Synthesis and biological activities of 8-arylflavones

Abstract

A number of 8-arylflavones have been synthesized as congeners of wogonin and evaluated for their inhibitory activities of PGE2 production. 8-Arylflavones were obtained from commercially available chrysin via two different synthetic pathways. Most 8-arylflavones exhibited much reduced inhibitory activities against COX-2 catalyzed PGE2 production compared to that of wogonin. Functional group replacement at the 8-position of wogonin from methoxy to aryl group caused loss of inhibitory activity. Our present results imply that the functional group at the 8-position of flavones seems to play very important roles for bioactivity.

Inhibition of prostaglandin E2 production by synthetic Wogonin analogs

“…8-Halogenoflavones were also prepared from chrysin following a known procedure as shown in Scheme 2 (Bovicelli et al, 2002;Dao et al, 2004). Methylation of chrysin followed by halogenation reactions gave 8-halogeno-5,7-dimethoxyflavones (7, 8 and 9).…”

Total Synthesis of Amentoflavone

“…The synthesis of amentoflavone is outlined in Scheme 1 by coupling flavones 5 and 10 which were prepared under reported conditions [12][13][14][15]. Briefly, p-anisaldehyde (1) was iodinated at the 3-position to afford compound 2.…”

Structural Alterations of Wogonin Significantly Reduce the Inhibitory Activity against COX-2 Catalyzed PGE2Production from LPS-Induced RAW 264.7 Cells

“…Wogonin was previously reported to suppress the induction of COX-2 and inucible nitric oxide synthase Chi et al, 2003;Lee et al, 2003;Wakabyashi, 1999Wakabyashi, , 2000. It was already reported that the functional group replacement at the 8-position of wogonin from methoxy to aryl group caused loss of inhibitory activity (Dao et al, 2004b). Similarly, the Wogonin derivatives modified at the B-ring of Wogonin exhibited much reduced inhibitory activities against COX-2 catalyzed PGE2 production compared to that of wogonin (Jang et al, 2005).…”