• Korean journal of applied entomology
• /
• v.36 no.3
• /
• pp.243-248
• /
• 1997

The local distribution and life cycle of Mahasma aurea (Butler) attacking Ginkgo biloba L. in Seoul and Incheon areas were studied during 1994 - 1996. The species had one generation a year. The overwintered 3rd larvae begin to feed on buds of the host plant from mid May and then on the leaves until early June. Newly hatched larvae mostly infested the leaves from mid August to late September. Pupation took place from mid June to early July, and the moths emerged in early July.

• Journal of Environmental Science International
• /
• v.11 no.12
• /
• pp.1189-1193
• /
• 2002

This study was conducted to determine the contents of heavy metals in leaves of roadside trees according to different growth stages in Daegu city. The orders of heavy metal contents in leaves of roadside tree and soil were Fe>Mn>Zn>Pb>Cu>Cr>Cd and Fe>Mn>Zn>Cu>Pb>Cr>Cd, respectively. The contents of heavy metals in leaves of roadside trees and soil showed an increasing tendency as the levels of traffic volume increased. The contents of heavy metals in loaves on October were higher than those on May. Zelkova serrate and Ginkgo biloba showed high contents of Cr, Cd and Pb.

• Korean Journal of Soil Science and Fertilizer
• /
• v.30 no.4
• /
• pp.377-383
• /
• 1997

Studies were conducted on the nature of allelopathic effect of the substances in the waste of ginkgo leaves from pharmaceutic factory. In the first step, to find out whether there was any allelophatic effect, young seedlings of radish and rice were grown in the water (crude) extract of ginkgo leaf waste and in different liquid/lquid partitioned fractions of EtOAc at pH 9, EtOAc at pH 3, and BuOH. As second step, attempts were made to isolate and identify the allelophatic substance in different liquid/liquid partitioned fractions using GC/MS and NMR techniques. The water (crude) extract of ginkgo leaf waste retarded the growth of radish seedlings under 10% concentration. In case of rice seedlings, the water extract of ginkgo leaf extract showed adverse effect on the growth when combined with $3.3{\times}10^{-6}M$ gibberellin A3. All of the liquid/liquid fractions of crude extract showed strong retardation of seedling growth of radish and rice at the concentration of 1%. Allelophatic substance was isolated from the crude extract using liquid/liquid partition, column chromatography and HPLC techniques. The analytical results of isolated componet using GC/MS and NMR proved that the allelophatic substance in the ginkgo leaf wastes is catechol; one of phenol compounds. Based on the experiences current study, a practical method for the testing of allelophatic effect of crude extract of some materials was proposed. In this method, rice seeds were allowed to sprout until the length of coleoptile to reach 0.5 mm. Such seedlings were submerged in the solution containing supposedly allelophatic substance and the length of shoot and root was measured 3 days after treatment.

• Biotechnology and Bioprocess Engineering:BBE
• /
• v.9 no.1
• /
• pp.35-40
• /
• 2004

Ginkgolides (GK) and bilobalide are valuable compounds that belong to the lactone terpene. The contents of these metabolites were determined by HPLC from female and male tree of Ginkgo biloba L. The productivity of G. biloba cells was also compared with the corresponding individual trees. High variations in the ginkgolides and bilobalide were observed from different individuals, plant parts, and cultured cells. The ginkgolides and bilobalide contents were different depending on the plant parts. Callus was obtained from various plant tissues, and NAA was better at callogenesis than 2,4-D in both the female and male trees. The plants and their corresponding cells showed considerable variation in their ginkgolides and bilobalide concentrations. The ginkgolides and bilobalide contents were not correlated with the production between dominant trees and their corresponding cells. Light irradiation enhanced the production of GK-A and GK-B, however, the concentration of bilobalide decreased under dark conditions.

• Journal of Applied Biological Chemistry
• /
• v.42 no.1
• /
• pp.40-44
• /
• 1999

The in vitro antioxidative activities of the 33 plant-derived essential oils and 37 phytochemicals including 3 Mentha arvensis leaf-, 2 Thymus vulgaris leaf- and 2 Syzygium aromaticum flower-derived isolates were determined by the inhibition of linoleic acid autoxidation, the generation of superoxide anion and scavenging of DPPH radical. They were then compared to those of the widely used plant-derived antioxidants (pyrogallol and quercetin) and synthetic antioxidant BHT. At a concentration of 0.01%, potent antioxidative effect was observed in the essential oils from Cinnamomum cassia roots, Mentha arvensis leaves, Ginkgo biloba fruits, and Syzygium aromaticum flowers. Of the phytochemicals used, eugenol and isoeugenol at 0.01% showed potent antioxidative activity, and their activities were comparable to those of pyrogallol, quercetin, and BHT. The Cinnamomum root-, the Mentha leaf-, the Ginkgo fruit-, and the Syzygium flower-derived materials may be a good source for an alternative to the currently used antioxidants.

• Journal of the Korea Furniture Society
• /
• v.23 no.1
• /
• pp.95-102
• /
• 2012

The objective of this study was to conduct the species identification and tree-ring dating of Lotus Pedestal of the Amitabha Statue at Ssangbong-Temple in Hwasun. The six wood blocks used for the Lotus Pedestal were hard pines (Pinus spp.; diploxilon) except one piece which was ginkgo (Ginkgo biloba L.). The lotus leaves surrounding the pedestal body were also made of ginkgo. Tree-ring patterns of 3 blocks were synchronized and a 133 years chronology was made. The chronology was crossdated well with the master chronology of Japanese red pine in South Korea. It dated back to A. D. 1551~1683, i.e. the last ring dated A. D. 1683. Through the estimation of the number of sapwood rings removed during carving, the felling year was calculated A. D. $1704{\pm}10$. The calligraphic writing on the Pedestal indicated that this statue was made in A. D. 1694. Therefore, the accuracy of the tree-ring dating has been proven.

• Archives of Pharmacal Research
• /
• v.29 no.12
• /
• pp.1074-1079
• /
• 2006

As part of our research on phytochemicals that exert protective effects against diseases related to reactive nitrogen species, we have evaluated the scavenging activity of the yellow leaves of Ginkgo biloba on $ONOO^{-}$. The methanol extract and ethyl acetate fraction obtained from yellow leaves of G. biloba evidenced a marked scavenging activity on authentic $ONOO^{-}$. Repeated column chromatography of the active ethyl acetate soluble fraction on silica gel, Sephadex LH-20, and RP-18, resulted in the purification of 15 known compounds, including sciadopitysin (1), ginkgolide B (2), bilobalide (3), isoginkgetin (4), kaempferol (5), luteolin (6), protocatechuic acid (7), bilobetin (8), amentoflavone (9), ${\beta}-sitosterol$ glucopyranoside (10), kaempferol 3-O-rhamnopyranoside (11), kaempferol 3-O-glucopyranoside (12), kaempferol $3-O-[{6^{'}-O-p-coumaroyl-{\beta}-D-glucopyranosyl(1{\rightarrow}2)-{\alpha}-L-rhamnopyranoside]$ (13), kaempferol 3-O-rutinoside (14), and 6-hydroxykynurenic acid (15). Among the compounds isolated, flavonoids (5, 6 and 11-14), protocatechuic acid (7), and 6-hydroxykynurenic acid (15) all exhibited marked scavenging activities on authentic $ONOO^{-}$. The $IC_{50}$ values of 5-7, 11-14 and 15 were as follows: $2.86{\pm}0.70,\;2.30{\pm}0.04,\;2.85{\pm}0.10,\;5.60{\pm}0.47,\;4.16{\pm}1.65,\;2.47{\pm}0.15,\;3.02{\pm}0.48,\;and\;6.24{\pm}0.27\;{\mu}M$, respectively. DL-Penicillamine ($IC_{50}=4.98{\pm}0.27\;{\mu}M$) was utilized as a positive control. However, the other compounds (1-4, 8-10) exerted no effects against $ONOO^{-}$.

• Food Science and Preservation
• /
• v.17 no.2
• /
• pp.261-266
• /
• 2010

Acidic hydrolysis conditions prior to HPLC analysis of plant flavonoids was investigated by response surface methodology (RSM), using leaves of Ginkgo biloba L. Ten hydrolysis conditions using 0.5-2.5 M HCl and 0.5-2.5 hr hydrolysis time were chosen to form a central composite rotatable design (CCRD), and optimization by RSM was achieved by measuring myricetin, quercetin, and kaempferol levels by HPLC. Optimum hydrolysis condition was 1.5 M HCl for 1.5 hr. The levels of flavonoids obtained under the condition were in good agreement with predicted maximum values, with yields of more than 95%. These optimum hydrolysis condition was applied to analysis of flavonoid content in the leaves of Camellia sinensis, Ficus carica, and Sageretia theezans.

• Journal of Korean Society of Forest Science
• /
• v.29 no.1
• /
• pp.20-53
• /
• 1976

For the purpose of detecting the capability of the trees to resist air pollution and of determining the tree species best suited for purification of polluted air, particularly with regard to $SO_2$ contamination, six following ornamental tree species were selected as experimental materials: i.e., Hibiscus syriacus L., Ginkgo biloba L., Forsythia koreana Nak., Syringa dilatata Nak., Larix leptolepis Gordon, and Pinus rigida Miller. The susceptiblities of the trees were observed and analyzed on the basis of area ratio of smoke injury spots to the total leaf area. The results of the experiments are as follows: I. The Susceptibilities to Sulfur Dioxide. (1) The decreasing order of tolerance to $SO_2$ by species was as follows: 1. Hibiscus syriacus 2. Ginkgo biloba, 3. Forsythia koreana, 4. Syringa dilatata, 5. Larix leptolepis, and 6. Pinus rigida. In general, Hibiscus syriacus and Ginkgo biloba can be grouped as the most resistant and Larix leptolepis and Pinus rigida as the least resistant and Forsythia koreana and Syringa dilatata as of intermediate resistance. (2) The sulfur content of the leaves treated by $SO_2$ increased in proportion to the increase of the concentration of the fumigation. The content in the coniferous species proved to be less than that of the broad-leaved species, but Ginkgo biloba proved to contain as much sulfur as broad-leaved species. (3) The earlier-stage leaves fumigated in June with the $SO_2$ concentration up-to-l-ppm showed that sulfur content increases in proportion to the increase of the concentration of the fumigation, but the difference between concentration was not so significant. (4) The later-stage leaves fumigated in October showed higher sulfur content than the earlier stage leaves, and a wider range of difference in sulfur content was detected among different concentrations. The limit of fumigation resulting in culmination of sulfur absoption in broad-leaved species, such as Syringa dilatata, Hibiscus syriacus, and Forsythia koreana proved to be around 0.6 ppm. (5) Due to the sprouting ability and the adventitious bud formation, the recovery from $SO_2$ fumigation was prominent in Hibiscus syriacus, Syringa dilatata, and Forsythia koreana. (6) The differences in the smoke spot color were recognized by species: namely, dirt-brown in Syringa dilatata, brilliant yellowish-brown in Pinus rigida and Ginkgo biloba, whitish-yellow in Hibiscus syriacus and reddish-brown in Forsythia koreana. (7) The leaf margins proved to be most susceptible, and the leaf bases of the mid-rib most tolerant. In both Ginkgo biloba and Larix leptolepis, the younger leaves were more resistant to $SO_2$ than the older ones. II. The ulfur Content of the Leaves of the Ornamental Trees Growing in the City of Seoul. (1) The sulfur contents in the leaves of the Seoul City ornamental trees showed a remarkably higher value than those of the leaves in the non-polluted areas. The sulfur content of the leaves in the non-polluted area proved to be in the following descending order: Salix pseudo-lasiogyne Leveille, Ginkgo biloba L., Alianthus altissima swingle, Platanus orientalis L., and Populus deltoides Marsh. (2) In respect to the sulfur contents in the leaves of the ornamental trees in the city of Seoul, the air pollution proved to be the worst in the areas of Seoul Railroad Station, the Ahyun Pass, and the Entrance to Ewha Womans University. The areas of Deogsu Palace, Gyeongbog Palace, Changdeog Palace, Changgyeong Park and the Hyehwa Intersection were least polluted, and the areas of the East Gate, the Ulchi Intersection and the Seodaemun Intersection are in the intermediate state.

• The Korean Journal of Physiology
• /
• v.29 no.1
• /
• pp.61-67
• /
• 1995

The extract of Ginkgo bibloba (EGb) is a complex mixture of natural products from the Ginkgo leaves and clinically used for the treatment of cerebral and peripheral circulatory disturbances due to its combined activity of several vasoactive principles. In this study we investigated the action of EGb and its mechanism in isolated rabbit corporal smooth muscle to evaluate the possibility of using this material as a pharmacoerecting agent. Strips of rabbit corpus cavernosum were mounted in organ chambers to measure isometric tension. EGb began to exert an relaxing effect at 1 mg/ml in the submaximally precontracted muscle strips with phenylephrine $(PHE,\;5{\times}10^{-6}\;M)$; causing concentration-dependent relaxation with maximal effect at $3{\sim}5\;mg/ml$. That relaxation was partially inhibited by removal of the smooth muscle endothelium or by pretreatment with a NO scavenger, pyrogallol $(10^{-4}\;M)$ or the guanylate cyclase inhibitor, methylene blue $(10^{-4}\;M)$. Pretreatment with EGb (3 mg/ml) inhibited PHE- $(5{\times}10^{-6}\;M)$ or KCI- (20 and 40 mM) induced contraction of muscle strip. In calcium-free high potassium solution EGb depressed the basal tone of the depolarized muscle strip and inhibited calcium-induced contraction when $CaCl_2$ $(10^{-4}\;M)$ was added. These results suggest that EGb relaxes rabbit corpus cavernosal smooth muscle through multiple action mechanisms that include increasing the release of nitric oxide from the corporal sinusoidal endothelium, sequestration of intracytosolic calcium, and maybe a hyperpolarizing action.