TY - JOUR
T1 - Isolation and structure elucidation of highly antioxidative 3,8″-linked biflavanones and flavanone-C-glycosides from garcinia buchananii bark
AU - Stark, Timo D.
AU - Matsutomo, Toshiaki
AU - Lösch, Sofie
AU - Boakye, Paul A.
AU - Balemba, Onesmo B.
AU - Pasilis, Sofie P.
AU - Hofmann, Thomas
PY - 2012/2/29
Y1 - 2012/2/29
N2 - The aim of this study was to identify antioxidants from Garcinia buchananii bark extract using hydrogen peroxide scavenging and oxygen radical absorbance capacity (ORAC) assays. LC-MS/MS analysis, 1D- and 2D-NMR, and circular dichroism (CD) spectroscopy led to the unequivocal identification of the major antioxidative molecules as a series of three 3,8″-linked biflavanones and two flavanone-C-glycosides. Besides the previously reported (2R,3R,2″R, 3″R)-naringenin-C-3/C-8″ dihydroquercetin linked biflavanone (GB-2; 4) and (2R,3S,2″R,3″R)-manniflavanone (3), whose stereochemistry has been revised, the antioxidants identified for the first time in Garcinia buchananii were (2R,3R)-taxifolin-6-C-β-D-glucopyranoside (1), (2R,3R)-aromadendrin-6-C-β-D-glucopyranoside (2), and the new compound (2R,3S,2″S)-buchananiflavanone (5). The H 2O 2 scavenging and the ORAC assays demonstrated that these natural products have an extraordinarily high antioxidative power, especially (2R,3S,2″R,3″R) -manniflavanone (3) and GB-2 (4), with EC 50 values of 2.8 and 2.2 μM, respectively, and 13.73 and 12.10 μmol TE/ μmol. These findings demonstrate that G. buchananii bark extract is a rich natural source of antioxidants.
AB - The aim of this study was to identify antioxidants from Garcinia buchananii bark extract using hydrogen peroxide scavenging and oxygen radical absorbance capacity (ORAC) assays. LC-MS/MS analysis, 1D- and 2D-NMR, and circular dichroism (CD) spectroscopy led to the unequivocal identification of the major antioxidative molecules as a series of three 3,8″-linked biflavanones and two flavanone-C-glycosides. Besides the previously reported (2R,3R,2″R, 3″R)-naringenin-C-3/C-8″ dihydroquercetin linked biflavanone (GB-2; 4) and (2R,3S,2″R,3″R)-manniflavanone (3), whose stereochemistry has been revised, the antioxidants identified for the first time in Garcinia buchananii were (2R,3R)-taxifolin-6-C-β-D-glucopyranoside (1), (2R,3R)-aromadendrin-6-C-β-D-glucopyranoside (2), and the new compound (2R,3S,2″S)-buchananiflavanone (5). The H 2O 2 scavenging and the ORAC assays demonstrated that these natural products have an extraordinarily high antioxidative power, especially (2R,3S,2″R,3″R) -manniflavanone (3) and GB-2 (4), with EC 50 values of 2.8 and 2.2 μM, respectively, and 13.73 and 12.10 μmol TE/ μmol. These findings demonstrate that G. buchananii bark extract is a rich natural source of antioxidants.
KW - (2R,3S,2″R)-3″ R)-manniflavanone
KW - (2R,3S,2″S)- buchananiflavanone
KW - 3,8″-linked biflavanones
KW - Antioxidants
KW - Flavanone-6-C-glycosides
KW - GARCINIA buchananii
UR - http://www.scopus.com/inward/record.url?scp=84859743120&partnerID=8YFLogxK
U2 - 10.1021/jf205175b
DO - 10.1021/jf205175b
M3 - Article
C2 - 22250972
AN - SCOPUS:84859743120
SN - 0021-8561
VL - 60
SP - 2053
EP - 2062
JO - Journal of agricultural and food chemistry
JF - Journal of agricultural and food chemistry
IS - 8
ER -