1. α-Imino Esters in Organic Synthesis: Recent Advances
Maryam Zirak, Bagher Eftekhari-Sis Chem Rev . 2017 Jun 28;117(12):8326-8419. doi: 10.1021/acs.chemrev.7b00064.
α-Imino esters are useful precursors for the synthesis of a variety of types of natural and unnatural α-amino acid derivatives, with a wide range of biological activities. Due to the adjacent ester group, α-imino esters are more reactive relative to other types of imines and undergo different kinds of reactions, including organometallics addition, metal catalyzed vinylation and alkynylation, aza-Henry, aza-Morita-Baylis-Hillman, imino-ene, Mannich-type, and cycloaddition reactions, as well as hydrogenation and reduction. This review discusses the mechanism, scope, and applications of the reactions of α-imino esters and related compounds in organic synthesis, covering the literature from the last 12 years.
2. Safety Assessment of Saccharide Esters as Used in Cosmetics
Ronald A Hill, Lillian J Gill, Laura N Scott, Daniel C Liebler, Paul W Snyder, James G Marks Jr, Thomas J Slaga, Curtis D Klaassen, Wilma F Bergfeld, Donald V Belsito, Ronald C Shank, Bart Heldreth Int J Toxicol . 2021 Oct;40(2_suppl):52S-116S. doi: 10.1177/10915818211016378.
This is a safety assessment of 40 saccharide ester ingredients as used in cosmetics. The saccharide esters are reported to function in cosmetics as emollients, skin-conditioning agents, fragrance ingredients, and emulsion stabilizers. The Expert Panel for Cosmetic Ingredient Safety (Panel) reviewed the relevant data for these ingredients. The Panel concluded that the saccharide esters are safe in cosmetics in the present practices of use and concentrations described in this safety assessment.
3. A Ketone Ester Drink Lowers Human Ghrelin and Appetite
Kieran Clarke, Malgorzata Cyranka, Brianna J Stubbs, Pete J Cox, Rhys D Evans, Heidi de Wet Obesity (Silver Spring) . 2018 Feb;26(2):269-273. doi: 10.1002/oby.22051.
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.
