Interaction of a ruthenium hexacationic prism with amino acids and biological ligands: ESI mass spectrometry and NMR characterisation of the reaction products

Abstract This work proposes a new method for the synthesis of N-borylated amino acids based on nucleophilic substitution reactions in the [B12H11IPh]– anion. Esters of glycine and L-phenylalanine were used as nucleophiles. The structure of the products has been determined by multinuclear NMR spectroscopy, IR spectroscopy, and ESI mass spectrometry.

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Homochiral or Heterochiral: A Systematic Study of Threonine Clusters Using a FT ICR Mass Spectrometer

Symmetry ◽

10.3390/sym14010086 ◽

2022 ◽

Vol 14 (1) ◽

pp. 86

Author(s):

Luyang Jiao ◽

Mengying Du ◽

Yameng Hou ◽

Yuan Ma ◽

Xianglei Kong

Keyword(s):

Mass Spectrometry ◽

Amino Acids ◽

The Other ◽

Cluster Ions ◽

Complex Ions ◽

Charged Clusters ◽

Magic Clusters ◽

Esi Mass Spectrometry ◽

Charged Ions ◽

Ft Icr

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.

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The Kinetics of Inhibition of the Action of Thrombin by the Fibrinopeptides Formed during the Clotting of Fibrinogen

Thrombosis and Haemostasis ◽

10.1055/s-0038-1655562 ◽

1966 ◽

Vol 16 (01/02) ◽

pp. 277-295 ◽

Cited By ~ 1

Author(s):

A Silver ◽

M Murray

Keyword(s):

Amino Acids ◽

Competitive Inhibition ◽

Amorphous Material ◽

Peptide Bond ◽

Initial Reaction ◽

Reaction Products ◽

Coagulation Mechanism ◽

Kinetics Of ◽

Kinetics Of Inhibition ◽

Burk Plot

SummaryVarious investigators have separated the coagulation products formed when fibrinogen is clotted with thrombin and identified fibrinopeptides A and B. Two other peaks are observed in the chromatogram of the products of coagulation, but these have mostly been dismissed by other workers. They have been identified by us as amino acids, smaller peptides and amorphous material (37). We have re-chromatographed these peaks and identified several amino acids. In a closed system of fibrinogen and thrombin, the only reaction products should be fibrin and peptide A and peptide B. This reasoning has come about because thrombin has been reported to be specific for the glycyl-arginyl peptide bond. It is suggested that thrombin also breaks other peptide linkages and the Peptide A and Peptide B are attacked by thrombin to yield proteolytic products. Thrombin is therefore probably not specific for the glycyl-arginyl bond but will react on other linkages as well.If the aforementioned is correct then the fibrinopeptides A and B would cause an inhibition with the coagulation mechanism itself. We have shown that an inhibition does occur. We suggest that there is an autoinhibition to the clotting mechanism that might be a control mechanism in the human body.The experiment was designed for coagulation to occur under controlled conditions of temperature and time. Purified reactants were used. We assembled an apparatus to record visually the speed of the initial reaction, the rate of the reaction, and the density of the final clot formed after a specific time.The figures we derived made available to us data whereby we could calculate and plot the information to show the mechanism and suggest that such an inhibition does exist and also further suggest that it might be competitive.In order to prove true competitive inhibition it is necessary to fulfill the criteria of the Lineweaver-Burk plot. This has been done. We have also satisfied other criteria of Dixon (29) and Bergman (31) that suggest true competitive inhibition.

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Studies on Chromatographic Fractioning by Cations Exchangers of a Bovine Hemoglobin Hydrolysate

Revista de Chimie ◽

10.37358/rc.18.10.6626 ◽

2018 ◽

Vol 69 (10) ◽

pp. 2794-2798

Author(s):

Alina Diana Panainte ◽

Ionela Daniela Morariu ◽

Nela Bibire ◽

Madalina Vieriu ◽

Gladiola Tantaru ◽

...

Keyword(s):

Mass Spectrometry ◽

Amino Acids ◽

Retention Time ◽

Chromatographic Separation ◽

Bovine Hemoglobin ◽

Reverse Phase ◽

Hplc System ◽

Fast Flow ◽

Hydrolysis Of ◽

Phase Column

A peptidic hydrolysate has been obtained through hydrolysis of bovine hemoglobin using pepsin. The fractioning of the hydrolysate was performed on a column packed with CM-Sepharose Fast Flow. The hydrolysate and each fraction was filtered and then injected into a HPLC system equipped with a Vydak C4 reverse phase column (0.46 x 25 cm), suitable for the chromatographic separation of large peptides with 20 to 30 amino acids. The detection was done using mass spectrometry, and the retention time, size and distribution of the peptides were determined.

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(2S,3R,6R)-2-[(R)-1-Hydroxyallyl]-4,4-dimethoxy-6-methyltetrahydro-2H-pyran-3-ol

Molbank ◽

10.3390/m1140 ◽

2020 ◽

Vol 2020 (2) ◽

pp. M1140

Author(s):

Jack Bennett ◽

Paul Murphy

Keyword(s):

Mass Spectrometry ◽

Nmr Spectroscopy ◽

Ir Spectroscopy ◽

13C Nmr ◽

Conjugate Addition ◽

13C Nmr Spectroscopy ◽

One Pot ◽

1H And 13C Nmr ◽

Esi Mass Spectrometry ◽

The One

(2S,3R,6R)-2-[(R)-1-Hydroxyallyl]-4,4-dimethoxy-6-methyltetrahydro-2H-pyran-3-ol was isolated in 18% after treating the glucose derived (5R,6S,7R)-5,6,7-tris[(triethylsilyl)oxy]nona-1,8-dien-4-one with (1S)-(+)-10-camphorsulfonic acid (CSA). The one-pot formation of the title compound involved triethylsilyl (TES) removal, alkene isomerization, intramolecular conjugate addition and ketal formation. The compound was characterized by 1H and 13C NMR spectroscopy, ESI mass spectrometry and IR spectroscopy. NMR spectroscopy was used to establish the product structure, including the conformation of its tetrahydropyran ring.

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Gas chromatography–mass spectrometry of hexafluoroacetone derivatives: First time utilization of a gaseous phase derivatizing agent for analysis of extraterrestrial amino acids

Journal of Chromatography A ◽

10.1016/j.chroma.2012.04.062 ◽

2012 ◽

Vol 1245 ◽

pp. 158-166 ◽

Cited By ~ 6

Author(s):

C. Geffroy-Rodier ◽

A. Buch ◽

R. Sternberg ◽

S. Papot

Keyword(s):

Mass Spectrometry ◽

Amino Acids ◽

Gas Chromatography ◽

Gaseous Phase ◽

Gas Chromatography Mass Spectrometry ◽

Chromatography Mass Spectrometry ◽

Derivatizing Agent ◽

Time Utilization ◽

First Time

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Magnesium Supplementation Alters Leaf Metabolic Pathways for Higher Flavor Quality of Oolong Tea

Agriculture ◽

10.3390/agriculture11020120 ◽

2021 ◽

Vol 11 (2) ◽

pp. 120 ◽

Cited By ~ 1

Author(s):

Jiuliang Xu ◽

Liangquan Wu ◽

Bingxin Tong ◽

Jiaxu Yin ◽

Zican Huang ◽

...

Keyword(s):

Mass Spectrometry ◽

Amino Acids ◽

Free Amino Acids ◽

Free Amino ◽

High Resolution Mass Spectrometry ◽

Southern China ◽

Substantial Reduction ◽

Sugar Accumulation ◽

Limiting Factor ◽

Oolong Tea

Oolong tea, one of the most famous tea beverages in China, contains specialized metabolites contributing to rich flavors and human health. Accumulation patterns of such metabolites and underlying regulatory mechanisms significantly vary under different growth conditions. To optimize quality and yield while minimizing environmental effects, three treatments were designed in this study: Conventional fertilization, optimized fertilization, and optimized fertilization supplemented with magnesium (Mg). We investigated the yield, taste quality, primary and secondary metabolites of oolong tea, and found that a substantial reduction in chemical fertilizers (nutrient optimization by reducing 43% N, 58% P2O5 and 55% K2O) did not affect the tea yield in this study. Interestingly, Mg fertilization is an important factor influencing amino acid and sugar accumulation in oolong tea, resulting in higher concentrations of total free amino acids and a lower ratio of tea polyphenols (TP) to free amino acids (FAA). Gas chromatography-time-of-flight mass spectrometry (GC-TOF-MS) and liquid chromatography-high resolution mass spectrometry (LC-HRMS) combined multivariate analyses revealed distinct features of metabolite accumulation in leaves of three different treatments, as indicated by 34 differentially accumulated characteristic compounds. The levels of serine, aspartic acid, isoleucine, phenylalanine, theanine, and proline were reduced by fertilizer optimization and increased by Mg supplementation. Mg particularly promoted theanine accumulation favoring a stronger umami taste of oolong tea, while decreasing astringency and bitter metabolites. Thus, Mg application paves a new path for tea quality improvement in Southern China where Mg deficiency in the soil is a frequent limiting factor for crop production.

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Mass spectrometry imaging of L-[ring-13C6]-labeled phenylalanine and tyrosine kinetics in non-small cell lung carcinoma

Cancer & Metabolism ◽

10.1186/s40170-021-00262-9 ◽

2021 ◽

Vol 9 (1) ◽

Author(s):

Jianhua Cao ◽

Benjamin Balluff ◽

Martijn Arts ◽

Ludwig J. Dubois ◽

Luc J. C. van Loon ◽

...

Keyword(s):

Mass Spectrometry ◽

Amino Acids ◽

Amino Acid ◽

Mass Spectrometry Imaging ◽

Tumor Tissue ◽

Small Cell Lung Carcinoma ◽

Small Cell ◽

Small Cell Lung ◽

Tracer Injection ◽

Cell Lung Carcinoma

Abstract Background Metabolic reprogramming is a common phenomenon in tumorigenesis and tumor progression. Amino acids are important mediators in cancer metabolism, and their kinetics in tumor tissue are far from being understood completely. Mass spectrometry imaging is capable to spatiotemporally trace important endogenous metabolites in biological tissue specimens. In this research, we studied L-[ring-13C6]-labeled phenylalanine and tyrosine kinetics in a human non-small cell lung carcinoma (NSCLC) xenografted mouse model using matrix-assisted laser desorption/ionization Fourier-transform ion cyclotron resonance mass spectrometry imaging (MALDI-FTICR-MSI). Methods We investigated the L-[ring-13C6]-Phenylalanine (13C6-Phe) and L-[ring-13C6]-Tyrosine (13C6-Tyr) kinetics at 10 min (n = 4), 30 min (n = 3), and 60 min (n = 4) after tracer injection and sham-treated group (n = 3) at 10 min in mouse-xenograft lung tumor tissues by MALDI-FTICR-MSI. Results The dynamic changes in the spatial distributions of 19 out of 20 standard amino acids are observed in the tumor tissue. The highest abundance of 13C6-Phe was detected in tumor tissue at 10 min after tracer injection and decreased progressively over time. The overall enrichment of 13C6-Tyr showed a delayed temporal trend compared to 13C6-Phe in tumor caused by the Phe-to-Tyr conversion process. Specifically, 13C6-Phe and 13C6-Tyr showed higher abundances in viable tumor regions compared to non-viable regions. Conclusions We demonstrated the spatiotemporal intra-tumoral distribution of the essential aromatic amino acid 13C6-Phe and its de-novo synthesized metabolite 13C6-Tyr by MALDI-FTICR-MSI. Our results explore for the first time local phenylalanine metabolism in the context of cancer tissue morphology. This opens a new way to understand amino acid metabolism within the tumor and its microenvironment.

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Mycosporine-Like Amino Acids from Red Macroalgae: UV-Photoprotectors with Potential Cosmeceutical Applications

Applied Sciences ◽

10.3390/app11115112 ◽

2021 ◽

Vol 11 (11) ◽

pp. 5112

Author(s):

Julia Vega ◽

Geniane Schneider ◽

Bruna R. Moreira ◽

Carolina Herrera ◽

José Bonomi-Barufi ◽

...

Keyword(s):

Mass Spectrometry ◽

Amino Acids ◽

High Performance ◽

Nitrogen Availability ◽

Antioxidant Properties ◽

Published Data ◽

Diverse Group ◽

Red Macroalgae ◽

Thermo Stability ◽

The Impact

Macroalgae belong to a diverse group of organisms that could be exploited for biomolecule application. Among the biocompounds found in this group, mycosporine-like amino acids (MAAs) are highlighted mainly due to their photoprotection, antioxidant properties, and high photo and thermo-stability, which are attractive characteristics for the development of cosmeceutical products. Therefore, here we revise published data about MAAs, including their biosynthesis, biomass production, extraction, characterization, identification, purification, and bioactivities. MAAs can be found in many algae species, but the highest concentrations are found in red macroalgae, mainly in the order Bangiales, as Porphyra spp. In addition to the species, the content of MAAs can vary depending on environmental factors, of which solar radiation and nitrogen availability are the most influential. MAAs can confer photoprotection due to their capacity to absorb ultraviolet radiation or reduce the impact of free radicals on cells, among other properties. To extract these compounds, different approaches can be used. The efficiency of these methods can be evaluated with characterization and identification using high performance liquid chromatography (HPLC), associated with other apparatus such as mass spectrometry (MS) and nuclear magnetic resonance (NMR). Therefore, the data presented in this review allow a broad comprehension of MAAs and show perspectives for their inclusion in cosmeceutical products.

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