Do peaches have vitamin C in them as well as other antioxidants? Yes, but very little. The amount of vitamin C they have (6.6 milligrams per 100 grams of fruit) is 8x less than oranges (53.2 milligrams per 100 grams of fruit). The good news though is that the total antioxidant content of peaches - as measured by its ORAC value - is only about 10% lower than oranges.
ORAC Source
USDA Database for the Oxygen Radical Absorbance Capacity (ORAC) of Selected Foods, Release 2 - Prepared by Nutrient Data Laboratory, Beltsville Human Nutrition Research Center (BHNRC), Agricultural Research Service (ARS), U.S. Department of Agriculture (USDA) - May 2010