scholarly journals Simultaneous Study of Anti-Ferroptosis and Antioxidant Mechanisms of Butein and (S)-Butin

Molecules ◽  
2020 ◽  
Vol 25 (3) ◽  
pp. 674 ◽  
Author(s):  
Liu ◽  
Li ◽  
Cai ◽  
Ren ◽  
Zhang ◽  
...  
Keyword(s):  
Ultra Performance Liquid Chromatography ◽  
Hydrogen Atom Transfer ◽  
Tandem Mass ◽  
Reaction Products ◽  
Antioxidant Power ◽  
Flow Cytometric ◽  
Simultaneous Study ◽  
Linoleic Acid Emulsion ◽  
Antioxidant Mechanisms ◽  
Tof Ms

To elucidate the mechanism of anti-ferroptosis and examine structural optimization in natural phenolics, cellular and chemical assays were performed with 2′-hydroxy chalcone butein and dihydroflavone (S)-butin. C11-BODIPY staining and flow cytometric assays suggest that butein more effectively inhibits ferroptosis in erastin-treated bone marrow-derived mesenchymal stem cells than (S)-butin. Butein also exhibited higher antioxidant percentages than (S)-butin in five antioxidant assays: linoleic acid emulsion assay, Fe3+-reducing antioxidant power assay, Cu2+-reducing antioxidant power assay, 2-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl 3-oxide radical (PTIO•)-trapping assay, and α,α-diphenyl-β-picrylhydrazyl radical (DPPH•)-trapping assay. Their reaction products with DPPH• were further analyzed using ultra-performance liquid chromatography coupled with electrospray ionization quadrupole time-of-flight tandem mass spectrometry (UPLC-ESI-Q-TOF-MS). Butein and (S)-butin produced a butein 5,5-dimer (m/z 542, 271, 253, 225, 135, and 91) and a (S)-butin 5′,5′-dimer (m/z 542, 389, 269, 253, and 151), respectively. Interestingly, butein forms a cross dimer with (S)-butin (m/z 542, 523, 433, 419, 415, 406, and 375). Therefore, we conclude that butein and (S)-butin exert anti-ferroptotic action via an antioxidant pathway (especially the hydrogen atom transfer pathway). Following this pathway, butein and (S)-butin yield both self-dimers and cross dimers. Butein displays superior antioxidant or anti-ferroptosis action to (S)-butin. This can be attributed the decrease in π-π conjugation in butein due to saturation of its α,β-double bond and loss of its 2′-hydroxy group upon biocatalytical isomerization.

scholarly journals 3′,8″-Dimerization Enhances the Antioxidant Capacity of Flavonoids: Evidence from Acacetin and Isoginkgetin

Molecules ◽  
2019 ◽  
Vol 24 (11) ◽  
pp. 2039 ◽  
Author(s):  
Xican Li ◽  
Xiaojian Ouyang ◽  
Rongxin Cai ◽  
Dongfeng Chen
Keyword(s):  
Sulfonic Acid ◽  
Mass Spectra ◽  
Relevant Literature ◽  
Radical Scavenging ◽  
Ultra Performance Liquid Chromatography ◽  
Tandem Mass ◽  
Comparison Standard ◽  
Ic50 Values ◽  
Transfer Potential ◽  
Tof Ms

To probe the effect of 3′,8″-dimerization on antioxidant flavonoids, acacetin and its 3′,8″-dimer isoginkgetin were comparatively analyzed using three antioxidant assays, namely, the ·O2− scavenging assay, the Cu2+ reducing assay, and the 2,2′-azino bis(3-ethylbenzothiazolin-6-sulfonic acid) radical scavenging assay. In these assays, acacetin had consistently higher IC50 values than isoginkgetin. Subsequently, the acacetin was incubated with 4-methoxy-2,2,6,6-tetramethylpiperidine-1-oxy radicals (4-methoxy-TEMPO) and then analyzed by ultra-performance liquid chromatography coupled with electrospray ionization quadrupole time-of-flight tandem mass spectrometry (UHPLC−ESI−Q−TOF−MS) technology. The results of the UHPLC−ESI−Q−TOF−MS analysis suggested the presence of a dimer with m/z 565, 550, 413, 389, 374, 345, 330, and 283 peaks. By comparison, standard isoginkgetin yielded peaks at m/z 565, 533, 518, 489, 401, 389, 374, and 151 in the mass spectra. Based on these experimental data, MS interpretation, and the relevant literature, we concluded that isoginkgetin had higher electron transfer potential than its monomer because of the 3′,8″-dimerization. Additionally, acacetin can produce a dimer during its antioxidant process; however, the dimer is not isoginkgetin.

scholarly journals A Null B-Ring Improves the Antioxidant Levels of Flavonol: A Comparative Study between Galangin and 3,5,7-Trihydroxychromone

Molecules ◽  
2018 ◽  
Vol 23 (12) ◽  
pp. 3083 ◽  
Author(s):  
Xiaojian Ouyang ◽  
Xican Li ◽  
Wenbiao Lu ◽  
Xiaojun Zhao ◽  
Dongfeng Chen
Keyword(s):  
Comparative Study ◽  
Radical Scavenging ◽  
Ultra Performance Liquid Chromatography ◽  
Reaction Products ◽  
Radical Adduct ◽  
Ic50 Values ◽  
Reducing Activity ◽  
Dpph Scavenging ◽  
Tof Ms

To clarify the role of the B-ring in antioxidant flavonols, we performed a comparative study between galangin with a null B-ring and 3,5,7-trihydroxychromone without a B-ring using five spectrophotometric assays, namely, •O2−-scavenging, 1,1-diphenyl-2-picrylhydrazyl radical (DPPH•)-scavenging, 2-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide radical-scavenging, 2,2′-azino-bis(3-ethylbenzo-thiazoline-6-sulfonic acid) radical-scavenging, and Fe3+-reducing activity. The DPPH•-scavenging reaction products of these assays were further analyzed by ultra-performance liquid chromatography coupled with electrospray ionization quadrupole time-of-flight tandem mass spectrometry (UPLC-ESI-Q-TOF-MS/MS) technology. In the five spectrophotometric assays, galangin and 3,5,7-trihydroxychromone dose-dependently increased their radical-scavenging (or Fe3+-reducing) percentages. However, galangin always gave lower IC50 values than those of 3,5,7-trihydroxychromone. In the UPLC-ESI-Q-TOF-MS/MS analysis, galangin yielded galangin-DPPH adduct MS peaks (m/z 662, 434, 301, 227,196, and 151) and galangin-galangin dimer MS peaks (m/z 538, 385, 268, 239, 211, 195, and 151). 3,5,7-Trihydroxychromone, however, only generated m/z 3,5,7-trihydroxychromone-DPPH adduct MS peaks (m/z 586, 539, 227, 196, and 136). In conclusion, both galangin and 3,5,7-trihydroxychromone could similarly undergo multiple antioxidant pathways, including redox-dependent pathways (such as electron transfer (ET) and ET plus proton transfer (PT)) and a non-redox-dependent radical adduct formation (RAF) pathway; thus, the null B-ring could hardly change their antioxidant pathways. However, it did improve their antioxidant levels in these pathways. Such improvement of the B-ring toward an antioxidant flavonol is associated with its π-π conjugation, which can provide more resonance forms and bonding sites.

scholarly journals Antioxidant Mechanisms of Echinatin and Licochalcone A

Molecules ◽  
2018 ◽  
Vol 24 (1) ◽  
pp. 3 ◽  
Author(s):  
Minshi Liang ◽  
Xican Li ◽  
Xiaojian Ouyang ◽  
Hong Xie ◽  
Dongfeng Chen
Keyword(s):  
Mass Spectrometry ◽  
Aqueous Solution ◽  
Radical Scavenging ◽  
Hydrogen Atom Transfer ◽  
Mass Spectrometry Data ◽  
Antioxidant Action ◽  
Licochalcone A ◽  
Colorimetric Measurements ◽  
Antioxidant Mechanisms ◽  
Tof Ms

Echinatin and its 1,1-dimethyl-2-propenyl derivative licochalcone A are two chalcones found in the Chinese herbal medicine Gancao. First, their antioxidant mechanisms were investigated using four sets of colorimetric measurements in this study. Three sets were performed in aqueous solution, namely Cu2+-reduction, Fe3+-reduction, and 2-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl 3-oxide radical (PTIO•)-scavenging measurements, while 1,1-diphenyl-2-picrylhydrazyl radical (DPPH•)-scavenging colorimetric measurements were conducted in methanol solution. The four sets of measurements showed that the radical-scavenging (or metal-reduction) percentages for both echinatin and licochalcone A increased dose-dependently. However, echinatin always gave higher IC50 values than licochalcone A. Further, each product of the reactions of the chalcones with DPPH• was determined using electrospray ionization quadrupole time-of-flight tandem mass spectrometry (UPLC-ESI-Q-TOF-MS/MS). The UPLC-ESI-Q-TOF-MS/MS determination for echinatin yielded several echinatin–DPPH adduct peaks (m/z 662, 226, and 196) and dimeric echinatin peaks (m/z 538, 417, and 297). Similarly, that for licochalcone A yielded licochalcone A-DPPH adduct peaks (m/z 730, 226, and 196) and dimeric licochalcone A peaks (m/z 674 and 553). Finally, the above experimental data were analyzed using mass spectrometry data analysis techniques, resonance theory, and ionization constant calculations. It was concluded that, (i) in aqueous solution, both echinatin and licochalcone A may undergo an electron transfer (ET) and a proton transfer (PT) to cause the antioxidant action. In addition, (ii) in alcoholic solution, hydrogen atom transfer (HAT) antioxidant mechanisms may also occur for both. HAT may preferably occur at the 4-OH, rather than the 4′-OH. Accordingly, the oxygen at the 4-position participates in radical adduct formation (RAF). Lastly, (iii) the 1,1-dimethyl-2-propenyl substituent improves the antioxidant action in both aqueous and alcoholic solutions.

Analysis of Main Components in Jujube and Mulberry Extracts by High-Sensitive HPLC-ESI-Q-TOF-MS/MS

2021 ◽  
Author(s):  
Ran Li ◽  
Min Wei ◽  
Guoning Guo ◽  
Yi Li ◽  
Xi Pan ◽  
...  
Keyword(s):  
Free Amino ◽  
High Performance ◽  
Direct Injection ◽  
Relative Molecular Mass ◽  
Maillard Reaction Products ◽  
Tandem Mass ◽  
Reaction Products ◽  
Fragmentation Behavior ◽  
Main Components ◽  
Tof Ms

Abstract In order to comprehensively reflect the cigarette quality, a method combining direct injection of diluted sample with high sensitive high-performance liquid chromatography (HPLC)- electrospray (ESI)- quadrupole (Q)- time of flight (TOF)- tandem mass spectrometry (MS/MS) was developed for the identification of major components of cigarette essences (jujube and mulberry extracts). Based on the observed relative molecular mass, MS/MS fragmentation behavior, MS/MS database and related literatures, the components of the jujube extract and mulberry extract were identified. The result shows that the composition of jujube extract and mulberry extract has some similarity. They all mainly contain amino acids, free amino compounds and Maillard reaction products, which are the main constituents of a cigarette essence.

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