Piceatannol, a potent bioactive stilbene, as major phenolic component in Rhodomyrtus tomentosa

► The phenolic profile of the sim fruit was analysed for the first time by HPLC/HR-MS. ► High levels of piceatannol and ellagitannins were detected. ► During maturation, piceatannol and ellagitannin contents decreased. ► Shade-grown fruits showed higher piceatannol content than sun-exposed ones. ► These data may promote the consumption and use of sim fruit.