polyphenols not only give red wine its characteristic dry flavor, they are also
the basis for the recent good reputation of this stimulant as a true health
drink. They are believed to prevent heart disease and
atherosclerosis. French
researchers working with Stéphane Quideau have now discovered more examples of
polyphenols in red wine, and these could have anticancer activity.
Polyphenols are a large class of substances that act as tannins and
pigments in
many fruits and vegetables. "A number of these substances have already made
their way into
medicine, but the potential has not been exhausted by a long
shot," says Quideau. He and his team have now found another interesting compound
in red wine. Acutissimin A is a flavano ellagitannin, meaning that it has both
flavonoid and tannin components. The substance was first discovered in the oak
species Quercus acutissima, from which it takes its name. What makes acutissimin
A so attractive is its inhibitory effect on DNA topoisomerase II, because this
enzyme is a target in cancer treatment. Acutissimin A inhibits this enzyme 250
times more strongly than the clinically used antitumor agent Etoposid.
The French team was able to produce acutissimin A semisynthetically in the
laboratory by binding together the flavanoid catechin and the tannin vescalagin.
If an isomer of catechin, epicatechin, is used, a closely related but previously
unknown compound, which the researchers called "epiacutissimin", is formed. The
team was later also able to detect this substance in red wine extracts.
How do acutissimin and epiacutissimin get into red wine? It's the
ageing in oak
barrels! Says Quideau: "The grape juice contains the flavonoid precursors
catechin and epicatechin. During storage, the alcoholic liquid then extracts a
whole bouquet of substances out of the oak barrels, including the necessary
co-reactant, vescalagin." Quideau and his colleagues won't go so far as to call
wine a cancer preventative. But one can hardly wait to see what surprises red
wine has in store for us next. The probability is high that these precious drops
contain more tannin hybrid molecules with interesting pharmacological activity.