Structural elucidation of phenolic compounds isolated from Opuntia littoralis and their antidiabetic, antimicrobial and cytotoxic activity

•This is the first instance of isolation and identification of different flavonoid and phenolic acid compounds from Opuntia littoralis cladodes and fruits.•8-Carbomethoxy-5‑hydroxyl‑6-methylisoflavone was isolated from the cladode extract (for the first time from family Cactaceae).•The ethanolic extract from the fruits of Opuntia littoralis has strong α-glucosidase inhibition activity, as well as antidiabetic activity.•Successive extracts from the cladodes showed strong antimicrobial activity against some strains of bacteria and fungi.•Fruit juice showed stronger antimicrobial effects than the ethanolic extract from the fruit.