(−)-Petrosiol E, a metabolite of sponge Petrosia strongylata, has been synthesized in 32% overall yield from cheap natural d-xylose in 10 steps. Our strategy provides an efficient way for the totalsynthesis of other petrosiol members, featuring the three contiguous stereogenic centers are easily constructed from d-xylose chiral template.
Synthesis and an Evaluation of the Bioactivity of the <i>C</i>-Glycoside of Pseudopterosin A Methyl Ether
作者:Wei Zhong、Claudia Moya、R. S. Jacobs、R. Daniel Little
DOI:10.1021/jo801432t
日期:2008.9.19
The Suzuki-Miyaura cross-coupling protocol was applied to the synthesis of 1a, the C-glycoside analogue of PsA methyl ether. This marks the first construction of a C-glycoside for this class of marine natural products, thereby offering an opportunity to compare its bioactivity to the natural substances. Its activity profile resembled that of PsA (1) and PsA O-methyl ether (1b) when assayed for its anti-inflammatory activity and its ability to inhibit phagocytosis. We conclude that the intact structure is present when a pseudopterosin expresses its anti-inflammatory and phagocytosis inhibitory properties and that they are, therefore, not likely to be prodrugs. Results show that 1a is an effective binding agent toward the A(2A) and A(3) adenosine receptors, displaying IC50 values of 20 and 10 mu M, respectively.
Glycosidation via conjugate addition of anomeric alkoxides to nitroalkenes and nitrosoalkenes
作者:Gary Trewartha、Jeremy N. Burrows、Anthony G.M. Barrett
DOI:10.1016/j.tetlet.2005.03.102
日期:2005.5
The conjugate addition reactions of protected pyranose alkoxides to both nitroalkenes and nitrosoalkenes, as a route to 2-nitroalkyl, 2-oximinoalkyl and 2-oxoalkyl glycosides, are described. (c) 2005 Elsevier Ltd. All rights reserved.