Thioether macrocycles of the microbisporicins via reductive desulfurization
作者:Samuel K. Kutty、Joshua A. Lutz、Simon Felder、Philip Hahn、Carol M. Taylor
DOI:10.1016/j.tet.2018.06.050
日期:2018.8
followed by reductive desulfurization. 1H NMR analysis of the reduction reaction mixture indicated the intermediacy of a dehydroalanine when excess hexamethylphosphorus triamide (HMPT) was employed for the reduction. Maintaining a stoichiometric amount of HMPT, in dilute methanolic solution, gave the corresponding thioethers, retaining stereochemicalintegrity.
微双孢菌素是迄今为止分离出的最有效的羊毛硫抗生素。受此抗菌剂家族的启发,环状四,六和八肽已由线性肽合成。报道了线性肽向硫醚大环的两步转化的一般反应条件:二硫化物的形成,然后还原性脱硫。还原反应混合物的1 H NMR分析表明,当使用过量的六甲基磷三酰胺(HMPT)进行还原时,是脱氢丙氨酸的中间体。在稀甲醇溶液中保持化学计量的HMPT,得到相应的硫醚,保持立体化学完整性。
A “Catch-and-Release” Protocol for Alkyne-Tagged Molecules Based on a Resin-Bound Cobalt Complex for Peptide Enrichment in Aqueous Media
and mild protocols for the specific enrichment of biomolecules is of significant interest from the perspective of chemical biology. A cobalt–phosphine complex immobilised on a solid‐phase resin has been found to selectively bind to a propargyl carbamate tag, that is, “catch”, under dilute aqueous conditions (pH 7) at 4 °C. Upon acidic treatment of the resulting resin‐bound alkyne–cobalt complex, the Nicholas
Synthesis of malformin‐A
<sub>1</sub>
, C, a glycan, and an aglycon analog: Potential scaffolds for targeted cancer therapy
作者:Farzana Hossain、Sharmeen Nishat、Peter R. Andreana
DOI:10.1002/pep2.24260
日期:2022.7
hydrolysis in the tumor microenvironment releasing the active malformin C a glycon analog. Furthermore, total synthesis of malformin C was carried out with overall improved strategies avoiding unwanted side reactions thus increasing easier purification. We also report on an improved solid phase peptide synthesis protocol for malforminA1.
在降低化疗副作用的同时提高治疗效果仍然是癌症治疗合成设计的重要目标。为了与治疗发展的精神保持一致,并受到 Warburg 效应的启发,该效应增强了环肽天然产物三甲双胍家族的生物活性,特别是抗肿瘤活性,β利用精确的糖基化和液相肽合成设计和合成了二甲双胍 C 的葡萄糖苷。我们利用不同的供体和受体优化了几种糖基化程序。本研究的首要目标是确保通过 D-葡萄糖部分的偶联有针对性地递送糖-二甲双胍 C 类似物。通过葡萄糖转运蛋白 (GLUT) 选择性转运到肿瘤细胞中,然后在肿瘤微环境中水解,释放活性的 malformin C a 糖基类似物。此外,采用整体改进的策略进行了三甲双胍 C 的全合成,避免了不需要的副反应,从而增加了更容易纯化。我们还报告了一种改进的三甲双胍 A 1固相肽合成方案。
High-pressure-promoted Fmoc-aminoacylation of N-ethylcysteine: preparation of key devices for the solid-phase synthesis of peptide thioesters
preparation of peptidethioesters by Fmoc solid-phase peptide synthesis (SPPS) is described. Condensation of Fmoc-aminoacyl fluoride and N-ethyl-S-triphenylmethylcysteine allyl ester, readily prepared from known S-triphenylmethylcysteine allyl ester, was efficiently promoted in CH2Cl2 under high-pressure (800 MPa). When the reaction was performed with the additive DIEA, considerable epimerization at the chiral
Synthesis of Plantazolicin Analogues Enables Dissection of Ligand Binding Interactions of a Highly Selective Methyltransferase
作者:Abhishek Sharma、Patricia M. B. Saint-Vincent、Douglas A. Mitchell
DOI:10.1021/ol402444a
日期:2013.10.4
A convergent strategy for the synthesis of truncated analogues of plantazolicin (PZN), a member of the thiazole/oxazole-modifiedmicrocin (TOMM) class of natural products, has been developed. These N-terminal mono-, tri-, and pentazole substructures of PZN were utilized to probe the substrate requirements and thermodynamic ligand binding parameters of an unusually selective PZN methyltransferase (BamL)