102195-79-9Relevant articles and documents
Diastereoselectivity in the alkylation of 4-fluoroproline methyl esters
Filosa, Rosanna,Holder, Claude,Auberson, Yves P.
, p. 8929 - 8932 (2006)
The reaction of alkylation of cis- and trans-4-fluoro-N-Boc-l-proline methyl esters has been examined by exposing their lithium enolates to a range of alkylating agents. The process showed a high degree of facial diastereoselectivity (except when methyl iodide was used as alkylating agent), invariably giving rise to products bearing the alkyl group in anti with respect to the fluorine atom. A tentative model to account for the observed stereoselectivity is also proposed.
4R- and 4S-iodophenyl hydroxyproline, 4R-pentynoyl hydroxyproline, and S-propargyl-4-thiolphenylalanine: Conformationally biased and tunable amino acids for bioorthogonal reactions
Forbes, Christina R.,Pandey, Anil K.,Ganguly, Himal K.,Yap, Glenn P. A.,Zondlo, Neal J.
, p. 2327 - 2346 (2016)
Bioorthogonal reactions allow the introduction of new functionalities into peptides, proteins, and other biological molecules. The most readily accessible amino acids for bioorthogonal reactions have modest conformational preferences or bases for molecular interactions. Herein we describe the synthesis of 4 novel amino acids containing functional groups for bioorthogonal reactions. (2S,4R)- and (2S,4S)-iodophenyl ethers of hydroxyproline are capable of modification via rapid, specific Suzuki and Sonogashira reactions in water. The synthesis of these amino acids, as Boc-, Fmoc- and free amino acids, was achieved through succinct sequences. These amino acids exhibit well-defined conformational preferences, with the 4S-iodophenyl hydroxyproline crystallographically exhibiting β-turn (φ, ψ ～ -80°, 0°) or relatively extended (φ, ψ ～ -80°, +170°) conformations, while the 4R-diastereomer prefers a more compact conformation (φ ～ -60°). The aryloxyproline diastereomers present the aryl groups in a highly divergent manner, suggesting their stereospecific use in molecular design, medicinal chemistry, and catalysis. Thus, the 4R- and 4S-iodophenyl hydroxyprolines can be differentially applied in distinct structural contexts. The pentynoate ester of 4R-hydroxyproline introduces an alkyne functional group within an amino acid that prefers compact conformations. The propargyl thioether of 4-thiolphenylalanine was synthesized via copper-mediated cross-coupling reaction of thioacetic acid with protected 4-iodophenylalanine, followed by thiolysis and alkylation. This amino acid combines an alkyne functional group with an aromatic amino acid and the ability to tune aromatic and side chain properties via sulfur oxidation. These amino acids provide novel loci for peptide functionalization, with greater control of conformation possible than with other amino acids containing these functional groups.
Total Synthesis and Stereochemical Revision of the 2-Formylpyrrole Alkaloid Hemerocallisamine i
Wood, James M.,Furkert, Daniel P.,Brimble, Margaret A.
, p. 1926 - 1929 (2017)
The first total synthesis of the 2-formylpyrrole alkaloid hemerocallisamine I is reported. The convergent synthesis features a key Maillard-Type condensation of a complex amine derived from cis-4-hydroxy-l-proline with a dihydropyranone, to directly furnish the 2-formylpyrrole ring system. The absolute configuration of hemerocallisamine I has been revised on the basis of optical rotation data obtained for the synthesized compound.
Selective l-nitroargininylaminopyrrolidine and l-nitroargininylaminopiperidine neuronal nitric oxide synthase inhibitors
Seo, Jiwon,Martasek, Pavel,Roman, Linda J.,Silverman, Richard B.
, p. 1928 - 1938 (2007)
Selective inhibition of the localized excess production of NO by neuronal nitric oxide synthase (nNOS) has been targeted as a potential means of treating various neurological disorders. Based on observations from the X-ray crystal structures of complexes of nNOS with two nNOS-selective inhibitors, (4S)-N-{4-amino-5-[(2-amino)ethylamino]pentyl}-N′-nitroguanidine (l-Arg(NO2)-l-Dbu-NH2 (1) and 4-N-(Nω-nitro-l-argininyl)-trans-4-amino-l-proline amide (2), a series of descarboxamide analogues was designed and synthesized (3-7). The most potent compound was aminopyrrolidine analogue 3, which exhibited better potency and selectivity for nNOS than parent compound 2. In addition, 3 provided higher lipophilicity and a lower molecular weight than 2, therefore having better physicochemical properties. Nα-Methylated analogues (8-11) also were prepared for increased lipophilicity of the inhibitors, but they had 4- to 5-fold weaker binding affinity compared to their parent compounds.
Altering the sex pheromone cyclo(L-pro-l-pro) of the diatom seminavis robusta towards a chemical probe
Bonneure, Eli,De Baets, Amber,De Decker, Sam,Van den Berge, Koen,Clement, Lieven,Vyverman, Wim,Mangelinckx, Sven
, p. 1 - 14 (2021)
As a major group of algae, diatoms are responsible for a substantial part of the primary production on the planet. Pennate diatoms have a predominantly benthic lifestyle and are the most species-rich diatom group, with members of the raphid clades being motile and generally having heterothallic sexual reproduction. It was recently shown that the model species Seminavis robusta uses multiple sexual cues during mating, including cyclo(L-Pro-L-Pro) as an attraction pheromone. Elaboration of the pheromone-detection system is a key aspect in elucidating pennate diatom life-cycle regulation that could yield novel fundamental insights into diatom speciation. This study reports the synthesis and bio-evaluation of seven novel pheromone analogs containing small structural alterations to the cyclo(L-Pro-L-Pro) pheromone. Toxicity, attraction, and interference assays were applied to assess their potential activity as a pheromone. Most of our analogs show a moderate-to-good bioactivity and low-to-no phytotoxicity. The pheromone activity of azide-and diazirine-containing analogs was unaffected and induced a similar mating behavior as the natural pheromone. These results demonstrate that the introduction of confined structural modifications can be used to develop a chemical probe based on the diazirine-and/or azide-containing analogs to study the pheromone-detection system of S. robusta.
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
, (2021)
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.
Cross-Linked Collagen Triple Helices by Oxime Ligation
Hentzen, Nina B.,Smeenk, Linde E. J.,Witek, Jagna,Riniker, Sereina,Wennemers, Helma
, p. 12815 - 12820 (2017)
Covalent cross-links are crucial for the folding and stability of triple-helical collagen, the most abundant protein in nature. Cross-linking is also an attractive strategy for the development of synthetic collagen-based biocompatible materials. Nature uses interchain disulfide bridges to stabilize collagen trimers. However, their implementation into synthetic collagen is difficult and requires the replacement of the canonical amino acids (4R)-hydroxyproline and proline by cysteine or homocysteine, which reduces the preorganization and thereby stability of collagen triple helices. We therefore explored alternative covalent cross-links that allow for connecting triple-helical collagen via proline residues. Here, we present collagen model peptides that are cross-linked by oxime bonds between 4-aminooxyproline (Aop) and 4-oxoacetamidoproline placed in coplanar Xaa and Yaa positions of neighboring strands. The covalently connected strands folded into hyperstable collagen triple helices (Tm 80 °C). The design of the cross-links was guided by an analysis of the conformational properties of Aop, studies on the stability and functionalization of Aop-containing collagen triple helices, and molecular dynamics simulations. The studies also show that the aminooxy group exerts a stereoelectronic effect comparable to fluorine and introduce oxime ligation as a tool for the functionalization of synthetic collagen.
Short, highly efficient syntheses of protected 3-azido- and 4-azidoproline and their precursors
Gomez-Vidal, Jose A.,Silverman, Richard B.
, p. 2481 - 2484 (2001)
matrix presented An improved synthesis of protected cis- and trans-3-azido-L-proline and cis- and frans-4-azido-L- and -D-proline is reported. These compounds have been synthesized from the corresponding hydroxyproline precursors using diphenylphosphoryl azide under Mitsunobu conditions. Short, highly efficient syntheses of these precursors are described, based on a new lactone-opening reaction and p-nitrobenzoate hydrolysis under very mild conditions.
(2 S,4 R)- and (2 S,4 S)-Perfluoro- tert -butyl 4-hydroxyproline: Two conformationally distinct proline amino acids for sensitive application in 19F NMR
Tressler, Caitlin M.,Zondlo, Neal J.
, p. 5880 - 5886 (2014)
(2S,4R)- and (2S,4S)-perfluoro-tert-butyl 4-hydroxyproline were synthesized (as Fmoc-, Boc-, and free amino acids) in 2-5 steps. The key step of each synthesis was a Mitsunobu reaction with perfluoro-tert-butanol, which incorporated a perfluoro-tert-butyl group, with nine chemically equivalent fluorines. Both amino acids were incorporated in model α-helical and polyproline helix peptides. Each amino acid exhibited distinct conformational preferences, with (2S,4R)-perfluoro-tert-butyl 4-hydroxyproline promoting polyproline helix. Peptides containing these amino acids were sensitively detected by 19F NMR, suggesting their use in probes and medicinal chemistry.
Design, Synthesis, and Biochemical Evaluation of Alpha-Amanitin Derivatives Containing Analogs of the trans-Hydroxyproline Residue for Potential Use in Antibody-Drug Conjugates
Braun, Alexandra,Gallo, Francesca,Hambira, Chido M.,Hechler, Torsten,Kato, Brandon,Müller, Christoph,Matinkhoo, Kaveh,Pahl, Andreas,Perrin, David M.,Wei, Charlie,Wong, Antonio A. W. L.
, p. 10282 - 10292 (2021/06/25)
Alpha-amanitin, an extremely toxic bicyclic octapeptide extracted from the death-cap mushroom, Amanita phalloides, is a highly selective allosteric inhibitor of RNA polymerase II. Following on growing interest in using this toxin as a payload in antibody-drug conjugates, herein we report the synthesis and biochemical evaluation of several new derivatives of this toxin to probe the role of the trans-hydroxyproline (Hyp), which is known to be critical for toxicity. This structure activity relationship (SAR) study represents the first of its kind to use various Hyp-analogs to alter the conformational and H-bonding properties of Hyp in amanitin.
