Microalgae of different phyla display antioxidant, metal chelating and acetylcholinesterase inhibitory activities

► Hexane extracts had the highest antiradical Fe2+-chelating activities. ► Chlorella minutissima, Tetraselmis chuii and Rhodomonas salina exhibit strong anti-AChE properties. ► Polyunsaturated fatty acids and sterols are the main compounds in bioactive extracts. ► The species under study are a valuable source of antioxidants, metal chelators and AChE inhibitors. ► This is the first study on chelating and AChE inhibitory activities in microalgal species.