Ampelopsin

Slimestad, R., Andersen, 0.M., and Francis, G.W., Ampelopsin 7-glucoside and other dihydro-flavonol 7-glucosides from needles of Picea abies, Phytochemistry, 35, 550, 1994. 

Only 15 newly reported simple dihydroflavonols are listed in Table 15.9. Several of the compounds are just simply the C-3 epimers of known (2i ,3i )-dihydroflavonols, e.g., (2R,3S)-3-hydroxy-5,7-dimethoxyflavanone (329) from the fern Woodsia scopulina (Dryopterida-ceae), (2i ,3S)-3,5,3, 4 -tetrahydroxy-7-methoxyflavanone (3-epipadmatin, 333) from Inula graveolens (Asteraceae),(2i ,3S)-3,5,3 -trihydroxy-7,4 -dimethoxyflavanone (337) from Lannea coromandelica (Anacardiaceae), and (2i ,3S)-3,5,7,3, 4, 5 -hexahydroxyflavanone (hovenitin III, 338) from the seeds and fruits of Hovenia dulcis (Rhamnaceae). The previously known (2i ,3i )-stereoisomer of hovenitin III has the trivial name ampelopsin. The same plant source has yielded the (27 ,37 )- and (27 ,3S)-epimers of 3,5,7,4, 5 -pentahydroxy-3 -methoxyflavanone, which are known as hovenitins I (340) and II (341), respectively. ... 

Ampelopsin A 66 can be viewed as the monomer of hopeaphenol isolated by Oshima et al. (90T5121, 95T11979). The quantity in wine is ca. 2-16mg/L (00MI591) on the cytotoxicity against cancer cells, cf. (99JOC6976,99PAC1611). 

Dihydroflavonols. Widely distributed 2,3-dihydroflavon-3-ols include the antioxidant 2,3-dihydroflavonols aromadendrin (3,5,7,4 -tetrahydroxyflavanone 2,3-dihydrokaempferol), ampelopsin (3,5,7,3, 4, 5 -hexahydroxyflavanone 2,3-dihydromyricetin), fustin (3,7,3, 4 -tetrahydroxyflavanone 2,3-dihydrofisetin) and taxifolin (3,5,7,3, 4 -pentahydroxy-flavanone 2,3-dihydroquercetin). Some flavanols are sweet-tasting, notably 6-methoxy-aromadendrin 3-O-aceate, 6-methoxytaxifolin and taxifolin 3-0-acetate. Taxifolin and fustin inhibit NADH and succinate dehydrogenases and taxifolin inhibits 5-LOX. 

Viniferin (446) occurs in Dipterocarpaceae, C5rperaceae, Gnetaceae and Leguminosae, whereas (+)-e-viniferin (445), only in Vitaceae. The relationship between enantiomers that exist in some plants of Dipterocarpaceae and Vitaceae (e.g. ampelopsins A, F, and H, hopeaphenol and isohopeaphenol) can be reasonably explained from the results of their biosynthesis [208]. 

Grape related products (red wine etc.) usually contain stilbene monomers, dimers and their glycosides [32]. The relative and absolute structures of (-t-)-ampelopsin F (465) [217], (-l-)-isoampelopsin F (468), (-)-ampelopsin F (469) [218-220], isoampelopsin F (467) [221], and those of the structurally related ones 2b-hydroxyampelopsin F (466) [222], gnemonol... 

The antifungal resveratrol dimers cyphostemmins A and B (481, 482) were isolated from the roots of Cyphostemma crotalarioides planch (Vitaceae). Cyphostemmins A (481) has the proposed cyclohexenic structure [230], while cyphostemmin B has the same structure as that of (-)-quadrangularin A isolated from Cissus quadrangularis [231]. Adesanya et al. considered that the reported structure of (-)-ampelopsin D... 

Amurensins I-M (737-741) were isolated from the roots of Vitis amurensis (Rupr.). Some of them had an ampelopsin A or balanocarpol unit, in which the conformations of the seven-membered carbon ring were identified for the first time. The authors claimed that (+)-vitisin A (698) and 7-2-viniferin (747) [330] should have the same structure with a pseudo-boat conformation of the seven-membered ring and y-2-viniferin (747) was erroneously elucidated [329]. 

Treatment of 3,4-dimethoxy-12-benzyloxymethyl stilbene under the same condition gave catechol analogs of ampelopsin F and of restrytisol C (587, 588) [289]. 

Many other c5 otoxic oligostilbenes have been found in the systemic screen [254, 473-475]. The noteworthy ones include gnemonol G (546), gnetin I [473], the acetate of (-)-ampelopsin A, (-)-hopeaphenol (715) [271,474] and suffruticosol B (590) [475]. tra 5-e-Viniferin (445), gnetin H and suffhiticosol B (590) also strongly suppressed HL-60 cell proliferation and induced DNA damage [475]. 

Some stilbenoids from the roots of Vitis thunbergii, such as vitisinols B, C, D (772, 773, 576), (+)-e-viniferin (445), (-)-viniferal (771), ampelopsin C and (+)-vitisin C (700), displayed strong free radicalscavenging activities (ICsos 2.8 to 6.6 //M) [245]. The antioxidant capacity of tra s-e-viniferin (445) has also been evaluated and compared with those of resveratrol (1) and s)mthetic stilhene derivatives [504]. 

The plant-insect chemical interactions concerning the stilbenoids have just been reviewed [509] (-i-)-Ampelopsin B (806) and ct-viniferin (635) antagonized the action of 20-hydroxyecdysone [510] cw-miyabenol A (735), kobophenol B and cw-miyabenol C (663) showed competitive binding to ecdysteroid receptors [337] resveratrol (1) and oligomers (suffruticosols A-C, 589-591) also exhibited ecdysteroid antagonistic activity [297]. 

Flowever, ampelopsin C and the mixture of (-i-)-vitisin A (698) and (+)-cw-vitisin A (702) were found to be powerful hepatotoxins. The coexistence of hepatoprotective and hepatotoxic agents in the same plant is very interesting, and the plant has been used to cure hepatic diseases such as hepatitis and liver cirrhosis [519]. 

---