• Biomolecules & Therapeutics
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• v.3 no.1
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• pp.28-33
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• 1995

Effects of Ginkgo biloba leaf extract (GBE) and its components kaempferol-coumaroyl glucosyl rhamnoside (Kc), quercetin-coumaroyl glucosyl rhamnoside (Qc), ginkolide (G) and bilobalide (B) on blood pressure and on the levels of neurotransmitters in the spontaneously hypertensive rat brain were examined. Blood pressure decreased about 10 mmHg after administration of GBE but without significance. The concentration of norepinephrine increased (3 times) and that of DOPAC was decreased (38%) after administration of Qc. And 3-MT concentration was increased (36%) by Kc administration in striatum. While Qc administration increased the concentration of Ach (260%) and Ch(29%) significantly, B administration increased Ch concentration in cerebral cortex.

• KSBB Journal
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• v.22 no.1
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• pp.58-61
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• 2007

A Insecticidal effect of Ginkgo biloba leaves extract was conducted for Dermatophagoides pteronyssinus as a predominant species in korea. D. pteronyssinus has been cultured in constant temperature and humidity chamber at the 25$^{\circ}C$ and 75% of relative humidity. The mortality of mites was determined by counting the dead bodies for every hour within 48 hours with pin hall microscope after treated by Ginkgo biloba leaves extract spreaded on 0.1 g of mass cultured media. The sequence of mortality for D. pteronyssinus are as follows, bilobalide was 91.6%, 80$^{\circ}C$ water extract was 82.8%, second water fraction was 75%, ethyl acetate fraction from 80$^{\circ}C$ water fraction was 73%, first ethyl acetate fraction from 80$^{\circ}C$ water extract was 69.4%, putaltrin was 65%, distilled water was 58%, methanol extract was 57.8%, Ginkgolide-A was 57.1 %, ethyl acetate fraction of 80$^{\circ}C$ water extract was 55%, respectively. From the these results we conclude that the bilobalide is the most effective component in the Ginkgo biloba leaves extract having insecticidal effect on house dust mite.

• Proceedings of the Korean Society of Plant Biotechnology Conference
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• 2005.04a
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• pp.182-182
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• 2005

• Proceedings of the Korean Society of Plant Biotechnology Conference
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• 2004.10a
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• pp.204-204
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• 2004

• Clean Technology
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• v.29 no.3
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• pp.200-216
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• 2023

Ginkgo leaves are considered waste biomass and can cause problems due to the strong insecticidal actions of ginkgolide A, B, C, and J and bilobalide. However, Ginkgo leaf biomass has high organic matter content that can be converted into fuels and chemicals if suitable technologies can be developed. In this study, the effect of pyrolysis temperature, minimum fluidized velocity, and Ginkgo leaf size on product yields and product properties were systematically analyzed. Fast pyrolysis was conducted in a bubbling fluidized bed reactor at 400 to 550℃ using silica sand as a bed material. The yield of pyrolysis liquids ranged from 33.66 to 40.01 wt%. The CO₂ and CO contents were relatively high compared to light hydrocarbon gases because of decarboxylation and decarbonylation during pyrolysis. The CO content increased with the pyrolysis temperature while the CO₂ content decreased. When the experiment was conducted at 450℃ with a 3.0×U_mf fluidized velocity and a 0.43 to 0.71 mm particle size, the yield was 40.01 wt% and there was a heating value of 30.17 MJ/kg, respectively. The production of various phenol compounds and benzene derivatives in the bio-oil, which contains the high value products, was identified using GC-MS. This study demonstrated that fast pyrolysis is very robust and can be used for converting Ginkgo leaves into fuels and thus has the potential of becoming a method for waste recycling.

• 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 $ONOO^{-}$.