The reaction of an aromatic heterocycle with a proton is called a protonation. One of articles about this theory is 《The beneficial effects of edible kynurenic acid from marine horseshoe crab (Tachypleus tridentatus) on obesity, hyperlipidemia, and gut microbiota in high-fat diet-fed mice》. Authors are Li, Jian; Zhang, Yaqi; Yang, Shen; Lu, Zhenhua; Li, Guiling; Wu, Shangyi; Wu, Da-Ren; Liu, Jingwen; Zhou, Bo; Wang, Hui-Min David; Huang, Shi-Ying.The article about the compound:4-Hydroxyquinoline-2-carboxylic Acidcas:492-27-3,SMILESS:O=C(C1=NC2=CC=CC=C2C(O)=C1)O).Reference of 4-Hydroxyquinoline-2-carboxylic Acid. Through the article, more information about this compound (cas:492-27-3) is conveyed.
The marine horseshoe crab (Tachypleus tridentatus) has been considered as food and traditional medicine for many years. Kynurenic acid (KA) was isolated from horseshoe crab in this study for the first time in the world. A previous study in 2018 reported that i.p. administration of KA prevented high-fat diet- (HFD-) induced body weight gain. Now, we investigated the effects of intragastric gavage of KA on HFD mice and found that KA (5 mg/kg/day) inhibited both the body weight gain and the increase of average daily energy intake. KA reduced serum triglyceride and increased serum high-d. lipoprotein cholesterol. KA inhibited HFD-induced the increases of serum low-d. lipoprotein cholesterol, coronary artery risk index, and atherosclerosis index. KA also suppressed HFD-induced the increase of the ratio of Firmicutes to Bacteroidetes (two dominant gut microbial phyla). KA partially reversed HFD-induced the changes in the composition of gut microbial genera. These overall effects of KA on HFD mice were similar to that of simvastatin (pos. control). But the effects of 1.25 mg/kg/day KA on HFD-caused hyperlipidemia were similar to the effects of 5 mg/kg/day simvastatin. The pattern of relative abundance in 40 key genera of gut microbiota from KA group was closer to that from the normal group than that from the simvastatin group. In addition, our in vitro results showed the potential antioxidant activity of KA, which suggests that the improvement effects of KA on HFD mice may be partially associated with antioxidant activity of KA. Our findings demonstrate the potential role of KA as a functional food ingredient for the treatment of obesity and hyperlipidemia as well as the modulation of gut microbiota.
After consulting a lot of data, we found that this compound(492-27-3)Reference of 4-Hydroxyquinoline-2-carboxylic Acid can be used in many types of reactions. And in most cases, this compound has more advantages.
Reference:
Copper catalysis in organic synthesis – NCBI,
Special Issue “Fundamentals and Applications of Copper-Based Catalysts”