Abstract:

High performance liquid chromatography (HPLC)-time of flight mass spectrometry (TOF) was used to
qualitatively determine the phenolic compounds of mulberry. It was found that using acetone-distilled water (4:1, V/V) as
the extraction solvent, ultrasonic extraction for 15 min was the optimal extraction method. Solid-phase extraction using
a C18 cartridge was effective for isolating polyphenols from sugars and amino acids, which facilitated the subsequent
identification by mass spectrometry. A total of 14 polyphenols in mulberry were found mainly in the forms of phenolic
acids, anthocyanin and flavonoids, including six phenolic acids, 3-O-caffeoylquinic acid, 4-O-caffeoylquinic acid, chlorogenic
acid dimer, 4-O-caffeoylquinic acid dimer, cis-iso-isomers chlorogenic acid, and 3,5-di-O-caffeoyl quinic acid; four anthocyanins,
prodelphinidin-3-galactosidase, prodelphinidin-3-glucoside, cyaniding-3-glucoside, and cyaniding-3-rutinoside; three flavonoids,
rutin, ellagic acid hexyl glycoside, and quercetin 3-O-(6’-O-malonyl) glycoside; as well as one resveratrol derivative.
Key words: mulberry; phenolic compounds; high performance liquid chromatography; quadrupole time of flight-mass
spectrometry (Q-TOF-MS)