Illumination of bioactive compounds in camellia sinensis (l.) o. kuntze flower extracts by hplc-dad and inhibition of bacterial dna polymerase

Camellia sinensis (tea) is a species of evergreen small tree whose leaves are used to produce tea. Flowers of this plant was blossom in fall and winter seasons. First, it was observed that methanol extract of tea flower showed strong inhibition on replicative DNA polymerases and this extract was successively fractionated with diethyl ether, ethyl acetate and n-butanol in order to find these inhibitory of active compounds. The phenolic acid and flavonoid contents of the three organic and the remaining aqueous fractions of methanol extract and acidic and basic hydrolyzed fractions were investigated by HPLC-DAD analysis and their antioxidant activity and capacities were determined spectrophotometrically. DNA polymerase inhibition and antimicrobial activities of all extracts and fractions except hydrolyzed extracts were determined. Ethyl acetate and butanol fractions showed strong inhibition on Gram (+) replicative DNA polymerase IIIα (PolC) isolated from Bacillus subtilis. On the other hand, all fractions except for the aqueous fraction and the methanol extract showed strong inhibition on Gram (-) DNA polymerase IIIα (DnaE) isolated from Escherichia coli. According to HPLC-DAD analyzes, catechin and syringic acid were highest in ethyl acetate extract while epicatechin, epigallocatechin gallate (EGCG), routine and luteolin derivatives were detected in the highest butanol extract. The ethyl acetate fraction of the methanol extract has the best DPPH free radical scavenging activity and the highest total phenolic content. In all extracts and fractions, the highest antioxidant capacity and activity was detected in the organic fraction of basic hydrolysis. The highest total flavonoid content was determined in the organic fraction of acidic hydrolysis.