13726-69-7Relevant articles and documents
An Unconventional Redox Cross Claisen Condensation-Aromatization of 4-Hydroxyprolines with Ketones
Tang, Mi,Sun, Rengwei,Li, Hao,Yu, Xinhong,Wang, Wei
, p. 8419 - 8425 (2017)
Reaction of α-amino acids, particularly prolines and their derivatives with carbonyl compounds via decarboxylative redox process, is a viable strategy for synthesis of structurally diverse nitrogen centered heterocyclics. In these processes, the decarboxylation is the essential driving force for the processes. The realization of the redox process without decarboxylation may offer an opportunity to explore new reactions. Herein, we report the discovery of an unprecedented redox Claisen-type condensation aromatization cascade reaction of 4-substituted 4-hydroxyproline and its esters with unreactive ketones. We found that the use of propionic acid as a catalyst and a co-solvent can change the reaction course. The commonly observed redox decarboxylation and aldol condensation reactions are significantly minimized. Moreover, unreactive ketones can effectively participate in the Claisen condensation reaction. The new reactivity enables a redox cyclization via an unconventional Claisen-type condensation reaction of in situ formed enamine intermediates from ketone precursors with 4-substituted 4-hydroxyproline and its esters as electrophilic acylation partners. Under the reaction conditions, the cascade process proceeds highly regio- and stereoselectively to afford highly synthetically and biologically valued cis-2,3-dihydro-1H-pyrrolizin-1-ones with a broad substrate scope in efficient 'one-pot' operation, whereas such structures generally require multiple steps.
β-L-Arabinofuranosylation Conducted by 5-O-(2-pyridinecarbonyl)-L-arabinofuranosyl Trichloroacetimidate
Li, Hong-Zhan,Ding, Jie,Cheng, Chun-Ru,Chen, Yue,Liang, Xing-Yong
, p. 1 - 7 (2018)
We describe a β-L-arabinofuranosylation method by employing the 5-O-(2-pyridinecarbonyl)-L-arabinofuranosyl trichloroacetimidate 10 as a donor. This approach allows a wide range of acceptor substrates, especially amino acid acceptors, to be used. Stereoselective synthesis of β-(1,4)-L-arabinofuranosyl-(2S, 4R)-4-hydroxy-L-proline (β-L-Araf-L-Hyp4) and its dimer is achieved readily by this method. Both the stereoselectivities and yields of the reactions are excellent. To demonstrate the utility of this methodology, the preparation of a trisaccharide in a one-pot manner was carried out.
Chemical Probes Unravel an Antimicrobial Defense Response Triggered by Binding of the Human Opioid Dynorphin to a Bacterial Sensor Kinase
Wright, Megan H.,Fetzer, Christian,Sieber, Stephan A.
, p. 6152 - 6159 (2017)
Host-microbe communication via small molecule signals is important for both symbiotic and pathogenic relationships, but is often poorly understood at the molecular level. Under conditions of host stress, levels of the human opioid peptide dynorphin are elevated, triggering virulence in the opportunistic pathogenic bacterium Pseudomonas aeruginosa via an unknown pathway. Here we apply a multilayered chemical biology strategy to unravel the mode of action of this putative interkingdom signal. We designed and applied dynorphin-inspired photoaffinity probes to reveal the protein targets of the peptide in live bacteria via chemical proteomics. ParS, a largely uncharacterized membrane sensor of a two-component system, was identified as the most promising hit. Subsequent full proteome studies revealed that dynorphin(1-13) induces an antimicrobial peptide-like response in Pseudomonas, with specific upregulation of membrane defense mechanisms. No such response was observed in a parS mutant, which was more susceptible to dynorphin-induced toxicity. Thus, P. aeruginosa exploits the ParS sensing machinery to defend itself against the host in response to dynorphin as a signal. This study highlights interkingdom communication as a potential essential strategy not only for induction of P. aeruginosa virulence but also for maintaining viability in the hostile environment of the host.
Synthesis and DNA binding property of a novel peptide nucleic acid that contains cis-4-adeninyl-L-prolinol unit
Shigeyasu, Masanori,Kuwahara, Masayasu,Sisido, Masahiko,Ishikawa, Teruhiko
, p. 634 - 635 (2001)
A novel oxy-peptide nucleic acid that contains a cis-4-adeninyl-L-prolinol unit in the main chain (PPNA) was synthesized. The peptide nucleic acid with nine adenine units [PPNA(A9)] hybridized with the complementary DNA (T9). The hybrid showed a very sharp melting curve with Tm = 34 °C.
The development of a new class of inhibitors for betaine-homocysteine S-methyltransferase
Pi?ha, Jan,Vaňek, Václav,Budě??sińsky, Milo?,Mlad?ková, Jana,Garrow, Timothy A.,Ji??acek, Ji??i
, p. 256 - 275 (2013)
Betaine-homocysteine S-methyltransferase (BHMT) is an important zinc-dependent methyltransferase that uses betaine as the methyl donor for the remethylation of homocysteine to form methionine. In the liver, BHMT performs to half of the homocysteine remethylation. In this study, we systematically investigated the tolerance of the enzyme for modifications at the "homocysteine" part of the previously reported potent inhibitor (R,S)-5-(3-amino-3-carboxy-propylsulfanyl)-pentanoic acid (1). In the new compounds, which are S-alkylated homocysteine derivatives, we replaced the carboxylic group in the "homocysteine" part of inhibitor 1 with different isosteric moieties (tetrazole and oxadiazolone); we suppressed the carboxylic negative charge by amidations; we enhanced acidity by replacing the carboxylate with phosphonic or phosphinic acids; and we introduced pyrrolidine steric constraints. Some of these compounds display high affinity toward human BHMT and may be useful for further pharmacological studies of this enzyme. Although none of the new compounds were more potent inhibitors than the reference inhibitor 1, this study helped to completely defi ne the structural requirements of the active site of BHMT and revealed the remarkable selectivity of the enzyme for homocysteine.
Locked conformations for proline pyrrolidine ring: Synthesis and conformational analysis of cis- and trans-4-tert-butylprolines
Koskinen, Ari M. P.,Helaja, Juho,Kumpulainen, Esa T. T.,Koivisto, Jari,Mansikkamaeki, Heidi,Rissanen, Kari
, p. 6447 - 6453 (2005)
The motional restrictions of the proline pyrrolidine ring allow this secondary amine amino acid to act as a turn inducer in many peptides and proteins. The pyrrolidine ring is known to exhibit two predominant pucker modes (i.e., C-4 (Cγ) exo and endo envelope conformers whose ratio can be controlled by proper substituents in the ring). In nature, the exo puckered 4(R)-hydroxy-L-proline plays a crucial role as a building block in collagen and collagen-like structures. It has been previously concluded that the electronegativity of the 4-cis-substituent increases the endo puckering while the electronegativity of the 4-trans-substituent favors the exo puckering. Here, we have introduced a sterically demanding tert-butyl group at C-4 in trans- and cis-configurations. In the case of trans-substitution, the induced puckering effect on the pyrrolidine ring was studied with X-ray crystallography and 1H NMR spectral simulations. Both cis- and trans-4-tert-butyl groups strongly favor pseudoequatorial orientation, thereby causing opposite puckering effects for the pyrrolidine ring, cis-exo and trans-endo for L-prolines, in contrast to the effects observed in the case of electronegative C-4 substituents. The syntheses and structural analysis are presented for the conformationally constrained 4-tert-butylprolines. The prolines were synthesized from 4-hydroxy-L-proline, substitution with t-BuCuSPhLi being the key transformation. This reaction gave N-Boc-trans-4-tert-butyl-L-proline tert-butyl ester in 94% ee and 57% de. Enantioselectivity was increased to 99.2% ee by crystallization of N-Boc-trans-4-tert-butyl-L-proline in the final step of the synthesis.
Multipodal insulin mimetics built on adamantane or proline scaffolds
Hajduch, Jan,Fabre, Benjamin,Klopp, Benjamin,Pohl, Radek,Budě?ínsky, Milo?,?olínová, Veronika,Ka?i?ka, Václav,K?prülüoglu, Cemal,Eyrilmez, Saltuk Mustafa,Lep?ík, Martin,Hobza, Pavel,Mitrová, Katarína,Lubos, Marta,Hernández, María Soledad Garre,Jirá?ek, Ji?í
, (2020/12/29)
Multi-orthogonal molecular scaffolds can be applied as core structures of bioactive compounds. Here, we prepared four tri-orthogonal scaffolds based on adamantane or proline skeletons. The scaffolds were used for the solid-phase synthesis of model insulin mimetics bearing two different peptides on the scaffolds. We found that adamantane-derived compounds bind to the insulin receptor more effectively (Kd value of 0.5 μM) than proline-derived compounds (Kd values of 15–38 μM) bearing the same peptides. Molecular dynamics simulations suggest that spacers between peptides and central scaffolds can provide greater flexibility that can contribute to increased binding affinity. Molecular modeling showed possible binding modes of mimetics to the insulin receptor. Our data show that the structure of the central scaffold and flexibility of attached peptides in this type of compound are important and that different scaffolds should be considered when designing peptide hormone mimetics.
Method for synthesizing tert-2-(3- (2S)-4- butyl)-1- ester of n-oxo-isothiazole alkyloxycarbonylpyrrolidinecarboxylic acid (by machine translation)
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Paragraph 0038-0040; 0053-0055; 0066-0068, (2020/02/14)
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