Antioxidant activity of five new phenolic compounds from Cirsium creticum subsp. creticum

In this study, five new alkyl catechol derivatives, 1, 2, 3, 4 and 5 were isolated for the first time from Cirsium creticum subsp. creticum L. and their structures were determined by using spectroscopic techniques, including mass spectrometry, 1D and 2D NMR. All of the isolated compounds were primarily evaluated for antioxidant activity against BHA and tocopherol. All compounds which were isolated from C. creticum subsp. creticum exhibited antioxidant activity, however it was noticed that the presence of a pentose sugar increased the antioxidant activity.