1,1-Diphenyl-2-picrylhydrazyl radical-scavenging active compounds from greater cardamom (Amomum subulatum Roxb.).
Constituents of the fruits of greater cardamom (Amomum subulatum) were fractionated into three fractions, the dichloromethane extract, and the ethyl acetate-soluble and water-soluble fractions of the 70% aqueous acetone extract. The ethyl acetate-soluble fraction showed a high radical-scavenging activity against 1,1-diphenyl-2-picrylhydrazyl (DPPH). Four compounds were isolated from the ethyl acetate-soluble fraction, and their structures were ascribed to protocatechualdehyde (1), protocatechuic acid (2), 1,7-bis(3,4-dihydroxyphenyl)hepta-4E,6E-dien-3-one (3) and 2,3,7-trihydroxy-5-(3,4-dihydroxy-E-styryl)-6,7,8,9-tetrahydro-5H-benzocycloheptene (4) on the basis of spectroscopic evidence. This is the first isolation of these compounds from greater cardamom. In particular, 4 was a new type of cyclic diarylheptanoid. DPPH radical-scavenging activity of these compounds was measured by colorimetric analysis. Compounds 1 and 3 showed stronger activity than such natural antioxidants as alpha-tocopherol and L-ascorbic acid. Compounds 2 and 4 were comparable to alpha-tocopherol and L-ascorbic acid.
Kikuzaki
H
H
Division of Food and Health Science, Graduate School of Human Life Science, Osaka City University, Sumiyoshi, Osaka, Japan.
Kawai
Y
Y
Nakatani
N
N
D000975:Antioxidants / Q000737:chemistry / Q000378:metabolism*; D015764:Bepridil / Q000031:analogs & derivatives* / Q000378:metabolism*; D001713:Biphenyl Compounds; D002855:Chromatography, Thin Layer; D003124:Colorimetry; D028523:Elettaria / Q000737:chemistry* / Q000378:metabolism; D016166:Free Radical Scavengers / Q000378:metabolism*; D005638:Fruit / Q000737:chemistry / Q000378:metabolism; D007202:Indicators and Reagents; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D010851:Picrates; D010936:Plant Extracts / Q000032:analysis / Q000737:chemistry / Q000378:metabolism*
D000975:Antioxidants; D001713:Biphenyl Compounds; D016166:Free Radical Scavengers; D007202:Indicators and Reagents; D010851:Picrates; D010936:Plant Extracts; D015764:Bepridil; C004931:1,1-diphenyl-2-picrylhydrazyl