Characterization of polyphenolic compounds in herbal infusions, decocts and macerates

Ljekovite biljke imaju dugu tradiciju korištenja u narodnoj medicini, no do danas brojni pozitivni zdrastveni učinci nisu potvrđeni rezultatima znanstvenih ispitivanja. Cilj ovog rada bio je odrediti ukune fenole, neflavanoide i flavanoide, udjel flavan-3-ola, tanina i procijanidina te antioksidacijski kapacitet sedam biljnih ekstrakata. Biljni ekstrakti su pripremljeni u obliku macerata, infuzija i dekokta. Udjel ukupnih fenola, neflavanoida i flavanoida određen je reakcijom s Folin-Ciocalteau reagensom, udjel flavan-3-ola određen je reakcijama s vanilinom i p-DAC-om, a udjel tanina reakcijom s kazeinom. Za polukvantitativno određivanje udjela procijanidina primjenjena je metoda po Bathe-Smith-u. Antioksidacijski kapacitet određen je reakcijama s željezo(III)-tripiridiltriazinom (FRAP) te radikalom 2,2“-azino-bis(3-etilbenzotiazolin-6-sulfonskom kiselinom) (ABTS). Način pripreme biljnih ekstrakata značajno utječe na ekstrakciju polifenolnih spojeva. Najveći udjel ukupnih fenola određen je u infuziji lista maline, a najveći udjel flavan-3-ola u dekoktu gloga, najveći udjel tanina pokazuje dekokt lista maline, dok najveći udjel ukupnih procijanidina pokazuje dekokt gloga.Medicinal plants have a long tradition of use in folk medicine, but numerous positive effects on health have not yet been confirmed by scientific research. The purpose of this study is to determine the total phenols, non-flavonoids and flavonoids, the content of flavan-3-ols and tannin and the antioxidant capacity of seven herbal extracts. Herbal extracts were prepared in the form of macerates, infusions and decocts. The content of total phenols, non-flavonoids and flavonoids was determined by reaction with Folin-Ciocalteu reagent, the content of flavan-3-ol was determined by reactions with vanilla and p-DAC, and the content of tannin by reaction with casein. For a semi-quantitative determination of procyanidin content the Bathe-Smith method was used. The antioxidant capacity was determined by reactions with Fe(III)-three pyridyl triazine (FRAP) and 2,2“-azino-bis(3-ethylbenzothiazoline -6-sulphonic acid) (ABTS) radical. The herbal extract preparation method significantly effects the extraction of polyphenolic compounds. The largest content of total phenols was determined in the infusion of raspberry leaf, and the largest content of flavan-3-ol in hawthorn decoct, the largest content of tannin was found in raspberry leaf decoct, while the largest content of total procyanidin was found in hawthorn decoct