Background: The objective of this study were to determine the antibacterial activity and antibiotic activity-enhancing effect of 70% ethanol extract of the root of Rumex japonicus Houtt. and its fractions when used in combination with gentamicin against aerobic skin flora. Methods and Results: The antibacterial activity and antibiotic (gentamicin) activity enhancing effect against aerobic skin flora were determined using the disc diffusion assay. Chloroform fraction (CF) and ethyl acetate fraction (EF) showed higher activities against Staphylococcus aureus and Staphylococcus epidermidis than those shown by other fractions. Regarding the antibiotic (gentamicin) activity-enhancing effect against aerobic skin flora, the n-hexane fraction (HF) and CF showed strong activity. The combination of HF and CF with gentamicin was evaluated using the broth dilution assay to determine the inhibitory effect on the growth of aerobic skin flora. The combination of CF with gentamicin exhibited the highest inhibitory effect on the growth of S. aureus and S. epdermidis. MTT assay performed to determine the viability of L929 cells revealed that EF treatment resulted in viability of 33.96 - 116.76% at the tested concentration. The combination of 70% ethanol extract and its other fractions with gentamicin showed low cell toxicity. Conclusions: Appropriate use of antimicrobial agents is important prior to the development of new antibiotics. The 70% ethanol extract of the root of R. japonicus Houtt. and its fractions showed significant synergism with gentamicin when used in combination against S. aureus and S. epdermidis. Thus, R. japonicus Houtt. could be used as a functional materials in antimicrobial-related fields.

Background: We investigated the antioxidative and tyrosinase inhibitory activities of 70% ethanol extract, and its fractions, of the root of Rumex japonicus HOUTT. Methods and Results: The total phenolic compound contents of the 70% ethanol extract and ethyl acetate fraction were 168.99㎎/ g and 651.78㎎/g, respectively. The antioxidant activity was compared through the DPPH radical and nitric oxide (NO) scavenging assays. The ethyl acetate fraction showed the highest DPPH radical and NO scavenging abilities, which confirmed the antioxidant activity. Specifically, the ethyl acetate fraction showed a higher DPPH radical scavenging ability than ascorbic acid. These results were related to the total phenolic compound content of the ethyl acetate fraction. Moreover, in the tyrosinase inhibition assay, the ethyl acetate fraction exhibited stronger inhibitory activity than arbutin, which was used as the positive control. The cell viability of L929 cells was analyzed by MTT assay after treatment with 70% ethanol extract and all fractions; no changes in viability were observed, which demonstrated the nontoxic nature of the extract and fractions. Conclusions: These results suggested that the extract from the root of R. japonicus and its ethyl acetate fraction could be a novel resource for the development of a cosmetic with antioxidant and tyrosinase inhibitory activity.

Background: This study aimed to investigate the antioxidat and antimicrobial activities of the methanol extract and its fractions prepared from the roots of Sanguisorba officinalis L. Methods and Results: The antioxidant activities were compared by evaluating the DPPH radical and nitric oxide (NO) scavenging ability. Measurement of DPPH radical scavenging ability showed that the SC50 values of the ethyl acetate fraction was 3.85 ㎍/㎖. The ethyl acetate fraction exhibited the most effective DPPH radical scavenging ability compared with the other samples. As for the NO scavenging ability, at all tested concentrations, the ethyl acetate fraction showed a higher scavenging activity than that of the extract and other fractions. These results are related to the total phenolic compound and flavonoid contents of the ethyl acetate fraction. Antimicrobial activity against foodborne pathogens was investigated using the disc diffusion assay. The ethyl acetate fraction showed the highest antimicrobial activity against gram-positive Staphylococcus aureus and Bacillus cereus. However, the chloroform fraction had a higher antimicrobial activity against gram-negative Vibrio vulnificus than that of the extract and other fractions. Conclusions: The results show that the ethyl acetate fraction had a higher antioxidant as well as antimicrobial activity, than did the other samples. Therefore, the ethyl acetate fraction has potential application in the food industry.

Background: In this study, we investigated the antibacterial and nitric oxide (NO) production inhibitory activities of 75% ethanol extract of Prunus sargentii branches and its fractions against acne pathogens. Methods and Results: The antibacterial activity against acne causing pathogens was determined using the disc diffusion assay. The ethyl acetate fraction showed higher activities against Propionibacterium acnes, Staphylococcus aureus and Staphylococcus epidermidis than those shown by other fractions. In the DPPH radical and NO scavenging assays, the butanol fraction showed strong DPPH radical and NO scavenging abilities. These activities were related to the total polyphenol and flavonoid contents of butanol fraction. On the other hand, the chloroform and ethyl acetate fractions exhibited the highest NO production inhibitory activity in Lipopolysaccharide (LPS)-stimulated Raw 264.7 cells compared to those exhibited by other fractions. Conclusions: The extract and its ethyl acetate fraction from the branches of P. sargentii exhibited antibacterial activity and could be used as functional materials in antimicrobial related fields. Moreover, the chloroform and ethyl acetate fractions are potential antiinflammatory agents and butanol fraction acts as an effective radical scavenger.

This study was carried out to investigate the antibacterial activity against pathogens of acne and the anti-inflammatory effect of 75% ethanol extract and its fractions from the leaves of Prunus sargentii. In the antibacterial activity by the disc diffusion assay, the extract showed the highest effect against Propionibacterium acnes, Staphylococcus aureus and Staphylococcus epidermidis in 5 mg/disc. However, the ethyl acetate fraction showed the highest antibacterial activity in 1 mg/disc. On the other hand, the hexane and chloroform fraction showed strong nitric oxide (NO) production inhibitory effect in lipopolysaccharide (LPS)-stimulated Raw 264.7 cell. In the cell viability of Raw 264.7 by MTT assay, the extract and all fractions were exhibited normal viabilities as nontoxic result. Consequently, the extract from the leaves of P. sargentii and its ethyl acetate fraction could be applicable to functional materials for antibacterial activity related fields. Moreover, the hexane and chloroform fraction could be applicable to candidate materials as anti-inflammatory agent.

In this study, we investigated the antibacterial activity, antioxidative activity and whitening effect of 75% ethanol extracts from different parts of Prunus sargentii. The total phenolic compound content of the branch extract was 277.92 mg/g as the highest level. In the measurement of DPPH radical scavenging ability, SC50 values of the cork layer and branch extract were 26.79 μg/ml and 30.13 μg/ml. In nitric oxide (NO) scavenging ability, SC50 values of the branch and leaf extract were 49.19 μg/ml and 55.55 μg/ml. All extracts exhibited higher NO scavenging ability than ascorbic acid used as positive control. On the other hand, in antibacterial activity against Staphylococcus epidermidis and Staphylococcus aureus by disc diffusion assay, the pure bark extract showed the highest activity. Moreover, tyrosinase inhibitory activity of cork layer, pure bark and branch extracts showed higher activity than arbutin used as positive control. In the cytotoxicity measurement by MTT assay, leaf extract was exhibited Raw 264.7 cell viabilities of 44.68~61.83% as cytotoxic result in tested concentration. In conclusion, the branch extract of Prunus sargentii will be a functional materials without damage compared to other parts such as pure bark or cork layer in the plant.

In this study, we investigated on antioxidative activity and nitric oxide production inhibitory activity of various solvent extracts of Lespedeza bicolor. The total polyphenol content of the methanol extract was 192.6 mg/g and flavonoid content of the acetone extract was 40.6 mg/g, as the highest content. In DPPH radical scavenging ability, SC50 values of the ethanol and methanol extract were exhibited 0.69mg/ml and 0.89mg/ml, respectively. However, in nitric oxide(NO) scavenging ability, SC50 values of the acetone was exhibited 0.72mg/ml as the highest activity. Moreover, the acetone extract showed strong NO production inhibitory effect in lipopolysaccharide(LPS)-stimulated Raw 264.7 cell. In the cytotoxicity measurement by MTT assay, the extracts were exhibited Raw 264.7 cell viabilities of 92.57~129.04% as nontoxic result in concentration of 65~650μg/ml. As a result, the acetone extract of L. bicolor could be applicable to functional materials for anti-inflammatory related fields.

In order to achieve a force controller with high performance, an accurate torque servo is required. However, the precise torque servo for a double vane rotary actuator system has not been developed till now, due to many nonlinear characteristics and system parameter variations. In this paper, the torque servo structure for the double vane rotary actuator system is proposed based on the torque model. Nonlinear equations are set up using dynamics of the double vane rotary hydraulic actuator system. Then, to derive the torque model, the nonlinear equations are linearized using a taylor series expansion. Both effectiveness and performance of the design of torque servo are verified by torque servo experiments and applying the suggested torque model to an impedance controller.

미생물 및 동물에 비해 식물에서는 혈전용해효소에 대한 연구가 매우 부족한 실정이며, 기존의 혈전용해효소가 가지는 혈전에 대한 비특이적, 부작용, 고가 등의 단점을 해결할 수 있는 새로운 혈전용해효소의 개발을 위하여 동백의 종자, 종피, 유엽 그리고 성엽으로부터 추출된 수용성 단백질의 혈전용해활성을 조사하였다. 각각의 동백부위로부터 추출된 조효소 용액은 기존 혈전 용해효소인 plasmin과 양성 대조군으로 하여 비교하여 fibrin agarose plate로 확인한 결과 fibrin clot을 효과적으로 분해하였다. 그 중 단백질 분해효소의 활성이 다른 부위보다 20-33배로 높았던 동백종자와 종피의 수용성 추출물의 혈전용해활성은 양성 대조군인 plasmin과 비교하여 1.6-2.0배의 높은 활성을 나타내었다. 전체 수용성 단백질은 30-80%황산암모늄을 이용하여 농축하였으며 혈전용해효소는 fibrin zymography를 수행하여 확인하였다. SDS-PAGE에 의하여 동백유엽의 혈전용해효소 분자량을 측정한 결과 45 kDa으로 단일 polypeptide임을 확인하였으며, 각종 pretense 저해제에 의한 영향을 조사한 결과 PMSF,그리고 TLCK에 강력하게 저해되는 것으로 보아 동백유엽의 혈전용해효소는 trypsin과 유사한 serine protease의 하나로 생각되었다. 그러나 EDTA와 DTT처리에 의해서는 효소활성의 저해가 두드러지게 나타나지 않고 오히려 증진된 양상을 확인할 수 있었다. 또한, 효소 활성에 미치는 pH 및 온도의 효과는 약간의 산성쪽에 가까운 pH 5.5와 30℃에서는 최적의 활성을 나타내었으며, 45℃ 이상의 온도에서는 효소활성이 급격히 감소하였다. 이상의 모든 결과로 볼 때 동백유엽의 혈전용해효소는 trypsin과 유사한 serine protease에 속하는 혈전용해효소임을 확인할 수 있었다.

기내배양을 통해 동백종자의 자엽절편으로부터 직접 체세포분화를 통하여 식물체를 재분화 시켰다. 종피를 제거한 후 표면살균 처리한 자엽절편을 2.4-D, NAA 및 BA가 단독 또는 조합 첨가된 MS 고체배지에 치상하였다. 원배체 형성을 통한 부정아 형성은 0.1 mg/l 2.4-D와 1 mg/l BA가 첨가된 처리구에서 이루어졌다. 부정아는 주로 자엽절편체의 배축에 가까운 기저부위에서 캘러스의 형성없이 직접 형성되었으며, 이로부터 형성된 유묘는 식물생장조절물질이 첨가되지 않은 기본배지에서 정상적인 개체로 발달 하였다. 이와같은 연구결과는 앞으로 동백나무의 육종과 산업적 이용에 필요한 형질전환 연구에 효과적으로 활용될 수 있을 것으로 사료된다.

천연물은 예로부터 건강의 증진 및 질병의 치료를 위하여 다양하게 이용되어 왔다. 특히 천연물 및 식품류에 포함되어 있는 폴리페놀성 화합물들은 항산화, 암세포 성장억제, 항돌연변이 등 다양한 생리활성을 나타내어 심혈관계 질환 및 암의 치료와 예방제로서의 활용 가능성을 검토하는 많은 연구가 이루어지고 있다. 따라서 본 연구에서는 동백나무의 기능성 물질 확보와 가공을 통한 고부가가치 창출을 목표로 국내에서 자생하는 동백나무를 부위별로 추출물을 제조하여 항산화 및 항미생물 활성을 평가하고자 하였다. 항산화효과는 항산화력 성분인 총페놀 화합물의 함량과 BPPH radical 소거법을 이용하여 항산화 활성을 측정하였는데 총페놀 화합물의 함량은 동백나무 부위별 추출물의 건조중량 100 g에 대하여 어린잎, 꽃봉오리 및 꽃 추출물에 각각 74.24mg , 65.02mg, 그리고 62.42mg로 나타났다. Free radical소거활성을 공존시킨 DPPH의 50%를 환원시키는데 필요한 시료의 양 (RC50)은 어린잎, 꽃봉오리 그리고 꽃의 추출물에서 각각 7.16 μg/ml, 14.45 μg/ml 및 18.4 μg/ml의 낮은 농도로 활성을 나타내어 기존의 합성 항산화제인 BHT의 61.23 μg/ml보다 높은 항산화 효과를 나타내어 천연 항산화제로서 이용 가능성을 보여주었다. 또한 B. subitillis, S. fradiae, S. aureus, E. coli, P. aeruginosa, Enterbacter spp. C1036 및 S. typhimurium 7종의 시험균을 사용하여 동백나무 부위별 추출물의 항균활성을 측정 하였는데 어린잎의 경우 15 μg/ml의 농도에서 9~13mm의 투명환을 보여 비교적 높은 항미생물 활성을 나타내었고, 꽃봉오리 추출물을 첨가하였을 때 P. aeruginosa와 Enterbacter spp. C1036 균주에서 가장 장한 억제활성을 나타내었다. 7종의 시험균에 대한 항균력이 가장 높았던 어린일 추출물의 최소저해농도 (MIC)는 1~15으로 나타났으며, 그람양성균이 그람음성균보다 각 농도에서 최소저해농도의 효과가 더 높은 것으로 나타났다.

동백나무의 잎과 꽃의 식용자원화를 위한 일환으로서 동백의 부위별 성분분석, DPPH radical 소거능에 의한 항산화활성, 및 항미생물 활성을 조사하였다. 수분 함량은 꽃과 어린 잎 부위에서 70% 이상의 함유율을 보였고, 조단백질의 함량은 꽃을 제외한 나머지 부위에서 3%이상이었으며, 지방 함량은 씨부위에서 23.08%로 많이 함유되어 있었다. 회분의 함량은 수피 부위에서 2.97%와 탄수화물의 함량은 에서 높게 나타났다. 항산화활성은 어린잎(RC50=30.37μg/mL), 꽃봉오리 (RC50=52.97μg/mL)와 꽃(RC50=59.48 μg/mL)이 높은 활성을 보였으며 합성 항산화제인 BHT의 RC50 값이 584.04μg/mL의 활성 보다 높은 항산화 활성을 가지고 있음을 확인하였다. 동백을 각 부위별로 추출하여 병원성균과 식중독균, 식품과 관련이 있는 세균 및 효모 등 4균주에 대하여 항미생물 활성을 검토한 결과, 동백의 수피 부위가 P. vulgaris와 B. subtilis에 대한 높은 항균성을 나타내었으며, 특히, 어린잎은 C. albicans와 T. beigelii 모두에 대하여 매우 강한 활성을 나타내었다.을 나타내었다.