Comprehensive analysis of Sini decoction and investigation of acid-base self-assembled complexes using cold spray ionization mass spectrometry

2021 ◽  
pp. 107008
Author(s):  
Qi Hu ◽  
Meng Chen ◽  
Mengmeng Yan ◽  
Penglong Wang ◽  
Haimin Lei ◽  
...  
2021 ◽  
Vol 56 (5) ◽  
Author(s):  
Lucie Percevault ◽  
Thomas Delhaye ◽  
Alain Chaumont ◽  
Rachel Schurhammer ◽  
Ludovic Paquin ◽  
...  

2021 ◽  
pp. 247255522110006
Author(s):  
Michael D. Scholle ◽  
Zachary A. Gurard-Levin

Arginase-1, an enzyme that catalyzes the reaction of L-arginine to L-ornithine, is implicated in the tumor immune response and represents an interesting therapeutic target in immuno-oncology. Initiating arginase drug discovery efforts remains a challenge due to a lack of suitable high-throughput assay methodologies. This report describes the combination of self-assembled monolayers and matrix-assisted laser desorption ionization mass spectrometry to enable the first label-free and high-throughput assay for arginase activity. The assay was optimized for kinetically balanced conditions and miniaturized, while achieving a robust assay (Z-factor > 0.8) and a significant assay window [signal-to-background ratio > 20] relative to fluorescent approaches. To validate the assay, the inhibition of the reference compound nor-NOHA (Nω-hydroxy-nor-L-arginine) was evaluated, and the IC50 measured to be in line with reported results (IC50 = 180 nM). The assay was then used to complete a screen of 175,000 compounds, demonstrating the high-throughput capacity of the approach. The label-free format also eliminates opportunities for false-positive results due to interference from library compounds and optical readouts. The assay methodology described here enables new opportunities for drug discovery for arginase and, due to the assay flexibility, can be more broadly applicable for measuring other amino acid–metabolizing enzymes.


2013 ◽  
Vol 91 (8) ◽  
pp. 671-678 ◽  
Author(s):  
Endler Marcel Borges ◽  
Dietrich A. Volmer ◽  
Marcos N. Eberlin

We report here that easy ambient sonic spray ionization − mass spectrometry (EASI−MS) allowed direct, rapid, and comprehensive analysis of active components (e.g., terpenetrilactones and intact flavonol glycosides) in Ginkgo tablets. Unlike conventional methods that hydrolyze flavonol glycosides to flavonoids prior to analysis, EASI−MS detects intact flavonol glycosides directly from the tablets enabling differentiation of these natural glycosides from the synthetic flavonoids. Adulteration of Ginkgo tablets is therefore readily recognized in less than 10 s measurement time. Sample preparation is simple and requires only 0.5 mL of methanol and a mortar and pestle. Additionally, no reference standards are needed and a comparison is made to a certified Ginkgo tablet. To demonstrate these abilities, 22 commercial Ginkgo tablets were analyzed by EASI−MS. The data revealed large variations of ingredients and strong deviations from the specified Ginkgo extract levels. These results emphasize the importance of monitoring Ginkgo products using appropriate methodologies as suggested in our work. The technique may replace more demanding LC−MS/MS methods, which can achieve comparable results but are considerably more labor-intensive. Importantly, the presented method is cheaper, faster, and much simpler to operate than chromatography-based mass spectrometric techniques.


2007 ◽  
Vol 79 (13) ◽  
pp. 4827-4832 ◽  
Author(s):  
Teruyuki Seino ◽  
Hiroaki Sato ◽  
Atsushi Yamamoto ◽  
Atsushi Nemoto ◽  
Masaki Torimura ◽  
...  

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