Electrospray Ionization
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2022 ◽  
Vol 20 (2) ◽  
pp. 411-418
Author(s):  
Wei Wang ◽  
Xuechun Wang ◽  
Qiang Zhang ◽  
Ru Jia ◽  
Chunjie Du ◽  
...  

Purpose: To study the pharmacokinetics of morroniside (MR) and loganin (LG) in rats after oral administration of raw and wine-processed Corni fructus by UPLC-QqQ-MS/MS. Methods: Arctiin (AT) was used as internal standard, and the plasma or tissue samples were extracted twice using ethyl acetate. Electrospray ionization (ESI) negative ion mode was used, and the multiple reaction monitoring mode (MRM) was set in acquisition mode. The extraction and detection method is supported by selectivity, sensitivity, precision, accuracy, stability, extraction, recovery and matrix effect. The non-atrioventricular model of das2.0 software was used to calculate the pharmacokinetic parameters. Results: The absorption rate of MR (PTmax=0.092) and LG (PTmax=0.092) in Corni Fructus after wine-processing was faster in rats. The mean residence time was longer, and distribution of MR (PMRT0~t = 0.294) and LG (PMRT0~t = 0.000) in wine-processed Corni Fructus group increased in liver and kidneys. Conclusion: The proposed method has been successfully validated and is suitable for studying the pharmacokinetics of the two analytes in rats.


Symmetry ◽  
2022 ◽  
Vol 14 (1) ◽  
pp. 86
Author(s):  
Luyang Jiao ◽  
Mengying Du ◽  
Yameng Hou ◽  
Yuan Ma ◽  
Xianglei Kong

The strong chiral preferences of some magic clusters of amino acids have attracted continually increasing interests due to their unique structures, properties and possible roles in homochirogenesis. However, how chirality can influence the generation and stability of cluster ions in a wild range of cluster sizes is still unknown for most amino acids. In this study, the preference for threonine clusters to form homochiral and heterochiral complex ions has been investigated by electrospray ionization (ESI) mass spectrometry. Abundant cluster [Thrn+mH]m+ ions (7 ≤ n ≤ 78, 1 ≤ m ≤ 5) have been observed for both samples of enantiopure (100% L) and racemic (50:50 L:D) threonine solutions. Further analyses of the spectra show that the [Thr14+2H]2+ ion is characterized by its most outstanding homochiral preference, and [Thr7+H]+ and [Thr8+H]+ ions also clearly exhibit their homochiral preferences. Although most of the triply charged clusters (20 ≤ n ≤ 36) are characterized by heterochiral preferences, the quadruply charged [Thrn+4H]4+ ions (40 ≤ n ≤ 59) have no obvious chiral preference in general. On the other hand, a weak homochiral preference exists for most of the quintuply charged ions observed in the experiment.


2022 ◽  
Author(s):  
Daniel Pasin ◽  
Meiru Pan ◽  
Brian Schou Rasmussen ◽  
Kristian Linnet ◽  
Petur Weihe Dalsgaard ◽  
...  

2022 ◽  
Vol 17 (1) ◽  
pp. 1934578X2110704
Author(s):  
Naoki Murata ◽  
Saki Keitoku ◽  
Hideo Miyake ◽  
Reiji Tanaka ◽  
Toshiyuki Shibata

Among the phlorotannins of seaweed polyphenols, eckols which have a dibenzodioxin linkage are known to have various physiological functions. The purpose of this study was to investigate the intestinal epithelial absorption of eckols using Caco-2 cell monolayers of the small intestinal membrane model. Each compound permeated from the apical (AP) side to the basolateral (BL) side in the monolayers was identified and quantitated by liquid chromatography-mass spectrometry with electrospray ionization. In the transport assays using five types of eckols (eckol, fucofuroeckol A, phlorofucofuroeckol A, dieckol, and 8,8'-bieckol), only the monomeric eckol showed limited transepithelial absorption with relatively small apparent permeability values (0.30  ±  0.04  ×  10−8 cm/s). Analyzing the Hanks’ balanced salt solution in the receiver on the BL side showed that phloroglucinol was detected in all experimental sections using eckols, and it's concentration increased with time over the course of the incubation. The other molecules corresponding to the unconjugated and conjugated metabolites of eckols were not detected in the AP and BL sides through the assays. These results suggest that eckols, including monomeric eckol, may be decomposed into phloroglucinol in the intestinal epithelium and the resulting phloroglucinol permeates to the BL side.


Metabolites ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 33
Author(s):  
Matthew J. Smith ◽  
Ralf J. M. Weber ◽  
Mark R. Viant

Untargeted lipidomics has previously been applied to the study of daphnids and the discovery of biomarkers that are indicative of toxicity. Typically, liquid chromatography—mass spectrometry is used to measure the changes in lipid abundance in whole-body homogenates of daphnids, each only ca. 3 mm in length which limits any biochemical interpretation of site-specific toxicity. Here, we applied mass spectrometry imaging of Daphnia magna to combine untargeted lipidomics with spatial resolution to map the molecular perturbations to defined anatomical regions. A desorption electrospray ionization—mass spectrometry (DESI-MS) method was optimized and applied to tissue sections of daphnids exposed to bisphenol-A (BPA) compared to unexposed controls, generating an untargeted mass spectrum at each pixel (35 µm2/pixel) within each section. First, unique lipid profiles from distinct tissue types were identified in whole-body daphnids using principal component analysis, specifically distinguishing appendages, eggs, eye, and gut. Second, changes in the lipidome were mapped over four stages of normal egg development and then the effect of BPA exposure on the egg lipidome was characterized. The primary perturbations to the lipidome were annotated as triacylglycerides and phosphatidylcholine, and the distributions of the individual lipid species within these classes were visualized in whole-body D. magna sections as ion images. Using an optimized DESI-MS workflow, the first ion images of D. magna tissue sections were generated, mapping both their baseline and BPA-perturbed lipidomes.


2021 ◽  
Vol 66 (2) ◽  
pp. 211-224
Author(s):  
Rémy Poncet ◽  
Françoise Lohézic – Le Dévéhat ◽  
Solenn Ferron ◽  
Jean Hivert ◽  
Christian Fontaine ◽  
...  

A systematic survey of lichens was performed in 2019 in four of the five territories constituting the French Scattered Islands (Europa Island, Juan de Nova, Glorioso Islands, and Tromelin) focusing on the genus Ramalina. Species were characterized using morphological (macroscopic and microscopic) features and an accurate chemical profiling method based on high-performance liquid chromatography coupled with diode-array detection and electrospray ionization tandem mass spectrometry (HPLC-DAD-MS). Five species were found in these territories. Two of them, Ramalina dumeticola and R. ovalis, are already known. Three species are introduced here as new to science: Ramalina gloriosensis sp. nov., R. hivertiana sp. nov., and R. marteaui sp. nov. An identification key is provided for the species found in the area and morphologically closely related taxa.


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