15042-01-0Relevant articles and documents
Assessing the pKa-Dependent Activity of Hydroxyl Hydrogen Bond Donors in the Organocatalyzed Cycloaddition of Carbon Dioxide to Epoxides: Experimental and Theoretical Study
Yingcharoen, Prapussorn,Kongtes, Chutima,Arayachukiat, Sunatda,Suvarnapunya, Kittipong,Vummaleti, Sai V. C.,Wannakao, Sippakorn,Cavallo, Luigi,Poater, Albert,D' Elia, Valerio
, p. 366 - 373 (2019)
The development of hydrogen bond donors (HBDs) as catalytic moieties in the cycloaddition of carbon dioxide to epoxides is an active field of research to access efficient, inexpensive and sustainable metal-free systems for the conversion of carbon dioxide to useful chemicals. Thus far, no systematic attempt to correlate the activity of a diverse selection of HBDs to their physico-chemical properties has been undertaken. In this work, we investigate factors influencing the catalytic activity of hydroxyl HBDs from different chemical families under ambient conditions by considering the HBDs Br?nsted acidity (expressed as pKa), the number of hydroxyls and structural aspects. As an effect, this study highlights the crucial role of the hydroxyl protons’ Br?nsted acidity in determining the catalytic activity of the HBDs, identifies an ideal range for the hydroxyl HBDs proton acidity (9 a 11) and leads to a revaluation of phenol and to the discovery of a simple ascorbic acid derivative as efficient HBDs for the title cycloaddition reaction. Density functional theory (DFT) calculations show mild reactions barriers for the reaction catalysed by phenol and suggest the occurrence of aggregation between molecules of ascorbic acid as a further factor affecting catalytic activity. (Figure presented.).
Discovery of a stable vitamin C glycoside in crab apples (Malus sylvestris)
Richardson, Alistair T.,Cho, Jung,McGhie, Tony K.,Larsen, David S.,Schaffer, Robert J.,Espley, Richard V.,Perry, Nigel B.
, (2020)
Non-targeted LC-MS metabolomics on fruit of three wild and domesticated apple species (Malus sylvestris, M. sieversii and M. domestica) showed that two crab apple (M. sylvestris) accessions were distinguished by high concentrations of an ascorbic acid glycoside (AAG). This was partly purified, but key NMR signals were masked by inseparable sucrose. Reference samples of 2-O-β-D-glucopyranosyl L-ascorbic acid and 2-O-β-D-galactopyranosyl L-ascorbic acid were synthesised, but both coincided with the crab apple AAG on LC-MS. Peracetylation of the crab apple extract allowed both purification and characterisation, and the AAG was proven to be 2-O-β-D-glucopyranosyl L-ascorbic acid by comparison of 1H NMR, HRMS and HPLC data with synthesised peracetylated ascorbyl glycoside standards. The stability of the natural AA 2-β-glycoside was similar to synthetic 2-O-α-D-glucopyranosyl L-ascorbic acid, used widely in cosmetic and pharmaceutical products. This discovery in crab apples (Rosaceae) is only the fourth reported occurrence of any ascorbyl glycoside from plants, the others being from Cucurbitaceae, Solanaceae and Brassicaceae. It is hypothesised that AAGs may be more widespread in plants than currently realised.
Synthesis of new L-ascorbic ferulic acid hybrids
Voisin-Chiret, Anne Sophie,Bazin, Marc-Antoine,Lancelot, Jean-Charles,Rault, Sylvain
, p. 2533 - 2545 (2007)
A feasibility and chemical study of the coupling conditions of L-ascorbic acid with ferulic acid derivatives are described on the basis of the known synergistic effects of mixtures of various antioxidants. Novel L-ascorbic ferulic hybrids linked at the C-3 hydroxyl group were prepared with the aim to protect the alcohol function and the enediol system.
Biosynthesis-Inspired Approach to Kujounin A2 Using a Stereoselective Tsuji-Trost Alkylation
Burtea, Alexander,Rychnovsky, Scott D.
, p. 5849 - 5852 (2018)
A new biosynthesis was proposed for the kujounins A1 and A2 beginning from ascorbic acid, which in turn inspired a synthetic approach to kujounin A2. The ring system was assembled in two steps using a stereoselective Tsuji-Trost reaction followed by ozonolysis. The chemically labile disulfide was introduced in several more steps. These results will make kujounin and its analogues available for further evaluation.
Design, synthesis, and neuroprotective effects of dual-brain targeting naproxen prodrug
Wang, Linhui,Zhang, Li,Zhao, Yi,Fu, Qiuyi,Xiao, Wenjiao,Lu, Runxin,Hai, Li,Guo, Li,Wu, Yong
, (2018)
A new dual-targeting naproxen prodrug conjugated with glucose and ascorbic acid for central nervous system (CNS) drug delivery was designed and synthesized in order to effectively deliver naproxen to the brain. Naproxen could be released from the prepared prodrugs when incubated with various buffers, mouse plasma, and brain homogenate. Also, the prodrug showed superior neuroprotective effect in vivo over naproxen. Our results suggest that chemical modification of therapeutics with warheads of glucose and ascorbic acid represents a promising and efficient strategy for the development of brain targeting prodrugs by utilizing the endogenous transportation mechanism of the warheads.
Ascorbic acid-based inhibitors of α-amylases
Abell, Andrew D.,Ratcliffe, Maureen J.,Gerrard, Juliet
, p. 1703 - 1706 (1998)
A series of ascorbic acid and isoascorbic acid derivatives has been evaluated as inhibitors of malt, bacterial, fungal, pancreatic and salivary α-amylase inhibition. Acylation of the primary and scondary alcohols, and the absolute configuration of the secondary alcohol, do not affect the potency of inhibition.
1,4-Dioxane-2,5-dione-type monomers derived from l-ascorbic and d-isoascorbic acids. Synthesis and polymerisation
Bueno, Manuel,Molina, Inmaculada,Galbis, Juan A.
, p. 2100 - 2104 (2009)
l-Ascorbic and d-isoascorbic acids have been used as the starting materials for the preparation of (3R,4′S)-3-(2′,2′-dimethyl-1′,3′-dioxolan-4′-yl)-1,4-dioxane-2,5-dione (IPTA), (3R and S, 4′S,6R)-3-methyl-6-(2′,2′-dimethyl-1′,3′-dioxolan-4′-yl)-1,4-dioxane-2,5-dione (IPTP) and (3R,4′R)-3-(2′,2′-dimethyl-1′,3′-dioxolan-4′-yl)-1,4-dioxane-2,5-dione (IPEA), three novel 1,4-dioxane-2,5-dione-type monomers. Ring-opening homopolymerisation and copolymerisation of the IPTA monomer, derived from l-ascorbic acid, with d,l-lactide have been performed. The polymers were characterised by elemental microanalysis, as well as IR and 1H and 13C NMR spectroscopies. GPC was used to estimate product molecular weights, and thermal studies (DSC and TGA) revealed that all the polymers were amorphous, being stable up to 250 °C under nitrogen.
A New Convenient Method for the Synthesis of Chiral C3-Synthons
Emons, Carry H.H.,Kuster, Ben F.M.,Vekemans, Jozef A.J.M.,Sheldon, Roger A.
, p. 359 - 362 (1991)
Routes are described for the facile preparation of protected optically pure D- and L-glyceric acid (1a,b; 2a,b) starting from D-mannitol, D-isoascorbic acid and L-ascorbic acid.The key step is a ruthenium catalyzed oxidative cleavage of the vicinal diols 4a,b or the α-hydroxy acids 7a,b; 10a,b.
Enhanced delivery of γ-secretase inhibitor DAPT into the brain via an ascorbic acid mediated strategy
Quelever, Gilles,Kachidian, Philippe,Melon, Christophe,Garino, Cedrik,Laras, Younes,Pietrancosta, Nicolas,Sheha, Mahmoud,Kraus, Jean Louis
, p. 2450 - 2457 (2005)
Inhibition of γ-secretase, one of the enzymes responsible for the cleavage of the amyloid precursor protein (APP) to produce pathogenic Aβ peptides, is an attractive approach for the treatment of Alzheimer's disease. We designed a γ-secretase inhibitor bearing an ascorbic acid moiety which allows a specific delivery of the drug to the brain. Through, on the one hand, Aβ peptide production measurements by specific in vitro assays (γ-secretase cell free assay and cell based assay on HEK 293 APP transfected cells) and on the other hand through pharmacokinetic studies on animal models, the new inhibitor shows a good pharmacokinetic profile as well as a potent γ-secretase inhibitory activity In vitro. From the obtained results, it is expected that drug 2 will be mainly delivered to the CNS with a low diffusion in the peripheral tissues. Consequently the side effects of this γ-secretase inhibitor on the immune cells could be reduced. The Royal Society of Chemistry 2005.
Site-Selective Photochemical Fluorination of Ketals: Unanticipated Outcomes in Selectivity and Stability
Capilato, Joseph N.,Pitts, Cody Ross,Rowshanpour, Rozhin,Dudding, Travis,Lectka, Thomas
, p. 2855 - 2864 (2020)
We report a method for the regioselective photochemical sp3 C-H fluorination of acetonide ketals that presents interesting problems in chemical reactivity. The question of why certain products of the reaction are stable while others are not is addressed, as is the question of why only select α-ethereal hydrogen atoms are targeted in the reaction. We demonstrate that the method can be employed to synthesize unprecedented fluorinated sugars and steroids, and it can also be applied toward the fluorination of carbamates. Though some substrates contain up to eight discrete α-ethereal C-H bonds, we observed site-selectivity in each case, prompting us to investigate potential transition states for the reaction. Finally, a remarkable regiochemical switch upon minor structural modification of a diketal is also analyzed.
