Echinacoside and Caffeoyl Conjugates Protect Collagen from Free Radical-Induced Degradation: A Potential Use of Echinacea Extracts in the Prevention of Skin Photodamage - Maffei Facino, Roberto; Carini, Marina; Aldini, Giancarlo; Saibene, Luisella; Pietta, Piergiorgio; Mauri, Pierluigi (Planta Medica, 1995)