Diversity of phenolic compounds in flowers of A. kolomikta (Rupr. & Maxim.) Maxim.

Abstract

The plants of Actinidia kolomikta are functionally dioecious so this species is characterized by both male and female flowers [1]. A. kolomikta flowers do not contain nectar and berry yields can be greatly reduced if pollinators do not visit the flowers. On the other hand, various chemical compounds in the flowers can attract pollinators. The aim of this work was to assess the diversity of phenolic compounds in male and female flowers of A. kolomikta. Separation of phenolic compounds was performed with the Acquity H-class UHPLC system (Waters, Santa Clara, CA, USA) equipped with a triple quadrupole tandem mass spectrometer (Xevo, Waters, USA) with an electrospray ionization source (ESI) to obtain MS/MS data using a previously described and validated UHPLC-ESI-MS/MS technique [2]. A total of 14 phenolic compounds were identified both in male and female flowers. Flavonols were the primary class found in flowers, other identified phenolic compounds were flavan-3-ols, phenolic acids and flavones. The major flavonols identified were kaempherol-3-O-glucoside, rutin, kaempherol, isorhamnetin, isorhamnetin-3-O-rutinoside, isorhamnetin-3-O-glucoside, quercetin, and quercitrin. Flavon-3-ols (+)-catechin, (-)-epicatechin, and procyanidin C1 represented the second most abundant class of phenolic compounds. For flavone class, small amounts of apigenin were found. Two compounds belonging to the hydroxycinnamic acids class, i.e., chlorogenic and neochlorogenic acids were detected in both male and female flowers.