80963-08-2Relevant articles and documents
Macrocyclic BACE1 inhibitors with hydrophobic cross-linked structures: Optimization of ring size and ring structure
Otani, Takuya,Hattori, Yasunao,Akaji, Kenichi,Kobayashi, Kazuya
, (2021/11/22)
Based on the X-ray crystallography of recombinant BACE1 and a hydroxyethylamine-type peptidic inhibitor, we introduced a cross-linked structure between the P1 and P3 side chains of the inhibitor to enhance its inhibitory activity. The P1 and P3 fragments bearing terminal alkenes were synthesized, and a ring-closing metathesis of these alkenes was used to construct the cross-linked structure. Evaluation of ring size using P1 and P3 fragments with various side chain lengths revealed that 13-membered rings were optimal, although their activity was reduced compared to that of the parent compound. Furthermore, the optimal ring structure was found to be a macrocycle with a dimethyl branched substituent at the P3 β-position, which was approximately 100-fold more active than the non-substituted macrocycle. In addition, the introduction of a 4-carboxymethylphenyl group at the P1′ position further improved the activity.
Improved enantioselective gram scale synthesis route to N-Fmoc-protected monofluoroethylglycine
Leppkes, Jakob,Hohmann, Thomas,Koksch, Beate
, (2020/02/11)
Fluorine, as a substituent in amino acids, has found its way into peptide and protein engineering. The basis for the use of this valuable tool is the synthetic accessibility of various fluorinated amino acids as building blocks of peptides and proteins. In this context, we present a straightforward eight-step synthesis of N-Fmoc-L-monofluoroethylglycine (MfeGly) via homoserine (Hse) as intermediate and using various nucleophilic fluorination strategies.
[18F](2S,4S)-4-(3-Fluoropropyl)glutamine as a tumor imaging agent
Wu, Zehui,Zha, Zhihao,Li, Genxun,Lieberman, Brian P.,Choi, Seok Rye,Ploessl, Karl,Kung, Hank F.
, p. 3852 - 3866 (2016/10/13)
Although the growth and proliferation of most tumors is fueled by glucose, some tumors are more likely to metabolize glutamine. In particular, tumor cells with the upregulated c-Myc gene are generally reprogrammed to utilize glutamine. We have developed new 3-fluoropropyl analogs of glutamine, namely [18F](2S,4R)- and [18F](2S,4S)-4-(3-fluoropropyl)glutamine, 3 and 4, to be used as probes for studying glutamine metabolism in these tumor cells. Optically pure isomers labeled with 18F and 19F (2S,4S) and (2S,4R)-4-(3-fluoropropyl)glutamine were synthesized via different routes and isolated in high radiochemical purity (>95%). Cell uptake studies of both isomers showed that they were taken up efficiently by 9L tumor cells with a steady increase over a time frame of 120 min. At 120 min, their uptake was approximately two times higher than that of L-[3H]glutamine ([3H]Gln). These in vitro cell uptake studies suggested that the new probes are potential tumor imaging agents. Yet, the lower chemical yield of the precursor for 3, as well as the low radiochemical yield for 3, limits the availability of [18F](2S,4R)-4-(3-fluoropropyl)glutamine, 3. We, therefore, focused on [18F](2S,4S)-4-(3-fluoropropyl)glutamine, 4. The in vitro cell uptake studies suggested that the new probe, [18F](2S,4S)-4-(3-fluoropropyl)glutamine, 4, is most sensitive to the LAT transport system, followed by System N and ASC transporters. A dualisotope experiment using L-[3H]glutamine and the new probe showed that the uptake of [3H]Gln into 9L cells was highly associated with macromolecules (>90%), whereas the [18F](2S,4S)-4-(3-fluoropropyl)glutamine, 4, was not (18F](2S,4S)-4-(3-fluoropropyl)glutamine, 4, may be useful for testing tumors that may metabolize glutamine related amino acids.
Synthesis of optically pure 4-fluoro-glutamines as potential metabolic imaging agents for tumors
Qu, Wenchao,Zha, Zhihao,Ploessl, Karl,Lieberman, Brian P.,Zhu, Lin,Wise, David R.,Thompson, Craig B.,Kung, Hank F.
supporting information; scheme or table, p. 1122 - 1133 (2011/04/16)
A versatile synthetic route to prepare all four stereoisomeric 4-fluoro-glutamines was developed by exploiting a Passerini three-component reaction. The skeleton of 4-substituted glutamine derivatives was efficiently constructed. Subsequent four-step reactions, highlighted by a "neutralized" TASF fluorination, provided the desired products with high yields and excellent optical purity. The optically pure fluorine-18 labeled 4-fluoroglutamines were also successfully prepared using either a 18-crown-6/KHCO3 or K[222]/K2CO3 catalysis system. Preliminary cell uptake and inhibition studies using the 9L tumor cells ana SF188BC1-XL tumor cells (a glutamine addicted tumor derived from glioblastoma) provided strong evidence for their potential application in conjunction with positron emission tomography (PET) for in vivo imaging of tumors, which use glutamine as an alternative energy source.
SINGLE DIASTEREOMERS OF 4-FLUOROGLUTAMINE AND METHODS FO THEIR PREPARATION AND USE
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Page/Page column 22, (2011/02/24)
The present invention is directed single diasteromers of 4-fluoroglutamine having a diastereomeric excess of at least 80%. Methods of preparing the single diastereomers are also described, as well as methods of using the single diastereomers of radiolabeled 4-fluoroglutamine as imaging agent is also described.
Using benzotriazole esters as a strategy in the esterification of tertiary alcohols
Morales-Serna, Jose Antonio,Vera, Aline,Paleo, Ehecatl,Garcia-Rios, Erendira,Gavino, Ruben,Garcia De La Mora, Gustavo,Cardenas, Jorge
experimental part, p. 4261 - 4267 (2011/02/25)
Benzotriazole esters formed in situ were found to be efficient intermediates in the esterification of tertiary alcohols using 4-(dimethylamino)pyridine (DMAP) as the base. These mild and basic reaction conditions allow the conversion of various substrates into esters in good yield
Asymmetric synthesis of differentially protected meso-2,6-diaminopimelic acid
Roberts, John L.,Chan, Cecil
, p. 7679 - 7682 (2007/10/03)
meso-2,6-Diaminopimelic acid, an important linking component of bacterial cell walls and a biosynthetic precursor of L-lysine has been prepared differentially protected in a stereospecific manner from both L-aspartic and L-glutamic acid. The key step to establish the second chiral center involves the asymmetric reduction of a pyruvate moiety with Alpine-Borane. S-2-Amino-6-oxopimelic acid, the hydrolyzed open chain form of tetrahydrodipicolinic acid, a biosynthetic precursor of meso-2,6-diaminopimelic acid, was also prepared via deprotection of the key pyruvate intermediate.
The synthesis of pyrimidin-4-yI substituted a-amino acids. a versatile approach from alkynyl ketones
Adlington, Robert M.,Baldwin, Jack E.,Catterick, David,Pritchard, Garcth J.
, p. 855 - 866 (2007/10/03)
The reaction of amidines with a-amino acid alkynyl ketones is shown to be a versatile route to pyrimidin-4-yl substituted a-amino acids. This route is also applicable to a parallel synthesis approach and has allowed the formation of a range of pyrimidin-4-yl substituted a-amino acids, including the naturally occurring a-amino acid L-lathyrine 4.
Chirospecific Synthesis of (1S,3R)-1-Amino-3-(hydroxymethyl)cyclopentane, Precursor for Carbocyclic Nucleoside Synthesis. Dieckmann Cyclization with an α-Amino Acid
Bergmeier, Stephen C.,Cobas, Agustin A.,Rapoport, Henry
, p. 2369 - 2376 (2007/10/02)
Carbocyclic nucleosides are important isosters of nucleosides possessing a variety of antiviral and antineoplastic activities.We report here a new method for the chirospecific synthesis of (1S,3R)-1-amino-3-(hydroxymethyl)cyclopentane.This compound is a key precursor for the synthesis of some carbocyclic nucleosides.The method involves (1) an improved synthesis of (S)-2-aminoadipic acid; (2) Dieckmann cyclization of this α-amino acid to an aminocyclopentanone; and (3) elaboration of the latter to the target (1S,3R)-1-amino-3-(hydroxymethyl)cyclopentane.The starting (S)-2-aminoadipic acid δ-methyl ester was prepared enantiomerically pure from (S)-aspartic acid in 51percent overall yield.Dieckmann condensation converted this amino acid to a (methoxycarbonyl)-cyclopentanone, and reduction of the ketone followed by elimination yielded (S)-3--1-(methoxycarbonyl)cyclopentene.Reduction of the double bond gave a mixture of the cis and trans diastereomers.This mixture was converted to a single diastereomer by epimerization and trapping of the cis isomer as (1S,4R)-2-(9-phenylfluoren-9-yl)-2-azabicycloheptan-3-one.Hydrolytic cleavage of the lactam followed by reduction gave (1S,3R)-1-amino-3-(hydroxymethyl)cyclopentane.
ISOPROPENYL CHLOROCARBONATE (IPCC) IN AMINO ACID AND PEPTIDE CHEMISTRY: ESTERIFICATION OF N-PROTECTED AMINO ACIDS; APPLICATION TO THE SYNTHESIS OF THE DEPSIPEPTIDE VALINOMYCIN
Zeggaf, Choukri,Poncet, Joel,Jouin, Patrick,Dufour, Marie-Noelle,Castro, Bertrand
, p. 5039 - 5050 (2007/10/02)
Esterification of N-protected α-amino acids was achieved via isopropenyl chlorocarbonate (IPCC) activation.In situ alcoholysis of the unstable mixed anhydride intermediate was catalised by 4-(dimethylamino)pyridine (DMAP).Competing isopropenyl ester formation was negligible when using methylene chloride as the solvent.A variety of esters from primary and secondary alcohols were obtained with good yields (60 to 90 percent), and even the more hindered tertiobutyl alcohol gave acceptable yields under more drastic conditions.The improvement in depsipeptide synthetic methodology is illustrated by preparation of the antibiotic valinomycin, using IPCC for ester bond formation, and BOP reagent for peptide coupling and the last-step cyclisation.
