Results 171 to 180 of about 5,247 (209)
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Tyrosine-based photoluminescent diketopiperazine supramolecular aggregates
Soft Matter, 2022A solution of l-tyrosine diketopiperazine in tetrahydrofuran turned into gel state based on intermolecular hydrogen bonding, resulting in π-orbital overlap of the terminal phenyl groups leading to photoluminescence.
Noritaka Shimosaraya +8 more
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2,5-Diketopiperazines as Neuroprotective Agents
Mini-Reviews in Medicinal Chemistry, 20122,5-diketopiperazines are the simplest cyclic peptides found in nature, commonly biosynthesized from amino acids by different organisms, and represent a promising class of biologically active natural products. Their peculiar heterocyclic structure confers high stability against the proteolysis and constitutes a structural requirement for the active ...
CORNACCHIA, CATIA +5 more
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Journal of Wine Research, 2018
ABSTRACTThis study describes the identification of cyclic dipeptides known as diketopiperazines in red, white and sparkling wines from Greek market. Diketopiperazines have been isolated from bottled wines after liquid–liquid extraction and identified using gas chromatography coupled with mass spectrometry.
Eygenia Stamatelopoulou +6 more
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ABSTRACTThis study describes the identification of cyclic dipeptides known as diketopiperazines in red, white and sparkling wines from Greek market. Diketopiperazines have been isolated from bottled wines after liquid–liquid extraction and identified using gas chromatography coupled with mass spectrometry.
Eygenia Stamatelopoulou +6 more
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International Journal of Peptide and Protein Research, 1985
As shown by the values of dCα (0.487 and 0.442 ÅA) and by the β angle of folding (41°), N‐(pyruvoyl)‐cyclo(‐L‐Phe‐D‐Pro‐) (I) in the crystals adopts a boat conformation whose high degree of buckling approaches the values found in proline containing homochiral diketopiperazines. Only one peptide bond is slightly non planar with ω2= ‐4.7°.
null ANNACALCAGNI +4 more
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As shown by the values of dCα (0.487 and 0.442 ÅA) and by the β angle of folding (41°), N‐(pyruvoyl)‐cyclo(‐L‐Phe‐D‐Pro‐) (I) in the crystals adopts a boat conformation whose high degree of buckling approaches the values found in proline containing homochiral diketopiperazines. Only one peptide bond is slightly non planar with ω2= ‐4.7°.
null ANNACALCAGNI +4 more
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Diastereoselective Spirocyclization: Entry to Spirocyclic Diketopiperazines
Organic Letters, 2023We report a novel approach to access spirocyclic compounds containing a diketopiperazine (DKP) motif fused on a pyrrolidine ring. The shared spirocyclic carbon is at the ketone oxidation state, bearing two carbon-nitrogen bonds, one of which is introduced stereoselectively during the cyclization event.
Hadi Gholami, Brandon M. Cornali
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Microbial hydrolysis of diketopiperazines: Different types of diketopiperazine-assimilating bacteria
Journal of Fermentation and Bioengineering, 1997Abstract Arthrobacter sp. 1-3-1 and a coryneform rod bacterium, strain T-1-3-Y, which assimilate cyclo(Gly-Gly) and cyclo(Gly- l -Tyr) at high rates, respectively, were isolated from soil. Both bacteria exhibit diketopiperazine-hydrolyzing activity intracellularly in contrast to the extracellular cyclo(Gly-Gly) hydrolase reported previously ...
Hiroshi Kanzaki +3 more
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Diketopiperazines: Biological Activity and Synthesis
ChemInform, 2007AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Maristela B. Martins, Ivone Carvalho
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Proline-based diketopiperazine-scaffolds
2009Introduction Proline-based diketopiperazine structures for the core of several interesting natural product classes such as marcfortines, paraherquamides, brevianamides and tryprostatines which show promising activities as potent cytotoxic compounds and have a known specifity for certain cancer cell lines.
Nina, Deppermann, Wolfgang, Maison
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Asymmetric hydrogenations of diketopiperazines
Topics in Catalysis, 2000The dehydrodiketopiperazines 6 undergo face selective hydrogenation with a 5% palladium on carbon catalyst to give the diketopiperazines 7 in high yield with excellent diastereoisomeric ratios (>97%).
Peter Leeming +3 more
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Die Makromolekulare Chemie, 1971
AbstractThe synthesis and characterization of new polymers is reported. These polymers were prepared by reaction of 3.6‐bifunctional 2.5‐diketopiperazines with aliphatic and aromatic diisocyanates. Using D‐3.6‐bis(aminoxymethyl)‐2.5‐diketopiperazine optically active polymers have been obtained.
V. Crescenzi +5 more
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AbstractThe synthesis and characterization of new polymers is reported. These polymers were prepared by reaction of 3.6‐bifunctional 2.5‐diketopiperazines with aliphatic and aromatic diisocyanates. Using D‐3.6‐bis(aminoxymethyl)‐2.5‐diketopiperazine optically active polymers have been obtained.
V. Crescenzi +5 more
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