Composition and content of anthocyanins and flavonoids in purple-red, pink, and white petals of Bauhinia variegata L.

The composition, content, and structure of anthocyanins and flavonoids in purple-red, pink, and white petals of Bauhinia variegata L. were studied to lay a foundation for further investigations of the floral pigment mechanisms and molecular breeding of this species. The anthocyanins and flavonoids were analyzed using liquid chromatography-mass spectrometry (LC-MS/MS). In total, 53 anthocyanins and 340 flavonoids were detected. However, the anthocyanins were markedly different among the different colored petals. Malvidin-3-O-galactoside, malvidin-3-O-glucoside, delphinidin-3-O-galactoside were higher in the purple-red petals than in the white and pink petals. Delphinidin-3-O-(coumaryl)-glucoside, malvidin-3-O-sophoroside, petunidin-3-O-(coumaryl)-glucoside were higher in the pink petals than in the purple-red and white petals. Pelargonidin-3-O-(coumaryl)-glucoside was higher in the white petals than in the purple-red and pink petals. The flavonoids also differed significantly among the different petals. Pelargonidin-3-O-sambubioside-5-O-glucoside, pelargonidin-3-O-sophoroside, and delphinidin-3-O-sambubioside were almost not detected in the white petals and delphinidin-3-O-sophoroside was almost not detected in the purple-red petals, while peonidin-3-O-glucoside, peonidin-3,5-O-diglucoside, chrysoeriol-7-O-rutinoside-5-O-glucoside, and isovitexin-7-O-(6''-sinapoyl) glucoside were higher in the pink than in the white and purple-red petals.