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1.
Summary Synthetic protocols are presented both for D-PheSar and the corresponding cyclised diketopiperazine, prepared from N-t-butoxycarbonylprotected D-PheSar. Deprotection conditions could be manipulated to yield either D-Phenylalanylsarcosine or (R)-1-methyl-3-(phenylmethyl)-2,5-piperazinedione. Molecular modelling revealed several low energy conformers which contained a Z-peptide bond and which were readily amenable to cyclisation. Cyclisation was found by HPLC to be fastest in strongly acidic conditions.Abbreviation HBTU
o-Benzotriazolyl-tetramethyluronium hexafluorophosphate 相似文献
2.
Two diketopiperazine derivatives, altenarizines A (1) and B (2), and a new glucosyl sesterterpene, 24-α-d-glucosyl-(−)-terpestacin (3), together with two known phytotoxic sesterterpenes, (−)-terpestacin (4) and fusaproliferin (5), were isolated from the fermentation broth of an endophytic fungus Alternaria alternata, which was obtained from the fresh root of Ceratostigma griffithii. Structures of all the isolates were identified by spectroscopic data. 相似文献
3.
Yamazaki Y Kido Y Hidaka K Yasui H Kiso Y Yakushiji F Hayashi Y 《Bioorganic & medicinal chemistry》2011,19(1):595-602
A new bioactive photoaffinity probe KPU-252-B1 (4) possessing a biotin tag on the oxazole ring of a potent plinabulin derivative KPU-244 (2) was synthesized via the CuI-catalyzed Huisgen’s cycloaddition reaction to understand the precise binding mode of the diketopiperazine-based anti-microtubule agent plinabulin on tubulin. Probe 4 showed significant binding affinity toward tubulin and cytotoxicity against an HT-29 cells. A photoaffinity labeling study suggested that probe 4 specifically recognizes tubulin at a binding site that binds plinabulin or colchicine, most likely near or at the colchicine binding site, which is located at the interfacial region formed by ??-and ??-tubulin association. The results also demonstrated that probe 4 may serve as a useful plinabulin chemical probe to investigate the molecular mechanism by which anti-microtubule diketopiperazine derivatives operate. 相似文献
4.
To create structural diversity of prenylated diketopiperazine derivatives, acceptance of cyclic dipeptides was tested using
FgaPT2, a prenyltransferase from Aspergillus fumigatus, which catalyses the conversion of l-tryptophan to 4-dimethylallyl-l-tryptophan. It could be shown that seven tryptophan-containing cyclic dipeptides were accepted by FgaPT2 at high protein
concentrations and regiospecifically converted to their C4 prenylated derivatives. The structures of the enzymatic products
were elucidated by NMR and LC-MS analyses. This substrate promiscuity of a dimethylallyltryptophan synthase towards cyclic
dipeptides increases the potential of the fungal indole prenyltransferases as tools for the production of biologically active
compounds.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
5.
Prospecting Anticancer Compounds in Actinomycetes Recovered from the Sediments of Saint Peter and Saint Paul's Archipelago,Brazil
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Elthon G. Ferreira Maria da Conceição M. Torres Alison B. da Silva Larissa L. F. Colares Karine Pires Tito M. C. Lotufo Edilberto R. Silveira Otília D. L. Pessoa Leticia V. Costa‐Lotufo Paula C. Jimenez 《化学与生物多样性》2016,13(9):1149-1157
Saint Peter and Saint Paul's Archipelago is a collection of 15 islets and rocks remotely located in the equatorial Atlantic Ocean. In this particular site, the present project intended to assess the biodiversity and biotechnological potential of bacteria from the actinomycete group. This study presents the first results of this assessment. From 21 sediment samples, 268 strains were isolated and codified as BRA followed by three numbers. Of those, 94 strains were grown in liquid media and submitted to chemical extractions with AcOEt (A), BuOH (B), and MeOH (M). A total of 224 extracts were screened for their cytotoxic activity and 41 were significantly active against HCT‐116 cancer cells. The obtained IC50 values ranged from 0.04 to 31.55 μg/ml. The HR‐LC/MS dereplication analysis of the active extracts showed the occurrence of several known anticancer compounds. Individual compounds, identified using HR‐MS combined with analysis of the AntiMarin database, included saliniketals A and B, piericidins A and C and glucopiericidin A, staurosporine, N‐methylstaurosporine, hydroxydimethyl‐staurosporine and N‐carbamoylstaurosporine, salinisporamycin A, and rifamycins S and B. BRA‐199, identified as Streptomyces sp., was submitted to bioassay‐guided fractionation, leading to isolation of the bioactive piericidins A and C, glucopiericidin, and three known diketopiperazines, cyclo(l ‐Phe‐trans‐4‐OH‐l ‐Pro), cyclo(l ‐Phe‐l ‐Pro), and cyclo(l ‐Trp‐l ‐Pro). 相似文献
6.
《Nucleosides, nucleotides & nucleic acids》2013,32(12):1815-1824
Different arabinosides and ribosides, viz. Ara‐DDA or 9(1‐β‐d‐arabinofuranosyl) 1,3‐dideazaadenine (6), Ara‐NDDP or 9(1‐β‐d‐arabinofuranosyl) 4‐nitro‐1,3‐dideazapurine (7), Ara‐DKP or 1(1‐β‐d‐arabinofuranosyl) diketopiperazine (8), Ribo‐DDA or 9(1‐β‐d‐ribofuranosyl) 1,3‐dideazaadenine (9) and Ribo‐NDDP or 9(1‐β‐d‐ribofuranosyl) 4‐nitro‐1,3‐dideazapurine (10) have been synthesized as probable antiviral agents. The arabinosides have been synthesized using the catalyst TDA‐1 that causes stereospecific formation of β‐nucleosides while a one‐pot synthesis procedure was adopted for the synthesis of the ribonucleosides where β‐anomers were obtained in higher yields. All the five nucleoside analogs have been screened for antiviral property against HIV‐1 (IIIB), HSV‐1 and 2, parainfluenza‐3, reovirus‐1 and many others. It was observed that arabinosides had greater inhibitory action than ribosides. The compound 7 or Ara‐NDDP has shown maximum inhibition of HIV‐1 replication than the rest of the molecules with an IC50 of 79.4 µg/mL. 相似文献
7.
We report the preparation of novel building units for backbone cyclization that have the general formula Fmoc-N[CH(R)CO2Al]Gly-OH. These building units were prepared by the reductive alkylation method using allyl esters of several amino acids as starting material and hence, respectively, contain the side chain of these amino acids. These N-alkylated Gly building units were incorporated in model backbone cyclic peptides. The resulting crude backbone cyclic peptides were obtained in high degree of purity according to HPLC and mass spectrometric analyses. 相似文献
8.
Arnab De Richard D. DiMarchi 《International journal of peptide research and therapeutics》2008,14(3):255-262
Two different chemical classes of putative amide-based prodrugs of glucagon-like peptide-1 (GLP), one with an amino and the
other with α hydroxyl terminal extension have been synthesized and biochemically characterized. The conversion of these terminally-extended
peptide hormone analogs to a peptide of much enhanced potency through cyclization of the terminal dipeptide was studied under
physiological conditions. The peptides studied demonstrated great stability and little propensity to cyclize to DKP and DMP
under physiological conditions. These results stand in contrast to previous reports with model amide-based peptides and indicate
that such cleavage is unlikely in larger peptides constituted by naturally coded amino acids.
An erratum to this article can be found at 相似文献
9.
Hongjin Bai Pengcheng Cui Chuanli Zang Shengkun Li 《Bioorganic & medicinal chemistry letters》2019,29(23):126718
The first enantioselective total synthesis of the antifungal natural product (indole-N-isoprenyl)-tryptophan-valine diketopiperazine 5 was accomplished. Four stereoisomers of 5 were intentionally prepared, and the (R, R)-isomer is more favorable in enhancing the antifungal bioactivity. Divergent structural optimization of this attractive model was conducted from the chiral pool amino acids. Fine-tuning of the structure protruded the broad-spectrum antifungal 6b, which also showed good preventative efficacy against Sclerotinia scleotiorum. Compound 5d could accelerate both hypocotyl elongation and root growth of Eclipta prostrata even at the concentration of <2.5 ppm. This unique and easily accessible scaffold will be of prime importance in achieving agrochemical candidates with the novel scaffold. 相似文献
10.
Summary 3(2)-O-glycyl-adenosine-5-monophosphate is an intermediate in the conversion of N-[imidazolyl-(1)-carbonyl]-glycine to diketopiperazine in the presence of adenosine-5-monophosphate. The significance of these observations to prebiotic chemistry is discussed.Abbreviations AMP
adenosine-5-monophosphate
- A
adenosine 相似文献