- Design, synthesis and in vitro characterization of novel hybrid peptidomimetic inhibitors of STAT3 protein
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Aberrant activation of oncogenic signal transducer and activator of transcription 3 (STAT3) protein signaling pathways has been extensively implicated in human cancers. Given STAT3's prominent dysregulatory role in malignant transformation and tumorigenesis, there has been a significant effort to discover STAT3-specific inhibitors as chemical probes for defining the aberrant STAT3-mediated molecular events that support the malignant phenotype. To identify novel, STAT3-selective inhibitors suitable for interrogating STAT3 signaling in tumor cells, we explored the design of hybrid molecules by conjugating a known STAT3 inhibitory peptidomimetic, ISS610 to the high-affinity STAT3-binding peptide motif derived from the ILR/gp-130. Several hybrid molecules were examined in in vitro biophysical and biochemical studies for inhibitory potency against STAT3. Lead inhibitor 14aa was shown to strongly bind to STAT3 (KD = 900 nM), disrupt STAT3:phosphopeptide complexes (Ki = 5 μM) and suppress STAT3 activity in in vitro DNA binding activity/electrophoretic mobility shift assay (EMSA). Moreover, lead STAT3 inhibitor 14aa induced a time-dependent inhibition of constitutive STAT3 activation in v-Src transformed mouse fibroblasts (NIH3T3/v-Src), with 80% suppression of constitutively-active STAT3 at 6 h following treatment of NIH3T3/v-Src. However, STAT3 activity recovered at 24 h after treatment of cells, suggesting potential degradation of the compound. Results further showed a suppression of aberrant STAT3 activity in NIH3T3/v-Src by the treatment with compound 14aa-OH, which is the non-pTyr version of compound 14aa. The effect of compounds 14aa and 14aa-OH are accompanied by a moderate loss of cell viability.
- Shahani, Vijay M.,Yue, Peibin,Fletcher, Steven,Sharmeen, Sumaiya,Sukhai, Mahadeo A.,Luu, Diana P.,Zhang, Xiaolei,Sun, Hong,Zhao, Wei,Schimmer, Aaron D.,Turkson, James,Gunning, Patrick T.
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experimental part
p. 1823 - 1838
(2011/04/17)
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- COMPOSITIONS AND METHODS FOR CYCLOFRUCTANS AS SEPARATION AGENTS
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The present invention relates to derivatized cyclofructan compounds, compositions comprising derivatized cyclofructan compounds, and methods of using compositions comprising derivatized cyclofructan compounds for chromatographic separations of chemical species, including enantiomers. Said compositions may comprise a solid support and/or polymers comprising derivatized cyclofructan compounds.
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Page/Page column 45-49; 59
(2010/12/31)
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- A class of novel conjugates of substituted purine and Gly-AA-OBzl: Synthesis and evaluation of orally analgesic activity
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Aimed at the chemotherapy of chronic pain two kinds of analgesic pharmacophores, substituted purine and Gly-AA-OBzl, were coupled via a five-step-reaction procedure and 19 novel conjugates N-[2-chloro-9- (tetrahydropyran-2-yl)-9H-purin-6-yl]-N-cyclopropylglycylamino acid benzylesters were provided. On mouse-tail flick model their in vivo analgesic activities were assayed. The results indicate that introducing Gly-OC2H 5 into the 6-position of the substituted purine leads to ambiguous increase of the analgesic activity, while introducing Gly-AA-OBzl into this position leads to significant increase of the analgesic activity.
- Kang, Guifeng,Zhao, Ming,Zhang, Xiaoyi,Peng, Li,Li, Chunbo,Mao, Wei,Ye, Weidong,Peng, Shiqi
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supporting information; experimental part
p. 6157 - 6160
(2010/12/19)
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- A class of novel carboline intercalators: Their synthesis, in vitro anti-proliferation, in vivo anti-tumor action, and 3D QSAR analysis
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Based on DOCK scores 18 N-(3-benzyloxycarbonylcarboline-1-yl)ethylamino acid benzylesters (6a-r) were synthesized as anti-tumor agents. Their IC 50 values against five human carcinoma cell lines ranged from 11.1 μM to more than 100 μM. The in vivo assay identified five derivatives of them had no anti-tumor action, the anti-tumor activity of nine derivatives of them equaled that of cytarabine, and the anti-tumor activity of three derivatives of them was higher than that of cytarabine. The UV and fluorescence spectra, as well as the relative viscosity and melting temperature measurements of calf thymus DNA (CT DNA) with and without the representative compound suggested that DNA intercalation could be their action mechanism. The 3D QSAR analysis of N-(3-benzyloxycarbonylcarboline-1-yl)ethylamino acid benzylesters (6a-r) revealed that their in vivo anti-tumor activity significantly depends on the molecular electrostatic and steric fields of the side chain of the amino acid residue.
- Wu, Jianhui,Li, Chunyu,Zhao, Ming,Wang, Wenjing,Wang, Yuji,Peng, Shiqi
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experimental part
p. 6220 - 6229
(2010/10/04)
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- Esterification of unprotected a-Amino acids in ionic liquids as the reaction media
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Ionic liquid 1,3-dimethylimidazolium methanesulfonate was used to prepare a-amino acids benzylic esters from unprotected amino acids and benzyl chloride. Esterification of several amino acids was achieved with satisfactory yields: by-products can be removed by a simple work-up procedure to afford the pure product. The described method is simple, mild, rapid and save.
- Biondini, Daniele,Brinchi, Lucia,Germani, Raimondo,Goracci, Laura,Savelli, Gianfranco
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experimental part
p. 39 - 44
(2010/08/22)
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- Synthesis and cytotoxic activities of β-carboline amino acid ester conjugates
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β-Carboline represents a class of compounds with potent anti-tumor activity by intercalating with DNA. To further enhance the cytotoxic potency and bioavailability of β-carboline, a series of novel β-carboline amino acid ester conjugates were designed and synthesized, and the cytotoxic activities of these compounds were tested using a panel of human tumor cell lines. In addition, the membrane permeability of these compounds was evaluated in vitro using a Caco-2 cell monolayer model. The β-carboline amino acid ester conjugates demonstrated improved cytotoxic activity compared to the parental β-carbolines. In particular, the Lys/Arg conjugates were the most potent analogs with an IC50 value of 4 and 1 μM against human cervical carcinoma cells. The low interaction energy of Arg conjugate based on molecular modeling may contribute to its enhanced cytotoxicity. Taken together, this study provided new insights into structure-activity relationships in the β-carboline amino acid ester conjugates and identified the β-carboline Lys/Arg conjugates as promising lead compounds for further in vivo biological and molecular evaluation.
- Zhao, Ming,Bi, Lanrong,Wang, Wei,Wang, Chao,Baudy-Floc'h, Michele,Ju, Jingfang,Peng, Shiqi
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p. 6998 - 7010
(2007/10/03)
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- Electrochemical removal of the picolinoyl group under mild acidic conditions, application to the protection of amines in peptide synthesis
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The picolinoyl group can be used as a convenient protective group for amines in peptide chemistry. Deprotection is performed by electrochemical reduction under mild acidic conditions.
- Auzeil, Nicolas,Dutruc-Rosset, Gilles,Largeron, Martine
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p. 2283 - 2286
(2007/10/03)
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- Synthesis of phenylalanines regiospecifically labelled with deuterium in the aromatic ring
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Phenylalanines regiospecifically labelled with deuterium in the aromatic ring can be prepared through the hydrogenolysis of tyrosine tetrazolyl ethers using D2 gas and a medium pressure catalytic hydrogenator.
- Nishiyama,Oba,Ueno,Morita,Nakamura,Kainosho
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p. 831 - 837
(2007/10/02)
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- Tumor-resolving and histolytic medicaments and their use
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Dehydrooligopeptides, some of which are known, demonstrate histolytic and tumor-resolving activity and may be used in medicaments causing the lysis of animal tissues and/or tumors in warm-blooded animals.
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