Which varieties of red wine contain the highest levels of resveratrol?

Resveratrol is a red pigment found in the skins of red and purple grapes, but not green grapes. Red wines have resveratrol, rose wines have some, but not much, and white wines have no resveratrol. The deeper the red, the more resveratrol the wine has. Syrrahs, Merlots, and Zinfandels have high resveratrol levels.