Antioxidant properties of benzylchroman derivatives from Caesalpinia sappan L. against oxidative stress evaluated in vitro.

The antioxidant activity of extracts from Caesalpinia sappan L. (CSL) was studied in vitro by evaluating the total phenolics, measuring the antioxidant activity by TEAC, measuring the scavenging effects on reactive oxygen species (ROS) and on reactive nitrogen species (RNS), and measuring the inhibitory effect on Cu(2+)-induced human low-density lipoprotein (LDL) oxidation. The CSL extracts were found to have a potent scavenging activity against all of the reactive species tested, as well as an inhibitory effect on LDL oxidation, especially in the ethyl acetate (EA) fraction. Therefore, we isolated and identified benzylchroman derivatives sappanchalcone (1) and 3'-deoxy-4-O-methylepisappanol (2) from the EA fraction of CSL and their antioxidant activities were evaluated. The studied CSL extracts and the compounds 1 and 2 were revealed to be very effective against the evaluated pro-oxidant species, including ROS and RNS.