| Popis: |
Aim: to investigate and compare antiradical and reducing abilities of caffeic acid and caffeic acid phenetyl ester. Tasks: 1) To evaluate CAPE and caffeic acid ability to reduce cytochrome c. 2) To evaluate CAFE and caffeic acid reducing abilities using FRAP method. 3) To evaluate CAFE and caffeic acid antiradical abilities in ABTS and DPPH methods. Research methods: This assay evaluated 5 µM, 10 µM and 15 µM concentrations of CAPE and caffeic acid on cytochrome c redox status in vitro studies. The spectrophotometry method was used and the wave length interval was chosen 500 – 600 nm. The maximal value of the cytochrome c absorption was observed at the 550nm wave length. The results were recorded at the 0 min, 3 min, 6 min, 9 min, 12 min, 15 min, 18 min and 21 min. Dithionite was used as a standart reducer, because its reduced cytochrome c amount was considered as a 100% in calculations. The antioxidant activity assessed by spectrophotometry using ABTS, DPPH and FRAP methods. Results: The following results were obtained regarding ability of CAPE and caffeic acid to reduce cytochrome C at the level of 5 μM: CAPE - 52% ±3%, caffeic acid - 44% ±2%; 10 μM: CAPE - 69% ±6%, caffeic acid - 45% ±3%; 15 μM: CAPE - 68% ± 4%, caffeic acid - 39% ±1%. The antioxidant activity of CAPE by the DPPH method was 76,7% ±0,1%, by caffeic acid - 58,3% ±3%, by the ABTS method – CAPE - 81,7% ±0,3%, caffeic acid - 68,6% ±0,3%, by the FRAP method – CAPE - 0,074 TE mol/l, caffeic acid - 0,057 TE mol/l. Conclusion: The highest antioxidant (antiradical and reducing) activity was refered to CAPE, rather than caffeic acid, it was observed using ABTS, DPPH and FRAP methods. Stronger cytochrome c reducing power distinguished CAPE (52-69%), whereas caffeic acid just 39-45%. Increased reducing power was related to the presence of phenetyl radical in CAFE structure |
