Are Highly Stable Covalent Organic Frameworks the Key to Universal Chiral Stationary Phases for Liquid and Gas Chromatographic Separations?
作者:Chen Yuan、Wenyan Jia、Ziyun Yu、Yanan Li、Min Zi、Li-Ming Yuan、Yong Cui
DOI:10.1021/jacs.1c11051
日期:2022.1.19
High-performance liquid chromatography (HPLC) and gas chromatography (GC) over chiralstationaryphases (CSPs) represent the most popular and highly applicable technology in the field of chiral separation, but there are currently no CSPs that can be used for both liquid and gas chromatography simultaneously. We demonstrate here that two olefin-linked covalent organic frameworks (COFs) featuring chiralcrown ether
Polypeptides and biosynthetic pathways for the production of monatin and its precursors
申请人:Hicks M. Paula
公开号:US20050282260A1
公开(公告)日:2005-12-22
Methods and compositions that can be used to make monatin from glucose, tryptophan, indole-3-lactic acid, indole-3-pyruvate, and 2-hydroxy 2-(indol-3-ylmethyl)-4-keto glutaric acid, are provided. Methods are also disclosed for producing the indole-3-pyruvate and 2-hydroxy 2-(indol-3-ylmethyl)-4-keto glutaric acid intermediates. Compositions provided include nucleic acid molecules, polypeptides, chemical structures, and cells. Methods include in vitro and in vivo processes, and the in vitro methods include chemical reactions.
2-Substituted 3-(4-amidinophenyl)propionic acid derivatives of the formula ##STR1## in which A, Ar and B have the meanings stated in the description, and the preparation thereof are described. The compounds are suitable for controlling diseases.
A di-enzymatic chewable dentifrice is provided which contains an oxidizable substrate and an oxidoreductase enzyme specific to such substrate for producing hydrogen peroxide upon chewing of the dentifrice and further contains a thiocyanate salt and lactoperoxidase for interacting with hydrogen peroxide to produce a hypothiocyanate bacterial inhibitor. The concentration of lactoperoxidase is at least about 2% of the concentration of the oxidoreductase enzyme, in International Units, to thereby limit the ratio of hydrogen peroxide to lactoperoxidase during oral chewing of the dentifrice. An illustrative enzymatic system for this purpose contains glucose, glucose oxidase, potassium thiocyanate and lactoperoxidase.
A di-enzymatic dentifrice is provided which contains an oxidizable substrate and an oxidoreductase enzyme specific to such substrate for producing hydrogen peroxide upon oral application of the dentifrice and further contains a thiocyanate salt and lactoperoxidase for interacting with hydrogen peroxide to produce a hypothiocyanate bacterial inhibitor. An illustrative enzymatic system for this purpose contains glucose, glucose oxidase, potassium thiocyanate and lactoperoxidase.