Session: Parallel session 8 - Plant and Food OMICS

Deprotonated glycosylated flavonoid dissociation model: a tool to describe the composition of Viola yedoensis extract and better understand its cosmetic benefits

Hydration is a key factor influencing the physical and mechanical properties of the skin. The stratum corneum (SC), the outermost layer of the epidermis, is responsible for the skin's barrier function. This study investigated the ability of a unique Viola yedoensis extract to improve skin hydration and barrier function. A detailed phytochemical characterization of the extract was performed using liquid chromatography coupled with high-resolution tandem mass spectrometry (LC-HRMS/MS). Dereplication against databases and de novo structural elucidation led to the identification of various secondary metabolites, including esculetin, esculin, and apigenin C-glycosides; astragalin and kaempferol-3-O-rhamnoside; megastigmane glycosides like roseoside, platanionoside B, and eriojaposide B isomer; and the rare calenduloside F and esculetin-diglucoside, reported for the first time in the genus Viola. To understand the mechanistic aspects of glycosylated flavonoid dissociation, their fragmentation under collision-induced dissociation (CID and HCD conditions) was investigated, proposing general rules, particularly regarding electron capture versus hydride transfer, using the ion/dipole complex model. This approach enables the localization of hexose/pentose moieties on the aglycon in de novo characterized glycol-conjugates. These findings provide new molecular insights into how Viola yedoensis extract may exert its hydrating and skin barrier-enhancing benefits.