Peer Review #2 of "Identification and quantification of flavonoids in 207 cultivated lotus (Nelumbo nucifera) and their contribution to different colors (v0.1)"

Sacred lotus (Nelumbo nucifera) is a large economic crop, which is also cultivated as a horticultural crop.This study performed a systematic qualitative and quantitative determination of five anthocyanins and 18 non-anthocyanin flavonoids from the petals of 207 lotus cultivars.Among the compounds identified in this study, quercetin 3-O-pentoseglucuronide, quercetin 7-O-glucoside, laricitrin 3-O-hexose, and laricitrin 3-O-glucuronide were discovered for the first time in sacred lotus.The relationships between these pigments and petals colors were also evaluated.A decrease in the total content of anthocyanins and increase in the content of myricetin 3-O-glucuronide resulted in a lighter flower color.Furthermore, petals were yellow when the content of quercetin 3-Oneohesperidoside and myricetin 3-O-glucuronide were increased, whereas petals were red when the total anthocyanin content was high and the quercetin 3-O-sambubioside content was low.These investigations contribute to the understanding of mechanisms that underlie the development of flower color and provide a solid theoretical basis for the further study of sacred lotus.