Thin-layer chromatography analysis and scavenging activity of marigold (Calendula officinalis L) extracts

Abstract

The methanol, petroleum ether, chloroform, ethyl acetate, n-butanol and water extracts were obtained by extraction of marigold flower (Calendula officinalis L). The content of total phenolic compounds, determined by UV spectrophotometric method using the Folin-Ciocalteu reagent, was 15.12 mg/g. The content of total flavonoids, determined by UV spectrophotometric method according to Markham, was 5.13 mg/g. Qualitative determination of phenolic compounds in the extracts was performed by one- and two-dimensional thin-layer chromatography (TLC) procedures. The results of one- and two-dimensional TLC analyses showed that different flavonoids and phenolic acids were present in the investigated extracts. The greatest number of flavonoids (rutin, quercetin and some unidentified flavonoid glycosides) and phenolic acids (chlorogenic, caffeic, coumaric and vanillic acid) were deteminated in methanol extract. The influence of marigold extracts, in concentration range 0.6-1.2 mg/mL, on 2,2?-diphenyl-1-picrylhydrazyl (DPPH) free radicals was investigated by electron spin resonance (ESR) spectroscopy. All extracts showed scavenging activity (SA) in the following order: ethyl acetate > n-butanol > methanol > water > chloroform > petroleum ether. The SA increased with increasing concentration of extracts. The ethyl acetate and n-butanol extracts exibited the most significant SA. These extracts in concentration of 1.2 mg/mL eliminated completely DPPH radicals. The lowest SA had chloroform and petroleum ether extracts (in concentration of 0.6 mg/mL SA=0%). The SA of marigold extracts is attributed to its hydrogen-donating ability and scavenging effect.Ekstrakcijom cvetova nevena (Calendula officinalis L) dobijeni su metanolni, petroletarski, hloroformski, etilacetatni, n-butanolni i vodeni ekstrakti. Sadrzaj ukupnih fenolnih jedinjenja u nevenu, odredjen UV spektrofotometrijskom metodom koristeci Folin-Ciocalteu reagens, bio je 15,12 mg/mL, dok je sadrzaj ukupnih flavonoida, odredjen UV spektrofotometrijskom metodom po Markham-u, 5,13 mg/mL. Na osnovu jedno- i dvodimenzionalne tankoslojne hromatografske (TLC) analize utvrdjeno je prisustvo razlicitih flavonoida i fenolnih kiselina u ispitivanim ekstraktima. Metanolni ekstrakt je najbogatiji flavonoidima (rutin kvercetin i neki neidentifikovani flavonoid-glikozidi) i fenolnim kiselinama (hlorogenska, kafena, kumarinska i vanilinska kiselina). Uticaj ekstrakata nevena, koncentracija 0,6-1,2 mg/mL, na stabilne 2,2(-difenil-1-pikrilhidrazil (DPPH) radikale ispitan je elektron spin rezonantnom (ESR) spektroskopijom. Svi ekstrakti su pokazali skevindzer aktivnost (SA). Utvrdjen je sledeci redosled aktivnosti ekstrakata etilacetatni > n-butanolni > metanolni > vodeni > hloroformski > petroletarski. SA ekstrakata je u korelaciji sa koncentracijom. Etilacetatni i n-butanolni ekstrakti pri koncentraciji od 1,2 mg/mL potpuno uklanjaju DPPH radikale. Hloroformski i petroletarski ekstrakti, pri koncentraciji od 0,6 mg/mL, ne pokazuju SA. SA ispitivanih ekstrakata najverovatnije je uslovljena sposobnoscu fenolnih jedinjenja da otpustaju vodonikov atom kao i aril radikala, nastalih otpustanjem vodonikovog atoma, da "hvataju" DPPH radikale.