A chemoenzymatic strategy has been developed for the synthesis of bastadins 2, 3, and 6. The requisite dimeric dityrosine and isodityrosine building blocks were successfully prepared by oxidative C-C and C-O phenolic coupling of mono- and dihalogenated derivatives of tyrosine and tyramine using horseradish and soybean peroxidases. By carefully controlling the experimental parameters, the requisite synthons may now be prepared in synthetically useful yields without the exhaustive protection and deprotection of the sensitive functional groups.
starting from commercially available thiols or disulfides. Additionally, the application of this mild method to the first total synthesis of psammaplin B is demonstrated. Non-toxic and inexpensive ferricyanide is used as the cyanidesource, which can be activated either in a mechanochemical, solvent-free approach, or in a biphasic solvent system allowing easier work-up. A total of 27 examples is demonstrated
在此,我们描述了两种互补的方法来制备各种有机硫氰酸盐,这些有机硫氰酸盐价格低廉、可靠并遵循可持续化学的原则,从市售的硫醇或二硫化物开始。此外,还展示了这种温和方法在 psammaplin B 的首次全合成中的应用。氰化物源使用无毒且廉价的铁氰化物,可以通过机械化学、无溶剂方法或双相溶剂系统激活,从而更容易进行后处理。总共展示了 27 个示例,具有高达定量的产量。
An improved synthesis of psammaplin A
作者:Amy M. Godert、Norman Angelino、Anna Woloszynska-Read、Shannon R. Morey、Smitha R. James、Adam R. Karpf、Janice R. Sufrin
DOI:10.1016/j.bmcl.2006.03.008
日期:2006.6
The marine natural product, psammaplin A, was first isolated from the Psammaplinaplysilla sponge in 1987. Since that time, psammaplin A has shown a wide spectrum of biological activities that include enzyme inhibitory activities resulting in antibacterial and antitumor effects. An improved synthesis of psammaplin A has been developed, making the compound more easily accessible for further biological evaluations. In this context, we find that psammaplin A is an effective DNA methyltransferase inhibitor in vitro but fails to alter genomic DNA methylation levels in treated human cancer cells. (c) 2006 Elsevier Ltd. All rights reserved.