A Novel Versatile Phosphoramidite Building Block for the Synthesis of 5'- and 3'-Hydrazide Modified Oligonucleotides
摘要:
We introduce a novel versatile phosphoramidite building block for the modification of oligonucleotides (ONs) with acyl hydrazides on the 5'- or 3'-terminus, or both. The reaction of these hydrazide functionalized ONs with 4-methoxyphenylaldehyde is demonstrated for solution derivatization. Hydrazides are considered nowadays as promising reactants, which show enhanced reactivity at neutral and slightly acidic conditions and higher stability of yielding products as compared to the aliphatic amines, which are broadly used for ONs derivatization.Our method to introduce hydrazides into ONs employs a phosphoramidite modifier designed to split, during ammonia or lithium hydroxide treatment, into two hydrazides via beta-elimination of a central bis-2-carbonylethoxysulfone unit. It allows the creation of ONs derivatized with a hydrazide moiety at the 5'-, 3'- and both 5- and 3'-termini, as well as two different hydrazide containing ONs at the same time, viz. in one sequence on the same solid support. In latter case one can, for example, synthesize two hydrazide containing ONs, where one is 5'-modified and second one is 3'-modified.
In order to systematically explore and understand the structure–activity relationship (SAR) of a lesinurad-based hit (1c) derived from the replacement of the S atom in lesinurad with CH2, 18 compounds (1a–1r) were designed, synthesized and subjected to in vitro URAT1 inhibitory assay. The SAR exploration led to the discovery of a highly potent flexible URAT1 inhibitor, 1q, which was 31-fold more potent than parent lesinurad (IC50 = 0.23 μM against human URAT1 for 1q vs 7.18 μM for lesinurad). The present study discovered a flexible molecular scaffold, as represented by 1q, which might serve as a promising prototype scaffold for further development of potent URAT1 inhibitors, and also demonstrated that the S atom in lesinurad was not indispensable for its URAT1 inhibitory activity.
Modular approach to functional hyaluronic acid hydrogels using orthogonal chemical reactions
作者:Dmitri A. Ossipov、Xia Yang、Oommen Varghese、Sujit Kootala、Jöns Hilborn
DOI:10.1039/c0cc03055d
日期:——
A modular approach for the synthesis of hyaluronic acid hydrogels using orthogonal chemoselective reactions for subsequent enzymatic decomposition to nanoparticles is described.
Functionalization of Hyaluronic Acid with Chemoselective Groups via a Disulfide-Based Protection Strategy for In Situ Formation of Mechanically Stable Hydrogels
作者:Dmitri A. Ossipov、Sonya Piskounova、Oommen P. Varghese、Jöns Hilborn
DOI:10.1021/bm1007986
日期:2010.9.13
either one-end coupling product or to intra/intermolecular cross-linking of the HA chains. However, after subsequent treatment of the amidation reaction mixture with dithiothreitol (DTT), these cross-linkages are cleaved, ultimately exposing free amine-type groups. The same methodology was applied to graft serine residues to the HA backbone, which were subsequently oxidized into aldehyde groups. The strategy
Rational designs of small-moleculeinhibitorstargetingprotein-protein interfaces have met little success. Herein, we have designed a series of triazole derivatives with a novel scaffold to specifically intervene with the interaction of TLR8 homomerization. In multiple assays, TH1027 was identified as a highly potent and specific inhibitor of TLR8. A successful solution of the X-ray crystal structure
Zur Kenntnis der 2-Amino-1,3,4-oxidiazole 27. Mitt.: Hydroxyalkyl-substituierte 2-Amino-1,3,4-oxdiazole
作者:H. Gehlen、K.-H. Uteg、J. Vieweg
DOI:10.1002/ardp.19693020205
日期:——
Aus aliphatischen Hydroxysäurehydraziden und Bromcyan sind 5‐[Hydroxyalkyl]‐2‐amino‐1,3,4‐oxdiazole zugänglich, deren reaktives Verhalten an einigen Beispielen untersucht wird. Charakteristische IR‐Absorptionsbanden werden angegeben.