• Korean Journal of Agricultural and Forest Meteorology
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• v.3 no.2
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• pp.114-120
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• 2001

Ginkgo biloba L. has been planted in the city as street trees because reported as resistant species to air pollutant. Especially, the trees planted on the street of 'Cheongro', Mt. 'Nam', and 'Jamsil' have been exposed to air pollutant for a long time. This study was conducted to examine chlorophyll contents and genetic variation of Ginkgo biloba in the areas. Chlorophyll contents measured in the above three areas were variable although the the diameter at breast height measured in 'Cheongro' and Mt. 'Nam' were constant. In addition, the result showed positive relation between chlorophyll contents and DBH in this study. Eight enzyme systems were analyzed in megagametophytes which were collected in the areas and separated to two groups based on chlorophyll contents. All the enzymes appeared to be polymorphic : Got-2, Pgi-2, Pgm, Acon, Mnr, Mdh, Skdh, and 6Pgd. The sensitive (S) groups varied from 1.253 to 2.571 in the genetic diversity and the tolerant (T) groups ranged from 1.416 to 2.825. The observed single locus heterozygosities (H$_{0}$) ranged from 0.056 to 0.611 in the S groups, and from 0.179 to 1.643 in the T groups. The expected heterozygosities (H$_{e}$) ranged from 0.208 to 0.629 in the S groups and from 0.321 to 0.658 in the T groups. In addition, the H$_{0}$ values averaged over all loci were 0.326 for the T groups and 0.299 for the S group, respectively. A difference between the two groups was 0.027. The T groups had the unique alleles and genotypes and all the parameters for genetic diversity showed that the T groups had higher genetic diversity than the S groups.s. genetic diversity than the S groups.

• Biotechnology and Bioprocess Engineering:BBE
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• v.9 no.1
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• pp.35-40
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• 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 Plant Biology
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• v.35 no.4
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• pp.359-364
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• 1992

The vascular cambium in Ginkgo biloba seedling began to differentiate in the cotyledonary node, and then the differentiation proceeded bidirectionally from the cotyledonary node toward the stem and root. In tangential view, procambium at the early developmental stage was a homogeneous structure consisted of almost similar cells in shape, and at the later stage the procambium became a heterogeneous one consisted of long cells and short cells. Such a differentiation pattern in the cotyledonary node was similar to that in the stem. However, it was different from that in the root. Fusiform initials and ray initials consisting the vascular cambium were originated from the long cells and the short cells, respectively. The long cells and the fusiform initials in the cotyledonary node were shorter and wider than those in the first internode.ernode.

• Preventive Nutrition and Food Science
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• v.3 no.4
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• pp.324-328
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• 1998

We screened the methanol extracts from 133 plant species growing in Korea for antimicrobial activity against enterohemorrhagic Escherichia coli 0157 : H7. Those are selected from three plant grouping ; traditional medicinal herbs, edible plants, and flowers. They were tested by disk diffusion assay. From evaluation of the inhibition zone diameter of microbial growth, we found that the flower extract of Rhododendron Schilpenbachii Max had the most significant antimicrobial activity against this bacteria. Extracts from most of the vegetables and plants did not show antimicrobial activity except for the leaves of Ginkgo biloba L. and seeds of Prunus Dallicina L. did not show antimicrobial activity except for the leaves of Ginkgo biloba L. and the seeds of Prunus sallicina L.

• KSBB Journal
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• v.11 no.6
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• pp.726-732
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• 1996

Selective adsorption of plant metabolites from a polar dilute solution onto a polycarboxyl ester sorbent (XAD-7) was investigated. Experimental results demonstrated that neutral resins could selectively concentrate specific flavonoids from dilute aqueous mixtures. Adsorption was dependent on the pH of medium, dosage of the resins and medium composition. Especially the medium composition was a key factor for the selective adsorption and it was found that the selective adsorption was dependent on specific sorbent-sorbate-medium characteristics. Under the optimum condition, selectivity increased up to 85% and the yield of recovery was approached to 98%. It was also found that XAD-7 adsorbed flavonoids in the order of hydrophobicity.

• Biotechnology and Bioprocess Engineering:BBE
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• v.9 no.1
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• pp.41-46
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• 2004

The influence of various culture conditions on growth and ginkgolides (GKA and GKB), and bilobalide formation in callus and suspension cultures of Ginkgo biloba were investigated. Callus induced from the leaf petioles exhibited distinct morphological and physiological responses. The cell biomass and ginkgolides content varied among the cell lines; brownish callus lines produced high levels of ginkgolides and bilobalide in spite of poor cell growth. Among the culture media used, MS medium showed significant effect on cell growth and ginkgolides production. Low concentration of sucrose (3%) improved cell growth, while higher sucrose levels (5 and 7%) improved ginkgolides production. Cultivation of callus cultures above 28$^{\circ}C$ dramatically reduced their growth rate; however the cell lines grown at 36$^{\circ}C$ showed increased levels of bilobalide content. A 2.5-L balloon type bubble bioreactor (BTBB) was successfully developed for the cell growth and ginkgolides production.

• The Korean Journal of Pesticide Science
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• v.5 no.1
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• pp.24-29
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• 2001

This study was conducted to investigate insecticidal activities of Ginkgo biloba (L.) leaves-derived bilobalide and its hydrolysis and oxidation products against adults of Nilaparavata lugens Stal. To find out active insecticidal moiety of bilobalide, decomposed intermediates and derivatives of bilobalide were made by hydrolysis, oxidation, and acetylation. The structures of hydrolysis product by base and oxidation product by acid were identified as cyclopentenone analogues and trilactone sesquiterpene from dehydration of bilobalide, respectively. Insecticidal activities of the decomposed intermediates and the derivatives of bilobalide decreased in the order of bilobalide, monoacetate, ginkgolide C, oxidation product, diacetate, and hydrolysis product. Therefore, trilactone structure of bilobalide may be essential for its insecticidal activity.

• Journal of the Korean Wood Science and Technology
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• v.46 no.2
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• pp.125-131
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• 2018

This study was conducted to understand and to compare the qualitative aspects of anatomical characteristics in compression wood (CW), lateral wood (LW), and opposite wood (OW) in a stem of Ginkgo biloba. The qualitative analysis was examined by optical microscopy and scanning electron microscopy. CW in Ginkgo biloba disks were dark brown in color, and the OW and LW were light brown in color. CW and OW showed abrupt transitions from earlywood to latewood, while LW showed a gradual transition. Cross sections of CW presented circular tracheids with angular outlines, many intercellular spaces, and varying sizes of lumens. Cross sections of LW and OW showed rectangular tracheids, fewer intercellular spaces, and varying sizes of lumens. In radial sections, CW showed an irregular arrangement of tracheids in earlywood, while LW and OW showed comparatively regular arrangements. Slit-like bordered pits on the tracheid cell wall, piceoid pits in the crossfield, and a few spiral checks were present in CW. LW and OW showed bordered pits with slightly oval-shaped apertures, as well as cuppresoid pits in the crossfields. Rays were primarily uniseriate, with few biseriate rays in the tangential sections of CW, LW, and OW. The tips of the tracheids were branched in CW but had a normal appearance in LW and OW.

• Journal of Microbiology and Biotechnology
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• v.8 no.3
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• pp.237-244
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• 1998

A study was carried out to elucidate the relation between the production of flavonol glycosides and the change of phenylalanine ammonia-lyase activity in cell suspension cultures of Ginkgo biloba by the unassisted and synergistic effects of various factors. The quercetin production showed a mixed-growth-associated pattern in cell suspension cultures. Fluorescent light and UV radiation increased phenylalanine ammonia-lyase (PAL) activity, and resulted in the increase of the production of quercetin and kaempferol ten- and four-fold, respectively, as compared to that obtained in the normal culture condition. The cell growth of Ginkgo biloba was enhanced .at higher temperatures whereas the quercetin production was at its maximum at low temperatures. Moreover, the quercetin production was increased by temperature change during the culture period. In particular, the quercetin production was at the highest level when the culture temperature was elevated from $10^{\circ}C\;to\;30^{\circ}C$. The addition of phenylalanine as a precursor in the culture medium stimulated an 8-fold increase in the production of quercetin; the addition of naringenin caused a l0-fold increase. The quercetin production was also greatly increased by feeding enzyme cofactors such as 2-ketoglutarate and ascorbic acid in the culture medium, but specific PAL activity was not increased except with phenylalanine feeding. The synergistic effect of UV radiation and naringenin feeding was observed, resulting in the increase of flavonol glycoside production at a rate higher than in any other case investigated.

• Korean Journal of Plant Resources
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• v.24 no.4
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• pp.461-471
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• 2011

This study was carried out to establish an in vitro culture method of callus having a high antioxidant activity from Ginkgo biloba L. Leaf explants were cultured on Murashige and Skoog's medium supplemented with various growth regulators. The explants were incubated in the dark or 3,000 lux cool-white light. Methanol extracts from incubated callus were evaluated for scavenging activity of the free radicals using DPPH. The best callus growth rate was achieved in MS medium combined with 10 ${\mu}M$ NAA and 5 ${\mu}M$ kinetin in the light condition. Total antioxidant activity of cell aggregates in suspension culture [MS medium supplemented with 10 ${\mu}M$ NAA in the light] was up to 80% of ascorbic acid. By means of HPLC analysis, quantification of the quercetin dehydrate and keamperol profiles from suspension callus was compared. Contents of quercetin dehydrate and keamperol from leaf extracts were 0.07 and 2.24 ${\mu}g/20{\mu}l$, and those from callus 0.56 and 0.18 ${\mu}g/20{\mu}l$, respectively.