• Korean Journal of Weed Science
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• v.17 no.1
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• pp.52-58
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• 1997

Rice (Oryza sativa L.) contains water-soluble substances that inhibit the germination of Echinochloa crus-galli. This study investigated the allelopathic potential of rice in which rice had been grown with E. crus-galli in the field. Extracts of forty-seven rice varieties were screened for allelopathic potential in the laboratory. Double distilled water was used as a control. Based on the germination percentage, the varieties may be classified in the following order of decreasing inhibition : Namweon(36%) and Gyehwa(38%) hulls extracts and Sambaeg(43%) and Seoan(46%) leaves extracts. In the comparison of allelopathic activity test between leaves and hulls extracts, hulls extracts contain more allelopathic toxic substances. In the effect of concentration treatment on the six levels of extract solutions(3, 6, 12, 25, 50, 100%, v/v) germination percentage was significantly inhibited as the extract concentration increased. The highest concentration(100%) caused the greatest reduction in E. crus-galli. Allelopathic potential effects were significantly different among the various varieties and between '94 and '95 year extracts. The results indicate that there are genetic differences among varieties for allelopathic potentiality on E. crus-galli. Allelopathic potential in the ecological aspects can be decided through variety selection.

• Food Science and Preservation
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• v.13 no.3
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• pp.273-278
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• 2006

In order to help the preservation of the cherry tomato and unshiu orange, antimicrobial paper incorporating grapefruit seed extract and zeolite was applied to the package. Cherry tomato and unshiu orange were packed in a box (38x25x20 cm) attached with antimicrobial paper and then stored respectively at $5^{\circ}C$. During the storage, weight loss, pH total acidity, soluble solid content microbial load and decay ratio were measured as quality indices. pH increase in cherry tomato was observed until 20 days, and decreased with litle difference between the packaging treatments thereafter pH and total acidity decrease in unshiu orange were shown till 30 days, and abrupt change was revealed by 40 days. This was due to physiological disorders. The microbial loads of total aerobic bacteria, and yeast/mold count were suppressed during storage by the box packaging incorporated with antimicrobial agents, which also contributed to reducing the decayed cherry tomato and unshiu orange. Antimicrobial paper was useful fur the reduction of microbial load in cherry tomato and unshiu orange pear without other quality deterioration.

• Journal of Oral Medicine and Pain
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• v.35 no.1
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• pp.19-29
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• 2010

Phytoncide, essential oil of trees, has microbicidal, insecticidal, acaricidal, and deodorizing effect. The present study was performed to examine the effect of phytoncide on Candida albicans, which is a commensal colonizer of the mucous membranes but has become an opportunistic pathogen. C. albicans was incubated with or without phytoncide extracted from Hinoki (Chamaecyparis obtusa Sieb. et Zucc.; Japanese cypress) and then changes were observed in its optical density, cell viability and morphology. As concentrations of phytoncide added to the culture medium increased, optical density and cell viability of C. albicans decreased. Minimum inhibitory concentration of phytoncide for C. albicans was observed to be 0.25%, and minimum fungicidal concentration was 0.5%. Numbers of morphologically atypical cells with electron-dense cytoplasm and granules and increased with increasing concentration of the phytoncide. At higher concentrations of phytoncide, compartments and organelles in the cytoplasm became indistinguishable. The overall results indicate that the phytoncide used for this study has a strong antimicrobial activity against C. albicans. Therefore, the phytoncide may be used as a candidate for prevention and therapeutic agent against oral candidiasis.

• Journal of Korean Society of Forest Science
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• v.101 no.2
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• pp.175-184
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• 2012

This study was conducted to develop new mattress systems with vegetation base materials for protecting stream bank and rapid rehabilitation. Vegetation base materials are primarily compounded with fine soil, organic composts and peat moss as plant fibers, a water retainer and a soil improver. Peat moss can usually provide necessary natural fibers and organic materials in soil. Especially, peat moss can absorb up to 25 times its own weight in water and is therefore valued as a water retainer to prevent drying effect of vegetation base materials which can harm the growth of vegetation in mattresses. Normally mattress systems resist the lateral earth pressures or stream power by their own weight. Therefore, filled materials must have suitable weight, compressive strength and durability to resist the loading, as well as the effects of water and weathering. In this project, 100 to 200-mm clean, hard stones were basically specified, and about 50-mm rubbles were also used. Test application of new mattress system carried out in the stream bank of a small stream in the Gwangreung experimental forest, belonging to Korea Forest Research Institute (KFRI) in December 16th, 2006. As a result of the monitoring of vegetation coverage of test application plots (each plot size is 4 by 2 m), the coverage of all plots reached 100% in the end of May, 2007 (approximately 50 days passed after the first gemination of vegetation). The coverage of the plots using big hard stones and organic composts and the plots containing peat moss increased more rapidly. The results show that peat moss is effective to retain soil moisture and establish more sound environment for vegetation gemination.

• Journal of Korean Society of Forest Science
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• v.80 no.4
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• pp.360-368
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• 1991

Utilizing chi-square test statistics, inter-species association and covariation were analyzed for the 37 woody plant species in a deciduous forest dominated by Quercus mongolica and Q. variabilis. within 50 temporarily established $20m{\times}20m$ square quadrats, the association for each pair of species was presented based on the presence-absence parameters. Acer palmatum had significant positive association with Acer mono and Kalopanax pictus, but negative association with Pinus densiflora. Other positively associated species pairs were Prunus sargentii-Macckia amurensis, Quercus serrata-Kalopanax pictus, Symplocos chinensis var. pilosa-Euonymus oxyphyllus, and Ulmus davidiana var. japonica-Lindera obtusiloba. The covariation far each pair of species was evaluated based on the quantitative measures, density and basal area. Overall results showed that the association and covariation values among species generally agreed with each other. Because covariation was calculated by density and basal area of the tallied species in the sample plots, the number of species pairs of covariation tended to be greater than those of association. Especially, Pinus densiflora, considered to be pioneer species in the successional stage, had negative covariation with most of climax species. These ecological information could be applied to silvicultural practices, such as ecosystem classification, establishment of mixed hardwood forest, and tending operations for marking crop trees and desirable species.

• Journal of Oral Medicine and Pain
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• v.32 no.1
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• pp.45-55
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• 2007

Plant extract has attracted considerable interest in oral disease therapy. The present study was performed to observe the antibacterial effect on cariogenic Streptococcus mutans GS5 and Streptococcus sobrinus 6715, and periodontopathic Actinobacillus actinomycetemcomitans Y4 of phytoncide from Chamaecyparis obtusa Sieb. et Zucc employing the measurement of optical density, viable cell counts, and antibiotic sensitivity. The results were as follows: 1. Minimum inhibitory concentration of the phytoncide for S. mutans, S. sobrinus, and A. actinomycetemcomitans was observed to be 0.5%, 1%, and 0.2%, respectively. 2. Minimum bactericidal concentration of the phytoncide for S. mutans, S. sobrinus, and A. actinomycetemcomitans was determined to be 0.5%, 2%, and 0.2%, respectively. 3. The bacteria exposed to the phytoncide become more sensitive to antibiotics. The phytoncide enhanced significantly antibacterial activity of ampicillin against S. mutans and S. sobrinus. It also increased significantly the activity of penicillin and amoxicillin against S. sobrinus. In contrast, the phytoncide augmented the activity of amoxicillin and cefotaxime against A. actinomycetemcomitans but the increase was not statistically significant. The overall results indicate that phytoncide from Chamaecyparis obtusa Sieb. et Zucc used for this study has a strong antibacterial activity against cariogenic and periodontopathic bacteria and that it also has permeabilizing effect on certain antibiotics against these bacteria. Therefore, the phytoncide may be used as a candidate for prevention and therapeutic agent against oral infectious disease including dental caries and periodontal disease.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.1
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• pp.14-18
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• 2009

This study was to determine the inhibitory effect against food borne pathogens of ethanol and water extracts from leaf, stem and root of Orostachys japonicus. On the paper disc assay, no detectable bactericidal activity in the water extracts from leaf, stem and root of Orostachys japonicus and ethanol extracts form stem and root of Orostachys japonicus was shown. However, ethanol extract of Orostachys japonicus leaf showed the highest antimicrobial activity. Minimum inhibitory concentration (MIC) of ethanol extracts was determined to range from 0.05 to 0.1% in leaf of Orostachys japonicus against gram positive bacteria and yeast. Antimicrobial activity of ethanol extracts was stable by heating at $121^{\circ}C$ for 15 min, and not affected by pH $2{\sim}10$ except for B. subtilis. These findings suggest ethanol extract from leaf of Orostachys japonicus may be useful as natural preservative.

• Journal of Plant Biotechnology
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• v.45 no.3
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• pp.279-286
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• 2018

Citrus grandis Osbeck pericarp is used as tea, herbal medicine, etc., but is not commercialized in various ways. So, in this study, we identified potential for use of Citrus grandis Osbeck as health functional foods, cosmetics and food preservatives. Methanol extract of Citrus grandis Osbeck pericarp was fractionated with hexane, dichloromethane, ethyl acetate and butanol, to quantitatively analyze total phenol and flavonoid, and investigate antioxidative and enzyme inhibitory activities. Total phenol and flavonoid contents were highest in ethyl acetate fraction, FRAP and ORAC results also revealed highest activity in proportion to total phenol content. DPPH radical scavenging activity revealed that ethyl acetate, butanol and dichloromethane fraction manifested highest activity without significant difference. However, dichloromethane fraction revealed higher TEAC value and tyrosinase inhibitory activity than ethyl acetate fraction, and hexane fraction manifested best results with superoxide radical scavenging activity and ${\alpha}-glucosidase$ inhibitory activity. Antimicrobial activity also revealed best effect in dichloromethane and hexane fractions. So, based on the following results, use of dichloromethane fraction as material of natural functional cosmetics, ethyl acetate fraction for health functional foods, and hexane fractions for pharmaceuticals and food preservatives, would be most practical for product development.

• Journal of Life Science
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• v.27 no.3
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• pp.339-345
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• 2017

Carotenoids are natural lipid-soluble pigments, which are produced primarily by bacteria, algae, and plants. Many studies have focused on the identification, production, and utilization of natural sources of astaxanthin from algae, yeast, and crustacean byproducts as an alternative to the synthetic pigment, which is mostly used today. The aim of the present study was to identify a mutant of Paracoccus haeundaensis by exposure to UV and ethyl methanesulfonate (EMS). The mutant was then exposed to nutrient stress conditions to isolate an astaxanthin-hyperproducing strain, followed by characterization of the mutant. The survival rate decreased in accordance with an increase in the UV exposure time and an increase in the EMS concentration. A mutant of the original P. haeundaensis strain was identified that showed hyperproduction of astaxanthin following exposure to UV irradiation (20 min) and EMS treatment (0.4 M concentration). The optimal culture conditions for the PUE mutant were $25^{\circ}C$, pH 7-8, and 3% NaCl. The effects of various carbon and nitrogen sources on the growth and astaxanthin production of PUE were examined. The addition of 1% raffinose and 3% potassium nitrate influenced cell growth and astaxanthin production. The selected mutant exhibited an increase of 1.58 folds in astaxanthin content compared to initial wild type strain. A genetically stable mutant strain obtained using mutagen (UV irradiation and EMS treatment) may be a suitable candidate for further industrial scale production of astaxanthin.

• Proceedings of the Korean Journal of Food and Nutrition Conference
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• 2003.07a
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• pp.82-82
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• 2003

오디는 옛부터 보혈자음(補血滋陰), 생진윤조(生津閏操), 현훈이명(眩最耳鳴), 심계실면(心悸失眠), 수발조백(鬚髮早白) 등을 치료하는 효능을 가진다고 알려져 있다. 상심자(桑 子)라 하여 뽕나무 열매로서 한방에서 상심(桑 ), 상실(桑實), 오심(烏 ), 흑심(黑 ) 등으로 지칭되며, 뽕나무과(Moraceae)에 속하는 뽕나무(Morus alba L)의 성숙한 과실로 취화과(聚花果)에 속하며 작은 수과(瘦果)가 많이 모여 이루어진 장원형으로 길이 1 내지 2 cm, 지름 0.5 내지 0.8 cm이며 황갈색, 갈홍색 또는 암자색을 띠고 짧은 줄기가 있다. 작은 수과(瘦果)는 난원형으로 조금 납작한 편이며, 길이는 약 2 mm, 너비는 약 1 mm 이고 육질의 화편(花片) 4개가 둘러싸고 있다. 그러나 아직까지는 오디에 대하여 자연과학적인 연구방법을 이용하여 구체적으로 연구된 바가 많지 않다. 또한 이의 생리활성 성분에 대해서도 그 작용과 연관지어 보고된 바가 많지 않다. 뇌졸중 가운데 뇌조직으로 가는 혈액 공급의 감소 혹은 차단으로 발생되는 허혈성 뇌졸중(ischemic stroke)은 전체 뇌졸중 환자의 약 80%정도를 차지하고 있으나 아직까지 뇌신경세포 손상기전의 복잡성 등으로 뇌졸중으로 발생하는 뇌신경세포의 손상을 보호해 줄 수 있는 물질이 개발되어 있지 못한 실정이다. 한편, 천연물로부터 뇌허혈 보호작용을 가지는 물질의 도출은 주로 한방에서 처방을 중심으로 이루어지고 있으며, 따라서 처방으로부터 신경보호작용을 가지는 물질의 도출은 그 처방에 함유되어 있는 각종 생약이 갖는 다양한 활성으로 인해 어려운 점이 있으며, 비록 효과가 있다고 하더라도 과학적인 입증자료가 매우 미비한 실정이다. 이에 본 연구에서는 위에 언급된 자료를 토대로 오디추출물이 뇌허혈에 효과가 있을 것이라는 가정하에 in vitro system을 이용하여 오디추출물의 신경보호작용기전을 검색하고자 DPPH radical 의 생성억제효과, PC12 cell line을 이용한 산화적 스트레스에 의한 오디추출물의 방어효과, LSP에 의하여 활성화된 BV-2 cell에 미치는 영향 등을 검색하였다. 오디의 DPPH 소거활성은 단일화랍물인 bacicalein과 유사한 효과를 나타냈으며 PC12 cell line을 이용한 산화적 스트레스에 의한 오디의 방어 효과는 LDH activity를 행한 결과 농도 의존적으로 LDH 유리 량을 감소시켰다. 뇌손상시에 오디추출물의 염증방어 효과를 관찰하기 위하여 microglial cell line인 BV2 세포주를 선택하여 배양한 후 LPS로 자극을 준 후 일차적인 염증지표인 NO양을 측정한 결과 BV2 cell에 LPS 100 ng/ml을 처리하는 경우 nitrite량이 유의적으로 증가하였는데 이때 오디추출물을 1, 5, 10 ug/ml의 용량으로 처리하는 경우 역시 저농도에서 NO생성량을 감소시켰다. 정리해보면 뽕나무과 식물인 오디는 신경보호효과가 있는 것으로 사료되는데 이러한 효과는 아마도 오디의 항산화효과에 기인한 것으로 추정된다.