• Journal of fish pathology
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• v.24 no.3
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• pp.289-295
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• 2011

The in-vitro eliminative effects of against three types of herbal extract and formalin Ichthyophthirius multifiliis were examined. All parasites were killed within one hour after exposure to the 500 fold dilution of the complex herb extract whereas the 10 fold dilution of the fertilized solution of Salvia plebeia R. Br. killed all parasites within one hour after exposure. The 5,000 fold dilution of the extracts of Ginkgo biloba leaves killed all parasites within one hour after exposure. As a comparative agent, formalin killed all parasites within one hour at 100 ppm. As the results, the extracts of Ginkgo biloba leaves extracts have the most eliminative ability against the parasite. No differences were found among different parasite density in eliminative effects of the three types of herbal extracts and formalin. Also there were no changes in the fish gill tissues after exposure for two hours to the 5,000 fold dilution of the extract of Ginkgo biloba leaves.

• 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.

• Korean Journal of Pharmacognosy
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• v.30 no.3
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• pp.306-313
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• 1999

Polyphenol Oxidase(PPO) was purified from an extract of Ginkgo biloba leaves by ammonium sulfate fractionation followed by sephadex G-150 column chromatography, which resulted in a 18-fold increase in specific activity. The enzyme was most active at pH 8.5 and the temperature optimum for the PPO catechol oxidation reaction was $45^{\circ}C$. Heat inactivation studies showed that heating for 7, 9 and 48 min, at 80, 70 and $60^{\circ}C$ respectively caused a 50% loss in enzymatic activity and that the enzyme was completely inactivated after heat treatment at $90^{\circ}C$ for 60 min. Km values of the PPO for catechol, hydroquinone and 4-methylcatechol derived from Lineweaver-Burk plots were $6.06\;{\times}\;10^{-4}M,\;1.02\;{\times}\;10^{-3}M,\;1.41\;{\times}\;10^{-3}M$ respectively. Of the substrates tested, 4-methylcatechol was oxidized most readily and the enzyme did not oxidize monophenols. The enzyme datalyzed browning reaction was completely inhibited in the presence of reducing reagents, namely ascorbic acid, cysteine, glutathione, 2-mercaptoethanol, potassium metabisulfite at 0.5 mM level. Sodium chloride showed very little inhibition effect on Ginkgo biloba leaves PPO. Lineweaver-Burk analysis of inhibition data revealed that the inhibition by cysteine, 2-mercaptoethanol, potassium cyanide was competitive with ki values of $1.1\;{\times}\;10^{-5}M,\;2.4\;{\times}\;10^{-5}M,\;8\;{\times}\;10^{-5}M$, respectively. Among the divalent cations, $Cu^{2+}ion$ was a strong activator on PPO and $Mn^{2+}ion$ was little or no effect on PPO activity $Ni^{2+}ion$ was an inhibitor on PPO.

• Archives of Pharmacal Research
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• v.29 no.12
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• pp.1074-1079
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• 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 $ONOO^{-}$.

• Biomolecules & Therapeutics
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• v.14 no.3
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• pp.160-165
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• 2006

Since platelet-activating factor (PAF) is involved in inflammation, allergic response and anaphylactic shock, PAF receptor antagonists may have potential for controlling these disease conditions. The extract of the leaves of Ginkgo biloba having a higher content of terpenoids (12%) with flavonoids (24%) (YY1224) was prepared in order to obtain the increasing PAF antagonistic activity. As expected, YY1224 showed a higher PAF antagonistic binding affinity ($IC_{50}\;=\;0.09\;{\mu}g/ml$) using $[^3H]PAF$ and rabbit platelets as ligand and receptor source, compared with an $IC_{50}$ of $>\;100\;{\mu}g/ml$ by Egb 761, a standardized extract. YY1224 also showed a higher inhibitory activity against PAF-induced platelet aggregation and NO production from lipopolysaccharide-treated RAW 264.7 cells. In addition, it protected PAF-induced death in mice by oral administration at 15 mg/kg. All these results suggest that YY1224 may show favorable effects on PAF-related disorders.

• Korean Journal of Organic Agriculture
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• v.29 no.1
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• pp.97-109
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• 2021

Plant parasitic nematodes are causing significant damage in crop production. There is a need to develop eco-friendly nematicide that reduces the damage of nematode and has little effect on the environment and human. In this study, we have isolated a substance having nematicidal activity from Ginkgo biloba L. outer seedcoat. Studies of G. biloba L. outer seedcoat are insufficient compared to the seed and leaves due to their odor and toxicity. The dried G. biloba L. outer seedcoat was extracted with dichloromethane:methanol (1:1) and fractionated into hexane, ethyl acetate and H₂O. Four steps TLC were performed from EtOAc fraction to purely isolate GB4-3 with nematicidal activity. To compare nematicidal activity, G. biloba L. seedcoat methanol extract and purified GB4-3 were investigated in terms of treatment concentration and time. As a result, the nematicidal activity increased with concentration and time. In the place treated with 20 ㎍/mL of crude G. biloba L. seedcoat MeOH extract, strong activity appeared after 12 hours, and 46% nematicidal activity shown after 18 hours. About 69% of nematicidal activity was confirmed in the place where GB4-3 purified from outer seedcoat was treated with 20 ㎍/mL, and the possibility of development as nematicide was very high. This study could be used as a basic data for the development of a nematode preparation from G. biloba L. outer seedcoat.

• 한국생물공학회:학술대회논문집
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• 2003.04a
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• pp.134-137
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• 2003

Acaricide effect against Tetranichus urticae, Myzus persica, Spodoptera litura and Plutella xylostella with the Ginkgo biloba leaves extracts was reviewed. This result was motality 74.3%, 88.7% respectively, after tretment 24hr, 72hr about $80^{\circ}C$ water extract(GLW80, 1%) of Tetranichus urticae and the insecticide took effect showed its effect in some 50% against the other three. But, motality of Tetranichus urticae against 10% GLW80 showed its 90.6%, 98.3% after tretment 24hr and 48hr.

• Proceedings of the PSK Conference
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• 2003.10b
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• pp.137.3-138
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• 2003

The major active components of EGb 761, extract of Ginkgo biloba leaves, include flavonoid glycosides and unique diterpenes known as ginkgolides. Ginkgolides are potent inhibitors of platelet activating factor. In this study, we investigated antiinflammatory activity of ginkgolides on the Complete Freund"s Adjuvant (CFA)-induced mice. The ginkgolides were extracted from commercially available EGb 761. This extracting procedure was done by sequential treatments of the EGb 761 with chloroform, methanol, and water. (omitted)tted)

• Current Research on Agriculture and Life Sciences
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• v.9
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• pp.61-69
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• 1991

Free phenolic acid, esterified and insoluble phenolic acid extract were extracted from Ginkgo nuts and leaves. Antioxidative effectiveness was measured by Peroxide value and TBA value at each extract, control, 0.02%(w/w) BHA and BHT in corn oil, at $45{\pm}1^{\circ}C$ and dark thermo static oven for 45 days. Laboratory tube was added by BHA, BHT, separated free phenolic acids, esterified and insoluble-bound phenolic acid extract of Ginkgo nuts and leaves 127, 95, 140, 121, 280 meq/kg, oil. On the other hand, at the same condition TBA values of each antioxidative matter were 0.430, 0.153, 0.059, 0.175, 0.260, 0.187, 0.160, 0.174, 0.195. This result remarkably appeared antioxidative effectiveness in corn oil substrate, ${\rho}$-Hydroxybenzoic acid, Syringic acid, Gallic acid, Protocatechuic acid, Pyrogallol, Caffeic acid, Coumaric acid, trans-Cinnamic acid, Phloroglucinol.

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