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Yang W, Wang F, Wang H, Ding D, Jiang S, Zhang G. Platform for the Immobilizing of Ultrasmall Pd Clusters for Carbonylation: In Situ Self-Templating Fabrication of ZIF-8 on ZnO. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2024; 20:e2306794. [PMID: 38072816 DOI: 10.1002/smll.202306794] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/08/2023] [Revised: 11/10/2023] [Indexed: 05/03/2024]
Abstract
Incorporating metal clusters into the confined cavities of metal-organic frameworks (MOFs) to form MOF-supported catalysts has attracted considerable research interest with regard to carbonylation reactions. Herein, a self-templating method is used to prepare the zinc oxide (ZnO)-supported core-shell catalyst ZnO@Pd/ZIF-8. This facile strategy controls the growth of metal sources on the ZIF-8 shell layer and avoids the metal diffusion or aggregation problems of the conventional synthesis method. The characteristics of the catalysts show that the palladium (Pd) clusters are highly dispersed with an average particle size of ≈1.2 nm, making them excellent candidates as a catalyst for carbonylation under mild conditions. The optimal catalyst (1.25-ZnO@Pd/ZIF-8) exhibits excellent activity in synthesizing α, β-alkynyl ketones under 1 atm of carbon monooxide (CO), and the conversion rate of 1, 3-diphenylprop-2-yn-1-one is 3.09 and 3.87 times more than those of Pd/ZIF-8 and Pd2+, respectively, for the first 2 h. Moreover, the 1.25-ZnO@Pd/ZIF-8 is recyclable, showing negligible metal leaching, and, under the conditions used in this investigation, can be reused at least five times without considerable loss in its catalytic efficiency. This protocol can also be applied with other nucleophile reagents to synthesize esters, amides, and acid products.
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Affiliation(s)
- Wei Yang
- Institute of Coal Chemistry, State Key Laboratory of Coal Conversion, Chinese Academy of Sciences, Taiyuan, Shanxi, 030001, P. R. China
| | - Fangchao Wang
- Institute of Coal Chemistry, State Key Laboratory of Coal Conversion, Chinese Academy of Sciences, Taiyuan, Shanxi, 030001, P. R. China
| | - He Wang
- The third Military Representative Office in Taiyuan, Taiyuan, Shanxi, 030001, P. R. China
| | - Ding Ding
- Institute of Coal Chemistry, State Key Laboratory of Coal Conversion, Chinese Academy of Sciences, Taiyuan, Shanxi, 030001, P. R. China
| | - Shaohua Jiang
- Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, International Innovation Center for Forest Chemicals and Materials, College of Materials Science and Engineering, Nanjing Forestry University, Nanjing, 210037, P. R. China
| | - Guoying Zhang
- Institute of Coal Chemistry, State Key Laboratory of Coal Conversion, Chinese Academy of Sciences, Taiyuan, Shanxi, 030001, P. R. China
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Zhang H, Lin S, Xie R, Zhong W, Wang H, Farag MA, Hussain H, Arroo RRJ, Chen X, Xiao J. Thermal degradation of (2R, 3R)-dihydromyricetin in neutral aqueous solution at 100 ℃. Food Chem 2024; 435:137560. [PMID: 37793280 DOI: 10.1016/j.foodchem.2023.137560] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2023] [Revised: 09/19/2023] [Accepted: 09/20/2023] [Indexed: 10/06/2023]
Abstract
In the field of thermal degradation of flavonoids, current studies mainly focused on flavonols. However, the thermal degradation of dihydroflavonols in aqueous solution has received limited attention compared to flavonols. The single C2-C3 bonds of dihydroflavonols, which differs from the C2-C3 double bond in flavonols, may cause different degradation mechanisms. Dihydromyricetin (DMY) is a typical dihydroflavonol with six hydroxyl groups, and possesses various health effects. We explored the thermal degradation of DMY in neutral aqueous solution (pH 7) at 100 ℃. Ultra-performance liquid chromatography combined with photodiode array and electrospray ionization quadrupole-time-of-flight tandem mass spectrometric detection (UPLC-PDA-ESI-QTOF-MS/MS) provided suitable platform for exploring DMY degradation pathways, and negative ion mode was applied. Thermal treatment led to a decline in DMY level with time, accompanied by the appearance of various degradation products of DMY. Degradation mechanisms of DMY included isomerization, oxidation, hydroxylation, dimerization and ring cleavage. The pyrogallol-type ring B of DMY might be initially oxidized into ortho-quinone, which could further attack another DMY to form dimers. In addition, hydroxylation is likely to occur at C-2, C-3 of DMY or DMY dimers, which then further yields ring-cleavage products via breakage of the O1-C2 bond, C2-C3 bond, or C3-C4 bond. The 3-hydroxy-5-(3,3,5,7-tetrahydroxy-4-oxochroman-2-yl) cyclohexa-3,5-diene-1, 2-dione (m/z 333.0244) and unknown compound m/z 435.0925 were annotated as key intermediates in DMY degradation. Four phenolic acids, including 3,4,5-trihydroxybenzoic acid (m/z 169.0136, RT 1.4 min), 2,4,6-trihydroxyphenylglyoxylic acid (m/z 197.0084, RT 1.7 min), 2-oxo-2-(2,4,6-trihydroxyphenyl) acetaldehyde (m/z 181.0132, RT 2.4 min), and 2,4,6-trihydroxybenzoic acid (m/z 169.0139, RT 2.5 min) were identified as the major end products of DMY degradation. In addition, 5-((3,5dihydroxyphenoxy) methyl)-3-hydroxycyclohexa-3,5-diene-1,2-dione (m/z 261.0399, RT 11.7 min) and unidentified compound with m/z 329.0507 (RT 1.0 min) were also suggested to be end products of DMY degradation. These results provide novel insights on DMY stability and degradation products. Moreover, the heat treatment of DMY aqueous solution was found to gradually reduce the antioxidant activities of DMY, and even destroy the beneficial effect of DMY on the gut microbiota composition.
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Affiliation(s)
- Haolin Zhang
- Institute of Chinese Medical Sciences, University of Macau, Macau.
| | - Shiye Lin
- Universidade de Vigo, Department of Analytical and Food Chemistry, Faculty of Sciences, 32004 Ourense, Spain.
| | - Ruiwei Xie
- Guangdong Provincial Key Laboratory of Aquatic Product Processing and Safety, College of Food Science and Technology, Guangdong Ocean University, Zhanjiang 524088, China.
| | - Weizhi Zhong
- Institute of Food Safety and Nutrition, Jinan University, Guangzhou, China.
| | - Hui Wang
- Guangdong Provincial Key Laboratory of Aquatic Product Processing and Safety, College of Food Science and Technology, Guangdong Ocean University, Zhanjiang 524088, China.
| | - Mohamed A Farag
- Pharmacognosy Department, College of Pharmacy, Cairo University, Cairo, Egypt.
| | - Hidayat Hussain
- Department of Bioorganic Chemistry, Leibniz Institute of Plant Biochemistry, Weinberg 3, D-06120 Halle (Saale), Germany.
| | - Randolph R J Arroo
- Leicester School of Pharmacy, De Montfort University, The Gateway, Leicester LE1 9BH, United Kingdom.
| | - Xiaojia Chen
- Institute of Chinese Medical Sciences, University of Macau, Macau.
| | - Jianbo Xiao
- Universidade de Vigo, Department of Analytical and Food Chemistry, Faculty of Sciences, 32004 Ourense, Spain.
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Wujec M, Feldo M. Can We Improve Diosmetin Activity? The State-of-the-Art and Promising Research Directions. Molecules 2023; 28:7910. [PMID: 38067639 PMCID: PMC10707807 DOI: 10.3390/molecules28237910] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2023] [Revised: 11/27/2023] [Accepted: 11/30/2023] [Indexed: 12/18/2023] Open
Abstract
Diosmetin is a natural substance widely distributed in nature, with documented multidirectional biological effects. The wide spectrum of biological activity of diosmetin gives hope that derivatives of this flavonoid may also be used as drugs or dietary supplements used in many diseases. Modification of the structure may, on the one hand, lead to an increase in biological potency, new biological activity, or an increase in solubility and thus bioavailability. This is an important direction of research because the use of pure diosmetin is limited due to its low bioavailability. This work is an attempt to collect information on the possibility of modifying the structure of diosmetin and its impact on biological activity.
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Affiliation(s)
- Monika Wujec
- Department of Organic Chemistry, Medical University of Lublin, Chodzki 4a St., 20-093 Lublin, Poland
| | - Marcin Feldo
- Department of Vascular Surgery, Medical University of Lublin, Staszica 11 St., 20-081 Lublin, Poland
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