Quali-quantitative analyses of flavonoids of Morus nigra L. and Morus alba l. (Moraceae) fruits

Morus nigra L., belonging to the Moraceae family, is a decidious tree widely cultivated in Europe and West Asia. It has a long history of medicinal use in Chinese medicine, as a remedy for many kinds of diseases. The aim of the present study was to evaluate the profile of the phenolic constituents of M. nigra fruits and to compare their content with the fruits of another species of Morus, Morus alba, which is also very well known in folklore medicine. The fruits of black and white mulberries have been studied, and five compounds from the methanol extract have been identified by means of HPLC/PDA/ESI-MS. Four compounds (quercetin 3-O-glucoside, quercetin 3-O-rutinoside, kaempferol 3-O-rutinoside, and 5-O-caffeoylquinic acid) have been isolated by use of Sephadex LH-20 column chromatography and HPLC and characterized by means of NMR and ESI-MS. Furthermore, HPLC/PDA/ESI-MS analysis of the red pigment of M. nigra fruits revealed the presence of four anthocyanins recognized as cyanidin 3-0-glucoside, cyanidin 3-O-rutinoside, pelargonidin 3-0-glucoside, and pelargonidin 3-O-rutinoside. All of the compounds were quantified.