- Synthesis and biological evaluation of a novel series of curcumin-peptide derivatives as PepT1-mediated transport drugs
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Curcumin (CUR) is a natural yellow pigment from turmeric with extensive bioactivities. However its relatively poor solubility limited its absorption and bioavailability. In this study, a novel series of CUR-peptide conjugates were designed and synthesized
- Zhang, Jiyun,Wen, Hongmei,Shen, Fei,Wang, Xinzhi,Shan, Chenxiao,Chai, Chuan,Liu, Jian,Li, Wei
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- Liquid Phase Peptide Synthesis via One-Pot Nanostar Sieving (PEPSTAR)
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Herein, a one-pot liquid phase peptide synthesis featuring iterative addition of amino acids to a “nanostar” support, with organic solvent nanofiltration (OSN) for isolation of the growing peptide after each synthesis cycle is reported. A cycle consists of coupling, Fmoc removal, then sieving out of the reaction by-products via nanofiltration in a reactor-separator, or synthesizer apparatus where no phase or material transfers are required between cycles. The three-armed and monodisperse nanostar facilitates both efficient nanofiltration and real-time reaction monitoring of each process cycle. This enabled the synthesis of peptides more efficiently while retaining the full benefits of liquid phase synthesis. PEPSTAR was validated initially with the synthesis of enkephalin-like model penta- and decapeptides, then octreotate amide and finally octreotate. The crude purities compared favorably to vendor produced samples from solid phase synthesis.
- Yeo, Jet,Peeva, Ludmila,Chung, Seoyeon,Gaffney, Piers,Kim, Daeok,Luciani, Carla,Tsukanov, Sergey,Seibert, Kevin,Kopach, Michael,Albericio, Fernando,Livingston, Andrew
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p. 7786 - 7795
(2021/03/01)
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- Bispidine as a helix inducing scaffold: Examples of helically folded linear peptides
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We designed and synthesized bispidine-anchored peptides and showed that these peptides as small as B3 (containing four chiral α-amino acid residues) adopt a right handed helical conformation. Bispidine anchored linear peptide B3 adopts a helical conformat
- Haridas,Sadanandan, Sandhya,Gopalakrishna,Bijesh,Verma, Ram. P.,Chinthalapalli, Srinivas,Shandilya, Ashutosh
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p. 10980 - 10982
(2013/11/19)
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- Antioxidant activity of peptide-based angiotensin converting enzyme inhibitors
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Angiotensin converting enzyme (ACE) inhibitors are important for the treatment of hypertension as they can decrease the formation of vasopressor hormone angiotensin II (Ang II) and elevate the levels of vasodilating hormone bradykinin. It is observed that bradykinin contains a Ser-Pro-Phe motif near the site of hydrolysis. The selenium analogues of captopril represent a novel class of ACE inhibitors as they also exhibit significant antioxidant activity. In this study, several di- and tripeptides containing selenocysteine and cysteine residues at the N-terminal were synthesized. Hydrolysis of angiotensin I (Ang I) to Ang II by ACE was studied in the presence of these peptides. It is observed that the introduction of l-Phe to Sec-Pro and Cys-Pro peptides significantly increases the ACE inhibitory activity. On the other hand, the introduction of l-Val or l-Ala decreases the inhibitory potency of the parent compounds. The presence of an l-Pro moiety in captopril analogues appears to be important for ACE inhibition as the replacement of l-Pro by l-piperidine 2-carboxylic acid decreases the ACE inhibition. The synthetic peptides were also tested for their ability to scavenge peroxynitrite (PN) and to exhibit glutathione peroxidase (GPx)-like activity. All the selenium-containing peptides exhibited good PN-scavenging and GPx activities. The Royal Society of Chemistry 2012.
- Bhuyan, Bhaskar J.,Mugesh, Govindasamy
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p. 2237 - 2247
(2012/04/10)
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- A novel L-amino acid ligase from bacillus subtilis NBRC3134 catalyzed oligopeptide synthesis
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L-Amino acid ligase catalyzes dipeptide synthesis from unprotected L-amino acids in an ATP-dependent manner. We have purified a new L-amino acid ligase, RizA, which synthesizes dipeptides whose N-terminus is Arg, from Bacillus subtilis NBRC3134, a microorganism that produces a rhizocticin peptide antibiotic. It was suggested that RizA is probably involved in rhizocticin biosynthesis. In this study, we performed sequence analysis of unknown regions around rizA, and newly identified a gene that encodes a protein that possesses an ATP-grasp motif upstream of rizA. This gene was designated rizB, and its recombinant protein was prepared. Recombinant RizB synthesized homo-oligo-mers of branched-chain L-amino acids and L-methionine consisting of two to five amino acids in an ATP-dependent manner. RizB also synthesized various heteropeptides. Further examination showed that RizB might elongate a peptide chain at the N-terminus. This is the first report on an L-amino acid ligase catalyzing oligopeptide synthesis.
- Kino, Kuniki,Arai, Toshinobu,Tateiwa, Daisuke
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experimental part
p. 129 - 134
(2010/04/24)
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- Synthesis of second-generation Sansalvamide A derivatives: Novel templates as potential antitumor agents
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We report the synthesis of 34 second-generation Sansalvamide A derivatives. San A derivatives have unique anticancer properties and target multiple cancers, including colon, pancreatic, breast, prostate, and melanoma. As novel templates, the derivatives d
- Rodriguez, Rodrigo A.,Pan, Po-Shen,Pan, Chung-Mao,Ravula, Suchitra,Lapera, Stephanie,Singh, Erinprit K.,Styers, Thomas J.,Brown, Joseph D.,Cajica, Julia,Parry, Emily,Otrubova, Katerina,McAlpine, Shelli R.
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p. 1980 - 2002
(2007/10/03)
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- Synthesis of Sansalvamide A derivatives and their cytotoxicity in the MSS colon cancer cell line HT-29
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We report the synthesis of thirty-six Sansalvamide A derivatives, and their biological activity against colon cancer HT-29 cell line, a microsatellite stable (MSS) colon cancer cell-line. The thirty-six compounds can be divided into three subsets, where t
- Styers, Thomas J.,Kekec, Ahmet,Rodriguez, Rodrigo,Brown, Joseph D.,Cajica, Julia,Pan, Po-Shen,Parry, Emily,Carroll, Chris L.,Medina, Irene,Corral, Ricardo,Lapera, Stephanie,Otrubova, Katerina,Pan, Chung-Mao,McGuire, Kathleen L.,McAlpine, Shelli R.
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p. 5625 - 5631
(2007/10/03)
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- Structures, sensory activity, and dose/response functions of 2,5-diketopiperazines in roasted cocoa nibs (Theobroma cacao)
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The taste compounds inducing the blood-like, metallic bitter taste sensation reported recently for a dichloromethane extract prepared from roasted cocoa nibs were identified as a series of 25 diketopiperazines by means of HPLC degustation, LC-MS/MS, and i
- Stark, Timo,Hofmann, Thomas
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p. 7222 - 7231
(2007/10/03)
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- β-sheet ligands in action: KLVFF recognition by aminopyrazole hybrid receptors in water
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Little is known about the precise mechanism of action of β-sheet ligands, hampered by the notorious solubility problems involved with protein misfolding and amyloid formation. Recently the nucleation site for the pathogenic aggregation of the Alzheimer's
- Rzepecki, Petra,Schrader, Thomas
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p. 3016 - 3025
(2007/10/03)
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- Application of nim-2,6-dimethoxybenzoyl histidine in solid-phase peptide synthesis
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Fmoc-histidine derivatives protected with 2,6-dimethoxybenzoyl (2,6-Dmbz) units, either on the τ- (1) or on the π-position (2) of the imidazole residue, have been prepared and applied to the synthesis of the dipeptide Fmoc-His(2,6-Dmbz)-Val-OMe, with high coupling efficiencies (99 and 95%, respectively) and low racemization (0.3 and 0.1%, respectively), as ascertained by HPLC analysis on the fully protected dipeptides. In addition, the hexapeptide H-Ala-Ser-Val-His-Val-Phe-OH (I) has been synthesized on a solid support employing the novel building blocks 1 and 2 as well as commercially available Fmoc-His(t-Trt)-OH (3). The crude deprotected products were analyzed by reverse-phase HPLC and mass spectrometry, which indicated that when the τ-protected derivatives 1 and 3 were employed the products were of comparable quality (93-94% major peak). The hexapeptide synthesized with the π-protected histidine 2 was contaminated with a product corresponding to 2,6-Dmbz-His-Val-Phe-OH (12), which was probably formed through the intramolecular acyl transfer of a 2,6-Dmbz unit from the π-nitrogen atom to the α-amino group of the N-terminal histidine unit upon removal of the Fmoc group. This side reaction was insignificant (less than 0.5%) when using the τ-protected derivative 1. ( Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003).
- Zaramella, Simone,Stroemberg, Roger,Yeheskiely, Esther
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p. 2454 - 2461
(2007/10/03)
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- Synthesis and properties of N-substituted saccharin derivatives
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Four different routes for the synthesis of saccharin containing peptids were studied. While reactions between saccharin sodium and α-halogeno acids were limited to two examples, reactions of sulfobenzoic anhydride (4) or saccharin-N-carboxylate (6) with amino acid esters yielded the ring opened products 5 and 7. Finally, we found, that the reaction between the benzoxathiol derivative 8 and amino acid derivatives represents a versatile route to the peptidic compounds 9 and 11. Hydrolysis and hydrogenolysis were studied, and by combination of the different routes the "saccharin tripeptides" 18 were obtained. Structures and stereochemistry were elucidated by spectroscopic and chromatographic methods. Selected compounds were tested as sweeteners of as inhibitors of elastase, but no exiting results were found.
- Soubh,Besch,Otto, Hans-Hartwig
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p. 384 - 392
(2007/10/03)
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- PhFl polystyrene: A new resin for solid phase organic synthesis
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A 9-phenylfluoren-9-yl polystyrene based resin is described for the attachment of nitrogen and oxygen nucleophiles. Higher acid stability compared to standard trityl resins makes this solid support an interesting alternative in solid phase organic synthes
- Bleicher, Konrad H.,Wareing, James R.
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p. 4587 - 4590
(2007/10/03)
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- Retroviral protease inhibitors
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Compounds of the formula I: STR1 wherein X, Y, Z, a, b, c, R1, R2, R3, R4 and R5 are defined in the specification are provided. The compounds are useful as inhibitors of retroviral protease enzymes.
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- Peptide-titanium complex as catalyst for asymmetric addition of hydrogen cyanide to aldehyde
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The complex of titanium ethoxide and an acyclic dipeptide ester whose terminal amino group is modified to a salicylal-type Schiff base catalyzes the asymmetric addition of hydrogen cyanide to aldehydes with high enantioselectivity. In the reaction of benzaldehyde and hydrogen cyanide, (R)-mandelonitrile is obtained with an enantiomeric excess of 90% when N-((2-hydroxy-1-naphthyl)methylene)-(S)-valyl-(S)-tryptophan methyl ester is employed. In place of the dipeptide, the amide derivatives of an amino acid modified by substituted salicylaldehyde, such as N-(3,5-dibromosalicylidene)-(S)-valine piperidide, exhibit an entirely opposite stereoselectivity to yield S-cyanohydrins with optical purities up to 97% ee. This novel peptide-titanium complex, therefore, enables us to afford optically active cyanohydrins of both absolute configurations by using natural S-amino acids as chiral auxiliaries.
- Nitta, Hideaki,Yu, Donghai,Kudo, Masanobu,Mori, Atsunori,Inoue, Shohei
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p. 7969 - 7975
(2007/10/02)
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- A Peptide-Aluminum Complex as a Novel Chiral Lewis Acid. Asymmetric Addition of Cyanotrimethylsilane to Aldehydes
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The enantioselective addition of cyanotrimethylsilane (TMSCN) to aldehydes promoted by the addition of a stoichiometric or catalytic amount of organoaluminum complexes of dipeptide esters or α-amino acid amides whose amino terminals are modified by a vari
- Ohno, Hiroshi,Nitta, Hideaki,Tanaka, Kenzo,Mori, Atsunori,Inoue, Shohei
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p. 6778 - 6783
(2007/10/02)
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- Peptide-metal complex as an asymmetric catalyst. A catalytic enantioselective cyanohydrin synthesis
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An acyclic dipeptide ester, 2-hydroxy-1-naphthylideneimino-(S)-valyl-(S)-tryptophane methyl ester (1a: Nap-S-Val-S-Trp-OMe), whose terminal amino group is modified to a Schiff base, is designed as a chiral auxiliary of an asymmetric catalyst. The mixture of 1 with titanium alkoxide catalyzes enantioselective hydrocyanation of benzaldehyde to afford optically active (R)-mandelonitrile with stereoselectivities up to 96:6.
- Mori,Nitta,Kudo,Inoue
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p. 4333 - 4336
(2007/10/02)
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- SYNTHESES OF CYCLOTETRAPEPTIDES, AM-TOXIN ANALOGS, CONTAINING α-HYDROXYALANINE
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Condensation of amide with α-keto acid to yield a α-hydroxyalanine (α-Hyala) or dehydroalanine residue was applied to syntheses of analogs of AM-toxins, cyclotetradepsipeptides.Cyclo(α-Hyala-L-Ala-L-Val-L-Phe-), cyclo(-α-Hyala-L-Ala-L-Hmb-L-Phe-) and cycl
- Shimohigashi, Yasuyuki,Izumiya, Nobuo
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p. 763 - 766
(2007/10/02)
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