Spray Mass Spectrometry Research Articles

Carfentanil structural analogs found in street drugs by paper spray mass spectrometry and their characterization by high-resolution mass spectrometry.

Carfentanil is one of the most potent synthetic opioids ever developed, with an estimated analgesic potency approximately 20-100 times that of fentanyl and 10,000 times that of morphine. Carfentanil has been appearing in the illicit drug supply in many regions and has been linked to fatal overdose events. A subset of 59 street drug samples obtained in Victoria, B.C., that were confirmed to contain carfentanil were analyzed by mass spectrometry for this study. Carfentanil quantitation by paper spray mass spectrometry ranged from 0.05 to 2.95 w/w% (median =0.32%) in the original drug sample. Paper spray mass spectrometry analysis also detected two unknown peaks at m/z 380.2 and 381.2 in 31 of these 59 samples (53%). Initial tandem mass spectrometry experiments revealed structural similarities between these unknown compounds and carfentanil, suggesting they were potential structural analogs, possibly arising from incomplete purification during synthesis. High-resolution mass spectrometry determined the chemical formulas of these compounds as C23 H29 N3 O2 (m/z 380.2333) and C23 H29 N2 O3 (m/z 381.2137). Literature and tandem mass spectrometry results were used to determine the identity of these potential new psychoactive substances, C23 H29 N3 O2 as desmethylcarfentanil amide and C23 H29 N2 O3 as desmethylcarfentanil acid. μ-Opioid receptor binding modeling determined that the binding poses of these analogs were nearly identical to that of carfentanil with relative binding energy calculations of 0.544 kJ/mol (desmethylcarfentanil amide) and -0.171 kJ/mol (desmethylcarfentanil acid); these data suggest they may share the toxic effects of carfentanil and have similar potencies.

A simple, quick and non-destructive approach for sampling drugs of abuse in tablets and blotter for qualitative analysis by paper spray mass spectrometry.

This study presents the development of a simple, fast, and inexpensive approach for the direct analysis of new psychoactive substances (NPS) in seized tablets and blotter paper, with improved sample preservation and increased analytical frequency. Paper triangles were gently rubbed against the surface of the samples containing synthetic drugs and then subjected to analysis by paper spray ionization mass spectrometry (PS-MS). Seized samples containing lysergic acid diethylamide (LSD) and several other substances from the classes of amphetamines, N-benzyl-substituted phenethylamines, synthetic cathinones, and synthetic cannabinoids, were analysed. Three types of paper were tested (filter paper, blotter paper, and synthetic paper) and several combinations of spray solvents were studied for the optimization. All samples were weighed and photographed before and after sequences of analysis in order to attest to the sample preservation. The results revealed that the approach is excellent for sample preservation, with less than 5% of mass loss even after 27 consecutive analyses. Moreover, no significant signal decreases were observed in mass spectrometry (MS) even after the experiments. It was possible to unequivocally identify illicit substances from seized samples (pills and blotter paper). By overcoming the solubilization and wet extraction process used for sample preparation, the waste was restricted to a volume of only 10 μL of solvent for the PS-MS analysis. The main advantage of our approach over existing methods is the sample preparation, which is simple and quick since the samples are just rubbed against the PS paper. This brings enormous benefits in terms of analytical frequency, economy of time and low consumption of solvents. Another important point is that the sample can remain intact for further analysis, which is crucial in forensic analysis.

APLICAÇÃO DA ESPECTROMETRIA DE MASSAS COM IONIZAÇÃO POR PAPER SPRAY E TÉCNICAS RELACIONADAS NA ANÁLISE DIRETA DE MATRIZES BIOLÓGICAS PARA DETECÇÃO DE DROGAS - UMA REVISÃO

APPLICATION OF PAPER SPRAY IONIZATION MASS SPECTROMETRY AND RELATED TECHNIQUES IN THE DIRECT ANALYSIS OF BIOLOGICAL MATRICES FOR DETECTION OF DRUGS - A REVIEW. In recent years, technological development in analytical instrumentation has progressed vigorously, which has allowed the evolution of analytical techniques that play an indispensable role within society, highlighting mass spectrometry. Parallel to the technological advance of this technique, the development of new ionization methods that are simpler, faster, and allow direct analysis without the need for prior treatment or sample processing is underway. The methods of ambient ionization derived from paper spray have been developing rapidly in current days, mainly in the forensic field, due to the chemical modifications made in the paper substrate and the introduction of new types of organic materials that function as a probe/substrate to collect, store, and ionize the sample, then enabling more efficient and selective analyzes. This review highlights direct analyzes by applying paper spray ionization in the forensic field and some variations of this technique, including Thread Spray Ionization (TSI) when a fabric thread is used; Touch Spray Ionization (TSI), which uses materials such as metallic needles, medical swabs, and wooden sticks; Fiber Spray Ionization (FSI), which applies polymeric fibers as substrates.

Rapid fabrication of hydrophobic/hydrophilic patterns on paper substrates for paper spray mass spectrometry.

A simple, rapid chemical coating and patterning method was developed and optimized for paper-based substrates for use in paper spray mass spectrometry (PS-MS). A variety of chlorosilanes were explored for coating paper substrates, and their effectiveness in forming hydrophobic surfaces was characterized via contact angle goniometry, scanning electron microscopy, and energy dispersive X-ray spectroscopy. Trichloromethylsilane was selected as the primary coating agent because of the short time required to produce a hydrophobic surface (contact angle > 130°), as well as the ease of patterning. Patterning was performed using 3D-printed masks and an oxygen/plasma cleaner. Optimal mask thickness and oxygen/plasma cleaning parameters were determined to produce channels varying from 0.5 to 2.5 mm in width. The effectiveness of the patterned substrates for PS-MS was determined via analysis of four antiretrovirals: emtricitabine, lamivudine, efavirenz, and dolutegravir. Calibration curves were made for each antiretroviral at varying channel widths, and the limits of detection and limits of quantification for each drug were determined. These results show that this patterning method results in an average 7.2-fold improvement in sensitivity and an average 190-fold improvement in limits of detection over uncoated paper substrates in a neat matrix. In a proof-of-concept experiment, calibration curves were generated for each antiretroviral in urine. A patterned paper substrate with a 2-mm channel resulted in an average 7.4-fold improvement in sensitivity and an average 18-fold improvement in limits of detection over uncoated paper substrates.

Analysis of 15 anti-obesity drugs in urine using thermal-assisted paper spray mass spectrometry.

Anti-obesity drugs, used to suppress appetite and reduce fat absorption, have been circulated and traded illegally worldwide. The traditional methods of liquid chromatography tandem mass spectrometry (LC-MS/MS) and gas chromatography-mass spectrometry (GC-MS) for analyzing these drugs in in vivo samples require complex sample pretreatment and time-consuming procedures. To address this issue, a thermal-assisted paper spray mass spectrometry (PS-MS) method was developed in this study to analyze anti-obesity drugs in raw urine. By incorporating a heat source and optimizing the spray solvent and paper substrate, this technique demonstrates reduced matrix effect and higher sensitivity compared to traditional PS-MS methodology for direct analysis of anti-obesity drugs in urine samples. A temperature range of 100-200 °C can be set for screening anti-obesity drugs in urine samples, with the flexibility to adjust the temperature according to the specific drug being analyzed. The limits of detection (LODs) for these 15 anti-obesity drugs in urine ranged between 1 and 500 ng mL-1. Furthermore, the thermal-assisted PS-MS method exhibited good linearities (R2, 0.9903-0.9997) within the range from 10-100 to 1000 ng mL-1 for the direct quantitation of anti-obesity drugs in urine samples with an internal standard. Therefore, the thermal-assisted PS-MS technique may provide a novel approach for the direct analysis of drugs in complex samples.

Combining presumptive color tests, pressure-sensitive adhesive-based collection, and paper spray-mass spectrometry for illicit drug detection.

Illicit drug trafficking and abuse is a significant public safety and health concern. Color tests are commonly used for drug screening, but their poor specificity results in false positives. This study demonstrates the combination of drug residue collection using pressure-sensitive adhesive paper, on-paper color testing, and post-reaction analysis by paper spray mass spectrometry (PS-MS) on both portable and benchtop ion trap MS. All steps, including residue collection, color testing, and paper spray analysis, were performed on the same piece of paper. Three common color tests were investigated: the cobalt thiocyanate test for cocaine, the Simon test for methamphetamine, and the Marquis test for phenethylamine stimulants and opiates. The detection threshold for color tests ranged from 1.25 to 10 μg on paper. Drug residues were successfully confirmed by paper spray MS at the color test threshold in all cases, except for heroin after reaction with the Marquis reagent, when using the portable MS. In this case, the MS detection threshold was 4-fold higher than the color test threshold. The stability of the color test products was assessed through a time study. Drug residues could be detected by MS at least 24 hours after reaction. A series of realistic samples, including false positives, were analyzed to demonstrate the technique's utility in real-world scenarios. Overall, combining color tests with PS-MS offers a rapid, low-cost method for the collection and analysis of illicit drugs.

OH radical-initiated single-electron transfer for accelerated degradation via carbocation intermediates.

Single electron transfer (SET) has made great contributions to a broad range of chemical processes, whose radical cation and carbocation intermediates are important for mechanism studies. Herein, hydroxyl radical (˙OH)-initiated SET was revealed in accelerated degradations, via the online examination of radical cations and carbocations by electrosonic spray ionization mass spectrometry (ESSI-MS). In the green and efficient non-thermal plasma catalysis system (MnO2-plasma), hydroxychloroquine was efficiently degraded upon SET via carbocations. In the plasma field full of active oxygen species, ˙OH was generated on the MnO2 surface to initiate SET-based degradations. Furthermore, theoretical calculations revealed that ˙OH preferred to withdraw the electron from the N atom that was conjugated to the benzene ring. This facilitated the generation of radical cations through SET, which was followed by the sequential formation of two carbocations for accelerated degradations. Transition states and energy barriers were calculated to study the formation of radical cations and subsequent carbocation intermediates. This work demonstrates an ˙OH-initiated SET for accelerated degradation via carbocations, providing a deeper understanding and the potential for the wider application of SET in green degradations.

Screening and diagnosis of triple negative breast cancer based on rapid metabolic fingerprinting by conductive polymer spray ionization mass spectrometry and machine learning.

We present the use of conductive spray polymer ionization mass spectrometry (CPSI-MS) combined with machine learning (ML) to rapidly gain the metabolic fingerprint from 1μl liquid extraction from the biopsied tissue of triple-negative breast cancer (TNBC) in China. The 76 discriminative metabolite markers are verified at the primary carcinoma site and can also be successfully tracked in the serum. The Lasso classifier featured with 15- and 22-metabolites detected by CPSI-MS achieve a sensitivity of 88.8% for rapid serum screening and a specificity of 91.1% for tissue diagnosis, respectively. Finally, the expression levels of their corresponding upstream enzymes and transporters have been initially confirmed. In general, CPSI-MS/ML serves as a cost-effective tool for the rapid screening, diagnosis, and precise characterization for the TNBC metabolism reprogramming in the clinical practice.

20 abnormal metabolites of Stage IV Grade C periodontitis was discovered by CPSI-MS.

Saliva is a noninvasive biofluid that contains the metabolic signature of severe periodontitis (SP, Stage IV and Grade C). Conductive polymer spray ionization mass spectrometry (CPSI-MS) was used to record a wide range of metabolites within a few seconds, making this technique a promising point-of-care method for the early detection of SP (Stage IV and Grade C). Saliva samples from 31 volunteers, consisting of 16 healthy controls (HC) and 15 patients with SP (Stage IV and Grade C), were collected to identify dysregulated metabolites. Twenty metabolites were screened out, including seven amino acids. Moreover, the results showed that amino acid metabolism is closely related to the development of periodontitis. The present study further confirmed that salivary metabolites in the oral cavity were significantly altered after plaque removal. These results suggest that the combination of CPSI-MS is a feasible tool for preclinical screening of SP (Stage IV and Grade C).

Dual-technique assay for the analysis of organophosphorus compounds for environmental and chemical defense applications

Forensic and environmental sciences often rely on chromatographic separations coupled to mass spectrometry to detect contaminants in complex matrices. However, these methods require lengthy analysis times and sample preparation that is not suitable for analysis in the field. In this work, two analytical methods were combined that are known for their potential for portable analysis. The ambient ionization technique, paper spray mass spectrometry (paper spray-MS) was coupled to paper-based surface enhanced Raman spectroscopy (pSERS) to detect toxic organophosphorus molecules from the same substrate, with a total analysis time of less than five minutes. The coupling of these techniques presents a potential for portable Raman screening followed by MS confirmation in a field-forward laboratory. A cartridge insert was designed and 3D printed to facilitate the sample collection and analysis for PS-MS and pSERS. Three chemical warfare agent simulants: dimethyl methylphosphonate (DMMP), diethyl phosphoramidate (DEPA), and diisopropyl methylphosphonate (DIMP) were included in the method due to having similar chemistries to G- and V-series chemical warfare agents (CWAs). Organophosphorus pesticides, malathion and dichlorvos, with similar mechanisms of action to the CWAs, were also included in the method. Because CWAs quickly degrade in the environment, the CWA hydrolysis products, ethyl methylphosphonic acid (EMPA), isopropyl methylphosphonic acid (IMPA), pinacolyl methylphosphonic acid (PinMPA), methylphosphonic acid (MPA), 2-Diethylaminoethanethiol (EDA), and 2-Diisopropylaminoethanethiol (IDA) were also studied. A mixture of the analytes was used to create calibration curves using the dual-polarity, PS-MS method with sub-ng to low ng limits of detection. A dilution series, spanning 3 orders of magnitude, was made using pSERS, also with low ng limits of detection. These experiments show the potential and feasibility for PS-MS coupled to pSERS to be used to rapidly, screen and confirm the presence of organophosphorus molecules, in complex matrices, with portable instrumentation.

Accelerated synthesis of phthalimide derivatives: Intrinsic reactivity of diamines towards phthalic anhydride evaluated by paper spray ionization mass spectrometry.

Paper spray (PS) is a simple and innovative ambient ionization technique for mass spectrometry (MS) analysis. Under PS-MS conditions, chemical reactions, which usually occur slowly on a bulk scale, are accelerated. Moreover, the formation of products and transient species can be easily monitored. In this manuscript, reactions between phthalic anhydride and diamines were conducted and monitored using a PS-MS platform. The reaction products (phthalimides) have many pharmaceutical applications, but their traditional syntheses can take hours under reflux, requiring laborious purification steps. In situ reactions were performed by dropping methanolic solutions of phthalic anhydride and diamines on a triangular paper. The analyses were achieved by positioning the triangle tip in front of the mass spectrometer entrance, whereas a metal clip was attached to the triangle base. After adding methanol to the paper, a high voltage was applied across the metal clip, and the mass spectra were acquired. The intrinsic reactivity of alkyl and aromatic diamines was evaluated. The carbon chain remarkably influenced the reactivity of aliphatic diamines. For aryl diamines, the ortho isomer was the most reactive. Moreover, for aryl amines with electron-withdrawing substituents, no reaction was noticed. Taking advantage of the unique characteristics of PS-MS, it was possible to investigate the intrinsic reactivity of model alkyl (ethylene versus propylene) and aryl (o-phenylene versus m-phenylene and p-phenylene) diamines towards phthalic anhydride. Some crucial parameters that affect the intrinsic reactivity of organic molecules, such as isomerism, intramolecular interaction, and conformation, were easily explored.

Boronate affinity paper spray mass spectrometry for determination of elevated levels of catecholamines in urine

The analysis of catecholamines, such as dopamine, epinephrine and norepinephrine in urine can be used in the diagnosis of certain pathologies, such as hormone-producing tumors. Here, a fast and simple quantitative boronate affinity paper spray tandem mass spectrometric (PS-MS/MS) method is established, which can improve selectivity and reduce ion suppression without needing any instrumental chromatography. We use here the property of boronic acids, which can selectively bind ortho-diol-containing compounds under alkaline conditions. Paper tip modification and catechol enrichment protocols were developed to selectively bind, clean up and subsequently desorb such catecholamines. Standard catecholamine solutions, as well as human urine samples were analyzed with the PS-MS(/MS) method, which is fast, cheap and easy-to-operate compared to HPLC-MS/MS. Despite its high simplicity, boronate affinity PS-MS/MS exhibits good performance compared to HPLC-MS/MS in human urine analysis in terms of precision (2.1%–7.2% vs. 1.1%–2.9%) and accuracy (−10.2%–9.3% vs. −4.8%–5.1%), and a physiologically relevant limit of detection (0.027–0.12 μg mL−1). The boronate affinity PS-MS/MS clearly achieved the detection limits that would allow the fast analysis of urine samples for clinical purposes, such as screening for pheochromocytoma (exceeding 0.5 μg mL−1).

Immunoaffinity Plastic Blade Spray Mass Spectrometry for Rapid Confirmatory Analysis of Food Contaminants.

The lack of chromatographic separation in ambient and direct mass spectrometry (MS) ionization techniques jeopardizes the overall selectivity of the developed methods. Incorporating a biosensing element at the ionization source could compensate for that inherent lack of selectivity. Thus, a simplified immunoaffinity-direct MS technique was developed, immunoaffinity blade spray (iBS), featuring a conductive polystyrene blade material. In iBS, the generic coating used in conventional coated blade spray is replaced with a layer of highly specific monoclonal antibodies (mAbs), while the stainless steel is replaced with conductive polystyrene to allow for simple ELISA platelike hydrophobic immobilization of mAbs. Because of its high relevance for climate change-induced food safety issues, the mycotoxin deoxynivalenol (DON) was chosen as a model substance. Following a rapid extraction from wheat flour, DON is immuno-captured, and the blade is positioned in front of the MS for direct iBS-MS/MS analysis. The method's applicability was demonstrated by analyzing spiked and incurred wheat flour samples, omitting the need for time-consuming chromatographic separation. Apart from DON, cross-reacting DON conjugates could be successfully analyzed as well. The direct iBS-MS/MS method is generic and adaptable to detecting any analyte in sample extracts, provided that specific mAbs are available.

Malaria Diagnosis Using Paper-Based Immunoassay for Clinical Blood Sampling and Analysis by a Miniature Mass Spectrometer.

In this work, we have developed a paper-based microfluidic device capable of remote biofluid collection followed by an analysis of the dried clinical samples using a miniature mass spectrometer. We have evaluated a portable mass spectrometer as a possible surveillance platform by analyzing the clinical malaria samples (whole blood) collected from Ghana. We synthesized pH-sensitive ionic probes and coupled them with monoclonal antibodies specific to the Plasmodium falciparum histidine-rich protein 2 (PfHRP2) malaria antigen. We then used the antibody-ionic probe conjugates in a paper-based immunoassay to capture PfHRP2 antigen from untreated whole blood. After the immunoassay, the bound ionic probes were cleaved, and the released mass tags were analyzed through an on-chip paper spray mass spectrometry strategy. During process optimization, we determined the detection limit for PfHRP2 in untreated human serum to be 0.216 nmol/L when using the miniature mass spectrometer. This sensitivity is comparable to the World Health Organization's suggested threshold of 0.227 nmol/L for PfHRP2, proving that our method will be applicable to diagnose symptomatic malaria infection (≥200 parasites per μL blood). The paper device can be stored at room temperature for at least 25 days without affecting the clinical outcome, with each stored paper chip offering good repeatability and reproducibility (RSD = 4-12%). The stability and sensitivity of the developed paper-based immunoassay platform will allow miniature mass spectrometers to be used for point-of-care malaria detection as well as in large-scale surveillance screening to aid eradication programs.

Carbon fiber paper spray ionization mass spectrometry

Carbon fiber paper (CFP) is commonly used as a proton exchange membrane in fuel cells due to its prominent areal electrosorption capacity, exceptional conductivity and excellent chemical stability. In this paper, we first explored the feasibility of carbon fiber paper as a specific paper substrate in paper spray ionization mass spectrometry (PSI-MS). The results demonstrated that CFPSI-MS combines the merits of PSI and carbon fiber ionization (CFI) and exhibits better performance of various compound analyses than either of these techniques alone. The application of CFP can highly enhance the signal stability and detection sensitivity of a diverse array of analytes, especially in negative ionization mode. The ion intensity of target analytes such as saccharides and flavonoids was improved 2-90-fold. Many nonpolar/low-polarity analytes, such as polycyclic aromatic hydrocarbons, which are difficult to ionize by traditional PSI-MS, were successfully detected by CFPSI-MS with a 2.5 kV high voltage. Moreover, CFPSI-MS presents high sensitivity in semiquantitative analysis, and the limits of detection (LODs) of cyclic adenosine monophosphate (CAMP), naringin and tivantinib in whole blood were improved 2-100-fold compared to those in traditional PSI-MS. In real sample analysis, CFPSI-MS also exhibits excellent capability in human breath analysis and blood metabolomic profiling.

Screening method for the characterization of anabolic steroids seized in Brazil using paper spray mass spectrometry and chemometric tools.

This paper reports the use of paper spray mass spectrometry (PS-MS) combined with chemometric models to analyze seized samples of anabolic steroids. Because many forensic laboratories typically demand high-throughput analysis for this type of sample, we developed a quicker and simpler alternative analytical method for routine analysis with minimal sample preparation. Oily samples (n = 39) resulting from seizures carried out by Brazilian Federal and State Police units were selected for this study. These samples were analyzed by PS-MS in the positive ion mode and full scan (50-1000 m/z), providing spectra containing patterns of the respective active ingredients present in each product. A principal component analysis (PCA) model was built, which discriminated samples mainly according to their active ingredients and allowed to detect and characterize some cases of product counterfeiting. The variable selection method ordered predictors selection was employed jointly with PCA to improve sample cluster separation and to provide model simplification. The final PCA model was built with three principal components and using only 28 spectral variables. This model accounted for 69.82% of the variance and discriminated samples according to their specific active ingredients.

Bisphenol determination in UHT milk and packaging by paper spray ionization mass spectrometry

This study evaluates the use of paper spray ionization mass spectrometry (PSI-MS) for rapid determination of bisphenol A (BPA) and bisphenol S (BPS) in UHT milk and milk packaging. The packages were analyzed by cutting the cartons into triangular shapes and submitting them to PSI-MS analysis. The milk samples were subjected to a simple liquid–liquid extraction and the supernatant was deposited onto a triangular paper that was subsequently used for PSI-MS analysis. In milk, BPS and BPA levels ranged from 60.0 to 150.8 ng mL−1. The LOD and LOQ values were 1.5 and 4.8 ng mL−1 for BPA, and 4.8 and 16.0 ng mL−1 for BPS, respectively. Linearity was R2 > 0.98 for both compounds. Precision values were below 20%, and recoveries close to 100%. The PSI-MS can be used as a simple, rapid, and accurate methodology to determine bisphenols in milk and milk packaging.

Rapid determination of aldehydes in food by high-throughput reactive paper spray ionization mass spectrometry

Due to endogenous existence and hazardous properties, the quantification of fatty and aromatic aldehydes in food matrices is indispensable to food safety. Current analytical methodologies for aldehydes in food suffer from several drawbacks (typically complicated pretreatment, long analysis time and low analytical throughput, low sensitivity, etc.). In this work, a highly sensitive, high-throughput and sample pretreatment-free method for aldehyde analysis was developed to address the above problems, where in situ extraction and derivatization of aldehydes with hydrazines to hydrazones were integrated into reactive paper spray ionization mass spectrometry (reactive PSI-MS) considering weakly ionizable properties of aldehydes. Four aldehydes, formaldehyde, acetaldehyde, propionaldehyde and benzaldehyde were reacted with dansyl hydrazine in 1.5 % v/v HAc acidified methanol on the qualitative fast-speed filter paper for 5 min, and then a voltage (+4 kV) was applied to initiate paper spray for mass spectrometry detection with internal calibration by dansyl amide. Once the completion of MS analysis, the glass plate was moved to introduce the second triangular tip towards the MS inlet (5 mm apart) for next trial, achieving high-throughput reactive PSI-MS analysis (60 h−1). The four aldehydes showed good linearity in the concentration range from 2 to 150 μM with low detection limits of 0.03–0.15 μM. The method was applied to direct quantification of four aldehydes in 15 kinds of foods such as vegetables, fruits and meat products. The proposed method has the advantages of simple operation, high efficiency and high sensitivity, making it attractive to routine analysis of aldehydes in food, environmental and biological samples.

A unique ternary Ce(III)-quercetin-phenanthroline assembly with antioxidant and anti-inflammatory properties

Quercetin is one of the most bioactive and common dietary flavonoids, with a significant repertoire of biological and pharmacological properties. The biological activity of quercetin, however, is influenced by its limited solubility and bioavailability. Driven by the need to enhance quercetin bioavailability and bioactivity through metal ion complexation, synthetic efforts led to a unique ternary Ce(III)-quercetin-(1,10-phenanthroline) (1) compound. Physicochemical characterization (elemental analysis, FT-IR, Thermogravimetric analysis (TGA), UV–Visible, NMR, Electron Spray Ionization-Mass Spectrometry (ESI-MS), Fluorescence, X-rays) revealed its solid-state and solution properties, with significant information emanating from the coordination sphere composition of Ce(III). The experimental data justified further entry of 1 in biological studies involving toxicity, (Reactive Oxygen Species, ROS)-suppressing potential, cell metabolism inhibition in Saccharomyces cerevisiae (S. cerevisiae) cultures, and plasmid DNA degradation. DFT calculations revealed its electronic structure profile, with in silico studies showing binding to DNA, DNA gyrase, and glutathione S-transferase, thus providing useful complementary insight into the elucidation of the mechanism of action of 1 at the molecular level and interpretation of its bio-activity. The collective work projects the importance of physicochemically supported bio-activity profile of well-defined Ce(III)-flavonoid compounds, thereby justifying focused pursuit of new hybrid metal-organic materials, effectively enhancing the role of naturally-occurring flavonoids in physiology and disease.

Determination of 14 Isoflavone Isomers in Natto by UPLC-ESI-MS/MS and Antioxidation and Antiglycation Profiles.

Natto is a famous traditional fermented food, but the influence of the fermentation process on the content and composition of soybean isoflavones and nutritional value is still unclear. In the present study, the variation in soybean isoflavones during fermentation by Bacillus subtilis natto was revealed by UPLC-ESI-MS/MS (Ultra high performance liquid chromatography-electron spray ionization-mass spectrometry) analysis. After 24 h of fermentation, the total isoflavone content in natto increased by 1.62 times compared with fresh soybean, and the content of aglycones was 3.07 times that of raw beans. More importantly, among 14 isoflavone isomers identified in natto, the isomers of daidzin, genistin, and succinyl genistin were detected for the first time, which might be due to the result of isomerase and succinylase and other corresponding enzymes’ action in Bacillus subtilis. In addition, natto isoflavones performed great antioxidant activity than its monomer components (glycosides daidzin and genistin, aglycones genistein and daidzein), except for genistein. Moreover, natto isoflavone and its aglycones (especially genistein) performed great inhibitory activity against AGEs (Advanced Glycation End Products) in three in vitro models. The mechanism test showed that genistein could form adducts (UPLC-Q-TOF-ESI-MS/MS analysis) with methylglyoxal. These findings demonstrated that soybean fermented with Bacillus subtilis natto had a significant influence on the isoflavone profiles and its bioactivity.