A useful and versatile procedure for the acylation of nucleosides through an enzymic reaction
摘要:
Lipase-mediated acylation of nucleosides with oxime esters in organic solvents has been achieved. Candida antarctica lipases (SP435 and SP435A) showed high regioselectivity toward the primary hydroxyl group of both deoxy- and ribonucleosides, whereas other lipases exhibited poor results for this goal. 2'-Deoxynucleosides, such as thymidine and 2'-deoxyadenosine, were acylated with oxime esters carrying saturated, unsaturated, aromatic, and functionalized chains, giving 5'-O-acylated compounds together with small quantities of the 3'-O-acylated regioisomer. Uridine, adenosine, and inosine, as representative ribonucleosides, were acylated exclusively at the 5'-OH by using the same methodology. Nucleosides bearing a cytosine ring were found to be unreactive with oxime esters under the same conditions. 2'-Deoxycytidine was acylated with acid anhydrides and C. antarctica lipase to give N,5'-O-diacylated compounds, whereas cytidine gave mixtures, reason for which it had to be previously chemically N-acylated and then subjected to the oxime esters and lipase, giving the same results as ribonucleosides.
[EN] FORCE-RESPONSIVE POLYMERSOMES AND NANOREACTORS; PROCESSES UTILIZING THE SAME<br/>[FR] POLYMERSOMES ET NANORÉACTEURS SENSIBLES À LA FORCE; PROCÉDÉS LES UTILISANT
申请人:ADOLPHE MERKLE INSTITUTE UNIV OF FRIBOURG
公开号:WO2019034597A1
公开(公告)日:2019-02-21
The mechanically induced melting properties of DNA were employed to achieve force labile membranes is described. Nucleobase pairs were used as mechanophores. Adenine and thymine functionalized complementary amphiphilic block copolymers were self-assembled into polymersomes. The nucleobases formed hydrogen bonds which were disrupted upon force stimulation. The exposure of the disconnected nucleobases to the hydrophobic matrix of the membranes lead to a change of permeability which permitted the exchange of water-soluble molecules throughout the polymer matrix. Moreover, the encapsulation of horseradish peroxidase enabled the reaction of luminol with hydrogen peroxide to yield a luminescence producing species similar to the marine bioluminescence. Moreover, the same nano-reactors were employed to catalyze the formation of a polyacrylamide gel when force was applied. Insights into the change of permeability of supramolecular networks upon force are provided. These systems are useful for drug delivery, as nanoreactors and for the selective release of curing agents for 3D printing, or fragrances.
IntramolecularDiels−Alderreactions of chiral 2-silahexa-3,5-dienyl α,β-unsaturated esters have been found to afford tetrahydro-4-silaisochroman-1-ones in moderate yields. The best diastereoselectivity was achieved in the reaction of silatriene 8c, in which methyl and triisopropylsilyloxymethyl groups are attached to the silicon atom, with an acrylate as the dienophile under EtAlCl2-catalyzed conditions
Macromolecular prodrugs of ribavirin combat side effects and toxicity with no loss of activity of the drug
作者:Mille B. L. Kryger、Benjamin M. Wohl、Anton A. A. Smith、Alexander N. Zelikin
DOI:10.1039/c3cc00315a
日期:——
Chemi-enzymatic synthesis of ribavirin acrylate and subsequent RAFT co-polymerization with acrylic acid afforded a formulation of a broad spectrum antiviral drug which avoids accumulation in erythrocytes, the origin of the main side effect of ribavirin. In cultured macrophages the macromolecularprodrugs exhibited decreased toxicity while maintaining the anti-inflammatory action of ribavirin.
Narrow Therapeutic Window of Ribavirin as an Inhibitor of Nitric Oxide Synthesis is Broadened by Macromolecular Prodrugs
作者:Benjamin M. Wohl、Anton A. A. Smith、Mille B. L. Kryger、Alexander N. Zelikin
DOI:10.1021/bm401048s
日期:2013.11.11
However, this effect was characterized by a rather narrow therapeutic window with experimental values of EC50 and IC50 being 7 and 19 μM, respectively. Macromolecularprodrugs were obtained using an acrylate derivative of RBV, RAFT polymerization technique, and N-vinyl pyrrolidone as a partner monomer. The synthesized polymers were characterized with uniform molecular weights, relatively narrow polydispersities
Macromolecular Prodrugs for Controlled Delivery of Ribavirin
作者:Mille B. L. Kryger、Anton A. A. Smith、Benjamin M. Wohl、Alexander N. Zelikin
DOI:10.1002/mabi.201300244
日期:2014.2
(RBV)‐containing polymers are synthesized based on poly(N‐vinylpyrrolidone) and poly(acrylicacid), two polymers with extensive characterization in biomedicine. The copolymers are shown to exhibit a minor to negligible degree of association with erythrocytes, thus effectively eliminating the origin of the main side effects of RBV. The therapeutic benefit of macromolecular RBV prodrugs is illustrated