Rapid Communications in Mass Spectrometry最新文献

{"title":"Chemical and metabolic profiling of Amaryllidaceae alkaloids in the bulbs of Narcissus tazetta L. var. chinensis Roem using liquid chromatography–tandem mass spectrometry with data mining strategy","authors":"Xinxin Huang,&nbsp;Ting Tan,&nbsp;Yun Luo","doi":"10.1002/rcm.9931","DOIUrl":"10.1002/rcm.9931","url":null,"abstract":"<div>\u0000 \u0000 <section>\u0000 \u0000 <h3> Rationale</h3>\u0000 \u0000 <p>The bulbs of <i>Narcissus tazetta</i> L. var. chinensis Roem (BNTCR) has been used as an herbal medicine for the treatment of carbuncles in China. The previous phytochemical studies indicated that the main active components of BNTCR were Amarllidaceae alkaloids (AAs). However, the comprehensive chemical and metabolic profiling of AAs in BNTCR remains underexplored. Therefore, it is necessary to establish an accurate and rapid approach for chemical characterization and metabolic profiling of AAs in BNTCR.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>The structural elucidation of natural products by ultra-high performance liquid chromatography coupled to quadrupole time of flight tandem mass spectrometry (UHPLC-QTOF-MS/MS) with outstanding properties is still limited due to complex mixtures that contain hundreds of compounds. In this study, we employed UHPLC-QTOF-MS/MS with a data mining strategy, including diagnostic fragment ions (DFIs) and neutral loss (NL), for rapid classifying and identifying AAs in BNTCR and prototypes absorbed into the blood of mice after oral administration of BNTCR extract.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>As a result, 87 AAs, including 13 narciclasine type, 13 homolycorine type, 17 lycorine type, 12 galanthamine type, 25 haemanthamine type, and 7 tazettine type, were tentatively characterized (6 verified with authentic standards). In addition, a total of 44 prototypes were identified in mice plasma, urine, and fecal samples. Among them, 8 prototypes were found in plasma, 36 in urine, and 40 in feces, respectively. Lycorine, pseudolycorine, homolycorine, 8-<i>O</i>-demetylhomolycorine, and tazettine, as major AAs in BNTCR, were absorbed into the blood.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>Our findings provided a crucial step for the elucidation of the active compounds in BNTCR for treatment of carbuncles. In the future, the developed strategy could also be applied for identifying AAs in other herbal medicines from Amarllidaceae.</p>\u0000 </section>\u0000 </div>","PeriodicalId":225,"journal":{"name":"Rapid Communications in Mass Spectrometry","volume":"39 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142542425","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Structural elucidation of 14-membered ring macrolide antibiotics using electrospray ionization tandem mass spectrometry and density functional theory calculations","authors":"Fausto Carnevale Neto,&nbsp;Ricardo Vessecchi","doi":"10.1002/rcm.9913","DOIUrl":"10.1002/rcm.9913","url":null,"abstract":"<div>\u0000 \u0000 <section>\u0000 \u0000 <h3> Rationale</h3>\u0000 \u0000 <p>Macrolides are critical antibiotics featuring a macrocyclic lactone core with deoxy sugars. Understanding their gas-phase fragmentation is challenging but essential for improving structural elucidation in mass spectrometry, which has implications for drug discovery and development.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>We used electrospray ionization collision-induced dissociation tandem mass spectrometry (ESI-CID-MS) combined with quantum chemical calculations to investigate the fragmentation pathways of erythromycin A and roxithromycin. This approach helps elucidate the preferred fragmentation routes influenced by protonation sites.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Macrolides showed similar fragmentation patterns, including sequential losses of saccharide or amino sugar units and dehydration from the macrocycle core. Multiple competitive pathways were observed, influenced by protonation sites. Computational studies confirmed the most favorable protonation sites and their impact on fragmentation, providing insights into key diagnostic product ions. Subsequent fragments involved rearrangement pathways such as alkene formation and cleavages via remote hydrogen transfers and pericyclic reactions.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>Our integrated approach offers a comprehensive understanding of macrolide fragmentation, enhancing structural elucidation and potential applications in drug development. This study advances mass spectrometry analysis of macrolides, contributing to pharmaceutical research by integrating orthogonal annotation methods and fragmentation studies.</p>\u0000 </section>\u0000 </div>","PeriodicalId":225,"journal":{"name":"Rapid Communications in Mass Spectrometry","volume":"38 24","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142491728","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"MALDI versus DESI mass spectrometry imaging of lipids in atherosclerotic plaque","authors":"Nuria Slijkhuis,&nbsp;Mark Towers,&nbsp;Emmanuelle Claude,&nbsp;Gijs van Soest","doi":"10.1002/rcm.9927","DOIUrl":"10.1002/rcm.9927","url":null,"abstract":"<p>Mass spectrometry imaging (MSI) is a powerful tool for detecting lipids in tissue sections, with matrix-assisted laser desorption/ionization (MALDI) and desorption electrospray ionization (DESI) as its key ionization techniques. In this study, we examine how MALDI compares with state-of-the-art DESI ionization in identifying lipids in heterogeneous samples, specifically atherosclerotic plaques. Carotid plaques (<i>n</i> = 4) from patients undergoing endarterectomy were snap-frozen, stored at −80°C, and then sectioned for MSI analysis and H&amp;E staining. Measurements were conducted using a SYNAPT XS mass spectrometer in positive ion mode, employing MALDI with a 2,5-dihydroxybenzoic acid (DHB) matrix and DESI with a methanol: water (<i>98:2</i>) (<i>v/v</i>) solvent. Our comparison covered spectral profiles, sensitivity, and image quality generated by these two techniques. We found that both MALDI and DESI are highly suitable techniques for detecting a wide range of lipids in atherosclerotic plaque sections. DESI-MSI exhibited higher ion counts for most lipid classes than MALDI-MSI and provided sharper images. MALDI detected larger amounts of ceramide and hexosylceramide species, possibly due to its efficient generation of dehydrated ions. In contrast, DESI showed greater peak intensities of cholesteryl ester and triacylglyceride species than MALDI, consistent with reduced fragmentation. These findings establish the relative merits of DESI and MALDI and demonstrate their complementarity as techniques for lipid research in MSI.</p>","PeriodicalId":225,"journal":{"name":"Rapid Communications in Mass Spectrometry","volume":"39 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/rcm.9927","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142454347","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Determination of nut varieties and their detection in festive cookies by MALDI-TOF mass spectrometry","authors":"Stepanka Kuckova,&nbsp;Lucie Kaderabkova","doi":"10.1002/rcm.9925","DOIUrl":"https://doi.org/10.1002/rcm.9925","url":null,"abstract":"<div>\u0000 \u0000 <section>\u0000 \u0000 <h3> Rationale</h3>\u0000 \u0000 <p>Nuts contain a large amount of essential fatty acids, amino acids, and whole range of minerals and vitamins valuable for human health, yet certain risks are associated with their consumption, of which allergic reaction is the most important. Considering the growing number of people suffering from allergies caused by allergens of protein origin, the aim of this work is to find out whether nuts can be distinguished from each other on the basis of contained proteins.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>A total of eleven raw and subsequently heat-treated nuts (almonds, Brazil nuts, cashews, coconuts, hazelnuts, macadamia nuts, peanuts, pecans, pine nuts, pistachios, and walnuts) were analyzed using MALDI-TOF (matrix-assisted laser desorption/ionization time-of-flight) mass spectrometry with the subsequent finding of characteristic <i>m/z</i> values for each analyzed nut. No previous method for protein extraction was used.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>The characteristic values were used to verify the composition of seven types of festive cookies – six commercial products and one “unknown” cookie, where it was not known in advance, which nut it was made from.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>The procedure, together with the found characteristic <i>m/z</i> values, could serve to rapidly identify the plant origin of nut products.</p>\u0000 </section>\u0000 </div>","PeriodicalId":225,"journal":{"name":"Rapid Communications in Mass Spectrometry","volume":"38 24","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142435599","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mathematical lipid correction of δ13C and effect of lipid extraction on δ15N of European eel (Anguilla anguilla) muscle","authors":"Raphaël Lagarde,&nbsp;Christophe Menniti,&nbsp;Nils Teichert,&nbsp;Elsa Amilhat,&nbsp;Elisabeth Faliex,&nbsp;Sarah Nahon","doi":"10.1002/rcm.9924","DOIUrl":"https://doi.org/10.1002/rcm.9924","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Rationale</h3>\u0000 \u0000 <p>Carbon (δ¹³C) and nitrogen (δ¹⁵N) stable isotope analysis is a powerful tool to investigate diverse questions in fish ecology, such as their trophic position or migration strategies. These questions appear particularly important to protect endangered European eel. However, elevated lipid content in eel muscle can bias δ¹³C values, as lipids are ¹³C-depleted compared to proteins and carbohydrates.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>We measured δ¹³C and δ¹⁵N values of bulk and lipid-free samples of eel muscle. Lipid-free samples were obtained after the extraction of lipids with cyclohexane. Lipid-corrected δ¹³C values, using five different mathematical equations based on bulk δ¹³C values, were compared to lipid-free δ¹³C values. We also evaluated the effect of lipid extraction on δ¹⁵N values. The analyses were based on linear regression performed on 333 individuals captured in nine lagoons and four rivers.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Independently to the capture site or habitat (river or lagoon), the predicted lipid-corrected δ¹³C values were highly consistent with the measured lipid-free δ¹³C values (<i>R</i>² &gt; 0.90). The application of specific equations for each habitat or capture site only slightly increases these <i>R</i>² (1.5% or less). The lipid extraction treatment significantly decreased by 0.2‰ the δ¹⁵N values compared to bulk samples.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>Given the excellent prediction of mathematical equations and the small decrease of δ¹⁵N values after lipids extraction, we propose to use mathematical correction to estimate δ¹³C values of eel muscle. As the habitats or sites did not strongly influence the results, the coefficients from our study can be applied to other studies on European eel.</p>\u0000 </section>\u0000 </div>","PeriodicalId":225,"journal":{"name":"Rapid Communications in Mass Spectrometry","volume":"38 24","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142435597","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"GC–MS quantification of fecal short-chain fatty acids and spectrophotometric detection of indole: Do rectal swabs produce comparable results as stool samples? - A pilot study","authors":"Vineetha K K,&nbsp;Archana P R,&nbsp;Bhamini Krishna Rao,&nbsp;Mamatha Ballal,&nbsp;Babi Dutta,&nbsp;Vani Lakshmi R,&nbsp;Rajeshwari G. Bhat","doi":"10.1002/rcm.9923","DOIUrl":"https://doi.org/10.1002/rcm.9923","url":null,"abstract":"<div>\u0000 \u0000 <section>\u0000 \u0000 <h3> Rationale</h3>\u0000 \u0000 <p>The exploration of the gut microbiome and related metabolites holds an exciting future in health science. The challenges associated with fecal sample testing are proper sample collection, sterile transportation, optimal transport conditions, and processing as all these factors could potentially change the microbiome composition, further exacerbated by the patient's customary discomfort regarding feces samples. The study aimed to compare the usage of rectal swabs and stool samples for short-chain fatty acid estimation using gas chromatography–mass spectrometry (GC–MS) and indole estimation using spectrophotometry.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Method</h3>\u0000 \u0000 <p>From May 2022 to June 2022, three women were recruited from the Department of Obstetrics and Gynecology (OBG) in a secondary care hospital in coastal Karnataka. During their clinical visit, a rectal swab was collected, and the stool sample was transported to the hospital from the patient's home in sterile containers provided. After the extraction, short-chain fatty acids (acetate, propionate, and butyrate) were quantified using GC–MS. The fecal indole concentration was determined using a hydroxylamine-based assay.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>The GC–MS analysis failed to detect the concentrations of short-chain fatty acids in rectal swab samples. Indole concentrations in stool and swab samples were significantly different.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusion</h3>\u0000 \u0000 <p>The study's findings do not support the use of rectal swabs to analyze gut metabolites.</p>\u0000 </section>\u0000 </div>","PeriodicalId":225,"journal":{"name":"Rapid Communications in Mass Spectrometry","volume":"38 24","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142429841","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Growth pattern and turnover of carbon and nitrogen measured by stable isotope ratios in the hair of sika deer (Cervus nippon)","authors":"Ayaka Hata,&nbsp;Anna Inoue,&nbsp;Yasuhiro Nakajima,&nbsp;Hikaru Uno,&nbsp;Tomoko Naganuma,&nbsp;Tatsuki Shimamoto","doi":"10.1002/rcm.9920","DOIUrl":"10.1002/rcm.9920","url":null,"abstract":"<div>\u0000 \u0000 <section>\u0000 \u0000 <h3> Rationale</h3>\u0000 \u0000 <p>Hair is known to preserve diet history and other physiological information during its growth period and is often used in chemical analyses. However, the growth patterns and turnover of hair vary according to the animal species or habitat, so understanding these patterns in the target animal is necessary for interpreting the results of hair analyses. In this study, we aimed to elucidate the growth pattern and dietary information of winter coat hair in captive sika deer (<i>Cervus nippon</i>).</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>Experiments involving hair-staining and shaving were conducted to elucidate the growth pattern of sika deer hair. A diet-switching experiment was conducted to ascertain what dietary information is reflected in the carbon and nitrogen stable isotope values of the deer winter coat. Hair samples collected from each body site (head, shoulder, back, and hip) were analyzed using an elemental analyser interfaced with an isotope-ratio mass spectrometer.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>The winter coat grows from early September to early November, and then stops after that. During the growth period of the winter coat, the hair of the shoulder and back grew at a constant rate. The carbon and nitrogen stable isotope values of hair reflected the deer's feeding history during hair growth, but there seemed to be a time lag in the hip hair.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>The results suggest that the guard hair of the shoulder is suitable for hair analysis in sika deer. The obtained information on growth patterns and isotopic change of hair from captive sika deer according to diet be useful for interpreting the results of future analyses using hair samples of wild deer.</p>\u0000 </section>\u0000 </div>","PeriodicalId":225,"journal":{"name":"Rapid Communications in Mass Spectrometry","volume":"38 24","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142379610","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Correction to “Dissection of potential anti-osteoporosis mechanism of isopsoralen – a quality control marker in Psoraleae Fructus – by metabolite profiling and network pharmacology”","authors":"","doi":"10.1002/rcm.9922","DOIUrl":"10.1002/rcm.9922","url":null,"abstract":"<p>\u0000 <span>Ruan, Y-J</span>, <span>Wang, G-W</span>, <span>Chen, Z-H</span>, et al. <span>Dissection of potential anti-osteoporosis mechanism of isopsoralen – a quality control marker in Psoraleae Fructus – by metabolite profiling and network pharmacology</span>. <i>Rapid Commun Mass Spectrom.</i> <span>2024</span>; <span>38</span>(<span>19</span>):e9880. 10.1002/rcm.9880.</p><p>The following changes are made to author affiliations of the above published article.</p><p>Chuan-Bao Han's affiliation should only be Beihai Hospital of Chinese Medicine, Beihai, Guangxi, China.</p><p>Wei Shi's affiliation should be State Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources, Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources (Ministry of Education of China), Collaborative Innovation Center for Guangxi Ethnic Medicine, School of Chemistry and Pharmaceutical Science, Guangxi Normal University, Guilin, China.</p><p>We apologize for this error.</p>","PeriodicalId":225,"journal":{"name":"Rapid Communications in Mass Spectrometry","volume":"38 24","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/rcm.9922","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142379609","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Analysis of the polymeric mixture in hypoxen, using high-performance liquid chromatography coupled with high-resolution mass spectrometry","authors":"Abdul Khader Karakka Kal,&nbsp;Michael Benedict Subhahar,&nbsp;Moses Philip,&nbsp;Tajudheen K. Karatt","doi":"10.1002/rcm.9918","DOIUrl":"https://doi.org/10.1002/rcm.9918","url":null,"abstract":"<div>\u0000 \u0000 <section>\u0000 \u0000 <h3> Rationale</h3>\u0000 \u0000 <p>Hypoxen is a medication known for providing individuals with a “second wind,” by lowering the threshold for muscle fatigue and enhancing the body's efficiency under challenging conditions. Athletes who have used this medication report enhanced training outcomes and increased physical endurance. It is crucial to emphasize that hypoxen is not categorized as a prohibited substance as yet and is thus assumed safe for use in competitive sports. However, the polymeric nature of hypoxen presents challenges in detection and identification.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>To prevent the potential misuse of this substance as a doping agent, doping control laboratories must therefore develop a detection method. This study aimed to address this gap by developing a comprehensive detection method for the polymeric mixtures within hypoxen, employing liquid chromatography-electrospray ionization-mass spectrometry.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Among the different columns tested, the Accucore and Syncronis HILIC columns demonstrated exceptional performance, yielding excellent separation with high-quality results. The study found that the hypoxen consisted of between 1 and 6 repetitions of 2,4-dihydroxyphenylene units. It was crucial to highlight that each unit contained multiple isomers due to the incorporation of the sulfonic acid group at both the -SH and -OH positions.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>The results of this study will significantly contribute to the precise identification of hypoxen use, thereby aiding in the scrutiny of its abuse in competitive sports.</p>\u0000 </section>\u0000 </div>","PeriodicalId":225,"journal":{"name":"Rapid Communications in Mass Spectrometry","volume":"38 24","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142328464","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of geometric isomerism in electron ionization mass spectra of dialkyl 1,4-cyclohexanedicarboxylates","authors":"Marina E. Zimens,&nbsp;Yersin A. Tussupkaliyev,&nbsp;Kairat A.Kadirbekov,&nbsp;Umirzak Zh. Jussipbekov,&nbsp;Roman S. Borisov,&nbsp;Vladimir G. Zaikin","doi":"10.1002/rcm.9915","DOIUrl":"https://doi.org/10.1002/rcm.9915","url":null,"abstract":"<div>\u0000 \u0000 <section>\u0000 \u0000 <h3> Rationale</h3>\u0000 \u0000 <p>1,4-Cyclohexanedicarboxylic acid and its esters are widely used as building blocks in the production of polymers and copolymers. The properties of such compounds directly depend on the ratio of cis- and trans-isomers in the starting materials. The identification of such stereoisomers by mass spectrometry can be used for the analysis of complex reactions and pyrolysis mixtures.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>1,4-Cyclohexanedicarboxylic acid propyl, isopropyl, butyl, 2-butyl, pentyl, 2-pentyl, 4-methylpentyl, heptyl, octyl, and nonyl esters were synthesized and analyzed by gas chromatography-electron ionization mass spectrometry. The general fragmentation patterns of the synthesized compounds in electron ionization conditions were determined using high-resolution mass spectrometry. The relative response factors for the isomers were established on the basis of NMR and GC–MS data.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Regardless of the structure of the alkyl groups, the EI mass spectra of cis- and trans-dialkyl 1,4-cyclohexanedicarboxylates differ very sharply. The stereoselectivity of fragmentation processes is due to the steric proximity of the substituents in the case of cis-isomers. Elemental composition of all ions appearing in the mass spectra of the analytes under study was confirmed by high-resolution mass spectrometry. Despite the perceptible differences in the EI mass spectra of the isomers their ionization efficiencies are close.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>The possibility of the unambiguous identification of stereoisomeric dialkyl cis and trans 1,4-cyclohexanedicarboxylates on the basis of their EI mass spectra was shown. The differences in mass spectra of the isomers are due to the conformational rigidity of the considered monocyclic molecules, which ensures the unique stereoselectivity of the elimination of neutral molecules owing to the 1,3-cis-diaxial proximity effect.</p>\u0000 </section>\u0000 </div>","PeriodicalId":225,"journal":{"name":"Rapid Communications in Mass Spectrometry","volume":"38 24","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142328465","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}