Quinofuracins A-E, novel anthraquinone derivatives containing beta-D-galactofuranose that were isolated from the fungus Staphylotrichum boninense PF1444, induced p53-dependent cell death in human tumor cells. The structures of quinofuracins A-E, including absolute configurations, were elucidated by extensive spectroscopic analysis and chemical transformation studies. Quinofuracins were classified into three groups according to the aglycone moieties. 5'-Oxoaverantin was present in quinofuracins A-C, whereas averantin and versicolorin B were identified in quinofuracins D and E, respectively. These quinofuracins induced p53-dependent growth suppression in human glioblastoma LNZTA3 cells.
Silyl Triflate-Mediated Ring-Closure and Rearrangement in the Synthesis of Potential Bisfuran-Containing Intermediates of Aflatoxin Biosynthesis
作者:Todd L. Graybill、Eduard G. Casillas、Kollol Pal、Craig A. Townsend
DOI:10.1021/ja990591x
日期:1999.9.1
strategy is described involving two silyl triflate-mediated cyclization and rearrangement processes that have enabled both furofuran oxidation states to be readily achieved and undesired but thermodynamically favorable side reactions to be avoided in the preparation of these ring systems. In the first an o-methoxymethyl phenylacetaldehyde is cyclized directly to the five-membered, differentially protected