method was applied to other biological fluids (plasma from the same visit as EBC donation; bronchoalveolar lavage fluid [BALF] from infants with CF; and healthy adult mouse BALF), giving reliable quantification of samples ranging from 10 nM to 100 µM. Thiocyanate concentrations in fluids besides EBC were (from lowest to highest): 0.73 ±â€¯0.39 µM in BALF of healthy adult mice (n = 6); 1.4 ±â€¯1.4 µM in BALF from infants with CF (n = 24); 46 ±â€¯22 µM in the plasma of adult volunteers (n = 7). These results demonstrate the utility of this new method for clinical determination of thiocyanate in EBC and other biological fluids.

In vivo study of erysolin metabolic profile by ultra high performance liquid chromatography coupleded to Fourier transform ion cyclotron resonance mass spectrometry.

An ultra high performance liquid chromatography coupled to Fourier transform ion cyclotron resonance mass spectrometry (UHPLC-FT-ICR-MS) method was developed for the first time to study the in vivo metabolism of erysolin, a compound derived from cruciferous plants which has a definite effect of anti-tumor and anti-nerve injury. In this research, the chromatographic separation was performed on an ACQUITY UPLC® BEH C18 column (2.1 mm×100mm, 1.7µm, Waters, USA) and eluted by a gradient program, the identification work was achieved on a Bruker ultra-high resolution spectrometer in positive ion mode. Plasma, urine, feces and bile samples were collected from rats to screen metabolites after an intragastric administration of erysolin at the dose of 100mg/kg. As a result, the parent drug and a total of six phase II metabolites were detected and preliminarily identified by analyzing their MS and MS/MS spectrometry profiles. Our results indicated that erysolin mainly metabolized via the mercapturic acid metabolic pathway, erysolin first react with glutathione to form glutathione conjugate, followed by taking off the glutamic acid and glycine to form cysteine conjugate, then the N-acetylation reaction occurs, the product would be excreted out of the body at last. In conclusion, results obtained in our study may contribute to a better understanding of the metabolism process and characteristics of erysolin in vivo, and provide an important reference for future research.