Synthesis of 9-(substituted phenoxycarbonyl)-10-methylacridinium trifluoromethanesulfonates: Effects of the leaving group on chemiluminescent properties.

Various 9-(substituted phenoxycarbonyl)-10-methylacridinium trifluoromethanesulfonates possessing electron-withdrawing substituents have been synthesized. The effect of substituents on the stability of the acridinium esters (AEs) at various temperatures in different buffers and the chemiluminescent properties have been examined. There was little correlation between the chemiluminescent properties of AEs and the pKa values of their associated phenols, but the steric effects of the ortho-substituents in the phenoxy group, as well as their electron-withdrawing natures, seem to play an important role in determining the properties. In general, when two identical substituents are present in the 2- and 6-positions, the compound is significantly more stable than when only a single substituent is present, presumably because of greater steric hindrance from the second group. The exception is the 2,6-difluorophenyl ester, which is less stable than the 2-fluorophenyl ester, presumably because the fluoro group is small. Addition of a third electron-withdrawing substituent at the 4-position, where it has no steric influence, typically increases susceptibility to decomposition. The presence of a nitro group has a significant destabilizing effect on AEs. Of the AEs studied, the 4-chlorophenyl ester showed the greatest chemiluminescent yield, while the 2-iodo-6-(trifluoromethyl)phenyl ester group showed the greatest stability in low pH buffers.

Unusual triflic acid-promoted oligomerization of arabinofuranosides during glycosylation.

We discovered an unusual triflic acid-promoted oligomerization of arabinofuranosides during glycosylation of the primary hydroxy group of α-(1 â†’ 5)-linked tetraarabinofuranoside bearing 4-(2-chloroethoxy)phenyl aglycone with α-(1 â†’ 5), ß-(1 â†’ 2)-linked tetraarabinofuranoside containing N-phenyltrifluoroacetimidoyl leaving group, which led to octa-, dodeca- and hexadecaarabinofuranosides. The possible mechanism of triflic acid-promoted oligomerization was proposed. The choice of promoter was found to be a critical factor for the discovered oligomerization of arabinofuranosides. The obtained octa-, dodeca- and hexadecaarabinofuranosides may serve as useful blocks in the synthesis of oligosaccharide fragments of polysaccharides of Mycobacterium tuberculosis.

Interaction between hydroxymethanesulfonic acid and several organic compounds and its atmospheric significance.

The interactions of the micro-mechanism of hydroxymethanesulfonic acid (HMSA) with the typical small organic molecule in atmospheric (X = methanol, formaldehyde, formic acid, methyl formate, dimethyl ether, acetone) has been investigated by density functional theory (DFT), quantum theory of atoms in molecules (QTAIM), Generalized Kohn-Sham Enery Decomposition Analysis (GKS-EDA) and the atmospheric clusters dynamic code (ACDC). The results of DFT show that the stable six- to eight-membered ring structures are easily formed in HMSA-X clusters. According to the topological analysis results of the AIM theory and the IRI method, a strong hydrogen bonding interaction is present in the complex. GKS-EDA results show that electrostatic energy is the main contributor to the interaction energy as it accounts for 51 %-55 % of the total attraction energy. The evaporation rates of HMSA-HMSA and HMSA-HCOOH clusters were much lower than those of the other HMSA complexes. In addition, the Gibbs energy of formation (ΔG) of HMSA-X dimers is investigated under atmosphere temperature T = 217-298 K and p = 0.19-1.0 atm, the ΔG decreased with decreasing of the atmosphere temperature and increased with the decrease of atmospheric pressure, indicating that the low temperature and high pressure may significantly facilitate to the formation of dimers.

MutL Activates UvrD by Interaction Between the MutL C-terminal Domain and the UvrD 2B Domain.

UvrD is a helicase vital for DNA replication and quality control processes. In its monomeric state, UvrD exhibits limited helicase activity, necessitating either dimerization or assistance from an accessory protein to efficiently unwind DNA. Within the DNA mismatch repair pathway, MutL plays a pivotal role in relaying the repair signal, enabling UvrD to unwind DNA from the strand incision site up to and beyond the mismatch. Although this interdependence is well-established, the precise mechanism of activation and the specific MutL-UvrD interactions that trigger helicase activity remain elusive. To address these questions, we employed site-specific crosslinking techniques using single-cysteine variants of MutL and UvrD followed by functional assays. Our investigation unveils that the C-terminal domain of MutL not only engages with UvrD but also acts as a self-sufficient activator of UvrD helicase activity on DNA substrates with 3'-single-stranded tails. Especially when MutL is covalently attached to the 2B or 1B domain the tail length can be reduced to a minimal substrate of 5 nucleotides without affecting unwinding efficiency.

Synthesis of 2-Substituted Indoles via Migration Reaction of 3-Substituted Indoles with Triflic Acid.

This study showcases the 1,2-migration reactions of alkyl and aryl groups on the indole molecule. Trifluoromethanesulfonic acid effectively facilitates the migration of the substituent from C3- to C2-position of the indole structure. The resulting C2-substituted indoles offer a valuable pathway for the synthesis of natural products and medicinal compounds.

Clinical outcomes of colistin methanesulfonate sodium in correlation with pharmacokinetic parameters in critically ill patients with multi-drug resistant bacteria-mediated infection: A systematic review and meta-analysis.

BACKGROUND: Colistin is a viable option for multidrug resistant gram-negative bacteria emerged from inappropriate antibiotic use. Nonetheless, suboptimal colistin concentrations and nephrotoxicity risks hinder its clinical use. Thus, the aim of this study is to investigate clinical outcomes in correlation with pharmacokinetic differences and infection types in critically ill patients on intravenous colistin methanesulfornate sodium (CMS). METHODS: A systematic literature search of Embase, Google Scholars, and PubMed was performed to identify clinical trials evaluating pharmacokinetic parameters along with clinical outcomes of CMS treatment from inception to July 2023. The pooled analyses of clinical impact of CMS on nephrotoxicity, mortality, clinical cure, and colistin concentration at steady state (Css,avg) were performed. This study was registered in the PROSPERO (CRD 42023456120). RESULTS: Total of 695 critically ill patients from 17 studies were included. The mortality was substantially lower in clinically cured patients (OR 0.05; 95% CI 0.02 - 0.14), whereas the mortality rate was statistically insignificant between nephrotoxic and non-nephrotoxic patients. Inter-patient variability of pharmacokinetic parameters of CMS and colistin was observed in critically ill patients. The standard mean differences of Css,avg were statistically insignificant between clinically cure and clinically failure groups (standard mean difference (SMD) -0.25; 95% CI -0.69 - 0.19) and between nephrotoxic and non-nephrotoxic groups (SMD 0.67; 95% CI -0.27-1.61). The clinical cure rate is substantially lower in pneumonia patients (OR 0.09; 95% CI 0.01 - 0.56), and pharmacokinetic parameters pertaining to microbiological cure were different among strains. CONCLUSION: The mortality rate was substantially lower in clinically cured patients with CMS. However, no significant differences in Css,avg of colistin were examined to determine the impact of pharmacokinetic differences on clinical outcomes including mortality rate and nephrotoxicity risk. Nevertheless, the clinical cure rate is substantially lower in patients with respiratory infection than patients with urinary tract infection.

Chemical Synthesis of Δ-4,5 Unsaturated Heparan Sulfate Oligosaccharides for Biomarker Discovery.

A methodology is described that can provide heparan sulfate oligosaccharides having a Δ4,5-double bond, which are needed as analytical standards and biomarkers for mucopolysaccharidoses. It is based on chemical oligosaccharide synthesis followed by modification of the C-4 hydroxyl of the terminal uronic acid moiety as methanesulfonate. This leaving group is stable under conditions used to remove temporary protecting groups, O-sulfation, and hydrogenolysis. Treatment with NaOH results in elimination of the methanesulfonate and formation of a Δ4,5-double bond.

DHEC mesylate attenuates pathologies and aberrant bisecting N-glycosylation in Alzheimer's disease models.

Tremendous progress has been made to develop the therapy of Alzheimer's disease (AD). Existing several anti-AD remedies, with certain limitations, are far from adequate. Evidence suggests that dihydroergocristine (DHEC) mesylate, one of the main components of Ergoloid mesylates, can reduce the production of amyloid-ß in vitro. However, the therapeutic effect of DHEC mesylate in AD and its underlying mechanism are still largely unknown. Herein, we characterized the pharmacological effect of DHEC mesylate in AD and found that the spatial memory disorders and Alzheimer-type pathologies were alleviated by DHEC mesylate administration. Moreover, we demonstrated that DHEC mesylate improved aberrant bisecting N-glycosylation, which was identified as a potential biomarker of AD. We further explored the underlying mechanism and confirmed that DHEC mesylate protected against AD via AMPK and ERK signaling, in which, AMPK was the dominant down-stream molecule of DHEC mesylate. In summary, our findings provide foundations for development of DHEC mesylate as a therapeutic approach for AD.

A randomized, open-label, 5-period crossover study evaluating the pharmacokinetics and safety of a single dose of intranasal dihydroergotamine (DHE) powder (STS101), intramuscular DHE mesylate, and liquid nasal spray DHE in healthy adults.

OBJECTIVE: To compare the safety and pharmacokinetics (PK) of dihydroergotamine (DHE) after administration of intranasal DHE powder (STS101), liquid nasal spray (LNS) DHE mesylate, and intramuscular (IM) DHE mesylate injection in healthy participants. BACKGROUND: DHE is an effective acute migraine treatment; however, self-administration difficulties have prevented its broader role in the management of migraine. METHODS: This randomized, active-controlled, five-period crossover study was conducted over 5 weeks separated by 1-week washout periods. Three STS101 dosage strengths (5.2, 7.0, 8.6 mg), and one dose each of LNS DHE 2.0 mg, and IM DHE 1.0 mg, were administered to 36 healthy participants. Liquid chromatography, tandem mass spectrometry was used to determine DHE (including its 8'OH-DHE metabolite) plasma levels and to calculate PK parameters (Cmax , Tmax , AUC0-2h , AUC0-last , AUC0-inf , and t1/2 ). Safety was evaluated by monitoring adverse events (AEs), vital signs, electrocardiograms, nasal examinations, and laboratory parameters. RESULTS: Thirty-six participants (mean age 36 years; 19% Hispanic Black and 81% Hispanic White) were enrolled. DHE plasma concentrations rose rapidly after STS101 5.2, 7.0, and 8.6 mg and IM DHE injection, with mean concentrations greater than 2000 pg/mL for all STS101 dose strengths at 20 min. All STS101 dose strengths showed approximately 3-fold higher Cmax , AUC0-2h , and AUC0-inf , than the LNS DHE. The mean AUC0-inf of STS101 7.0 and 8.6 mg were comparable to IM DHE (12,600 and 13,200 vs. 13,400 h × pg/mL). All STS101 dose strengths showed substantially lower variability (CV%) compared to LNS DHE for Cmax (35%-41% vs. 87%), and AUC0-inf (37%-46% vs. 65%). STS101 was well tolerated, and all treatment-emergent AEs were mild and transient. CONCLUSION: STS101 showed rapid absorption and was well tolerated with mild and transient treatment-emergent AEs. Achieving effective DHE plasma concentrations within 10 min, STS101 displayed a favorable PK profile relative to the LNS with higher Cmax , AUC0-2h , and AUC0inf , and with greater response consistency. The AUC0-inf was comparable to IM DHE.

A novel Zn2+-coordination fluorescence probe for sensing HPPD inhibitors and its application in environmental media and biological imaging.

Mesotrione, topramezone, tembotrione, and sulcotrione are four types of 4-hydroxyphenylpyruvate dioxidase (HPPD) inhibitor herbicides that are extensively employed in agricultural practices, but their usage also leads to environmental pollution and poses risks to human health. A probe (E)-1-((2-(pyridin-2-yl) hydrazineylidene) methyl) naphthalen-2-ol (CHMN) based on chelation enhancement (CHEF) effect synthesized. CHMN was first chelated with Zn2+ to form a probe system with green, which can be further used to detect mesotrione, topramezone, tembotrione and sulcotrione in complicated environment. CHMN-Zn2+ detection of four pesticides was accurate, with an excellent linear relationship between 0 and 100 µM. The detection limits were LODmesotrione = 7.79 µM, LODtopramezone = 1.91 µM, LODtembotrione = 1.38 µM and LODsulcotrione = 2.43 µM. The detection time is 1 min, and it is successfully applied in real water sample and bioimaging. This work can provide a novel method for studying the migration and behavior of environmental pollutants.

Does the anesthetic tricaine methanesulfonate (MS-222) distort oxidative status parameters in tadpoles?

The effect of anesthesia/euthanasia with ethyl 3-aminobenzoate methanesulfonate (MS-222) on the oxidative status of Hyla arborea tadpoles was examined to determine whether the use of the anesthetic can confound the experimental results of the oxidative stress-based investigation. The experiment was conducted on two groups of tadpoles reared at different temperatures to produce differences in antioxidant capacity between the groups. After development at different temperatures (20 °C and 25 °C), the animals were exposed to different concentrations of MS-222 (0, 0.1, 1, and 5 g/L) for 15 min. The higher temperature decreased catalase activity, glutathione and protein carbonyl levels and increased glutathione reductase activity. The glutathione level and glutathione/thiol-related parameters were significantly changed after MS-222 exposure. However, individuals from the different temperature groups responded differently to the tested anesthetic, pointing to the possible influence of the initial levels of antioxidant capacity. The analysis of the interaction between the factors (temperature and MS-222) confirmed that the anesthetic can confound the results regarding the effects of temperature on the oxidative status parameters. The concentration of 0.1 g/L MS-222 had the lowest influence on the alterations in oxidative status and the results of the effect of temperature. A brief review of the current literature on the use of MS-222 in tadpoles made clear the absence of precise information on anesthetic concentration and exposure time. Similar studies should be repeated and extended to other amphibian species and other factors of interest to provide better guidance on tadpole anesthesia/euthanasia for future experiments that consider oxidative status parameters.

Efficient purification and high-quality regeneration of graphite from spent lithium-ion batteries by surfactant-assisted methanesulfonic acid.

With the vigorous development of the new energy industry, the use of lithium-ion batteries (LIBs) is growing exponentially, and the recycling of spent LIBs has gradually become a research hotspot. Currently, recycling both cathode and anode materials of LIBs is important to environmental protection and resource recycling. This research reportsa method ofefficient purification and high-quality regeneration of graphite from spent LIBs by surfactant-assisted methanesulfonic acid (MSA). Under the optimal conditions (0.006 mol/L sodium dodecyl sulfonate, 0.25 mol/L MSA, 10 vol% hydrogen peroxide, liquid-solid ratio of 30:1 mL/g, 60 °C, 1.5 h), the purity of the regenerated graphite was 99.7 %, and the recovery efficiency was 98.0 %. The regenerated graphite showed the characteristics of small interplanar spacing, high degree of graphitization, a small number of surface defects, and excellent pore structure, which was closer to commercial graphite. Furthermore, the regenerated graphite electrode exhibited superior rate performance and cycling stability with a high specific capacity of 397.03 mAh/g after 50 cycles at 0.1C and a charge-discharge efficiency of 99.33 %. The recovery of anode graphite beneficial for resource utilization, environmental protection, and cost control throughout the entire production chain.

[Clinical Efficacy and Safety of Flumatinib in the Treatment of Patients with Newly Diagnosed Chronic Myeloid Leukemia in Chronic Phase].

OBJECTIVE: To explore the clinical efficacy and safety of flumatinib mesylate produced in China in patients with newly diagnosed chronic myeloid leukemia in chronic phase (CML-CP). METHODS: 32 newly diagnosed CML-CP patients admitted to the Hematology Department of the Affiliated Hospital of Southwest Medical University from March 1, 2020 to March 31, 2022, who had never received any tyrosine kinase inhibitor (TKI) were included in the study. The patients were treated by flumatinib mesylate 600mg once daily. The hematologic, cytogenetic and molecular responses were assessed at 3-, 6- and 12-month, and adverse effects of the drug were evaluated. RESULTS: 31 patients were treated with flumatinib for≥3 months, of which 24 patients were treated for ≥6 months and 14 patients were treated for≥12 months. At 3rd month of treatment, 30 out of 31 patients achieved complete hematologic response (CHR); 24 patients underwent cytogenetic testing and 22 cases achieved major cytogenetic response(MCyR), of which 21 cases achieved complete cytogenetic response (CCyR); Among 25 patients who underwent molecular testing, 22 patients had BCR-ABLIS≤10%, including 10 patients with BCR-ABLIS≤0.1%, and 6 patients with BCR-ABLIS≤0.01%. At 6th month of treatment, 23 out of 24 patients achieved CHR; 17 patients underwent cytogenetic testing and all achieved CCyR; Among 23 patients who underwent molecular testing, 20 patients had BCR-ABLIS≤1%, including 16 patients with BCR-ABLIS≤0.1% and 12 patients with BCR-ABLIS≤0.01%. At 12nd month of treatment, all 14 patients achieved CHR and CCyR; Among them, 10 patients had BCR-ABLIS≤0.1%, including 9 patients with BCR-ABLIS≤0.01%. The grade Ⅲ/Ⅳ leukopenia, thrombocytopenia and anemia rates in the patients were 13.3%, 20.0% and 3.3%, respectively. One patient stopped flumatinib therapy due to severe and persistent hematologic toxicity. The major non-hematologic adverse events were abnormal liver function (20%), diarrhea (10%), bone/joint pain (10%), muscle spasm (10%), rash (6.7%), acute kidney injury (6.7%) and nausea(3.3%), most of which were grade I-II. No patient experienced grade Ⅳ non-hematologic adverse events. No drug toxicity-related death occurred. CONCLUSION: Flumatinib mesglate, as the first-line treatment for newly diagnosed CML-CP, can enable the patients to achieve early and deep molecular and cytogenetic responses, and shows good safety.

[Real-World Efficacy and Safety of China-Made Flumatinib Mesylate in the Treatment of Chronic Myeloid Leukemia in Chronic Phase].

OBJECTIVE: To evaluate the efficacy and safty of China-made flumatinib mesylate in the treatment of chronic myeloid leukemia in chronic phase (CML-CP). METHODS: 42 CML-CP patients treated with Chinese produced flumatinib (oral, 600 mg, 1/d) were included in the study, including 14 newly diagnosed patients and 28 patients underwent conversion therapy. The hematological, cytogenetic and molecular response and safety were observed and evaluated after 3, 6 and 12 months of treatment. RESULTS: 35 patients were treated for more than 3 months, among which 31 patients were treated for more than 6 months and 17 patients were treated for more than 12 months. After 3 months of treatment, 33 patients underwent hematological, cytogenetic and molecular examination. Of these, 32 patients achieved complete hematological response (CHR), 13 patients achieved complete cytogenetic response (CCyR), 20 patients showed BCR-ABLIS≤10% and 7 patients reached major molecular response (MMR). After 6 months of treatment, all 30 patients who could evaluate efficacy achieved CHR, of which 17 patients achieved CCyR, 18 patients showed BCR-ABLIS≤1% and 16 patients reached MMR. After 12 months of treatment, all 17 patients were evaluated for efficacy, all achieved CHR, 10 patients obtained CCyR, 7 patients reached MMR. Grade III or IV thrombocytopenia, leukopenia and anemia occurred in 7, 2 and 1 patients, respectively. The non-hematological adverse reactions were diarrhea in 6 cases, renal function damage in 4 cases, rash and pruritus in 3 cases, liver function damage in 3 cases, nausea in 1 case, fever in 1 case, bone/joint or muscle pain in 1 case. CONCLUSION: In the real world, China-made flumatinib mesylate has a positive short-term efficacy and reliable safety in the treatment of CML-CP patients, whether as first-line treatment or second- and third-line conversion therapy.

Organoids derived from patients provide a new opportunity for research and individualized treatment of malignant peritoneal mesothelioma.

BACKGROUND: Malignant peritoneal mesothelioma (MPM) is an extremely rare and highly invasive tumor. Due to the lack of accurate models that reflect the biological characteristics of primary tumors, studying MPM remains challenging and is associated with an exceedingly unfavorable prognosis. This study was aimed to establish a new potential preclinical model for MPM using patient-derived MPM organoids (MPMOs) and to comprehensively evaluate the practicality of this model in medical research and its feasibility in guiding individualized patient treatment. METHODS: MPMOs were constructed using tumor tissue from MPM patients. Histopathological analysis and whole genome sequencing (WGS) were employed to determine the ability of MPMOs to replicate the original tumor's genetic and histological characteristics. The subcutaneous and orthotopic xenograft models were employed to assess the feasibility of establishing an in vivo model of MPM. MPMOs were also used to conduct drug screening and compare the results with retrospective analysis of patients after treatment, in order to evaluate the potential of MPMOs in predicting the effectiveness of drugs in MPM patients. RESULTS: We successfully established a culture method for human MPM organoids using tumor tissue from MPM patients and provided a comprehensive description of the necessary medium components for MPMOs. Pathological examination and WGS revealed that MPMOs accurately represented the histological characteristics and genomic heterogeneity of the original tumors. In terms of application, the success rate of creating subcutaneous and orthotopic xenograft models using MPMOs was 88% and 100% respectively. Drug sensitivity assays demonstrated that MPMOs have different medication responses, and these differences were compatible with the real situation of the patients. CONCLUSION: This study presents a method for generating human MPM organoids, which can serve as a valuable research tool and contribute to the advancement of MPM research. Additionally, these organoids can be utilized as a means to evaluate the effectiveness of drug treatments for MPM patients, offering a model for personalized treatment approaches.

EVALUATION OF PLASMA CORTISOL AND LACTATE IN KOI (CYPRINUS CARPIO) EUTHANIZED BY IMMERSION IN TRICAINE METHANESULFONATE, CLOVE OIL, OR CARBON DIOXIDE GAS DISSOLVED IN WATER.

Little research has taken place on the effect of euthanasia methods on biophysical and biochemical changes at the time of euthanasia in fish. These changes are used in multiple species to determine stress levels before death. Koi (Cyprinus carpio) are an important fish species often used in laboratory research, kept in backyard ponds, and managed in zoological and aquarium collections. The current study evaluated euthanasia of koi by immersion in 0.5 g/L tricaine methanesulfonate (MS-222) (n = 10), 0.5 g/L clove oil (n = 8), 1 g/L clove oil (n = 10), and CO2 (n = 7) on time to cessation of opercular movement, plasma lactate levels, and plasma cortisol levels. CO2 had the longest mean time to cessation of opercular movement, and MS-222 had the shortest (mean CO2: 24.9 min, range 13.18-31.35 min; MS-222: 2.68 min, range 1.33-4.5 min). The difference was not significant between any of the groups for plasma cortisol or lactate levels. MS-222 demonstrated the highest cortisol levels, and CO2 had the lowest (mean CO2: 108.7 ng/ml, range 33.9-195.8 ng/ml; MS-222: 650.6 ng/ml, range 77.3-2374.9 ng/ml). Average lactate levels were highest for 1 g/L clove oil and lowest for 0.5 g/L clove oil (mean 0.5 g/L clove oil: 5.1 mmol/L, range 1.8-8.1 mmol/L; 1 g/L clove oil: 7.4 mmol/L, range 5.6-10.5 mmol/L).

Comparing the EU and Chinese carbon trading market operations and their spillover effects.

A carbon trading market (CTM) policy for trading carbon dioxide emission rights as a commodity was created to reduce greenhouse gas emissions. CTMs operate differently in different countries and regions, and their interactions deserve an in-depth study. This study focused on the world's largest CTM, the European Union (EU), and the CTM of China, largest carbon-emitting country. First, we evaluate the liquidity and volatility of the two CTMs. Subsequently, the VAR model is used to explore the mean spillover effect between the two markets and the BEKK-GARCH model is used to explore the volatility spillover effect between the two markets. The study concludes that: (1) The liquidity of China's CTM is better than that of the EU's CTM. (2) Both the EU and Chinese CTMs are unstable, but the volatility of the Chinese CTM is lower than that of the EU CTM. (3) Price changes in the EU and Hubei CTMs have a mutual influence. (4) There are interactions between the market fluctuations of the EU CTM and the Shanghai CTM and those of the EU CTM and the Hubei CTM. The results of this study have implications for the construction and development of CTMs in the EU and China.

Introducing a protic ionic liquid from aminoethyl piperazine and triflic acid immobilized on pectin as a reusable nanocatalyst for the selective Schmidt synthesis of nitriles.

Preparation of reusable protic ionic liquid, triflic acid-immobilized aminoethyl piperazine-modified pectin (Pec-AEP-TfOH), with excellent activity and selectivity in modified Schmidt synthesis of nitriles from aldehydes and Si(CH3)3N3 has been described. The structure of the catalyst was characterized using FT-IR, XRD, FE-SEM, EDX-mapping, and TGA-DTA. The reaction demonstrated a broad substrate scope for a variety of benzaldehyde derivatives with electron withdrawing/donating substituents and heterocyclic aldehydes with yields between 85 and 96 % at room temperature. Also, the Pec-AEP-TfOH showed an excellent selectivity for the nitriles in which no formanilide was obtained. Furthermore, the Pec-AEP-TfOH revealed a remarkable chemoselectivity for aldehydes in the presence of acids or ketones. It is worth noting that TfOH as a precious superacid was immobilized for the first time in the selective Schmidt synthesis of nitriles to improve the eco-friendliness and economic efficiency of the process. Furthermore, the catalyst was cost-effective, metal-free, safe, scalable, and reusable (5 times) and its heterogeneity was confirmed by hot-filtration test.

HIO3-HIO2-Driven Three-Component Nucleation: Screening Model and Cluster Formation Mechanism.

Iodine oxoacids (HIO3 and HIO2)-driven nucleation has been suggested to efficiently contribute to new particle formation (NPF) in marine atmospheres. Abundant atmospheric nucleation precursors may further enhance HIO3-HIO2-driven nucleation through various multicomponent nucleation mechanisms. However, the specific enhancing potential (EP) of different precursors remains largely unknown. Herein, the EP-based screening model of precursors and enhancing mechanism of the precursor with the highest EP on HIO3-HIO2 nucleation were investigated. The formation free energies (ΔG), as critical parameters for evaluating EP, were calculated for the dimers of 63 selected precursors with HIO2. Based on the ΔG values, (1) a quantitative structure-activity relationship model was developed for evaluating ΔG of other precursors and (2) atmospheric concentrations of 63 (precursor)1(HIO2)1 dimer clusters were assessed to identify the precursors with the highest EP for HIO3-HIO2-driven nucleation by combining with earlier results for the nucleation with HIO3 as the partner. Methanesulfonic acid (MSA) was found to be one of the precursors with the highest EP. Finally, we found that MSA can effectively enhance HIO3-HIO2 nucleation at atmospheric conditions by studying larger MSA-HIO3-HIO2 clusters. These results augment our current understanding of HIO3-HIO2 and MSA-driven nucleation and may suggest a larger impact of HIO2 in atmospheric aerosol nucleation.