characteristic fragment
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2021 ◽  
Vol 9 ◽  
Author(s):  
Ying Xue ◽  
Yanghao Sheng ◽  
Jue Wang ◽  
Qi Huang ◽  
Fengyu Zhang ◽  
...  

Ultra-high-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UHPLC-QTOF-MS) with all-ion fragmentation (AIF) acquisition was established for an identification and quantification of illegal adulterated glucocorticoids in dietary supplements and herbal products. Next, a novel method called characteristic fragment ion list classification (CFILC) was developed for a fast screening of adulterated compounds. CFILC could provide the characteristic ions comprehensively and completely through direct extract from the MS2 library instead of finding them manually. This is time-saving and provides fast screening results with a high confidence level by filtering of a pre-calculated threshold of similarity scores for illegal adulterants that are not included in the library as well as for new emerging structural analogs. The obtained results demonstrated the great qualitative and quantitative strength of this approach, providing a promising and powerful method for a routine fast screening of illegal adulterated glucocorticoids.


2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Yaqian Dong ◽  
Guoxiang Jia ◽  
Jingwen Hu ◽  
Hui Liu ◽  
Tingting Wu ◽  
...  

This study is based on UHPLC-Q-TOF/MS and fragment ions to achieve classification and identification of alkaloids and flavonoids in Sophora flavescens. By reviewing the available and relevant literature, the mass fragmentation rules of alkaloids and flavonoids were summarized. 0.1% formic acid water (A) and acetonitrile (B) were used as mobile phases. 37 chemical constituents were identified, including 13 alkaloids and 24 flavonoids. This research method offers a complete strategy based on the fragmentation information of characteristic fragment ions and neutral loss obtained by MS/MS to characterize the chemical composition of Sophora flavescens.


Molecules ◽  
2021 ◽  
Vol 26 (12) ◽  
pp. 3498
Author(s):  
Shusuke Uekusa ◽  
Mayu Onozato ◽  
Tatsuya Sakamoto ◽  
Maho Umino ◽  
Hideaki Ichiba ◽  
...  

Taurine (Tau) has some important ameliorating effects on human health and is present in bivalve. For the selective analysis of Tau with other amino acids, we designed a derivatization reagent, 2,5-dioxopyrrolidin-1-yl(4-(((2-nitrophenyl)sulfonyl)oxy)-6-(3-oxomorpholino)quinoline-2-carbonyl)pyrrolidine-3-carboxylate (Ns-MOK-β-Pro-OSu). After derivatization with Ns-MOK-β-Pro-OSu, amino acids with Tau in Japanese littleneck clams were determined through ultra-high-performance-liquid chromatography with high-resolution tandem mass spectrometry (UHPLC-HRMS/MS) using an octadecyl silica column. We could detect 18 amino acids within 10 min. Tau, valine, glutamine, glutamic acid, and arginine in the clams were determined in the negative ion mode using the characteristic fragment ion, C6H4N1O5S, which corresponded to the 2-nitrobenzenesulfonylate moiety. The fragment ion, C6H4N1O5S, was recognized as a common feature regardless of the amino acid to be derivatized, and it was convenient for detecting amino acid derivatives with high selectivity and sensitivity. Therefore, highly selective quantification using UHPLC-HRMS/MS was possible using Ns-MOK-β-Pro-OSu.


2021 ◽  
pp. 096032712110011
Author(s):  
F Fu ◽  
Y Guo ◽  
X Lu ◽  
P Zhao ◽  
S Zou ◽  
...  

The verification of exposure to nerve agents is a serious challenge, especially in cases of soman (GD) poisoning. Protein adducts are reliable biomarkers, that provide forensic information and evidence during incidents of terrorism or sporadic poisoning. Mass spectrometry, coupled with a proteomics approach, was established for the forensic analysis of GD-based protein adducts. The fragmentation pathways of GD-based protein adducts were investigated for the first time using electrospray ionization tandem mass spectrometry. Three abundant natural loss product ions, [M+2H-54]2+ (loss of two carbon cations), [M+2H-72]2+ (loss of tert-butyl and methyl moieties), and [M+2H-84]2+ (loss of the pinacolyl moieties), were observed in each of the GD-labeled adducts, and the product ions were independent of protein structure and exposure route. A unique mechanism for the formation of product ions involving GD-protein adducts is proposed here. These findings support the development of a simple and precise forensic analysis technique to rapidly verify GD poisoning using these three GD-related product ions.


Antioxidants ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 1185
Author(s):  
Maroussia Parailloux ◽  
Simon Godin ◽  
Susana C. M. Fernandes ◽  
Ryszard Lobinski

Mycosporines and mycosporine-like amino acids have been described as natural sunscreens and antioxidant compounds presenting a great potential for health and cosmetic applications. Herein, an untargeted screening approach for mycosporines and mycosporine-like amino acids (MAAs) was developed by the coupling of zwitterionic hydrophilic interaction liquid chromatography (HILIC) with multistage electrospray mass spectrometry MS2/MS3 using an Orbitrap analyzer and fragment ion search (FISh). This method was applied to study the mycosporine and MAA contents of five algae extracted using a 50% methanol solution and sonication. Candidate-MAAs were detected by mining eight characteristic fragment ions in their HILIC data-dependent MS2 mass spectrum. Their exact masses were measured with 3 ppm mass accuracy and their structures were elucidated on the basis of the MS3/MS4 mass spectra. The method developed was validated with a targeted analysis using an extract of Gymnogongrus devoniensis which confirmed the detection of 14 MAAs reported in the literature. In addition, 23 previously unreported MAAs were detected and the structures could be assigned for seven of them. The developed method was applied to the analysis of four algae: Gelidium sesquipedale, Halopithys incurva, Porphyra rosengurtii and Cystoseira tamariscifolia allowing the detection of MAAs, including some reported here for the first time.


2020 ◽  
Vol 2 (1) ◽  
pp. 27-35
Author(s):  
P. Skryabin

The article is devoted to environmentally oriented urban development for the purpose of resettlement. The study of natural urban resettlement system is a new scientific field, which gives much attention. The author proposes to consider one of the most interesting territories located in the southern part of Siberia and stretching south of the Trans-Siberian Railway in the direction of the Altai Mountains, between the Ob river (along the settlement axis "Novosibirsk - Barnaul - Biysk - Gorno-Altaysk") and Tom river (along the settlement axis "Kemerovo - Novokuznetsk"). As a result, the author identified certain morphotypes, in each of which a resettlement framework and a natural-ecological framework were identified. For one of the morphotypes, the one characteristic fragment – Katun (Chemal region) with characteristic problems was selected along. As a result, a 3D model of the natural-urban planning system of settlement was designed. The key element in the work is the methodology for the development of such 3D models, which allows making a connection between urban exploration and development, taking into account the saving of the ecological balance of unique natural landscapes.


2020 ◽  
Vol 92 (19) ◽  
pp. 13144-13154
Author(s):  
Hyun Kyoung Lee ◽  
Dae-In Ha ◽  
Jeong Gu Kang ◽  
Gun Wook Park ◽  
Ju Yeon Lee ◽  
...  

2020 ◽  
Author(s):  
Mengyu Xia ◽  
Xue Zhang ◽  
Hongwei Wu ◽  
Yun Wang ◽  
Cun Zhang

Abstract Background Zhi-Zi-Da-Huang decoction (ZZDHD) is a famous Traditional Chinese Medicine decoction due to its therapeutic effects on clinical hepatobiliary disorders. ZZDHD is composed of Gardeniae Fructus, Rhei Radix et Rhizoma, Fructus Aurantii Immaturus, and Sojae Semen Praeparatum. With the development of current technology, dispensing granules have been widely used for convenience. However, limited research has been conducted to determine differences in the chemical compounds between dispensing granules and traditional decoction. Methods A strategy based on UPLC-qTOF-MS/MS and UPLC-DAD was established to quantitatively and qualitatively analyze the chemical compounds present in single- and co-boiled ZZDHD. First, we utilized UPLC-qTOF-MS/MS to identify the compounds in single- and co-boiled ZZDHD. Then, 15 compounds were quantitatively analyzed in ZZDHD by UPLC-DAD. Finally, fingerprint and chemometric analyses were adopted to evaluate the difference between single- and co-boiled ZZDHD. Results One hundred and forty-seven compounds were authenticated or determined according to their retention behaviors, mass mensuration, and characteristic fragment ions. In addition, 15 analytes of single- and co-boiled ZZDHD indicated a significant difference in the content of many compounds, including geniposide (G2), emodin, chrysophanol, daidzin, and crocin-I. The similarities of single and co-boiled ZZDHD were higher than 0.99, as evaluated by fingerprinting; 30 common peaks were evaluated by the chemometric analysis, which found 13 important variable values (VIP > 1) including C3, A3, crocetin, daidzin, C5, physcion, G2, genipin-1-O-β-D-gentiobioside (G1), chrysophanol, emodin, A2, A5, and C6. Conclusions This study provided an experimental basis for explaining the rationality of single-and co-boiled ZZDHD, and a study model for comparing the chemical substances between traditional decoctions and dispensing granules.


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