| Summary: | 碩士 === 東海大學 === 食品科學系 === 84 === The purposes of this study were to isolate and identify the
major antioxidative compounds and anthocyanins from the flowers
of Delonix regia and the fruit hulls of Garcinia mangostana L.
The antioxidative mechanisms of the isolated compounds were also
studied. The antioxidative ethyl acetate extract of flowers
of Delonix regia was fractionated and purified by various
chromatographies to obtain four isolated compounds which were
identified as 2''-(3'''',4'''',5''''-trihydroxy-phenyl)-ethyl-
margarate, quercetin, quercetin-3-O-β-D-xylopyranoside and
isorhamnetin 3-O-β-D-glucopyranoside. The methanol extract of
the fruit hulls of Garcinia mangostana L. was also separateded
to obtain two compounds which were identified asα-mangostin and
γ-mangostin. By using ferric thanate method, the antioxidative
efficiency of the isolated compounds found in the order of γ-
mangostin＞BHA＝2''-(3'''',4'''',5''''-trihydroxyphenyl)-ethyl-
margarate＞quercetin-3-O-β-D-xylopyranoside＞quercetin＞α-
tocopherol＞isorhamnetin 3-O-β-D-glucopyranoside＞α-mangostin
＞control. The result from antioxidative mechanism studies
showed that 2''-(3'''',4'''',5''''-trihydroxyphenyl)-ethyl-margarate
had strong activity on hydrogen peroxide-scavenging effect. It
also showed good activity on hydrogen-donating effect,
superoxide anion-scavenging effect and inhibition on DEMP-OH
formation, but had poor activity on singlet oxygen-scavenging
and metal-chelating effect. Isorhamnetin 3-O-β-D-
glucopyranoside didn''t show any good activity in all
antioxidative mechanism tests although it exhibited
wentioxidative activity by the ferric thiocyanate method. Both
quercetin-3-O-β-D-xylopyranoside and quercetin had equal
activity to BHA on hydrogen-donating, superoxide anion-
scavenging and hydrogen peroxide-scavenging effect. In spite of
their metal-chelating ability were not as good as EDTA, they
exhibited the better activity on metal-chelating effect, hydroxy
radical-scavenging and singlet oxygen-scavenging effect than
other isolated compounds.α-mangostin had weak antioxidative
activity by the ferric thiocyanate method and low ability in
hydrogen peroxide-scavenging effect but showed no activity on
other antioxidative measurement. γ-mangostin showed equal or
better effect than BHA in the ferric thiocyanate method and
other antioxidative measurements, especial in superoxide anion-
scavenging efficiency. The acidic methanol extract of the
flowers of Delonix regia were fractionated and isolated by
various chromatographies to obtain two major anthocyanins
identified as cyanidin-3-O-β-D-rutinoside、cyanidin-3-O-β-D-
glucoside. Cyanidin-3-O-β-D-sophoroside was major anthocyanin
isolated from the fruit hulls of Garcinia mangostana L. All
three anthocyanins showed antioxidative activity, but only
cyanidin-3-O-β-D-glucoside exhibited equal activity as measured
by the ferric thiocyanate method to α-tocophero
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