Chemical structural characterization of phenolic compounds from the red ("Biqi") and white ("Shuijing") bayberries was carried out in the present study. With the aid of Global Natural Products Social Molecular Networking (GNPS), 18 flavonoid glycosides and 13 proanthocyanidins (PACs) in bayberry extracts were tentatively identified. Three cyanidin-3-glucoside derivatives (cyanidin-acetylapiosyl-glucoside, catechin-cyanidin-3-glucoside, and gallocatechin-cyanidin-3-glucoside), two quercetin derivatives (quercetin-3-arabinoside and quercetin-3-glucuronide), patuletin-7-glucoside, and individual PACs consisting of (epi)catechin or (epi)gallocatechin units were reported for the first time in bayberry fruits. In addition, "Biqi" exhibited a considerable increase of flavonoid glycoside content together with a dramatic decrease in the content of PACs in mature fruits, while "Shuijing" showed a decrease in levels of PACs but failed to accumulate flavonoid glycosides during fruit development.
Keywords: Chinese bayberry; GNPS; LC−ESI-MS; developmental stages; flavonoid glycosides; phenolic compound identification; proanthocyanidins.