| Summary: | 碩士 === 中國醫藥大學 === 生態暨演化生物學研究所碩士班 === 99 === In previous studies, some phytochemicals isolated from species of Eurya, a
member of Theaceae family, showed various bioactivities. For example, chrysoeriol
from methanolic extract of leaves of Eurya ciliata stimulated proliferation and
differentiation of osteoblastic MC3T3-E1 cells. E. emarginata is also used as a
traditional folk medicine in Korea to treat ulcers and diuretic. E. glaberrima Hayata is
one of the endemic species distributed in broad-leaved and mixed forest at elevations
between 1500 to 3300 m above sea level in Taiwan. In order to clarify the medical and
ecological roles of E. glaberrima, the natural products of E. glaberrima with
anti-hepatocarcinoma cell, allelopathic activity were investigated. In this study, we
used the methanolic extract of twigs and leaves of E. glaberrima to test the
cytotoxicity and isolated natural compounds. On the other hand, we used the aqueous
extract of E. glaberrima leaves to test the allelopathic potential.
Five known compounds, namely, rengyolone (1), betulinic acid (2), taxifolin
3‒O‒β‒D‒xylopyranoside (3), quercitrin (4) and hyperin (5), were isolated from
methanolic extract of E. glaberrima and one acetylated product 3-O-acetyl betulinic
(2a) were identified by NMR and ESI-MS-MS data analyses. Rengylone revealed 50
% inhibitory effect at 40 μg/ml on HepG2 2.2.15. 3-O-acetyl betulinic had better
cytotoxic effect than betulinic acid. All of them didn’t show the anti-HBV effect.
In addition, in order to test the allelopathic potential of E. glaberrima, the
aqueous extracts (1~5%) of leaves of E. glaberrima were bioassayed by using six
tested plants, namely, Brassica chinensis, Lactuca sativa, Setaria italica, Ocimum
basilicum, Cucumis sativus and Bidens pilosa. The results exhibited that the aqueous
extracts of E. glaberrima could inhibit the radicle growth but not seed germination of
the six tested plants. The leachate of E. glaberrima leaves could significantly inhibit the radicle elongation of B. chinensis and S. italica. In our study, betulinic acid and
hyperin didn’t show the allelopathic effect of the tested plants.
In conclusion, E. glaberrima maybe has relative low potential for developing as
a medicinal plant. The aqueous extracts and leachate of E. glaberrima have the
phytotoxic potential, exhibiting suppressive effect on some species underneath the
Eurya vegetation in the field.
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