Two novel glucosides of 6-gingerdiol were isolated from fresh ginger (Zingiber officinale Roscoe). Their structures were determined as 1-(4-O-β-d-glucopyranosyl-3-methoxyphenyl)-3,5-dihydroxydecane (1) and 5-O-β-d-glucopyranosyl-3-hydroxy-1-(4-hydroxy-3-methoxyphenyl)decane (2) by HRFAB-MS and NMR analyses, and the absolute configurations of both aglycons were identified as (3S,5S) by a comparison with synthetic compounds. After incubating these glucosides with acetone powder prepared from fresh ginger, they were confirmed to have been hydrolyzed to 6-gingerdiol by HPLC. This result suggests that these glucosides are the precursors or intermediates of 6-gingerdiol. To recognize their function, their antioxidative activities were investigated and compared to that of their aglycon, 6-gingerdiol, by a linoleic acid model system and by their DPPH radical-scavenging ability. Although 1 did not indicate any activity, 2 had as strong activity as the aglycon in both measurements.
ginger (Zingiber officinale Roscoe); 6-gingerdiol; 6-gingerdiol glucoside; antioxidant; 1-(4-O-β-d-glucopyranosyl-3-methoxyphenyl)-3, 5-dihydroxydecane; 5-O-β-d-glucopyranosyl-3-hydroxy-1-(4-hydroxy-3-methoxyphenyl)decane
NCBI PubMed ID: 10691642Publication DOI: 10.1021/jf990674xJournal NLM ID: 0374755Publisher: American Chemical Society
Correspondence: sekiwa@cc.ocha.ac.jp
Institutions: Graduate School of Humanities and Sciences, Laboratory of Food Chemistry, Department of Nutrition and Food Science, Ochanomizu University, Tokyo, Japan
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