resveratrol, phenolic compound produced by grapevines (and other plants such as peanut and eucalyptus trees), particularly in response to microbial attack (see phytoalexins) or artificial agents such as ultraviolet radiation. It is one of a number of compounds (including catechin and quercetin) found in wine thought to contribute to health aspects of its moderate consumption. Resveratrol is also found in other grape products such as juice and raisins. Resveratrol belongs to a class of compounds called stilbenes. In grapevines this also includes its derivatives, piceid, pterostilbene, and the viniferins. Woody parts of the vine normally contain large amounts of stilbenes, principally viniferins, which are thought to protect against wood decay. In the vineyard, leaves and berry skins produce resveratrol only in response to some action, such as fungal attack, where its subsequent accumulation may slow or stop the infection. There are numerous factors in the growing of grapes and vinification that can affect resveratrol concentration in the finished wine. Species, variety, clone, and rootstock influence potential stilbene production. For example, wines made from muscadinia grapes or from pinot noir tend to have high levels of resveratrol, whereas cabernet sauvignon has lower levels. Wines produced in cooler regions or areas with greater disease pressure such as Burgundy and New York often have more resveratrol, while wines from hot, dry climates such as Australia and California frequently have lower resveratrol concentrations.