Piceatannol

When the dehydration of 39 was carried out (H3PO4 or DMSO under reflux) instead of its dehydroxylation, a different class of stilbene derivatives, such as pinosilvine 44, resveratrol 45 or piceatannol 46, were easily obtained . From these compounds, resver-atrol has shown very potent anticancer properties in vivo, this activity being proven in rats . 

Compounds 1 and 2, possessing antitumor and antimetastatic activities, were isolated from the methanol extract. Compounds 1 and 2 were identified as cassigarol A and piceatannol (3, 3 , 4, 5 -tetrahydroxy stilbene), respectively, based on the 1H-NMR spectral data and products... 

Fig 22. Effects of piceatannol (a) andptceaiannol acetate (b) on tumor growth m LLC-bearing mice. 

On day 15, tumor weight reduced by piceatannol acetate (100 mg/kg twice daily), but piceatannol did not affect Fig. (23) . 

Fig. 23. Effects ofpiceatannol and piceatannol acetate on tumor weight in LLC-bearing mice.

Cassigarol A, piceatannol and piceatannol acetate, at the dose of 50 and 100 mg/kg x 2/day, prolonged the survival time and increased the survival rate as compared to those in tumor-removed mice Fig. (24) and Fig. (25) . 

On day 15, the solid tumor tissues were removed wider anesthetic pentobarbital and weighed. Thereafter, precatannol, piceatannol acetate Fig. (25) or casssigarol A Fig. (26) was again ufcninistered orally twice daily for 17 days, starting 24 hours after resection of tumor tissues on day 0. The survival time and number of surviving tumor-removed mice woe determined. 

Z Carcinectomized mice treated with piceatannol acetate 15 r... 

Fig. 27. Effects of piceatannol and piceatannol acetate on the number of metastatic colonies in the lungs of carcinetomized mice.

Fig. tt. Effects of cassigarol A on Matrigel-mduced capillary- Fig. 29 Effects of piceatannol and piceatannol acetate on Malngel-mduced...

HUVECs were seeded on the Matiigel in 270 pi of DMEM supplemented with 20% FBS and incubated with the indicated amounts of cassigarol A, piceattanol or piceatannol acetate for 24 h in a humidified 5% COj atmosphere. 

Rimando AM, Kalt W, Magee JB, Dewey J, Ballington JR. 2004. Resveratrol, pterostilbene, and piceatannol in vaccinium berries. J Agric Food Chem 52 4713-4719. 

Roupe KA, Yanez JA, Teng XW, Davies NM. 2006. Pharmacokinetics of selected stilbenes rhapontigenin, piceatannol and pinosylvin in rats. J Pharm Pharmacol 58 1443-1450. 

Richard N, Porath D, Radspieler A, Schwager J. 2005. Effects of resveratrol, piceatannol, tri-acetoxystilbene, and genistein on the inflammatory response of human peripheral blood leukocytes. Mol Nutr Food Res 49 431-442. 

Finally, we tested the actions of other phenolic compounds derived from various sources including fruits, vegetables, and plants. Among those tested, piceatannol, a natural resveratrol analog, was the most potent, followed by morin and myricetin. In contrast, quercetin and kaempferol were ineffective. Moreover, phenolic acids— namely, tannic and gallic acids—were the only ones that were neuroprotective in our model, as summarized in Table 6.1. 

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