An Unusual Occurrence of Tamoxifen-Induced Maculopathy in a Young Woman With Hormone Receptor-Positive Post-mastectomy Breast Carcinoma.

Tamoxifen, a selective estrogen receptor modulator (SERM), is a hormone therapy used for the treatment of estrogen receptor (ER)-positive breast cancer. We report the case of a 29-year-old premenopausal lady with a history of infertility treatments who was diagnosed with ER-positive infiltrating ductal carcinoma (IDC) of the breast. Following a modified radical mastectomy (MRM) and adjuvant systemic chemotherapy, tamoxifen was recommended as part of her adjuvant hormonal therapy. After over three years of tamoxifen use, the patient complained of gradual blurring of vision in both eyes. Ophthalmological examinations indicated bilateral maculopathy, a rare but alarming ocular side effect attributed to tamoxifen use. This case report emphasizes the significance of ophthalmic tests in patients on tamoxifen therapy to monitor any potential ocular side effects. While tamoxifen has shown remarkable benefits in the adjuvant treatment of ER-positive breast cancer, including lowering the chance of recurrence and increasing survival rates, clinicians must be acquainted with rare but potential vision-threatening consequences such as tamoxifen-induced maculopathy. Early detection and timely management are critical in reducing the risk of vision loss in patients receiving tamoxifen for breast cancer.

Solid-phase extraction followed by gas chromatography-mass spectrometry for the quantitative analysis of small molecule N-nitrosamine impurities in antitussive syrups.

A quantitative testing method was developed for the analysis of low molecular weight (small molecules) nitrosamine impurities in cough syrups using solid phase extraction (SPE) on strong cation-exchange functionalized polymeric sorbent cartridges followed by gas chromatography-mass spectrometry. The matrix spike recoveries of the nitrosamine impurities from the cough syrup samples was observed to be within the range of 90 %-120 %. Limit of detection (LOD) achieved for NNitrosodimethylamine (NDMA) and NNitroso morpholine (NMOR) was about 0.1 ng/mL while the LOD for NNitrosodiethylamine (NDEA), NNitrosodiisopropylamine (NDIPA) and NNitrosoisopropylethylamine (NIPEA) impurities was about 0.02 ng/mL. The method was evaluated and found to meet the acceptable criteria as per the ICH Q2 guidelines for a working concentration range of 0.02 ng/mL to 1.2 ng/mL for the analyzed impurities. The selectivity of the nitrosamine impurities against the presence of drug product was established using multiple reaction monitoring (MRM) transitions during analysis.

Eliciting Callus Cultures for the Production of Cytotoxic Polyphenolics from Maesa indica Roxb. Sweet.

Maesa indica Roxb. Sweet is a shrub known for its richness in secondary metabolites. A callus culture protocol was established to enhance its chemical profile. Sixteen elicitation culture treatments were evaluated, and we confirmed that the treatment of 200 mg/L polyethylene glycol (4000) coupled with exposure to 30 W UV irradiation for 60 min (PEG4) resulted in the highest total phenolic and total flavonoid contents, which were 4.1 and 4.9 times those of the plant ethanolic extract and 4.9 and 4.8 times those of a control sample, respectively. The phenolic compounds in the different treatments were identified qualitatively and quantitatively using the LC-ESI-MS/MS-MRM technique. Molecular docking studies of the phenolic compounds were conducted using MOE software and revealed that rutin showed the highest binding affinity toward the anti-cancer target (p38α MAPK). The cytotoxicity of the ME and PEG 4 treatment was tested against colon, breast, prostate, lung, and liver cell lines using an MTT assay. The highest cytotoxic effect of PEG4 was against prostate cancer with an IC50 value of 25.5 µg/mL. Hence, this study showed enhanced secondary metabolite accumulation and identified the phenolic compounds in the 16 treatments. The cytotoxicity assay highlighted the possible cytotoxic effect of the PEG4 treatment, and we recommend further investigations into its activity.

A Reverse Thinking Based on Partially Methylated Aldononitrile Acetates to Analyze Glycoside Linkages of Polysaccharides Using Liquid Chromatography-Multiple Reaction Monitoring Mass Spectrometry.

Glycoside linkage analyses of medicine and food homologous plant polysaccharides have always been a key point and a difficulty of structural characterization. The gas chromatography-mass spectrometry (GC-MS) method is one of the commonly used traditional techniques to determine glycoside linkages via partially methylated alditol acetates and aldononitrile acetates (PMAAs and PMANs). Due to the simplicity of derivatization and the highly structural asymmetry of PMANs, reverse thinking is proposed using liquid chromatography-electrospray ionization-multiple reaction monitoring mass spectrometry (LC-ESI-MRM-MS) for the first time to directly determine the neutral and acidic glycosyl linkages of polysaccharides. The complete characterization of glycoside linkages deduced from PMANs was achieved using a combination of tR values, characteristic MRM ion pairs, diagnostic ESI+-MS/MS fragmentation ions (DFIs), and optimal collision energy (OCE). The DFI and OCE parameters were confirmed to be effective for the auxiliary discrimination of some isomers of the PMANs. The practicality of LC-ESI+-MRM-MS was further verified by analyzing the glycoside linkages of polysaccharides in five medicine and food homologous plants. This method can serve as an alternative to GC-MS for the simultaneous determination of neutral and acidic glycosyl linkages in polysaccharides.

A Pilot Study to Show Longitudinal Trends in Health-Related Quality of Life (HRQOL) in a Cohort of Breast Cancer Patients Under Treatment at a Tertiary Healthcare Facility in Bhubaneswar, India.

Introduction: Breast cancer incidence has overtaken that of cervical cancer among women in India according to the Globacon 2020 reports. Cancer management is also being streamlined at the Center and district levels, such that comprehensive integrated management is offered to cases to optimize the best results. In breast cancer, there are two modes of surgery namely Breast Conservation Surgery(BCS) and Modified Radical Mastectomy (MRM) now over 2 decades, with recommended Chemo radiation depending on the extent of the disease. HRQOL (Health-related Quality of Life) studies have been done in these groups of patients, due to their added relevance in terms of the loss of a vital organ like the breast. EORTC 30 and BR23 are standardized and detailed tools that have been seen to estimate QOL, keeping in mind a whole array of domains that are affected by the disease. Objective: To evaluate the "Body Image" and "Quality of life" (QOL) in operated breast cancer patients using BR -23 and EORTC - QLQ- questionnaire at 1month (after surgery) and then 3 to 4 months after surgery. Methods: This article attempts to draw a comparison among of EORTC30 and BR 23 scores calculated for 46 breast cancer patients operated during the pandemic time in one center and consenting to repeat the measures at pre-decided three time periods during the course of management. Results: No significant differences are noted in the mean scores for EORTC 30 and BR23 for the two types of surgeries. Visit 1 scores for both modes of surgery are over 75 and by Visit 3 become less than 55 for EORTC. BR 23 (which measures the symptoms core to Breast cancer) at all 3 visits are between 45 to 55. Friedman's test shows that the scores are not significant for age groups, the number of living children, or lifestyle factors like alcohol or tobacco chewing, though quadratic graphs depict the distinct variations in the scores at the 3 times reinforcing the need for follow-up of mental health in these subjects at intervals. The study largely brings out a strong need for repeated follow-up and counseling at regular and short intervals, post-surgery in breast cancer patients. EORTC 30 and BR 23 tools are excellent to use to essay information on the mental health of patients with breast cancer.

A Retrospective Analysis of Breast Cancer Presentation Among Young and Older Women in an Indian Cohort of 70 Patients.

Introduction In females, carcinoma of the breast is a common malignancy. Disease management can be challenging for the treating clinician if the condition is presented in a locally advanced stage. Clinical presentation of a disease in a defined area provides a comprehensive map to target the at-risk population efficiently and select the appropriate intervention accordingly. In this retrospective study, we analyzed different factors that can affect breast carcinoma outcomes by assessing patients for a specific period of one year. Methods This is a retrospective study of carcinoma of breast patients and was conducted between 2017 and 2018. Results We reported a 25.83% incidence of breast cancer during the study period. A painful breast lump was present in 54.2% of patients, axillary nodes were present in 50% of patients, ulcers were present in 10% of patients, and nipple discharge was present in 8.5% of patients. According to the side and quadrant of involvement, the right side was the most common site of involvement in 55.7% of patients, and the upper outer quadrant was the most common quadrant involved in 61.4% of patients. The most familiar stage of the presentation was stage II, presented in 45.7% of patients. The most common histology was infiltrating ductal carcinoma, presented in 85.7% of patients. Conclusions This retrospective cohort study shows that carcinoma of the breast is a predominant malignancy among middle-aged females in developing countries such as India. This predominance is due to unawareness regarding disease symptoms and the fear of diagnosed malignancy during the investigation of symptoms. Early detection by screening and intervention at an early stage is the core of treatment success in this malignant disease. However, it is still challenging to apply screening as a tool to pick up early malignant disease in developing countries like India.

Cervical Epidural Anesthesia in the Management of a Patient With Breast Cancer With Cardiac Dysfunction: A Case Report.

As one of the most common cancers in the world, breast cancer management is fraught with difficulties. Modified radical mastectomy (MRM) is one of the surgical procedures that is essential to the treatment of breast cancer. Cardiovascular issues, especially a reduced ejection fraction (EF), make these procedures more complex. Due to their increased vulnerability to adverse cardiac events during surgery, it is imperative to preserve hemodynamic stability and reduce physiological stress responses in these patients. A promising option in this changing field of anesthetic techniques is cervical epidural anesthesia (CEA). It effectively reduces hemodynamic fluctuations frequently linked to general anesthesia while providing analgesia. We report the case of an elderly patient with decreased EF and breast cancer scheduled for an MRM. To ensure the best possible outcomes in complex cases, the case report covers preoperative assessment, anesthesia technique, intraoperative management, and postoperative outcomes. This highlights the critical significance of customizing anesthesia and surgical procedures, informed consent, and meticulous postoperative pain management, and ultimately advocates for the broader implementation of CEA in such settings.

Determination of nine bisphenol analogues in human urine by high-throughput solid-phase extraction and ultra-high performance liquid chromatography-tandem mass spectrometry analysis.

Bisphenol analogues (BPs) are a class of typical environmental endocrine-disrupting chemicals (EDCs). This study aimed to establish a highly sensitive and high-throughput method utilizing 96-well solid-phase extraction (96-well SPE) in conjunction with ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) employing multiple reaction monitoring (MRM), information-dependent acquisition (IDA), and enhanced product ion (EPI) scan modes for the identification and quantitative analysis of nine BPs in human urine. Urine samples were initially thawed to room temperature, followed by digestion using ß-glucuronidase in an ammonium acetate buffer solution at 37 °C overnight. Subsequently, they were purified using 96-well SPE and finally analyzed by UHPLC-MS/MS. The limits of detection (LOD) for the nine BPs ranged from 0.05 µg∙kg-1 to 0.3 µg kg-1. Average recoveries fell within the range of 92.8 % to 111.7 %. Moreover, both the intra-day and inter-day precisions were satisfactory, with relative standard deviations (RSDs) ranging from 2.2 % to 6.7 % and 3.5 % to 6.3 %, respectively. The targets in the samples exhibited a perfect match, with a purity fit value exceeding 70 % from the self-built library. The analytical method developed in this study demonstrates high accuracy and sensitivity. In addition, the MRM-IDA-EPI mode can effectively identifies the target BPs and prevents false positive detection of analytes in the urine.

A Targeted LC-MRM3 Proteomic Approach for the Diagnosis of SARS-CoV-2 Infection in Nasopharyngeal Swabs.

Since its first appearance, severe acute respiratory syndrome coronavirus 2 quickly spread around the world and the lack of adequate PCR testing capacities, especially during the early pandemic, led the scientific community to explore new approaches such as mass spectrometry (MS). We developed a proteomics workflow to target several tryptic peptides of the nucleocapsid protein. A highly selective multiple reaction monitoring-cubed (MRM3) strategy provided a sensitivity increase in comparison to conventional MRM acquisition. Our MRM3 approach was first tested on an Amsterdam public health cohort (alpha-variant, 760 participants) detecting viral nucleocapsid protein peptides from nasopharyngeal swabs samples presenting a cycle threshold value down to 35 with sensitivity and specificity of 94.2% and 100.0%, without immunopurification. A second iteration of the MS-diagnostic test, able to analyze more than 400 samples per day, was clinically validated on a Leiden-Rijswijk public health cohort (delta-variant, 2536 participants) achieving 99.9% specificity and 93.1% sensitivity for patients with cycle threshold values up to 35. In this manuscript, we also developed and brought the first proof of the concept of viral variant monitoring in a complex matrix using targeted MS.

An Optimized Method for LC-MS-Based Quantification of Endogenous Organic Acids: Metabolic Perturbations in Pancreatic Cancer.

Accurate and reliable quantification of organic acids with carboxylic acid functional groups in complex biological samples remains a major analytical challenge in clinical chemistry. Issues such as spontaneous decarboxylation during ionization, poor chromatographic resolution, and retention on a reverse-phase column hinder sensitivity, specificity, and reproducibility in multiple-reaction monitoring (MRM)-based LC-MS assays. We report a targeted metabolomics method using phenylenediamine derivatization for quantifying carboxylic acid-containing metabolites (CCMs). This method achieves accurate and sensitive quantification in various biological matrices, with recovery rates from 90% to 105% and CVs ≤ 10%. It shows linearity from 0.1 ng/mL to 10 µg/mL with linear regression coefficients of 0.99 and LODs as low as 0.01 ng/mL. The library included a wide variety of structurally variant CCMs such as amino acids/conjugates, short- to medium-chain organic acids, di/tri-carboxylic acids/conjugates, fatty acids, and some ring-containing CCMs. Comparing CCM profiles of pancreatic cancer cells to normal pancreatic cells identified potential biomarkers and their correlation with key metabolic pathways. This method enables sensitive, specific, and high-throughput quantification of CCMs from small samples, supporting a wide range of applications in basic, clinical, and translational research.

A validated ultra-performance liquid chromatography with tandem mass spectrometry method for the quantification of Brazilian green propolis main compounds.

Brazilian green propolis is used in folk medicine because of its various biological properties. The hydroalcoholic extract of Brazilian green propolis is characteristic for possessing several pharmacological properties. Phytochemical investigations have attributed some of these properties to the presence of compounds, which were chosen as analytical markers. This paper reports the development and analytical validation using UPLC-MS/MS in MRM mode. Veratraldehyde was used as an internal standard in qualitative and quantitative analyses of the extracts. Relative standard deviation values obtained for intra-day and inter-day precision were lower than 4%. Of the five parameters for robustness, wavelength detection and flow rate were the critical ones. Limits of detection and quantification ranged from 0.300 to 39.500 ng.mL-1 and from 1.400 to 85.00 ng.mL-1, respectively. The recoveries were between 94.00 and 119.00%, with relative standard deviation values around 5.0%. The developed method is precise, sensitive, and reliable for analysing Brazilian green propolis.

Comparison of Analgesic Efficacy of Ultrasound Guided PEC II Block Using Dexamethasone as an Adjuvant to Ropivacaine Versus Plain Ropivacaine in Patients Undergoing Modified Radical Mastectomy: A Double-Blind, Randomized Controlled Trial.

INTRODUCTION:  Pain after breast cancer surgery is one of the main reasons for postoperative morbidity and pulmonary complications leading to increased hospital stay. Therefore, effective management of postoperative pain becomes necessary to alleviate patients' suffering and allow early mobilization and hospital discharge. Traditionally, opioids have been used to manage perioperative pain but they are associated with side effects. So, an opioid-sparing multimodal analgesia approach is used nowadays. Ultrasound-guided pectoral type-II (PEC II) block is increasingly being used to address acute postoperative pain after breast cancer surgery. However, to date, not many studies have been done regarding prolonging the duration of analgesia of PEC II blocks for postoperative pain relief in patients undergoing modified radical mastectomy (MRM). So, we undertook this study to compare the analgesic efficacy of PEC II block using dexamethasone as an adjuvant to ropivacaine versus plain ropivacaine in patients undergoing MRM. METHODS:  After obtaining approval from the institute ethics committee and written informed consent from the patients, this prospective, double-blind, parallel group, randomized controlled study was carried out at All India Institute of Medical Sciences (AIIMS) Raipur, from March 2021 to March 2022. Sixty-four female patients, aged 18 years and above, belonging to the American Society of Anesthesiologists, physical status I, II, and III, undergoing unilateral, elective MRM under general anesthesia, were randomly allocated to two groups A and B, with 32 patients in each to receive 30 mL of 0.25% ropivacaine plus 2 mL (8 mg) of dexamethasone and 30 mL of 0.25% ropivacaine plus 2 mL of normal saline, respectively. The primary outcome measure was total opioid consumption till 12 hours postoperatively. Secondary outcome measures were the difference in pain scores based on the numeric rating scale till 12 hours postoperatively, post-operative sedation scores, the incidence of postoperative nausea vomiting (PONV), and other adverse events (if any). RESULTS: The mean (SD) of morphine (mg) consumed intraoperatively was 5.50 (1.05) and 5.95 (0.86) with P = 0.033 and that consumed postoperatively was 1.00 (0.00) and 1.69 (0.93) with P <0.001 in group A and B respectively, with morphine consumption being higher in the group. The difference in the NRS score for pain at rest was statistically significant at 2 h (P=0.030), 4 h (P=0.004), 6 h (P=0.002), and, 12 h (P=0.039) time points with the score being higher in group B. The groups were comparable in terms of postoperative sedation score (P > 0.05) and incidence of postoperative nausea and vomiting. None of the patients in group A and 6.2% of the patients in group B had nausea (P = 0.492). None of the patients in either of the groups had vomiting. No other complication occurred during the entire study in either of the groups. CONCLUSION: In comparison to plain ropivacaine, the addition of dexamethasone as an adjuvant to ropivacaine for PEC II block in patients undergoing MRM significantly reduced perioperative opioid consumption and postoperative NRS scores. No significant change was noted in terms of postoperative sedation score, incidence of PONV, and other side effects between the groups. Therefore, we conclude that the analgesic efficacy of US-guided PEC II block using dexamethasone, as an adjuvant to ropivacaine is superior to that of plain ropivacaine in patients undergoing MRM.

Surface dose measurement and comparison between TLD and OSLD during modified re constructive mastectomy irradiation.

Radiotherapy (RT) is one of the major treatment modalities among surgery and chemotherapy for carcinoma breast. The surface dose study of modified reconstructive constructive Mastectomy (MRM) breast is important due to the heterogeneity in the body contour and the conventional treatment angle to save the lungs and heart from the radiation. These angular entries of radiation beam cause an unpredictable dose deposition on the body surface, which has to be monitored. Thermoluminescent dosimeter (TLD) or optically stimulated luminescent dosimeter (nano OSLD) are commonly preferable dosimeters for this purpose. The surface dose response of TLD and nano OSLD during MRM irradiation has been compared with the predicted dose from the treatment planning system (TPS). The study monitored 100 MRM patients by employing a total 500 dosimeters consisting of TLD (n = 250) and nano OSLD (n = 250), during irradiation from an Elekta Versa HD 6 MV Linear accelerator. The study observed a variance of 3.9% in the dose measurements for TLD and 3.2% for nano OSLD from the planned surface dose, with a median percentage dose of 44.02 for nano OSLD and 40.30 for TLD (p value 0.01). There was no discernible evidence of variation in dose measurements attributable to differences in field size or from patient to patient. Additionally, no variation was observed in dose measurements when comparing the placement of the dosimeter from central to off-centre positions. In comparison, a minor difference in dose measurements were noted between TLD and nano OSLD, The study's outcomes support the applicability of both TLD and nano OSLD as effective dosimeters during MRM breast irradiation for surface dose evaluation.

Analytical Method Development and Dermal Absorption of 4-Amino-3-Nitrophenol (4A3NP), a Hair Dye Ingredient under the Oxidative or Non-Oxidative Condition.

The chemical 4-amino-3-nitrophenol (4A3NP) is classified as an amino nitrophenol and is primarily utilized as an ingredient in hair dye colorants. In Korea and Europe, it is exclusively used in non-oxidative or oxidative hair dye formulations, with maximum allowable concentrations of 1% and 1.5%, respectively. Despite this widespread use, risk assessment of 4A3NP has not been completed due to the lack of proper dermal absorption data. Therefore, in this study, both the analytical method validation and in vitro dermal absorption study of 4A3NP were conducted following the guidelines provided by the Korea Ministry of Food and Drug Safety (MFDS). Before proceeding with the dermal absorption study, analytical methods were developed for the quantitation of 4A3NP through multiple reaction monitoring (MRM) via liquid chromatography-mass spectrometry (LC-MS) in various matrices, including swab wash (WASH), stratum corneum (SC), skin (SKIN, comprising the dermis and epidermis), and receptor fluid (RF). These developed methods demonstrated excellent linearity (R2 = 0.9962-0.9993), accuracy (93.5-111.73%), and precision (1.7-14.46%) in accordance with the validation guidelines.The dermal absorption of 4A3NP was determined using Franz diffusion cells with mini-pig skin as the barrier. Under both non-oxidative and oxidative (6% hydrogen peroxide (H2O2): water, 1:1) hair dye conditions, 1% and 1.5% concentrations of 4A3NP were applied to the skin at a rate of 10 µL/cm2, respectively. The total dermal absorption rates of 4A3NP under non-oxidative (1%) and oxidative (1.5%) conditions were determined to be 5.62 ± 2.19% (5.62 ± 2.19 µg/cm2) and 2.83 ± 1.48% (4.24 ± 2.21 µg/cm2), respectively.

[Simultaneous determination of seven artemisinin-related compounds in Artemisia annua by UPLC-QQQ-MS/MS].

A variety of compounds in Artemisia annua were simultaneously determined to evaluate the quality of A. annua from multiple perspectives. A method based on ultra-high performance liquid chromatography-triple quadrupole tandem mass spectrometry(UPLC-QQQ-MS/MS) was established for the simultaneous determination of seven compounds: amorpha-4,11-diene, artemisinic aldehyde, dihydroartemisinic acid, artemisinic acid, artemisinin B, artemisitene, and artemisinin, in A. annua. The content of the seven compounds in different tissues(roots, stems, leaves, and lateral branches) of A. annua were compared. The roots, stems, leaves, and lateral branches of four-month-old A. annua were collected and the content of seven artemisinin-related compounds in different tissues was determined. A multi-reaction monitoring(MRM) acquisition mode of UPLC-QQQ-MS/MS was used, with a positive ion mode of atmospheric pressure chemical ion source(APCI). Chromatographic separation was achieved on an Eclipse Plus RRHD C_(18) column(2.1 mm×50 mm, 1.8 µm). The gradient elution was performed with the mobile phase consisted of formic acid(0.1%)-ammonium formate(5 mmol·L~(-1))(A) and the methanol(B) gradient program of 0-8 min, 55%-100% B, 8-11 min, 100% B, and equilibrium for 3 min, the flow rate of 0.6 mL·min~(-1), the column temperature of 40 ℃, the injection volume of 5 µL, and the detection time of 8 min. Through methodological investigation, a method based on UPLC-QQQ-MS/MS was established for the simultaneous quantitative determination of seven representative compounds involved in the biosynthesis of artemisinin. The content of artemisinin in A. annua was higher than that of artemisinin B, and the content of artemisinin and dihydroartemisinic acid were high in all the tissues of A. annua. The content of the seven compounds varied considerably in different tissues, with the highest levels in the leaves and neither artemisinene nor artemisinic aldehyde was detected in the roots. In this study, a quantitative method based on UPLC-QQQ-MS/MS for the simultaneous determination of seven representative compounds involved in the biosynthesis of artemisinin was established, which was accurate, sensitive, and highly efficient, and can be used for determining the content of artemisinin-related compounds in A. annua, breeding new varieties, and controlling the quality of Chinese medicinal materials.

Removal of isobaric interference using pseudo-multiple reaction monitoring and energy-resolved mass spectrometry for the isotope dilution quantification of a tryptic peptide.

Energy-resolved mass spectrometry (ERMS) and an isotopically labelled internal standard were successfully combined to accurately quantify a tryptic peptide despite the presence of an isobaric interference. For this purpose, electrospray ionisation tandem mass spectrometry (ESI-MS/MS) experiments were conducted into an ion trap instrument using an unconventional 8 m/z broadband isolation window, which encompassed both the tryptic peptide and its internal standard. Interference removal was assessed by determining an excitation voltage that was high enough to maintain a constant value for the analyte/internal standard peaks intensity ratio, thus ensuring accurate quantification even in the presence of isobaric contamination. Pseudo-multiple reaction monitoring (MRM) was employed above this excitation voltage to quantify the trypic peptide. The internal standard calibration model showed no lack of fit and exhibited a linear dynamic range from 0.5 µM up to 2.5 µM. The detection limit was 0.08 µM. The accuracy of the method was evaluated by quantifying the tryptic peptide of three reference samples intentionally contaminated with the isobaric interference. All the reference samples were accurately quantified with ∼1% deviation despite the isobaric contamination. Furthermore, we have demonstrated that this methodology can also be applied to quantify the isobaric peptide by standard additions down to 0.2 µM. Finally, liquid chromatography ERMS (LC ERMS) experiments yielded similar results, suggesting the potential of the proposed methodology for analysing complex samples.

Detection of Extremely Low Level Ciguatoxins through Monitoring of Lithium Adduct Ions by Liquid Chromatography-Triple Quadrupole Tandem Mass Spectrometry.

Ciguatera poisoning (CP) is the most common type of marine biotoxin food poisoning worldwide, and it is caused by ciguatoxins (CTXs), thermostable polyether toxins produced by dinoflagellate Gambierdiscus and Fukuyoa spp. It is typically caused by the consumption of large fish high on the food chain that have accumulated CTXs in their flesh. CTXs in trace amounts are found in natural samples, and they mainly induce neurotoxic effects in consumers at concentrations as low as 0.2 µg/kg. The U.S. Food and Drug Administration has established CTX maximum permitted levels of 0.01 µg/kg for CTX1B and 0.1 µg/kg for C-CTX1 based on toxicological data. More than 20 variants of the CTX1B and CTX3C series have been identified, and the simultaneous detection of trace amounts of CTX analogs has recently been required. Previously published works using LC-MS/MS achieved the safety levels by monitoring the sodium adduct ions of CTXs ([M+Na]+ > [M+Na]+). In this study, we optimized a highly sensitive method for the detection of CTXs using the sodium or lithium adducts, [M+Na]+ or [M+Li]+, by adding alkali metals such as Na+ or Li+ to the mobile phase. This work demonstrates that CTXs can be successfully detected at the low concentrations recommended by the FDA with good chromatographic separation using LC-MS/MS. It also reports on the method's new analytical conditions and accuracy using [M+Li]+.

In-vitro antioxidant and anti-inflammatory potential along with p.o. pharmacokinetic profile of key bioactive phytocompounds of Snow Mountain Garlic: a comparative analysis vis-à-vis normal garlic.

Snow mountain garlic (SMG) is a trans-Himalayan medicinal plant used in the traditional medicine system for several ailments, including inflammatory arthritis. Research studies are insufficient to validate its folk medicinal applications. In the present study, the comparative abundance of its key bioactive phytocompounds, viz., S-allyl-L-cysteine (SAC), alliin, and S-methyl-L-cysteine (SMC) against normal garlic were assessed using the LC-MS/MS-MRM method. In addition, the study also explored the antioxidant and anti-inflammatory potency of crude extract of SMG and purified signature phytocompounds (i.e., SMC, SAC, and alliin) in comparison with normal garlic and dexamethasone in LPS-stimulated RAW264.7 macrophage cells. The LC-MS/MS-MRM study revealed significant differences among SMG and normal garlic, viz., alliin 22.8-fold higher in SMG, and SMC could be detected only in SMG. In the bioassays, SMG extract and purified signature phytocompounds significantly downregulated oxidative damage in activated macrophages, boosting endogenous antioxidants' activity. SMG extract-treated macrophages significantly suppressed NF-κB expression and related inflammatory indicators such as cytokines, COX-2, iNOS, and NO. Notably, the observed anti-inflammatory and antioxidant bioactivities of SMG extract were comparable to signature phytocompounds and dexamethasone. In addition, SAC being uniformly found in SMG and normal garlic, its comparative pharmacokinetics was studied to validate the pharmacodynamic superiority of SMG over normal garlic. Significantly higher plasma concentrations (Cmax), half-life (t1/2), and area under curve (AUC) of SAC following SMG extract administration than normal garlic validated the proposed hypothesis. Thus, the abundance of bioactive phytocompounds and their better pharmacokinetics in SMG extract might be underlying its medicinal merits over normal garlic.

Simultaneous determination of BGT-002 and its acyl glucuronide metabolite ZM326E-M2 in human plasma by liquid chromatography-tandem mass spectrometry and its application to a pharmacokinetic study.

BGT-002, a new type of ATP-citrate lyase inhibitor, is a promising therapeutic for treatment of hypercholesterolemia. After an oral administration of BGT-002 to subjects, it underwent extensive metabolism and an acyl monoglucuronide (ZM326E-M2) on 1- carboxylic acid group was the major circulating metabolite. In this study, an LC-MS/MS method was developed and validated for the simultaneous determination of BGT-002 and ZM326E-M2 in plasma and the evaluation of their pharmacokinetic characteristics in humans. After extraction from the plasma by acetonitrile-induced protein precipitation, the analytes were separated on a Waters ACQUITY UPLC® BEH C18 column using acetonitrile and 2 mM ammonium acetate containing 0.1% formic acid as the mobile phase for gradient elution. Negative electrospray ionization was performed using multiple reaction monitoring (MRM) of m/z 501.3→325.4 for ZM326E-M2 and m/z 507.3→331.2 for D6-ZM326E-M2, and pseudo-MRM of m/z 325.3→325.3 for BGT-002 and m/z 331.3→331.3 for D6-ZM326E, respectively. The method was validated with respect to accuracy, precision, linearity, stability, selectivity, matrix effect, and recovery. The analytical range in human plasma was linear over a concentration range of 0.0500-50.0 µg/mL for BGT-002 and 0.0100-10.0 µg/mL for ZM326E-M2. The pharmacokinetic results showed that after a single oral administration of 100 mg BGT-002, the parent drug was rapidly absorbed with a mean time to peak concentration (tmax) of 1.13 h, compared with BGT-002, the tmax (4.00 h) of ZM326E-M2 was significantly delayed. The peak concentration and plasma exposure of ZM326E-M2 were about 14.1% and 19.5% of the parent drug, suggesting that attention should be paid to the safety and efficacy of ZM326E-M2 in clinical research.

Discrimination and prediction of Qingzhuan tea storage year using quantitative chemical profile combined with multivariate analysis: Advantages of MRMHR based targeted quantification metabolomics.

The duration of storage significantly influences the quality and market value of Qingzhuan tea (QZT). Herein, a high-resolution multiple reaction monitoring (MRMHR) quantitative method for markers of QZT storage year was developed. Quantitative data alongside multivariate analysis were employed to discriminate and predict the storage year of QZT. Furthermore, the content of the main biochemical ingredients, catechins and alkaloids, and free amino acids (FAA) were assessed for this purpose. The results show that targeted marker-based models exhibited superior discrimination and prediction performance among four datasets. The R2Xcum, R2Ycum and Q2cum of orthogonal projection to latent structure-discriminant analysis discrimination model were close to 1. The correlation coefficient (R2) and the root mean square error of prediction of the QZT storage year prediction model were 0.9906 and 0.63, respectively. This study provides valuable insights into tea storage quality and highlights the potential application of targeted markers in food quality evaluation.