Flavonol glycosides in berries of two major subspecies of sea buckthorn (Hippophaë rhamnoides L.) and influence of growth sites

•Sea buckthorn flavonols were studied in berries of different origins.•Wild Chinese berries are richer in flavonols than those of Russian cultivars.•Flavonol glycoside profile varies among subspecies, cultivars, and growth sites.•Content of flavonols increases with altitude and decreases with latitude.•The results provide guidance for application and plant breeding of sea buckthorn. Flavonol glycosides of wild sea buckthorn (Hippophaë rhamnoides ssp. sinensis) berries from China and cultivated berries (H. rhamnoides ssp. mongolica) from Finland and Canada were identified and quantified. Twenty-six flavonol glycosides were found with isorhamnetin and quercetin as the major aglycones. The contents of flavonol glycosides ranged 23–250mg/100g fresh berries and were significantly higher in the berries of ssp. sinensis than in those of ssp. mongolica. Among the cultivars of ssp. mongolica, the berries of ‘Oranzhevaya’ had the lowest (23mg/100g) content, and those of ‘Prevoshodnaya’ the highest content of flavonol glycosides (80mg/100g). Within the ssp. mongolica, the samples from Kittilä (Northern Finland) had higher levels of most flavonol glycosides than those from Turku (Southern Finland) and Québec. Among the ssp. sinensis berries of different growth sites, increasing trends were detected in the contents of most of the compounds as the altitude increased and as the latitude decreased. The wild berries (ssp. sinensis) from Sichuan had remarkably high contents and unique profiles of flavonol glycosides.