3917-41-7Relevant academic research and scientific papers
METHOD FOR SYNTHESISING VITAMIN A
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, (2021/10/11)
A method for preparing dehydro-cyclofarnesal from dehydro-farnesal by cyclization in the presence of an acid may include the dehydro-farnesal being obtained from the farnesal by dehydrogenation and may further includes the cyclization being carried out in the presence of an acid selected from Lewis acids, Bronstedt acids, and zeolites. The synthesis of vitamin A using this method further includes the conversion of dehydro-cyclofarnesal into vitamin A.
Method for preparing vitamin A and vitamin A ester
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Paragraph 0061; 0064; 0067; 0070; 0073; 0076, (2020/04/17)
The invention provides a novel method for preparing vitamin A and vitamin A ester by taking farnesol as a raw material. The method comprises the following steps: carrying out oxidation reaction on farnesol and oxygen under the action of a catalyst and a cocatalyst to generate farnesal; carrying out dehydrogenation reaction on farnesal to generate dehydrofarnesal; carrying out cyclization reactionon the dehydrofarnesal under the catalysis of acid to generate a cyclized intermediate; carrying out a reaction on the cyclized intermediate with chloroisopentenol to generate vitamin A; carrying outan esterification reaction on vitamin A to generate vitamin A ester. The method avoids the defects of an existing process, and the process line is economical and effective.
Expansion of first-in-class drug candidates that sequester toxic all-trans-retinal and prevent light-induced retinal degeneration
Zhang, Jianye,Dong, Zhiqian,Mundla, Sreenivasa Reddy,Hu, X. Eric,Seibel, William,Papoian, Ruben,Palczewski, Krzysztof,Golczak, Marcin
supporting information, p. 477 - 491 (2015/01/30)
All-trans-retinal, a retinoid metabolite naturally produced upon photoreceptor light activation, is cytotoxic when present at elevated levels in the retina. To lower its toxicity, two experimentally validated methods have been developed involving inhibition of the retinoid cycle and sequestration of excess of all-trans-retinal by drugs containing a primary amine group. We identified the first-in-class drug candidates that transiently sequester this metabolite or slow down its production by inhibiting regeneration of the visual chromophore, 11-cis-retinal. Two enzymes are critical for retinoid recycling in the eye. Lecithin:retinol acyltransferase (LRAT) is the enzyme that traps vitamin A (all-trans-retinol) from the circulation and photoreceptor cells to produce the esterified substrate for retinoid isomerase (RPE65), which converts all-trans-retinyl ester into 11-cis-retinol. Here we investigated retinylamine and its derivatives to assess their inhibitor/substrate specificities for RPE65 and LRAT, mechanisms of action, potency, retention in the eye, and protection against acute light-induced retinal degeneration in mice. We correlated levels of visual cycle inhibition with retinal protective effects and outlined chemical boundaries for LRAT substrates and RPE65 inhibitors to obtain critical insights into therapeutic properties needed for retinal preservation.
Synthetic control of retinal photochemistry and photophysics in solution
Bassolino, Giovanni,Sovdat, Tina,Liebel, Matz,Schnedermann, Christoph,Odell, Barbara,Claridge, Timothy D.W.,Kukura, Philipp,Fletcher, Stephen P.
supporting information, p. 2650 - 2658 (2014/03/21)
Understanding how molecular structure and environment control energy flow in molecules is a requirement for the efficient design of tailor-made photochemistry. Here, we investigate the tunability of the photochemical and photophysical properties of the retinal-protonated Schiff base chromophore in solution. Replacing the n-butylamine Schiff base normally chosen to mimic the saturated linkage found in nature by aromatic amines results in the reproduction of the opsin shift and complete suppression of all isomerization channels. Modification of retinal by directed addition or removal of backbone substituents tunes the overall photoisomerization yield from 0 to 0.55 and the excited state lifetime from 0.4 to 7 ps and activates previously inaccessible reaction channels to form 7-cis and 13-cis products. We observed a clear correlation between the presence of polarizable backbone substituents and photochemical reactivity. Structural changes that increase reaction speed were found to decrease quantum yields, and vice versa, so that excited state lifetime and efficiency are inversely correlated in contrast to the trends observed when comparing retinal photochemistry in protein and solution environments. Our results suggest a simple model where backbone modifications and Schiff base substituents control barrier heights on the excited-state potential energy surface and therefore determine speed, product distribution, and overall yield of the photochemical process.
Base-induced decarboxylation of polyunsaturated α-cyano acids derived from malonic acid: Synthesis of sesquiterpene nitriles and aldehydes with β-, φ-, and ψ-end groups
Dufossé, Laurent,Cartier, Dominique,Valla, Benoist,Fouillaud, Mireille,Labia, Roger,Valla, Alain
, p. 259 - 265 (2013/03/28)
Catalytic base-induced decarboxylation of polyunsaturated α-cyano-β-methyl acids derived from malonic acid led to the corresponding nitriles 3 (Schemes 2 and 3), 6 (Scheme 5), and 9 (Scheme 6). This decarboxylation occurred with previous deconjugation of
A cross-metathesis approach to the synthesis of new etretinate type retinoids, ethyl retinoate and its 9Z-isomer
Maj, Jadwiga,Morzycki, Jacek W.,Rárová, Lucie,Wasilewski, Grzegorz,Wojtkielewicz, Agnieszka
supporting information, p. 5430 - 5433 (2012/11/07)
Two aromatic retinoids were synthesized from styrene derivatives using a novel strategy with a cross-metathesis reaction as a key step. The biological activity of the new etretinate analogues was tested. Cross-metathesis reactions were also employed for the preparation of ethyl retinoate and its 9Z-isomer via the C15 + C5 route.
Syntheses of 13C2-labelled 11Z-retinals
McLean, Neville J.,Gansmuller, Axel,Concistre, Maria,Brown, Lynda J.,Levitt, Malcom H.,Brown, Richard C.D.
supporting information; experimental part, p. 8404 - 8410 (2011/11/12)
To enable solid-state NMR investigations of the rhodopsin chromophore and its photointermediates, a series of 11Z-retinal isotopomers have been synthesised containing pairs of adjacent 13C labels at C9/C10, C10/C11 or C11/C12, respectively. The C9 labelled carbon atom was introduced through the Heck reaction of a 13C-labelled Weinreb acrylamide derivative, and the label at the C12 position derived from a 13C-containing ethoxy Bestmann-Ohira reagent. The 13C labels at C10 and C11 were introduced through the reaction of β-ionone with labelled triethyl phosphonoacetate.
New syntheses of retinal and its acyclic analog γ-retinal by an extended aldol reaction with a C6 building block that incorporates a C5 unit after decarboxylation. A formal route to lycopene and β-carotene
Valla, Alain,Valla, Benoist,Le Guillou, Regis,Cartier, Dominique,Dufosse, Laurent,Labia, Roger
, p. 512 - 520 (2008/02/07)
Since the C15 β-end-group aldehyde 10 ((β-ionylidene) acetaldehyde), an excellent intermediate in the syntheses of retinoids, can be synthesized in many ways from β-ionone, and since the corresponding acyclic C15 ψ-end-group aldehyde 5 can easily be synthesized from citral (1) (Scheme 3), we applied the C15 + C5 route to the syntheses of γ-retinal ((all-E)-8) (Scheme 3) and retinal ((all-E)-13) (Scheme 4), and therefore, by coupling (2 x C20 → C 40), to the preparation of lycopene (14) and β-carotene (15) (Scheme 5). Our new syntheses of retinal ((all-E)-13) and γ-retinal ((all-E)-8 use an extended aldol reaction with a C6 building block that incorporates a C5 unit after decarboxylation.
Substituted Cyclohexadienals - Syntheses and Applications
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Page/Page column 17, (2010/11/28)
The present invention is generally directed to the use of L-proline and certain derivatives thereof to catalyze the asymmetric self-condensation of α,β-unsaturated aldehydes to form homodimer and heterodimer cyclohexadienals. Reaction conditions are mild
Accurate measurements of 13C-13C J-couplings in the rhodopsin chromophore by double-quantum solid-state NMR spectroscopy
Lai, Wai Cheu,McLean, Neville,Gansmueller, Axel,Verhoeven, Michiel A.,Antonioli, Gian Carlo,Carravetta, Marina,Duma, Luminita,Bovee-Geurts, Petra H. M.,Johannessen, Ole G.,De Groot, Huub J. M.,Lugtenburg, Johan,Emsley, Lyndon,Brown, Steven P.,Brown, Richard C. D.,DeGrip, Willem J.,Levitt, Malcolm H.
, p. 3878 - 3879 (2007/10/03)
A new double-quantum solid-state NMR pulse sequence is presented and used to measure one-bond 13C-13C J-couplings in a set of 13C2-labeled rhodopsin isotopomers. The measured J-couplings reveal a perturbation of the electronic structure at the terminus of the conjugated chain but show no evidence for protein-induced electronic perturbation near the C11-C12 isomerization site. This work establishes NMR methodology for measuring accurate 1JCC values in noncrystalline macromolecules and shows that the measured J-couplings may reveal local electronic perturbations of mechanistic significance. Copyright
