A series of substituted 8,8-dimethyl-8H-pyrano[2,3-f]chromen-2-ones (chromeno-coumarin hybrids) was synthesized from scopoletin (11) as vasorelaxing agents. The synthesized compounds 21a-f, 22, 23a-e and scopoletin (11) were evaluated for vasorelaxation in endothelium intact rat main mesenteric artery (MMA). Compounds 11, 21a, 21c-f and 22 showed significant vasorelaxation in precontracted MMA within
Bioassay-guided fractionation of the ethanolic extract of the roots of Toddaliaasiatica led to the isolation of seven new prenylated coumarins (1–7) and 14 known analogues (8–21). The structures of 1–7 were elucidated by spectroscopic analysis, and their absolute configurations were determined by combined chemical methods and chiral separation analysis. Compounds 1–5, named toddalin A, 3‴-O-demethyltoddalin
A One-Pot Synthesis of Pyranocoumarins Through Microwave-Promoted Propargyl Claisen Rearrangement/Wittig Olefination
作者:Bernd Schmidt、Christiane Schultze
DOI:10.1002/ejoc.201701684
日期:2018.1.17
A method towards the synthesis of angular pyranocoumarins from propargylic ethers has been developed. The sequence proceeds through a microwave‐promoted tandem propargyl Claisen rearrangement, Wittigolefination, E/Z isomerization, and cyclization series of reactions in times as low as 10 min.
chromenocoumarin present in the plants of the family Rutaceae and Meliaceae and possesses vasorelaxing and anti-inflammatory activities. In this study, six 6-alkoxy (10b, 15–19), and twelve 6-hydroxy-alkyl amine (20a-20l) derivatives of braylin (11 and 12) were synthesized to delineate its structural requirement for vasorelaxingactivity. The synthesized compounds were evaluated for vasorelaxation response in preconstricted
Anti-AIDS agents-XXVIII.1 Synthesis and Anti-HIV activity of methoxy substituted 3′,4′-Di-O-(−)-camphanoyl-(+)-cis-khellactone (DCK) analogues
作者:Yasuo Takeuchi、Lan Xie、L.Mark Cosentino、Kuo-Hsiung Lee
DOI:10.1016/s0960-894x(97)10050-6
日期:1997.10
Four isomeric methoxy substituted DCK analogues (3-6) were asymmetrically synthesized from different starting materials. 5-Methoxy-3',4'-di-O-(-)-camphanoyl-(+)-cis-khellactone (5) exhibited extremely potent anti-HIV activity against HIV-1 replication in H9 lymphocyte cells with EC50 and therapeutic index values of 0.00038 mu M and >402,632, respectively, which are better than those of DCK and AZT in this assay. (C) 1997 Elsevier Science Ltd.