Epigenetic profiling of the antitumor natural product psammaplin A and its analogues
摘要:
A collection of analogues of the dimeric natural product psammaplin A that differ in the substitution on the ( halo) tyrosine aryl ring, the oxime and the diamine connection has been synthesized. The effects on cell cycle, induction of differentiation and apoptosis of the natural-product inspired series were measured on the human leukaemia U937 cell line. Epigenetic profiling included induction of p21(WAF1), effects on global H3 histone and tubulin acetylation levels as well as in vitro enzymatic assays using HDAC1, DNMT1, DNMT3A, SIRT1 and a peptide domain with p300/CBP HAT activity. Whereas the derivatives of psammaplin A with modifications in the length of the connecting chain, the oxime bond and the disulfide unit showed lower potency, the analogues with changes on the bromotyrosine ring exhibited activities comparable to those of the parent compound in the inhibition of HDAC1 and in the induction of apoptosis. The lack of HDAC1 activity of analogues modified on the disulfide bond suggests that its cleavage must occur in cells to produce the monomeric Zn2+-chelating thiol. This assumption is consistent with the molecular modelling of the complex of psammaplin A thiol with h-HDAC8. Only a weak inhibition of DNMT1, DNMT3A and residual activities with SIRT1 and a p300/CBP HAT peptide were measured for these compounds. (C) 2010 Elsevier Ltd. All rights reserved.
Epigenetic profiling of the antitumor natural product psammaplin A and its analogues
摘要:
A collection of analogues of the dimeric natural product psammaplin A that differ in the substitution on the ( halo) tyrosine aryl ring, the oxime and the diamine connection has been synthesized. The effects on cell cycle, induction of differentiation and apoptosis of the natural-product inspired series were measured on the human leukaemia U937 cell line. Epigenetic profiling included induction of p21(WAF1), effects on global H3 histone and tubulin acetylation levels as well as in vitro enzymatic assays using HDAC1, DNMT1, DNMT3A, SIRT1 and a peptide domain with p300/CBP HAT activity. Whereas the derivatives of psammaplin A with modifications in the length of the connecting chain, the oxime bond and the disulfide unit showed lower potency, the analogues with changes on the bromotyrosine ring exhibited activities comparable to those of the parent compound in the inhibition of HDAC1 and in the induction of apoptosis. The lack of HDAC1 activity of analogues modified on the disulfide bond suggests that its cleavage must occur in cells to produce the monomeric Zn2+-chelating thiol. This assumption is consistent with the molecular modelling of the complex of psammaplin A thiol with h-HDAC8. Only a weak inhibition of DNMT1, DNMT3A and residual activities with SIRT1 and a p300/CBP HAT peptide were measured for these compounds. (C) 2010 Elsevier Ltd. All rights reserved.
A catalytic method for the formation of amide bonds was developed in which the amidation of N-hydroxyimino esters with a broad range of amino acid tert-butyl esters is promoted by a niobium catalyst in the absence of solvent. Contrary to the predominant protocol based on reagent control commonly applied to amidation reactions, this study provides insight into an approach based on substrate control
Iridium‐Catalyzed Acid‐Assisted Hydrogenation of Oximes to Hydroxylamines
作者:Josep Mas‐Roselló、Christopher J. Cope、Eric Tan、Benjamin Pinson、Alan Robinson、Tomas Smejkal、Nicolai Cramer
DOI:10.1002/anie.202103806
日期:2021.7.5
stoichiometric amounts of methanesulfonic acid and reduced at room temperature, remarkably without cleavage of the fragile N−O bond. The exquisite functional group compatibility of our hydrogenation system was further demonstrated by additive tests. Experimental mechanistic investigations support an ionic hydrogenation platform, and suggest a role for the Brønstedacid beyond a proton source. Our studies
我们发现环金属化环戊二烯基铱 (III) 配合物是将肟均相氢化成羟胺产物的独特高效催化剂。稳定的铱 C,N 螯合至关重要,烷氧基取代的芳基酮亚胺配体可提供最佳催化性能。通过 X 射线晶体分析绘制了几种 Ir 配合物,以收集空间参数,这些参数可能指导更活性催化剂的合理设计。大量的肟和肟醚被化学计量的甲磺酸活化并在室温下被还原,显着地没有断裂脆弱的 NO 键。添加剂测试进一步证明了我们加氢系统的精细官能团兼容性。实验机理研究支持离子氢化平台,并建议布朗斯台德酸在质子源之外的作用。我们的研究提供了对这种新型酸性氢化的深入理解,并可能促进其改进和应用于其他具有挑战性的底物。
Epigenetic profiling of the antitumor natural product psammaplin A and its analogues
作者:José García、Gianluigi Franci、Raquel Pereira、Rosaria Benedetti、Angela Nebbioso、Fátima Rodríguez-Barrios、Hinrich Gronemeyer、Lucia Altucci、Angel R. de Lera
DOI:10.1016/j.bmc.2010.12.026
日期:2011.6
A collection of analogues of the dimeric natural product psammaplin A that differ in the substitution on the ( halo) tyrosine aryl ring, the oxime and the diamine connection has been synthesized. The effects on cell cycle, induction of differentiation and apoptosis of the natural-product inspired series were measured on the human leukaemia U937 cell line. Epigenetic profiling included induction of p21(WAF1), effects on global H3 histone and tubulin acetylation levels as well as in vitro enzymatic assays using HDAC1, DNMT1, DNMT3A, SIRT1 and a peptide domain with p300/CBP HAT activity. Whereas the derivatives of psammaplin A with modifications in the length of the connecting chain, the oxime bond and the disulfide unit showed lower potency, the analogues with changes on the bromotyrosine ring exhibited activities comparable to those of the parent compound in the inhibition of HDAC1 and in the induction of apoptosis. The lack of HDAC1 activity of analogues modified on the disulfide bond suggests that its cleavage must occur in cells to produce the monomeric Zn2+-chelating thiol. This assumption is consistent with the molecular modelling of the complex of psammaplin A thiol with h-HDAC8. Only a weak inhibition of DNMT1, DNMT3A and residual activities with SIRT1 and a p300/CBP HAT peptide were measured for these compounds. (C) 2010 Elsevier Ltd. All rights reserved.