Effect of plant extracts and phenolic compounds on phenolic profile of chinese cabagge (Brassica rapa L. subsp. pekinensis (Lour.) Hanelt) seedlings

U sklopu ovog rada metodom tekućinske kromatografije visoke moći razlučivanja istraţen je utjecaj vodenih ekstrakata gospine trave, koprive i kadulje, te flavonoida kempferola i izoramnetina, odnosno kiselina ferulične i p-kumarinske na sadrţaj flavonoida i hidroksicimetnih kiselina u klijancima pekinškog kupusa (Brassica rapa L. subsp. pekinensis (Lour.) Hanelt). Rezultati su pokazali da je vodeni ekstrakt gospine trave znatno povećao količinu kvercetina, što ukazuje na mogućnost korištenja ovog vodenog ekstrakta za obogaćivanje klijanaca pekinškog kupusa kvercetinom. S obzirom da su za kvercetin zabiljeţeni brojni pozitivni biološki učinci, obogaćivanje biljaka ovim flavonoidom moglo bi imati potencijal u proizvodnji biljnog materijala vrijednog za industrijsku primjenu (npr. poljoprivrednu, prehrambenu i farmaceutsku). Rezultati su takoĎer pokazali da je vodeni ekstrakt kadulje znatno povećao količinu kempferola, kavene, ferulične i sinapinske kiseline, ali ujedno je i negativno utjecao na rast i razvoj klijanaca pekinškog kupusa. Od fenolnih spojeva jedino je tretman p-kumarinskom kiselinom znatno povećao koncentraciju kavene kiseline u klijancima pekinškog kupusa. Pekinški kupus vrlo je zastupljena prehrambena vrsta iz porodice krstašica (Brassicaceae) zahvaljujući visokom sadrţaju vitamina i minerala, a obogaćivanjem njenog fenolnog profila dodatno se doprinosi njenoj prehrambenoj vrijednosti.In this work, using high performance liquid chromatography method, the influence of St. John's wort, nettle and sage aqueous extracts, and flavonoids kaempferol and isorhamnetin, or ferulic and p-coumaric acid on the content of flavonoids and hydroxycinnamic acids in Chinese cabbage (Brassica rapa L. subsp. pekinensis (Lour.) Hanelt) seedlings was investigated. The results showed that St. John's wort extract significantly increased the amount of quercetin, indicating the possibility of using this extract to enrich Chinese cabbage seedlings with quercetin. Given that quercetin exerts numerous positive biological effects, enrichment of plants with this flavonoid may have potential in the production of plant material valuable for industrial applications (e.g. agricultural, food and pharmaceutical). The results also showed that the water extract of sage significantly increased the amount of kaempferol, caffeic, ferulic and sinapic acid, however this extract also negatively affected the growth and development of Chinese cabbage seedlings. Among phenolic compounds, only treatment with p-coumaric acid significantly increased the concentration of caffeic acid in Chinese cabbage seedlings. Chinese cabbage is a very often used vegetable from the family Brassicaceae thanks to the high content of vitamins and minerals, and the enrichment of its phenolic profile further contributes to its nutritional value