Evolution of a Protecting-Group-Free Total Synthesis: Studies en Route to the Neuroactive Marine Macrolide (−)-Palmyrolide A
作者:Rodolfo Tello-Aburto、Tara D. Newar、William A. Maio
DOI:10.1021/jo301121f
日期:2012.7.20
neuroactive marine macrolide (−)-palmyrolide A is described. Our first-generation approach aimed to unlock the unknown C(5)–C(7) stereochemical relationship via the synthesis of four diastereomers of palmyrolide A aldehyde, a known degradation product. When these efforts provided inconclusive results, recourse to synthesizing all possible stereocombinations of the 15-memberedmacrolide was undertaken.
Detailed Analysis of (−)-Palmyrolide A and Some Synthetic Derivatives as Voltage-Gated Sodium Channel Antagonists
作者:Suneet Mehrotra、Brendan M. Duggan、Rodolfo Tello-Aburto、Tara D. Newar、William H. Gerwick、Thomas F. Murray、William A. Maio
DOI:10.1021/np500644k
日期:2014.11.26
A small library of synthetic (-)-palmyrolide A diastereomers, analogues, and acyclic precursors have been examined with respect to their interaction with voltage-gated sodium channels (VGSCs). Toward this goal, the ability of (-)-palmyrolide A and analogues to antagonize veratridine-stimulated Na(+) influx in primary cultures of mouse cerebrocortical neurons was assessed. We found that synthetic (-)-palmyrolide A and its enantiomer functioned as VGSC antagonists to block veratridine-induced sodium influx. A detailed NMR and computational analysis of four diastereomers revealed that none had the same combination of shape and electrostatic potential as exhibited by natural (-)-palmyrolide A. These data indicate that the relative configuration about the tert-butyl and methyl substituents appears to be a prerequisite for biological function. Additional testing revealed that the enamide double bond was not necessary for blocking veratridine-induced sodium influx, whereas the acyclic analogues and other macrolide diastereomers tested were inactive as inhibitors of VGSCs, suggesting that the intact macrolide was required.
Synthesis and biological evaluation of palmyrolide A macrocycles as sodium channel blockers towards neuroprotection
作者:Satish Chandra Philkhana、Suneet Mehrotra、Thomas F. Murray、D. Srinivasa Reddy
DOI:10.1039/c6ob01372d
日期:——
spontaneous calcium ion oscillations through its voltage-gated sodium channel blocking ability which is of significant interest in CNS drug discovery. Herein, we give a detailed account on total synthesis of (+)-palmyrolide A and synthesis of a focused library of macrocycles around the scaffold, followed by their biologicalevaluation. Use of the chiral pool approach, Zhu's oxidative homologation,
Expedient Synthesis of Large-Ring<i>trans</i>-Enamide Macrolides by CuI-Mediated Intramolecular Coupling of Vinyl Iodide with Amide: Total Synthesis of Palmyrolide A
An efficient and improved procedure for copper-catalyzed coupling of vinyl iodide with amide in an intramolecular fashion is described. The protocol utilizes a combination of copper iodide, CsF and (±)-1,2-diaminocyclohexane as ligand. The vinyl iodide couples efficiently with the amide to generate an enamide macrolide without any alteration in the double -bond geometry. The developed method was applied