• Korean Journal of Plant Resources
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• v.26 no.1
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• pp.19-25
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• 2013

This study focused on the usefulness of plant extracts for a city organic farm. Insecticidal activity of 8 plant species, plants crude extracts by ethanol and water, against third instar larvae (susceptible strain) of Plutella xylostella was evaluated in this study. Ethanol(25%) extracts of plant materials had better insecticidal activity than water extracts at the room temperature. Insecticidal activity were investigated by leaf disc spray method. Five plant extracts (Capsicum annuum, Chelidoniun majus, Leonurus sibiricus, Coptis japonica, Mentha piperascens) showed over 50% insecticidal activity to P. xylostella at the concentration of $1500mg{\cdot}L^{-1}$. Extract of C. annuum showed the highest insecticidal activity (83.3%) against P. xylostella. Phytotoxicity was not observed on Raphanus sativus and Brassica campestris with spray application. Seed germination and growth of two plants were not affected. Extract of C. japonica revealed 73.3% control efficacy against P. xylostella of R. sativus and showed 70% control efficacy against those of B. campestris, respectively, in plastic house. Insecticidal activity against various insects was observed in C. japonica extract as 87.4% for R. sativus and 74.3% for B. campestris in the field. These results suggested that extracts of C. annuum, C. japonica showed the highest insecticidal activity, and could be used as city farm insecticides for organic farming.

• Korean Journal of Organic Agriculture
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• v.18 no.4
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• pp.573-586
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• 2010

This study was carried out to evaluate characteristics of Chrysanthemum sp. and to bioassay Tetranychus urticae, Nilaparvata lugens, and Aphis gossypii by different extracts part and method. Flower type of Chrysanthemum sp. line was anemone except 0706 line which was pompon. The flowering date was from April to June but 0721 line kept up November. They could overwinter except 0706 line. The Ethanol extracts of 0718 line of flower was high mortality as 63.8% on Tetranychus urticae. Ethanol mixed emulsifier extracts were the highest mortality as 69.4% at 5 days after. Mortality in water extract was lower than in ethanol and ethanol mixed emulsifier extracts. Ethanol mixed emulsifier extracts were higher mortality as 69.4% at 5 days after in 0718 line on Nilaparvata lugens. Mortality in water extract was lower than in ethanol and ethanol mixed emulsifier extracts. On Aphis gossypii, Chrysanthemum flower extracts could decrease the density of aphids in early days but the density of that was increase as time goes by because aphids produce offspring.

• The Journal of the Korea Contents Association
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• v.19 no.1
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• pp.242-255
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• 2019

In this study, we examined the antimicroboal effect against Actinobacillus actinomycetemcomitans and Prevotella intermedia which were the bacteria causing the Periodontopathic by using 34 types of natural plant extracts. Therefore, this study measures growth inhibition activity and Minimum Inhibition Concentration (MIC) of a sample extract with the use of organic solvent extracts in order to analyze the antibacterial effect of natural plant extracts on periodontopathic bacteria. Each of the 34 types of natural plant extracts were extracted by using the ethanol, and subsequently, the size of growth inhibition zone(clear zone, ㎜) of respective extracts were measured through the disk diffusion method. As a result, it was found that the growth inhibitory activity was found for A. actinomycetemcomitans, which is the bacteria causing the Periodontitis, in 13 types of natural plant extracts such as Raphanus sativus, Akebia quinata, Paeonia lactiflora, Belamcanda chinensis, Inula britannics, Houttuynia cordata, Forsythia saxatilis, Gentiana macrophylla, Melia azedarach, Scutellaria baicalensis, Coptis chinensis, Phellodendron amurense, Kalopanax Pictus, etc. In the case of P. intermedia, the growth inhibitory activity was found in 13 types of natural plant extracts such as Raphanus sativus, Angelica acutiloba, Akebia quinata, Belamcanda chinensis, Inula britannics, Houttuynia cordata, Cinnamomum cassia, Aster tataricus, Melia azedarach, Scutellaria baicalensis, Coptis chinensis, Phellodendron amurense, Kalopanax Pictus etc. For A. actinomycetemcomitans, anti-bacterial effect was exhibited in Belamcanda chinensis, Cinnamomum cassia, Kalopanax Pictus, Phellodendron amurense, Coptis chinensis. The Coptis chinensis showed the most excellent growth inhibitory activity in all organic solvent fragment, while P. intermedia showed the growth inhibitory activity in Belamcanda chinensis, Cinnamomum cassia, Meliaazedarach, Phellodendron amurense, and Coptis chinensis.

• Korean Journal of Medicinal Crop Science
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• v.20 no.5
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• pp.331-338
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• 2012

In the present work, mulberry fruit extracts by four extraction processes, namely wet pressing extraction (WPE), hot-water extraction (HWE), enzymatic hydrolysis (EH), and lactic-acid bacteria fermentation (LBF) by Lactobacillus plantarum TO-2100, were analyzed for nutrients and functional compounds. The sugar contents of extracts by WPE, HWE, EH, and LBF were 12.0, 10.9, 14.5, and 14.3 brix, respectively, and the extraction yields by EH and LBF were 1.65 and 1.50 times higher than those by WPE. Among the organic acids, tartaric acid and malic acid contents were the highest in the extracts by WPE. Acetic acid was best extracted by LBF, and citric acid was best extracted by EH. Lactic acid was detected only in LBF. The extracts by EH showed the highest contents of all vitamins with an exception that the extracts by LBF showed the highest contents of the folic acid, vitamin B12, and vitamin C. We also noted that vitamin B group was not detected in the extracts by LBF. The extracts by EH showed the highest contents of all the amino acids, whereas LBF showed the lowest. Polyphenol contents of extracts by EH and LBF were 3.05 and 2.51 times more than those by WPE respectively. Anthocyanin contents were 7.66, 7.14 times higher for EH and LBF compare to WPE. We manufactured mulberry fruit granular teas with different compositions and tested them for their sensory characteristics. We found that 15% mulberry fruit extracts by enzymatic hydrolysis and 85% dextrin composition gave the most satisfactory result.

• Journal of Conservation Science
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• v.23
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• pp.95-102
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• 2008

To investigate bioactive materials for development of natural conservative agent on organic cultural heritage, methanol extracts from 11 wood species which populate in Korea were screened for antifungal and insecticidal activity against 9 wood contaminant fungi and adult of Lasioderma serricorne. Antifungal activity of extracts was tested by using paper disc soaking method and feeder strip test against wood-rot fungi and wood surface contaminant fungi. Among these extracts, the most significant antimicrobial activity was observed from the extract of Phellodendron amurense at 5 mg/disc against Coniophora puteana, Lentinus lepideus, Tyromyces palustris and Aspergillus niger. The insecticidal activity of extracts was examined by topical application against L. serricorne adults. The extracts from Taxus cuspidata and Abies holophylla gave 56.7 % mortality at 25 ${\mu}g$/adult for 24 hr. From these result, the methanol extract from T. cuspidata, A. holophylla and P. amurense described could be useful for conservation of organic cultural heritage against biological deterioration by insect and wood contaminant fungi.

• Journal of Physiology & Pathology in Korean Medicine
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• v.29 no.1
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• pp.27-32
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• 2015

Streptococcus mutans triggers dental caries establishment by two major factors. One is synthesis of organic acids which demineralize dental enamel and the other is synthesis of glucans which mediate the attachment of bacteria to the tooth surface. In the present study, we evaluated the effect of the ethanol extracts of Aconitum koreanum (A. koreanum ) on the growth and acid production of S. mutans. Ethanol extracts of the A. koreanum showed concentration dependent inhibitory activity against the growth and acid production of S. mutans, and produced significant inhibition at the concentration of 0.016 mg/ml compared to the control groups (p<0.05). The extracts inhibited S. mutans adherence to hydroxyapatite treated with saliva, and cell adherence was repressed by 50%, 54% at the concentration of 0.063, 0.125 mg/ml. On the study of activation of glucosyltransferase which synthesizes water insoluble glucan form sucrose, the ethanol extract of A. koreanum showed remarkable inhibition over the concentration of 0.016, 0.031, 0.063 and 0.125 mg/ml (p<0.05). Especially on the concentration of 0.063, 0.125 mg/ml, the extracts suppressed the glucan synthesis by 100%. We analyzed the component of the extracts of A. koreanum. The results showed that the extract of A. koreanum had strong phenolic compound, glycosides and organic acids. These results suggest that A. koreanum may inhibit the caries-inducing properties of S. mutans, and which may be related with strong phenolic compound, glycosides and organic acids.

• Korean Journal of Organic Agriculture
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• v.22 no.2
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• pp.269-280
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• 2014

This study was performed to test the insecticidal and antimicrobial activity of plant extracts from clove, Sophora flavescens Aiton and neem. As the result of antimicrobial activity test, clove extract showed the strongest activity against Botrytis cinerea. In insecticidal activity test, the extract of Sophora flavescens Aiton was the highest against Nilaparvata lugens. The pyroligneous liquor (10%) and emulsified spreader (10%) were added to the extracts of clove and Sophora, respectively, to apply the environment-friendly rice field. In the field treated clove extract, disease damage occurred 49.1% and insect damage occurred 29.5% compared to control plot (100%). In the field treated Sophora extract, disease damage was 56.7% and insect damage was 21.0% compared to control plot (100%). In conclusion, plant extracts from Sophora and clove could control about 50% of disease and about 70% of insect damage that they could be used as environment-friendly resources to control disease and insect in rice farming.

• Korean Journal of Food Science and Technology
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• v.34 no.2
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• pp.244-248
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• 2002

The effects of extracts from bean sprout (Glycine max), dropwort (Oenathe javanica) and radish (Raphanus sativus Var. hortensis for. acanthiformis) by solvent separation on alcohol dehydrogenase (ADH) activity in vitro were investigated. The extracts were obtained from alcohol extracts of bean sprout, dropwort and radish, followed by solvent separation. Aqueous fractions facilitated much higher ADH activity than organic fractions. The facilitating rates of bean sprout, dropwort and radish in aqueous fractions were 125.75%, 104.94% and 87.63%, respectively. Basic fractions showed the highest facilitating rate with about 40%. Also other fractions showed below 20% facilitating rate and didn't show great difference from organic fractions. Phenolic fractions didn't show great effect on ADH activity.

• Microbiology and Biotechnology Letters
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• v.32 no.4
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• pp.352-355
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• 2004

The extracts from 70 different plant natural products were used to investigate the antimicrobial activities against Brachyspira hyodrsenteriae, the causative agent of swine dysentery. Among them, the extracts from Terminalia chehula exhibited the highest antimicrobial activities against B. hyodysenteriae. It showed the antimicrobial activity against B. hyodysensteriae mostly in parts of its shell. Minimum inhibitory concentration (MIC) of the water extracts of T chehula was 12.5 mg/ml. After organic solvent extractions, the ethylacetate extracts exhibited higher antimicrobial activities against B. hyodysenteriae, and their antimicroactivities were similar to that of the tannin. In conclusion, these findings suggest that the extracts from T chebula may be used as animal feed additives for their antimicrobial activities against B. hyodysenteriae.

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.53-53
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• 2022

Modem agricultural production needs to provide sustainable management practices that are eco-friendly and low cost. Plant extracts are a cost-effective and environmentally friendly alternative to synthetic plant growth regulators. This study was therefore carried out to investigate the effects of various plant extracts produced using different extraction methods on the vegetative growth of rice under laboratory and greenhouse conditions. For this study, seventeen plant extracts were made from plant species such as leaves of M. arvense, C. asiatica, M. oleifera, V. radiata, V. unguiculate, P. guajava, A. vera, and A. tuberosum, aboveground plant parts of C. rotundus, M. sativa, and P. frutescens, roots of R. undulatum, tubers of A. sativum, leaves and stems of G. max (cv. Taegwang) as well as rice straw and hulls (cv. Hopyeong). As a test crop, we applied these extracts to rice plants. For the purpose of making our extracts, some plant materials and species were collected in fields and others were purchased from Chonnam Hanyaknonghyup Cooperation (South Korea). Leaves, roots, and aboveground plant parts of plant species were dried, ground, extracted (water, boiling water and ethanol) and fermented. Rice growth promotion effects were determined using plant extracts at 0, 0.05, 0.1, 0.5, and 1% concentrations under petri dish conditions. Seven selected plant extracts were applied to rice seeds with soil drench application or seedling at 3-4 leaf stages with soil and foliar applications under greenhouse conditions. For comparison with extracts, we used urea at 0.6%. Of the 17 water extracts used in this study, 10 extracts reduced rice growth, but the other 7 extracts (P. guajava, A. vera, A. tuberosum, M. sativa, A. sativum, and G. max) increased growth by 40-60% on compared to the control in Petri dish bioassay. Thus, these 7 extracts were selected for further study. Under greenhouse conditions, rice growth also increased by 20-40% when the same 7 extracts were applied to rice seeds using soil drench application. Furthermore, at the 3-4 leaf stage rice growth also increased 30-80% or 30-60% when the same 7 extracts were applied using soil and foliar applications. Overall, the 7 extracts produced higher rates of growth promotion when soil drench application was used than when foliar application was used. In the case of boiling water and ethanol extracts, rice growth increased only 20% in response to both soil drench and foliar application of the same 7 extracts. Rice growth promotion was greater when extracts were produced using water extraction method than boiling water and ethanol extraction methods. Most notably, the 7 water extracts used in this study produced higher rates of growth promotion than urea at 0.6% which is typically used for crop growth promotion. Overall, the 7 water extracts when applied using soil drenching method can be used as effective growth promotors of rice in organic agriculture.