479547-20-1Relevant academic research and scientific papers
Understanding the regioselectivity in the oxidative condensation of catechins using pyrogallol-type model compounds
Yanase, Emiko,Ochiai, Yuto,Hirose, Sayumi
supporting information, p. 12359 - 12366 (2020/11/10)
Catechins are found in many foods, including tea. These compounds are bioactive. Previous studies have shown that catechins form dimers on oxidation, and there seem to be distinct regioselective effects. However, the dimerization mechanism and regioselectivity are not well understood. Therefore, we investigated the oxidation of four pyrogallol-type model compounds of epigallocatechin (EGC) having various substituents with 1 equiv of copper chloride and 30% dioxane in water. Compounds having 2C-2C or 2C-4C bonds in the B-ring were obtained in different product ratios. Comparison of the oxidation rates of each compound revealed that the model compounds having an oxygen atom corresponding to the 1-position of the C-ring of EGC underwent slow oxidation. In addition, using density functional theory calculations, we found that the highest occupied molecular orbital energies of these compounds were higher than those of the others. Further, the 2C-2C-bonded oxidation product having an A-ring and an oxygen atom at the C-ring 1-position was confirmed to have the highest thermodynamic stability. From these results, it is suggested that the regioselective condensation reaction of the catechin B-ring is related to interactions between the A-rings, as indicated by earlier studies, and the presence of oxygen at the 1-position of the C-ring in EGC.
PHOTO-CLEAVABLE PRIMER COMPOSITIONS AND METHODS OF USE
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Paragraph 0084, (2017/08/24)
In one embodiment, the present application discloses a photo-cleavable surface binding compound of the Formula I and Formula II: wherein the variables EG, EG1, SP1, SP2, SP3, Ar and BG are as defined herein. In another embodiment, the application discloses a method for forming a coating on a surface of a substrate using the surface binding compound.
SURFACE PRIMER COMPOSITIONS AND METHODS OF USE
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Paragraph 0082, (2017/08/21)
In one embodiment, the present application discloses a surface binding compound of the Formula I or Formula II: wherein the variables EG, EG1, SP1, SP2, SP3, Ar and BG are as defined herein. In another embodiment, the application discloses a method for forming a coating on a surface of a substrate using the surface binding compound of the Formula I or Formula II.
Synthesis of salidroside analogues and their ability of DPPH radical scavenging activity
Zheng, Cheng,Guo, Yibing,Meng, Ying,Dou, Sufeng,Shao, Jian,Yang, Yumin
, p. 654 - 664 (2013/07/11)
Salidroside is a phenylpropanoid glycoside isolated from Rhodiolarosea L., a traditional Chinese medicinal plant, and has displayed a broad spectrum of pharmacological properties. In this paper, about 22 novel glycosides have been synthesized and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenge activity of each glycoside has been evaluated. 2-(3,4,5-Trihydroxyphenyl)ethyl β-D-galactopyranoside and 3-(3,4,5-trihydroxyphenyl)propyl β-D-glucopyranoside exhibit significant activity prior to salidroside and Vitamin C with EC50 values of 35.85 μM and 36.71 μM, respectively. The results indicate that the phenolic hydroxyl group of these compounds is important for radical scavenging activity and phenyl ring substitution by electron-donating substituents lead to increased antioxidant activity.
A new convergent approach to dendritic macromolecules
Cao, Xiaoping,Wang, Feng,Guo, Shu
, p. 3149 - 3158 (2007/10/03)
The novel convergent growth approach to dendritic macromolecules is described. Polyether dendritic sectors [G-na]-OH from the first to the fourth generations, respectively, were prepared by this approach from readily available starting material.
