Identification and quantification of free, conjugate and total phenolic compounds in leaves of 20 sweetpotato cultivars by HPLC–DAD and HPLC–ESI–MS/MS.

Highlights: [•] Profile and content of phenolics in leaves of 20 sweetpotato cultivars were studied. [•] Free, conjugate and total phenolics were obtained using three preparation methods. [•] Twenty-nine phenolics in samples were identified using HPLC–DAD and HPLC–ESI–MS/MS. [•] Two dihexosides and one hexoside of quercetin were first characterised. [•] Artefacts of esterification during acidic alcoholic hydrolyses were revealed. [Copyright &y& Elsevier]