Oploxynes A and B, Polyacetylenes from the Stems of <i>Oplopanax elatus</i>
作者:Min Cheol Yang、Hak Cheol Kwon、Young-Joo Kim、Kang Ro Lee、Hyun Ok Yang
DOI:10.1021/np900628j
日期:2010.5.28
Two new polyacetylenes, oploxynes A (1) and B (2), and the known oplopandiol (3) and falcarindiol (4) were isolated from the stein of Oplopanax clams. The structures of compounds 1 and 2 were determined to be 9,10-epoxyheptadeca-4,6-diyne-3,8-diol and 10-methoxyheptadeca-4,6-diyne-3,8,9-triol, respectively, on the basis of their UV, MS, and NMR data. The absolute configurations of these compounds were determined using the modified Mosher's method and acetonide formation. Oploxyne A (1), oplopandiol (3), and falcarindiol (4) inhibited the formation of nitric oxide (NO) and prostaglandin E(2) (PGE(2)) in lipopolysaccharide (LPS)-induced murine macrophage RAW 267.7 cells.
Stereoselective Total Synthesis of (+)-Oploxyne A, (−)-Oploxyne B, and Their C-10 Epimers and Structure Revision of Natural Oploxyne B
作者:J. S. Yadav、Kumaraswamy Boyapelly、Sathish Reddy Alugubelli、Srihari Pabbaraja、Janakiram R Vangala、Shasi V Kalivendi
DOI:10.1021/jo102445h
日期:2011.4.15
The first totalsynthesis of recently isolated diacetylene alcohols oploxyne A, oploxyne B, and their C-10 epimers was accomplished. The structure of natural oploxyne B has been revised. The key steps involved are base-induced double elimination of a carbohydrate-derived β-alkoxy chloride to generate the chiral acetylenic alcohol and Cadiot−Chodkiewicz cross-coupling reaction. The target compounds
A stereoselectivetotalsynthesis of oplopandiol, oploxyne A, and (−)-oploxyne B is described. The key reactions include Sharpless asymmetric epoxidation, d-proline catalyzed aminoxylation, Cadiot–Chodkiewicz cross-coupling reaction, m-CPBA induced substrate-controlled stereoselective epoxidation, and Lewis acid catalyzed stereo- and regioselective ring-opening of epoxide.