1. Palladium-Catalyzed Tandem Ester Dance/Decarbonylative Coupling Reactions
Masayuki Kubo, Naomi Inayama, Eisuke Ota, Junichiro Yamaguchi Org Lett. 2022 Jun 3;24(21):3855-3860. doi: 10.1021/acs.orglett.2c01432. Epub 2022 May 23.
"Dance reaction" on the aromatic ring is a powerful method in organic chemistry to translocate functional groups on arene scaffolds. Notably, dance reactions of halides and pseudohalides offer a unique platform for the divergent synthesis of substituted (hetero)aromatic compounds when combined with transition-metal-catalyzed coupling reactions. Herein, we report a tandem reaction of ester dance and decarbonylative coupling enabled by palladium catalysis. In this reaction, 1,2-translocation of the ester moiety on the aromatic ring is followed by decarbonylative coupling with nucleophiles to enable the installation of a variety of nucleophiles at the position adjacent to the ester in the starting material.
2. Lactose esters: synthesis and biotechnological applications
Jakub Staroń, Janusz M Dąbrowski, Ewelina Cichoń, Maciej Guzik Crit Rev Biotechnol. 2018 Mar;38(2):245-258. doi: 10.1080/07388551.2017.1332571. Epub 2017 Jun 6.
Biodegradable nonionic sugar esters-based surfactants have been gaining more and more attention in recent years due to their chemical plasticity that enables the various applications of these molecules. In this review, various synthesis methods and biotechnological implications of lactose esters (LEs) uses are considered. Several chemical and enzymatic approaches are described for the synthesis of LEs, together with their applications, i.e. function in detergents formulation and as additives that not only stabilize food products but also protect food from undesired microbial contamination. Further, this article discusses medical applications of LEs in cancer treatment, especially their uses as biosensors, halogenated anticancer drugs, and photosensitizing agents for photodynamic therapy of cancer and photodynamic inactivation of microorganisms.
3. A Ketone Ester Drink Lowers Human Ghrelin and Appetite
Brianna J Stubbs, Pete J Cox, Rhys D Evans, Malgorzata Cyranka, Kieran Clarke, Heidi de Wet Obesity (Silver Spring). 2018 Feb;26(2):269-273. doi: 10.1002/oby.22051. Epub 2017 Nov 6.
Objective: The ketones d-β-hydroxybutyrate (BHB) and acetoacetate are elevated during prolonged fasting or during a "ketogenic" diet. Although weight loss on a ketogenic diet may be associated with decreased appetite and altered gut hormone levels, it is unknown whether such changes are caused by elevated blood ketones. This study investigated the effects of an exogenous ketone ester (KE) on appetite. Methods: Following an overnight fast, subjects with normal weight (n = 15) consumed 1.9 kcal/kg of KE, or isocaloric dextrose (DEXT), in drinks matched for volume, taste, tonicity, and color. Blood samples were analyzed for BHB, glucose, insulin, ghrelin, glucagon-like peptide 1 (GLP-1), and peptide tyrosine tyrosine (PYY), and a three-measure visual analogue scale was used to measure hunger, fullness, and desire to eat. Results: KE consumption increased blood BHB levels from 0.2 to 3.3 mM after 60 minutes. DEXT consumption increased plasma glucose levels between 30 and 60 minutes. Postprandial plasma insulin, ghrelin, GLP-1, and PYY levels were significantly lower 2 to 4 hours after KE consumption, compared with DEXT consumption. Temporally related to the observed suppression of ghrelin, reported hunger and desire to eat were also significantly suppressed 1.5 hours after consumption of KE, compared with consumption of DEXT. Conclusions: Increased blood ketone levels may directly suppress appetite, as KE drinks lowered plasma ghrelin levels, perceived hunger, and desire to eat.
