%0 Journal Article
%T Chemical constituents and antioxidative activity of the extracts from Dyera costulata leaves
%A Sanan Subhadhirasakul
%A Bamrung Jankeaw
%A Apai Malinee
%J Songklanakarin Journal of Science and Technology
%D 2003
%I Songkla University
%X Chloroform and n-butanol extracts from the leaves of Dyera costulata exhibited EC50 values for DPPH radical scavenging activity of 79.8¡À0.2 and 12.0¡À0.1 ¦Ìg/ml, respectively. Chemical investigation of the extracts was conducted by means of column chromatography. ¦Â-Amyrin and rhamnazin were isolated from the chloroform extract and quercetin-3-O-¦Á-L-rhamnopyranoside was isolated from the n-butanol extract. The chemical structures of the isolated compounds were identified by comparison of their spectroscopic data with those reported in the literature. The EC50 value of quercetin-3-O-¦Á-L-rhamnopyranoside in DPPH radical scavenging activity was 9.37¡À0.02 ¦ÌM. Its antioxidative activity is therefore about 8 times higher than that of the well known antioxidant, BHT, which has an EC50 value of 80.78¡À0.01 ¦ÌM.
%K antioxidative
%K flavone
%K quercetin
%K rhamnazin
%K Dyera costulata
%U http://www.sjst.psu.ac.th/journal/25-3-pdf/08antioxidativeleaves.pdf