• Korean Journal of Pharmacognosy
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• v.36 no.3 s.142
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• pp.245-251
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• 2005

Phytochemical examination of the barks of Actinidia arguta led to the isolation of five flavonoids. Structures of compounds were elucidated as catechin (1), (-)-epicatechin (2), quercetin (3), $quercetin-3-O-{\beta}-D-glucopyranoside$ (4), $quercetin-3-O-{\beta}-D-galactopyranoside$ (5) by comparison with previously reported spectral evidences. To investigate the anti-oxidative effect and nitric oxide (NO) production inhibitory activity of these compounds, DPPH radical scavenging activity and nitric oxide production inhibitory activity in $IFN-{\gamma}$, LPS stimulated RAW 264.7 cell were examined. The $IC_{50}s$ were determinied as follows : $1\;$IC_{50}=26.61\;{\mu}g/ml$, $2\;IC_{50}=25.30\;{\mu}g/ml$, $3\;IC_{50}=20.41\;{\mu}g/ml$, $4\;IC_{50}=18.23\;{\mu}g/ml$ , $5\;IC_{50}=30.46\;{\mu}g/ml$, $6\;IC_{50}=28.0;{\mu}g/ml$, $7\;IC_{50}=27.24\;{\mu}/ml$. These NO production inhibitory effects were significantly different compared with the positive control, L-NMMA $(IC_{50}=20.77\;{\mu}g/ml)$, respectively. Compound $1\;(IC_{50}=6.19\;{\mu}g/ml)$, $2\;(IC_{50}=8.98\;{\mu}g/ml)$, $3\;(IC_{50}=7.30\;{\mu}g/ml)$ and $4\;(IC_{50}=7.64\;{\mu}g/ml)$ also showed potent antioxidative activities similar level to ascorbic acid $(IC_{50}=9.22\;{\mu}g/ml)$. These results suggest that barks of A. arguta have a potent anti-oxidative and anti-inflammatory activity.

• Korean Journal of Medicinal Crop Science
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• v.14 no.5
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• pp.267-272
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• 2006

Phytochemical study on the EtOAc fraction from the MeOH extract of the leaves of Cedrela sinensis led to the isolation of five known phenolic compounds (1-5), whose structures were identified as (+)-catechin (1), $kaempferol-3-0-{\alpha}- L-rhamnopyranoside$ (2), quercetin (3), $quercetin-3-O-{\alpha}-L-rhamnopyranoside$ (4), and $quercetin-3-O-{\beta}-D-glucopyranoside$ (5), respectively, by comparing their spectral $(uv,\;JR,\;IH\;and\;^{13}C-NMR,\;and\;ESI-MS)$ and physicochemical data with those reported in the literature. Among the isolated compounds (1-5), compounds 1 and 3-5 exhibited significant DPPH radical scavenging effects with $IC{_50}$ values ranging from $21.3{\pm}1.4\;to\;38.1{\pm}3.2 {\mu}M$ as well as superoxide anion radical scavenging effects with $IC{_50}$ values ranging from $9.4{\pm}0.7\;to\;21.2{\pm}3.6 {\mu}M$. Furthermore, compounds 1 and 3-5 also exhibited considerable inhibitory effects on LDL peroxidation induced by either $CU^{2+}$ or AAPH with $IC{_50}$ values ranging from $1.4{\pm}0.4\;to\;11.9{\pm}1.4\;{\mu}M$. These results indicated that flavonoids are the major constituents of C. sinensis and considered to be antioxidant principles of this plant.

• Journal of Korea Foresty Energy
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• v.19 no.2
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• pp.93-101
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• 2000

Wood of Robinia pseudoacacia and bark of Populus alba$\times$P. glandulosa, Fraxinus rhynchophylla and Ulmus davidiana var. japonica were collected and extracted with acetone-water(7:3, v/v) in glass jar to examine whether its bioactive compounds exist. The concentrated extracts were fractionated with hexane, chloroform, ethylacetate and water, and then freeze-dried for column chromatography and bioactive tests. The isolated compounds were sakuranetin-5-O-$\beta$-D-glucopyranoside from Populus alba $\times$Pl glandulosa, 4--ethyoxy-(+)-leucorobinetinidin frm R. pseudoacacia and fraxetion from F. rhynchophylla and were characterized by $^1H$ and$^{13}C $ NMR and positive FAB-MS. Decay-resistant activity was expressed by weight loss ratio and hyphae growth inhibition in the wood dust agar medium inoculated wood rot fungi. R. pseudoacacia showed best anti-decaying property in both test and its methanol untreated samples, indicating higher activity than methanol treated samples in hyphae grwoth test. In antioxidative test, $\alpha$-tocopherol, one of natural antioxidants, and BHT, one of synthetic antioxidants, were used as references to cmpare with the antioxidant activities of the extacted fractions. Ethylacetate fraction of F. rhynchophylla bark indicated the hightest activity in this test and all fractions of R. pseudiacacia extractives also indicated higher activities compared with the other fractions. In the isolated compounds, aesculetin isolated from F. rhynchophylla bark showed best activity and followed by robonetinidin from R. pseudoacaica.

• Journal of the Korean Geotechnical Society
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• v.19 no.6
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• pp.71-84
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• 2003

The metallic shell of soil-steel structures are so weak in bending moment that it should sustain the applied load by the interaction of the backfill soil around the structures. The shell can be subjected to excessive bending moment during side backfilling or under live-load when the soil cover is less than the minimum value. The current design code specifies the allowable deformation and Duncan(1979) and McGrath et al.(2001) suggested the strength analysis methods to limit the moments by the plastic capacity of the shell. However, the allowable deformation is an empirically determined value and the strength analysis methods are based on the results of FE analysis, hence the experimental verification is necessary. In this study, the full-scale tests were conducted on the high-profile arch to investigate its behaviors during backfilling and under static live-loads. Based on the measurements, the allowable deformation of the tested structure could be estimated to be 1.45% of rise, which is smaller than the specified allowable deformation. The comparison between the measurements and the results of two strength analyses indicate that Duncan underestimates the earth-load moment and overestimates the live-load moment, while McGrath et al. predicts both values close to the actual values. However, as the predicted factors of safeties using two methods coincide with the actual factor of safety, it can be concluded that both methods can predict the structural stability under live-loads adequately when the cover is less than the minimum.