- Crystal (6S,9aS)-N-benzyl-8-({6-[3-(4-ethylpiperazin-1-yl)azetidin-1-yl]pyridin-2-yl}methyl)-6-(2-fluoro-4-hydroxybenzyl)-4,7-dioxo-2-(prop-2-en-1-yl)hexahydro-2H-pyrazino[2,1-c][1,2,4]triazine-1(6H)-carboxamide
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The present invention provides a crystal of (6S,9aS)-N-benzyl-8-({6-[3-4-ethylpiperazin-1-yl)azetidin-1-yl]pyridin-2-yl} methyl)-6-(2-fluoro-4-hydroxybenzyl)-4,7-dioxo-2-(prop-2-en-1-yl)hexahydro-2H-pyrazino[2,1-c][1,2,4]triazine-1(6H)-carboxamide.
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- Improved synthetic routes to the selenocysteine derivatives useful for Boc-based peptide synthesis with benzylic protection on the selenium atom
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Selenocysteine (Sec) derivatives, i.e., Boc-Sec(MBn)-OH (1) and Boc-Sec(MPM)-OH (2), which are useful for chemical synthesis of selenopeptides, were obtained from L-serine in five steps with total yields of 73% and 74%, respectively. The enantiomeric excesses were confirmed to be >99% e.e. by optical resolution using a chiral column on HPLC. On the other hand, for the case of a Fmoc-protected Sec derivative, i.e., Fmoc-Sec(MPM)-OH, similar reactions resulted in low yields and partial racemization taking place. [PRESENTED EQUATION]
- Shimodaira, Shingo,Iwaoka, Michio
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p. 260 - 271
(2017/03/09)
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- (6S,9aS)-N-Benzyl-6-[(4-hydroxyphenyl)methyl]-4,7-dioxo-8-(methyl)-2-(prop-2-en-1-yl)-octahydro-1H-pyrazino[2,1-c][1,2,4]triazine-1-carboxamide compound
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A compound represented by formula (1) or pharmaceutically acceptable salt thereof: wherein R1 is a C1-6 alkyl group; R2 and R3 are the same or different from each other and each is a hydrogen atom or a C1-6 alkyl group; X2, X3 and X4 are the same or different from each other and each is a hydrogen atom or a halogen atom; and X5 is a hydrogen atom or —P(═O)(OH)2 has a Wnt Pathway modulating activity.
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- Strain-Promoted Reaction of 1,2,4-Triazines with Bicyclononynes
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Strain-promoted inverse electron-demand Diels-Alder cycloaddition (SPIEDAC) reactions between 1,2,4,5-tetrazines and strained dienophiles, such as bicyclononynes, are among the fastest bioorthogonal reactions. However, the synthesis of 1,2,4,5-tetrazines is complex and can involve volatile reagents. 1,2,4-Triazines also undergo cycloaddition reactions with acyclic and unstrained dienophiles at elevated temperatures, but their reaction with strained alkynes has not been described. We postulated that 1,2,4-triazines would react with strained alkynes at low temperatures and therefore provide an alternative to the tetrazine cycloaddition reaction for use in in vitro or in vivo labelling experiments. We describe the synthesis of a 1,2,4-triazin-3-ylalanine derivative fully compatible with the fluorenylmethyloxycarbonyl (Fmoc) strategy for peptide synthesis and demonstrate its reaction with strained bicyclononynes at 37°C with rates comparable to the reaction of azides with the same substrates. The synthetic route to triazinylalanine is readily adaptable to late-stage functionalization of other probe molecules, and the 1,2,4-triazine-SPIEDAC therefore has potential as an alternative to tetrazine cycloaddition for applications in cellular and biochemical studies.
- Horner, Katherine A.,Valette, Nathalie M.,Webb, Michael E.
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p. 14376 - 14381
(2015/10/05)
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- The use of 2,2′-dithiobis(5-nitropyridine) (DTNP) for deprotection and diselenide formation in protected selenocysteine-containing peptides
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In contrast to the large number of sidechain protecting groups available for cysteine derivatives in solid phase peptide synthesis, there is a striking paucity of analogous selenocysteine Se-protecting groups in the literature. However, the growing interest in selenocysteine-containing peptides and proteins requires a corresponding increase in availability of synthetic routes into these target molecules. It therefore becomes important to design new sidechain protection strategies for selenocysteine as well as multiple and novel deprotection chemistry for their removal. In this paper, we outline the synthesis of two new Fmoc selenocysteine derivatives [Fmoc-Sec(Meb) and Fmoc-Sec(Bzl)] to accompany the commercially available Fmoc-Sec(Mob) derivative and incorporate them into two model peptides. Sec-deprotection assays were carried out on these peptides using 2,2′-dithiobis(5-nitropyridine) (DTNP) conditions previously described by our group. The deprotective methodology was further evaluated as to its suitability towards mediating concurrent diselenide formation in oxytocin-templated target peptides. Sec(Mob) and Sec(Meb) were found to be extremely labile to the DTNP conditions whether in the presence or absence of thioanisole, whereas Sec(Bzl) was robust to DTNP in the absence of thioanisole but quite labile in its presence. In multiple Sec-containing model peptides, it was shown that bis-Sec(Mob)-containing systems spontaneously cyclize to the diselenide using 1eq DTNP, whereas bis-Sec(Meb) and Sec(Bzl) models required additional manipulation to induce cyclization.
- Schroll, Alayne L.,Hondal, Robert J.,Flemer, Stevenson
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p. 155 - 162
(2012/05/20)
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- Coupled conformational equilibria in β-sheet peptide-dendron conjugates
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A series of peptide-dendron conjugates, based on an intrinsically α-helical, alanine-rich sequence, were constructed to explore how the conformational equilibria of each structural element can be conformationally coupled. The interdendron spacing was vari
- Shao, Hui,Lockman, Jeffrey W.,Parquette, Jon R.
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p. 1884 - 1885
(2007/10/03)
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- Preparation of enantiomerically pure pyridyl amino acids from serine.
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A range of substituted pyridyl amino acids have been prepared by palladium catalysed cross-coupling of serine-derived organozinc reagents with differently substituted halopyridines. Following this procedure a DMAP analogue has been synthesised and used as
- Tabanella, Stefania,Valancogne, Ingrid,Jackson, Richard F W
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p. 4254 - 4261
(2007/10/03)
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- Enantioselective synthesis of N-Boc and N-Fmoc protected diethyl 4-phosphono(difluoromethyl)-L-phenylalanine; agents suitable for the solid-phase synthesis of peptides containing nonhydrolyzable analogues of O-phosphotyrosine
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Enantioselective convergent syntheses of N-Boc and N-Fmoc protected diethyl 4-phosphono(difluoromethyl)-L-phenylalanine are reported.
- Smyth,Burke Jr.
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p. 551 - 554
(2007/10/02)
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