Liquid Chromatography Ionization Mass Spectrometry Research Articles

Physical activity (PA) impact on metabolome and immunity of oncogene addicted non-small cell lung cancer (NSCLC): The EXcellenT trial.

e20582 Background: Today patients (pts) with oncogene addicted advanced NSCLC receive molecular targeted therapies as first-line treatment ensuring high compliance to therapy, few side effects and long survival time. These pts are usually young and with a strong wish to regain the pre-diagnosis quality of life (QoL), including the ability to perform PA. It’s known that PA can impact significantly on metabolomic and immunity status, but to date only few studies on its role in NSCLC have been performed. The aim of the EXcellenT trial is to evaluate if a tailored PA program may have an impact on QoL and performances of this homogeneous subgroup of pts. An exploratory objective was to explore the complex interplay between PA and immune status and the influence of PA on metabolome. Methods: EXcellenT (Exercise in Extended oncogene addicted Lung Cancer in Active Treatment - NCT05306652) is an Italian monocentric prospective study enrolling 40 pts with oncogene-addicted advanced NSCLC in active treatment with tyrosine kinase inhibitors (TKI). Pts are randomized in 2 arms: an interventional arm of a personalized supervised PA program or a counselling group of home-based exercise. We explored peripheral variations of T cells subsets during TKI treatment combined with exercise training to better define the immuno-dependence of these tumors. Fatty acid composition (FA) of plasma has been carried out using gas chromatography-flame ionization detection (GC-FID) and liquid chromatography-mass spectrometry (LC-MS). Immature and mature neutrophils, monocytes, CD34+ cells and megakaryocytes (MK) precursors have been determined through flow cytometry analysis. Results: A preliminary exploratory analysis on the first patients enrolled with 3 complete time point (baseline; week 4 and 12) was performed. To date 23 out of 40 pts have been enrolled, 46% of them with pre-diagnosis leisure-time physical activity. The oncogene identified are: ALK 52%, EGFR 26%, BRAF 9%, RET 4%, ROS1 9%. 35% had stable brain metastasis (mts) and 39% bone mts not at risk of skeletal-related events. FA analysis (4 pts) showed significant increase of monounsaturated fatty acids (p = 0.0329) during the study. According to immunophenotype, we observed (3 pts) a significant reduction of CD34+ cancer stem cell (p 0.0112) and a consistent increase in mature CD66b+CD10+ neutrophils with a trend of decrease in CD66b+CD10- cells. Conclusions: The ExcellenT trial is showing that PA programs are feasible and well accepted by patients with oncogene-addicted NSCLC. The QoL analysis will be performed at the end of enrolment. The preliminary analysis on metabolomic and immunity status shows an improvement of fatty acid composition and an increase of mature cell precursors compared to immature counterpart suggesting a potential role of PA in hindering tumor immune escape strategies. Clinical trial information: NCT05306652 .

Redox-sensitive high-mobility group box-1 isoforms contribute to liver fibrosis progression and resolution in mice

High-mobility group box-1 (HMGB1) significantly increases and undergoes post-translational modifications (PTMs) in response to liver injury. Since oxidative stress plays a major role in liver fibrosis and induces PTMs in proteins, we hypothesized that redox-sensitive HMGB1 isoforms contribute to liver fibrosis progression and resolution. We used ESI-LC-MS (electrospray ionization-liquid chromatography-mass spectrometry) to study PTMs of HMGB1 during fibrosis progression and resolution. Conditional knockout mice were used for functional analyses. We identified that disulfide ([O]) and sulfonated ([SO3]) HMGB1 increase during carbon tetrachloride-induced liver fibrosis progression, however, while [O] HMGB1 declines, [SO3] HMGB1 drops but remains, during fibrosis resolution. Conditional knockout of Hmgb1 revealed that production of [O] and [SO3] HMGB1 occurs mostly in hepatocytes. Co-injection of [O] HMGB1 worsens carbon tetrachloride-induced liver fibrosis more than co-injection of [H] HMGB1. Conversely, ablation of [O] Hmgb1 in hepatocytes reduces liver fibrosis. Moreover, ablation of the receptor for advanced-glycation end-products (Rage) reveals that the profibrogenic effect of [O] HMGB1 is mediated by RAGE signaling in hepatic stellate cells (HSCs). Notably, injection of [SO3] HMGB1 accelerates fibrosis resolution due to RAGE-dependent stimulation of HSC apoptosis. Importantly, gene signatures activated by redox-sensitive HMGB1 isoforms in mice, classify patients with fibrosis according to fibrosis and inflammation scores. Dynamic changes in hepatocyte-derived [O] and [SO3] HMGB1 signal through RAGE-dependent mechanisms on HSCs to drive their profibrogenic phenotype and fate, contributing to progression and resolution of liver fibrosis. Since oxidative stress plays a major role in liver fibrosis and induces post-translational modifications of proteins, we hypothesized that redox-sensitive HMGB1 isoforms contribute to liver fibrosis progression and resolution. This study is significant because a rise in [H] HMGB1 could flag 'patient at risk', the presence of [O] HMGB1 could suggest 'disease in progress or active scarring', while the appearance of [SO3] HMGB1 could point at 'resolution under way'. The latter could be used as a readout for response to pharmacological intervention with anti-fibrotic agents.

Identification of metabolic biomarkers for diagnosis of epithelial ovarian cancer using internal extraction electrospray ionization mass spectrometry (iEESI-MS).

Epithelial ovarian cancer (EOC) is the leading cause of death from gynecologic malignancies. The poor prognosis of EOC is mainly due to its asymptomatic early stage, lack of effective screening methods, and a late diagnosis in the advanced stages of the disease. This study investigated metabolomic abnormalities in epithelial ovarian cancers. Our study developed a novel strategy to rapidly identify the metabolic biomarkers in the plasma of the EOC patients using Internal Extraction Electrospray Ionization Mass Spectrometry (IEESI-MS) and Liquid Chromatography-mass Spectrometry (HPLC-MS), which could distinguish the differential metabolites in between plasma samples collected from 98 patients with epithelial ovarian cancer, including 78 cases with original (P), and 20 cases with self-configuration (ZP), as well as 60 healthy subjects, including 30 cases in the original sample (H), 30 cases in self-configuration (ZH), and 6 cases in a blind sample (B). Our study detected 880 metabolites based on criteria variable importance in projection (VIP) > 1, among which 26 metabolites were selected for further identification. They are mainly metabolism-related lipids, amino acids, nucleic acids, and others. The metabolic pathways associated with the differential metabolites were explored by the KEGG analysis, a comprehensive database that integrates genome, chemistry, and system function information. The abnormal metabolites of EOC patients identified by IEESI-MS and HPLC-MS included Lysophosphatidylcholine (16:0) [Lyso PC (16:0)], L-Phenylalanine, L-Leucine, Phenylpyruvic acid, L-Tryptophan, and L-Histidine. Identifying the abnormal metabolites of EOC patients through metabolomics analyses could provide a new strategy to identify valuable potential biomarkers for the screening and early diagnosis of EOC.

Influence of Tobacco Variety and Curing on Free Radical Production in Cigarette Smoke.

Cigarette smoke contains highly reactive free radicals thought to play an important role in tobacco smoke-induced harm. Previously, large variations in free radical and toxicant output have been observed in commercial cigarettes. These variations are likely because of cigarette design features (paper, filter, and additives), tobacco variety (burley, bright, oriental, etc.), and tobacco curing methods (air, sun, flue, and fire). Previous reports show that tobacco varieties and curing methods influence the production of tobacco smoke constituents like the tobacco-specific carcinogen nicotine-derived nitrosamine ketone (NNK). We evaluated free radical, nicotine, and NNK production in cigarette smoke from cigarettes produced with 15 different types of tobacco. Gas-phase free radicals were captured by spin trapping with N-tert-butyl-α-phenylnitrone and particulate-phase radicals were captured on a Cambridge Filter pad (CFP). Both types of radicals were analyzed using electron paramagnetic resonance spectroscopy. Nicotine and NNK were extracted from the CFP and analyzed by gas chromatography flame ionization detection and liquid chromatography-mass spectrometry, respectively. Gas-phase radicals varied nearly 8-fold among tobacco types with Saint James Perique tobacco producing the highest levels (42 ± 7 nmol/g) and Canadian Virginia tobacco-producing the lowest levels (5 ± 2 nmol/g). Nicotine and NNK levels in smoke varied 14-fold and 192-fold, respectively, by type. Gas-phase free radicals were highly correlated with NNK levels (r = 0.92, p < .0001) and appeared to be most impacted by tobacco curing method. Altogether, these data suggest that tobacco types used in cigarette production may serve as a target for regulation to reduce harm from cigarette smoking. Variations in cigarette free radical and NNK levels vary based on the tobacco variety and curing method. Reducing the ratio of high-producing free radical and NNK tobacco types offer a potential tool for regulators and producers looking to reduce toxicant output from cigarettes.

Structure Determination of Felodipine Photoproducts in UV-Irradiated Medicines Using ESI-LC/MS/MS

Dihydropyridine drugs are well known as photodegradable pharmaceuticals. Herein, we evaluate the photostability of felodipine (FL) medicine (Splendil® (SPL) tablets) and its altered forms (powders and suspensions). FL is a type of dihydropyridine drug, but its photochemical behavior is unknown. FL contents after ultraviolet light (UV) irradiation for 24 h were monitored using high-performance liquid chromatography (HPLC). Values of the residual amounts of FL in UV-irradiated SPL powders and suspensions were 32.76 ± 4.88% and 0.79 ± 0.74%, respectively, with the generation of two photoproducts (FL photoproduct 1 and 2). To identify the chemical structures of these photoproducts, electrospray ionization liquid chromatography mass spectrometry (ESI-LC/MS/MS) analysis was performed. Based on their mass-to-charge ratio values and fragment patterns, it was proposed that FL photoproduct 1 was a pyridine derivative and FL photoproduct 2 was an FL dimer. Interestingly, generation rates of FL photoproduct 1 and 2 were dependent on the presence of the aqueous media. The photodimerization of FL was induced in UV-irradiated SPL suspensions. This is the first report evaluating the photostability of SPL tablets and its altered forms and estimating FL photoproducts induced by UV irradiation in the formulation of SPL.

Enzymatic degradation and metabolic pathway of acid blue 129 dye by crude laccase from newly isolated Trametes hirsuta EDN 082

Crude laccase from Trametes hirsuta EDN 082 was used in this study for the decolorization of anthraquinone and azo dyes. Characterization of degradation products from one selected dye, Acid Blue 129 (AB129), was investigated using liquid chromatography high-resolution mass spectrometry (LC-HRMS). The results showed that laccase from T. hirsuta EDN 082 (0.25 U/mL dyes) was able to decolourize AB 129, AB 113, RBBR, AB 25, RB4, and RB5 dyes with a decolorization efficiency of 88%, 73%, 71%, 72%, 42%, and 6%, respectively for 7 h. During the degradation of AB129 dye, nine metabolites were identified and characterized by electrospray ionization–liquid chromatography–mass spectrometry Quadrupole-Time of flight (ESI-LCMS-Q-TOF) analysis. Evaluation of peak area showed decreasing of the two metabolites, 1-amino-4-hydroxy-9,10-dioxo-9,10-dihydroanthracene-2-sulfonic acid (D2) and 2,4,6-trimethylaniline (D4) during 7 h reaction indicated these two compounds become the centre of the degradation after cleaving the AB129 dye, and from these results, metabolic pathways were proposed. This study offers the potency of laccase from T. hirsuta EDN 082 for bioremediation of synthetic dyes in the fields.

What’s next after bevaciumab resistance? Targeting metabolic vulnerabilities in ovarian cancer (022)

What’s next after bevaciumab resistance? Targeting metabolic vulnerabilities in ovarian cancer (022)

In-Sewer Stability Assessment of Anabolic Steroids and Selective Androgen Receptor Modulators.

Wastewater-based epidemiology is a potential complementary technique for monitoring the use of performance- and image-enhancing drugs (PIEDs), such as anabolic steroids and selective androgen receptor modulators (SARMs), within the general population. Assessing in-sewer transformation and degradation is critical for understanding uncertainties associated with wastewater analysis. An electrospray ionization liquid chromatography mass spectrometry method for the quantification of 59 anabolic agents in wastewater influent was developed. Limits of detection and limits of quantification ranged from 0.004 to 1.56 μg/L and 0.01 to 4.75 μg/L, respectively. Method performance was acceptable for linearity (R2 > 0.995, few exceptions), accuracy (68-119%), and precision (1-21%RSD), and applicability was successfully demonstrated. To assess the stability of the selected biomarkers in wastewater, we used laboratory-scale sewer reactors to subject the anabolic agents to simulated realistic sewer environments for 12 h. Anabolic agents, including parent compounds and metabolites, were spiked into freshly collected wastewater that was then fed into three sewer reactor types: control sewer (no biofilm), gravity sewer (aerobic conditions), and rising main sewer (anaerobic conditions). Our results revealed that while most glucuronide conjugates were completely transformed following 12 h in the sewer reactors, 50% of the investigated biomarkers had half-lives longer than 4 h (mean residence time) under gravity sewer conditions. Most anabolic agents were likely subject to biofilm sorption and desorption. These novel results lay the groundwork for any future wastewater-based epidemiology research involving anabolic steroids and SARMs.

Evaluation of the Photodegradation of Crushed- and Suspended Pranoprofen Tablets

Herein, we evaluate the photostability of pranoprofen (PP) tablets (NIFLAN® 75 mg), its powdered and suspended forms. PP is a member of the 2-arylpropionic acid family of NSAIDs. The content of the active compound was monitored by high-performance liquid chromatography (HPLC) using an ODS column with ultraviolet light (UV) detector. The residual amount of PP in the powder was 86.5%, which was comparable to that of in the suspension (85.4%) after UV irradiation for 24 hr. Further UV irradiation (total irradiation time of 7 days) resulted in the significant photodegradation of PP in the suspension (residual amount: 55.5%), compared to that of 1 day irradiation. However, the residual amount of PP in the powder was 78.6% after 7 days irradiation as the same to that of 1 day irradiation. To identify the chemical structure of five photoproducts generated from the UV-irradiated PP dosage forms, electrospray ionization liquid chromatography mass spectrometry (ESI-LC/MS/MS) analysis was performed. From these results, photodegradation of PP was observed through changing dosage forms. This is the first report evaluating the generation of PP photoproducts induced by the UV irradiation in the formulation.

Anion-Responsive Manganese Porphyrin Facilitates Chloride Transport and Induces Immunogenic Cell Death

Anion-Responsive Manganese Porphyrin Facilitates Chloride Transport and Induces Immunogenic Cell Death

N-Terminally Truncated and Pyroglutamate-Modified Aβ Forms Are Measurable in Human Cerebrospinal Fluid and Are Potential Markers of Disease Progression in Alzheimer's Disease.

Alzheimer’s disease (AD) is a pathology characterized by the accumulation in the brain of intracellular and extracellular amyloid-β (Aβ) aggregates, especially of Aβ1–40 and Aβ1–42 peptides. It is known that N-terminally truncated or modified Aβ forms also exist in AD brains and cerebrospinal fluid (CSF), and they play a key role in the pathogenesis of the disease. Herein, we developed an antibody-free method based on Solid-Phase Extraction and Electrospray Ionization Liquid Chromatography Mass Spectrometry for the identification and quantitation in human CSF of Aβ isoforms. In human CSF, we could detect and quantify a panel of 19 Aβ isoforms, including N-terminally truncated and pyroglutamate-modified forms, never quantified before in CSF. Among these, we identified novel N-terminally truncated Aβ species: four bound to copper and two phosphorylated forms, which were found to be the most common proteoforms in human CSF along with Aβ1–40, Aβ3–40, and AβpE11–42. We tested the newly developed and validated method in a pilot study on CSF from elderly individuals with subjective memory complaints (SMCs, n = 9), mild cognitive impairment (MCI, n = 18), and AD (n = 15); along with Aβ1–42, five N-terminally truncated forms (Aβ11–40, Aβ3–42, AβpE11–42, AβpE3–40, and Aβ4–40 Cu2+) are altered in AD/MCI. Thus, we demonstrated that N-terminally truncated and pyroglutamate-modified Aβ can be quantified in human CSF, and five of them, along with Aβ1–42, are potential markers of AD progression. The described method could represent a useful tool for patients’ stratification and monitoring. Moreover, the newly identified Aβ CSF species might represent new potential therapeutic targets.

Improved identification and quantification of peptides in mass spectrometry data via chemical and random additive noise elimination (CRANE).

MotivationThe output of electrospray ionization–liquid chromatography mass spectrometry (ESI-LC-MS) is influenced by multiple sources of noise and major contributors can be broadly categorized as baseline, random and chemical noise. Noise has a negative impact on the identification and quantification of peptides, which influences the reliability and reproducibility of MS-based proteomics data. Most attempts at denoising have been made on either spectra or chromatograms independently, thus, important 2D information is lost because the mass-to-charge ratio and retention time dimensions are not considered jointly.ResultsThis article presents a novel technique for denoising raw ESI-LC-MS data via 2D undecimated wavelet transform, which is applied to proteomics data acquired by data-independent acquisition MS (DIA-MS). We demonstrate that denoising DIA-MS data results in the improvement of peptide identification and quantification in complex biological samples.Availability and implementationThe software is available on Github (https://github.com/CMRI-ProCan/CRANE). The datasets were obtained from ProteomeXchange (Identifiers—PXD002952 and PXD008651). Preliminary data and intermediate files are available via ProteomeXchange (Identifiers—PXD020529 and PXD025103).Supplementary information Supplementary data are available at Bioinformatics online.

First occurrence of Cylindrospermopsin in the Azores (Lake São Brás, S. Miguel Island)

Anthropogenic impacts have been reported as one of the main causes of eutrophication in freshwater systems and nutrient availability, mainly from discharges, are key to cyanobacteria development and harmful cyanobacteria blooms (cyanoHABs) upsurge. As these scenarios are common in the Azores, a cyanobacteria monitoring program was implemented in the lakes of the archipelago, which comprises cyanobacteria identification and cyanotoxin (only microcystin) analysis in over 15 lakes. However other cyanotoxins should be searched as is the case of cylindrospermopsin (CYN). This cyanotoxin has been reported more recently in a wider range of countries, because of global warming. Using ESI–LC–MS/MS (electrospray ionization–liquid chromatography–mass spectrometry), the presence of CYN was investigated in samples from four eutrophic lakes. Cylindrospermopsin was detected in one sample from Lake Sao Bras, which represents a threat to environmental and public health. This is the first CYN identification in the Azores reinforcing the necessity for lake monitoring. We propose the use of a polyphasic approach to fully understand CYN presence in the Azorean lakes, investigating the producing taxa, the environmental factors that promote cyanobacteria growth, and CYN toxicity effects.

Analysis of 14 endocannabinoids and endocannabinoid congeners in human plasma using column switching high-performance atmospheric pressure chemical ionization liquid chromatography-mass spectrometry.

The endocannabinoid system (ECS) is a complex cell-signaling system. To address the growing need of analytics capturing endocannabinoid levels to investigate the ECS, we developed and validated an assay for the quantitative analysis of 14 endocannabinoids and congeners. A simple extraction using protein precipitation with acetonitrile followed by online-trapping high-performance liquid chromatography-tandem mass spectrometry (LC/LC-MS/MS) was used to monitor the levels of 14 endocannabinoids in plasma. The assay was validated and intra-run and inter-run accuracies and imprecisions as well as matrix effects, recoveries, and sample stabilities were determined. As a proof of concept, a subset of study samples after naturalistic administration of Cannabis flower and concentrate was analyzed. With the exception of N-oleoyl dopamine and oleamide, all endocannabinoids fulfilled the predefined acceptance criteria. Reproducible recoveries and no significant matrix effects were observed. Sample stability was an issue. Analysis of the proof-of-concept study samples revealed a significantly (p = 0.006) higher concentration of docosatetraenoyl ethanolamide in concentrate users (300 ± 13pg/mL) compared to flower users (252 ± 11pg/mL). A robust, sensitive high-throughput assay for the quantitation of 14 endocannabinoids and congeners was successfully validated. Our study showed that it is mandatory to (A) appropriately stabilize samples and (B) separate and separately quantify 1-AG and 2-AG; otherwise, study results are unreliable. The analysis of study samples from Cannabis flower users versus Cannabis concentrate users revealed higher levels of docosatetraenoyl ethanolamide and anandamide (n.s.) in high THC concentrate users in accordance with the existing literature, supporting the validity of the assay measurements. Graphical abstract.

Reduced hepatic global hydroxymethylation in mice treated with non-genotoxic carcinogens is transiently reversible with a methyl supplemented diet

Non-genotoxic carcinogens (NGCs) are known to cause perturbations in DNA methylation, which can be an early event leading to changes in gene expression and the onset of carcinogenicity. Phenobarbital (PB) has been shown to alter liver DNA methylation and hydroxymethylation patterns in mice in a time dependent manner. The goals of this study were to assess if clofibrate (CFB), a well-studied rodent NGC, would produce epigenetic changes in mice similar to PB, and if a methyl donor supplementation (MDS) would modulate epigenetic and gene expression changes induced by phenobarbital. CByB6F1 mice were treated with 0.5% clofibrate or 0.14% phenobarbital for 7 and 28 days. A subgroup of PB treated and control mice were also fed MDS diet. Liquid Chromatography-Ionization Mass Spectrometry (LC-MS) was used to quantify global liver 5-methylcytosine (5mC) and 5-hydroxymethylcytosine (5hmC) levels. Gene expression analysis was conducted using Affymetrix microarrays. A decrease in liver 5hmC but not 5mC levels was observed upon treatment with both CFB and PB with varying time of onset. We observed moderate increases in 5hmC levels in PB-treated mice when exposed to MDS diet and lower expression levels of several phenobarbital induced genes involved in cell proliferation, growth, and invasion, suggesting an early modulating effect of methyl donor supplementation. Overall, epigenetic profiling can aid in identifying early mechanism-based biomarkers of non-genotoxic carcinogenicity and increases the quality of cancer risk assessment for candidate drugs. Global DNA methylation assessment by LC-MS is an informative first step toward understanding the risk of carcinogenicity.

Localisation of clozapine during experimental autoimmune encephalomyelitis and its impact on dopamine and its receptors

Multiple sclerosis is a disease characterised by axonal demyelination in the central nervous system (CNS). The atypical antipsychotic drug clozapine attenuates experimental autoimmune encephalomyelitis (EAE), a mouse model used to study multiple sclerosis, but the precise mechanism is unknown and could include both peripheral and CNS–mediated effects. To better understand where clozapine exerts its protective effects, we investigated the tissue distribution and localisation of clozapine using matrix-assisted laser desorption ionization imaging mass spectrometry and liquid chromatography-mass spectrometry. We found that clozapine was detectable in the brain and enriched in specific brain regions (cortex, thalamus and olfactory bulb), but the distribution was not altered by EAE. Furthermore, although not altered in other organs, clozapine levels were significantly elevated in serum during EAE. Because clozapine antagonises dopamine receptors, we analysed dopamine levels in serum and brain as well as dopamine receptor expression on brain-resident and infiltrating immune cells. While neither clozapine nor EAE significantly affected dopamine levels, we observed a significant downregulation of dopamine receptors 1 and 5 and up-regulation of dopamine receptor 2 on microglia and CD4+-infiltrating T cells during EAE. Together these findings provide insight into how neuroinflammation, as modelled by EAE, alters the distribution and downstream effects of clozapine.

In silico estrogen receptor alpha antagonist studies and toxicity prediction of Melia azedarach leaves bioactive ethyl acetate fraction.

The estrogen hormone dependent accounts for a major cause in the incidence of women breast cancer. Thus, their receptor, especially the estrogen receptor α (ER-α), is becoming a target in endocrine treatment. These ligand-inducible nuclear functions are regulated by an array of phytochemical and synthetic compounds, such as 17 β-estradiol and tamoxifen (4-hydroxytamoxifen [4OHT]). The Chinaberry (Melia azedarach) leaves are known naturally for relieving internal and external diseases. Previous studies revealed the potency of Melia's ethanolic extract and ethyl acetate fractions as anticancer; furthermore, this study aimed to resolve possible ER-α antagonist's mechanism and safety from M. azedarach leaves ethyl acetate fraction contents. Melia's phytochemical content was analyzed with electrospray ionization liquid chromatography-mass spectrometry, while its ER-α antagonist's potency was investigated by in silico. The computational docking was used to 3ERT (a human ER-α-4OHT binding domain complex) with Autodock Vina and related programs. The results presented Energy binding (ΔG) of Melia's quercetin 3-O-(2'',6''-digalloyl)-β-D-galactopyranoside was similar to 4OHT, and lower than its agonist 17 β-estradiol. Furthermore, the toxicity prediction of these compounds were revealed safer than 4OHT. The Melia's leaves ethyl acetate fraction, therefore, is a potential pharmacological material for further studies.

Evaluation of pranoprofen photodegradation induced by ultraviolet-light irradiation in aqueous media

The photodegradation of pranoprofen (PP), which is a member of the 2-arylpropionic acid family of non-steroidal anti-inflammatory drugs, in aqueous media under ultraviolet light (UV) irradiation was studied herein. Our purpose is to clarify the photostability and photochemical behavior of PP. The photodegradation of PP and the generation of its photoproducts were monitored by means of high-performance liquid chromatography (HPLC). PP was degraded completely after 2 h of UV irradiation with the generation of several photoproducts identified in HPLC analysis. The chemical structures of nine PP photoproducts were elucidated based on the mass/charge ratio (m/z) values and fragmentation patterns of protonated ions obtained from electrospray ionization liquid chromatography mass spectrometry (ESI-LC/MS/MS). Among these nine PP photoproducts, the main product was 7-acetyl-5H-[1]benzopyrano[2,3-b]pyridin-5-one, which was the final oxidized form of PP. The photodegradation pathways are proposed, showing that oxidation of excited PP might be an initial process. This is the first study showing the photochemical behavior of PP, and these results allow further research focused on the photostability of PP in commercial tablets and its changed formulation, the toxicological potencies of photoproducts and photostabilization approaches.

Controlling formation of metal ion adducts and enhancing sensitivity in Liquid Chromatography Mass Spectrometry

Formation of metal ion adducts in mass spectrometry, particularly in electrospray ionization liquid chromatography mass spectrometry (ESI-LC-MS), is a nightmare scenario for an analyst dealing with quantitative analysis. We have studied in detail the metal adduct formation and concluded that the use of fluorinated alkanoic acids along with formic acid and volatile ammonium salts was extremely useful in suppressing metal adduct formation in positive ion mode of ESI-LC-MS. The extremely high electronegativity of fluorine atom and unique electrostatic nature of C—F bond coupled with stereo-electronic interactions with neighboring bonds or lone pairs enables the polyfluorinated alkanoic acids in trapping highly electropositive ions (Na+, K+) thereby letting proton do its job efficiently. Addition of formic acid, trifluoroacetic acid, heptafluorobutyric acid and ammonium acetate was found to be extremely effective in controlling metal ion adducts and producing [M+H]+ ions almost exclusively resulting in significant increase in the sensitivity. This technique has been successfully used in our laboratory for the estimation of targeted and nontargeted analysis of pesticides, marine toxins, drugs and pharmaceuticals etc. in various matrices including environmental waters using liquid chromatography-time of flight mass spectrometer operated in all ion acquisition mode and triple quadruples (QQQ) in multiple reaction monitoring (MRM) mode.

The heterogeneity and complexity of Cannabis extracts as antitumor agents.

The Cannabis plant contains over 100 phytocannabinoids and hundreds of other components. The biological effects and interplay of these Cannabis compounds are not fully understood and yet influence the plant’s therapeutic effects. Here we assessed the antitumor effects of whole Cannabis extracts, which contained significant amounts of differing phytocannabinoids, on different cancer lines from various tumor origins. We first utilized our novel electrospray ionization liquid chromatography mass spectrometry method to analyze the phytocannabinoid contents of 124 Cannabis extracts. We then monitored the effects of 12 chosen different Cannabis extracts on 12 cancer cell lines. Our results show that specific Cannabis extracts impaired the survival and proliferation of cancer cell lines as well as induced apoptosis. Our findings showed that pure (-)-Δ9-trans-tetrahydrocannabinol (Δ9-THC) did not produce the same effects on these cell lines as the whole Cannabis extracts. Furthermore, Cannabis extracts with similar amounts of Δ9-THC produced significantly different effects on the survival of specific cancer cells. In addition, we demonstrated that specific Cannabis extracts may selectively and differentially affect cancer cells and differing cancer cell lines from the same organ origin. We also found that cannabimimetic receptors were differentially expressed among various cancer cell lines and suggest that this receptor diversity may contribute to the heterogeneous effects produced by the differing Cannabis extracts on each cell line. Our overall findings indicate that the effect of a Cannabis extract on a specific cancer cell line relies on the extract’s composition as well as on certain characteristics of the targeted cells.