Potential of Raspberry Flower Petals as a Rich Source of Bioactive Flavan-3-ol Derivatives Revealed by Polyphenolic Profiling

Abstract

Inspired by the potential functional activity of polyphenol compounds contained in raspberry (Rubus idaeus), we previously explored the effects of the cultivation environment and maturity on the polyphenolic profiles of raspberry leaves and fruits. Herein, building on our previous studies, we used high-performance liquid chromatography and liquid chromatography–mass spectrometry to profile the polyphenol compounds contained in five parts of raspberry flowers (receptacles, sepals, pistils, stamens, and petals), revealing the presence of (+)-catechin, (−)-epicatechin, procyanidin B4, procyanidin C3, sanguiin H-6, and lambertianin C in all flower parts. Petals also contained (−)-epicatechin-3,5-di-O-gallate, kaempferol-7-O-glucoside, and naringenin-7-O-glucoside as well as other flavan-3-ol derivatives efficiently scavenging free radicals and inhibiting the growth of cancer (HeLa S3) cells. Thus, raspberry flower petals were concluded to be a good source of characteristic and highly functional flavan-3-ol derivatives.