Identification and quantification of kukoamine A and kukoamine B as novel μ-opioid receptor agonists in potato and other solanaceous plants

•Virtual screening of a food-compound database for novel µ-opiod receptor agonists.•Identification of kukoamine A as full agonist and kukoamine B as partial agonist.•Up to 16 µg of kukoamine A and 157 µg of kukoamine B quantified in potato varieties.•Kukoamines are mainly located in the potato peel and are stable during cooking.•Concentrations in tomato, pepper, and eggplant were below or close to LOQ.