• 펄프종이기술
• /
• 제45권4호
• /
• pp.16-20
• /
• 2013

Yellow poplar grown in Korea and imported eucalyptus were compared their kraft pulping characteristics and evaluated the replacing possibility of eucalyptus by yellow poplar. Difference between yellow poplar and eucalyptus were investigated in chemical composition and fiber morphology. Yellow poplar kraft pulp resulted in the higher yield, longer fiber length and thicker fiber, and higher pulp strength than that of eucalyptus. More xylan survived in eucalyptus than yellow poplar during kraft pulping, which led to similar pulp yield even though polysaccharides in Eucalyptus was 4.5% less than in yellow poplar. Longer and thicker yellow poplar pulp fiber resulted in better beating response and pulp strength properties.

• 미생물학회지
• /
• 제52권4호
• /
• pp.421-427
• /
• 2016

여드름은 만성 염증 질환으로 주로 청소년기에 발생하는 것으로 알려져 있으나 대기오염, 약물 남용 등의 원인에 의해 아동기 및 성인기에도 나타날 수 있다고 알려져 있다. 여드름을 유발하는 정확한 원인은 밝혀져 있지 않으나 한 가지 원인보다 스트레스, 호르몬의 변화, 유전, 외부 환경 등 다양한 요인들이 복합적으로 작용한다고 여겨지고 있다. Propionibacterium acnes (P. acnes)는 여드름을 유발하는 균으로 모낭 내에 상주하여 피지의 중성지방을 분해하고 유리 지방산을 형성하여 모낭 내 염증을 유발한다. 따라서 피지의 생성 증가는 P. acnes의 생존에 좋은 영향을 주고 피부에서 염증반응을 유발하는 monocytic cell의 활성화와 염증성 사이토카인(pro-inflammatory cytokine)의 증가를 유발한다. 따라서 여드름 치료를 위해서는 P. acnes의 증식 억제 및 염증반응을 최소화하는 것이 중요하다. 본 논문에서는 유칼립투스(Eucalyptus globules) 추출물이 P. acnes에 의한 염증반응에 나타내는 효과를 확인하고자 하였다. 유칼립투스 추출물 처리는 P. acnes가 유도하는 염증 매개자로 알려진 $TNF-{\alpha}$, $IL-1{\beta}$, IL-2와 인플라마좀 복합체인 NLRP3의 유전자 발현을 효과적으로 감소시키는 것을 확인하였다. 뿐만 아니라 염증성 사이토카인의 유전자 발현에 중요하다고 알려진 전사인자(transcription factors) $NF-{\kappa}B$와 NFAT의 활성 역시 유칼립투스 추출물을 처리하였을 때 감소하는 것을 알 수 있었다. 따라서 본 논문을 통해 유칼립투스 추출물이 P. acnes에 의해 초래되는 여드름의 치료 보조제로 사용될 수 있으며, 천연 추출물의 사용이 항생제 장기 복용으로 인해 유발되는 항생제 내성을 해결하는 좋은 대안이 될 것이라고 예상할 수 있다.

• The Plant Pathology Journal
• /
• 제24권3호
• /
• pp.322-327
• /
• 2008

Antifungal activities of natural substrances from Eucalyptus darlympleana, E. globules, E. gunnii and E. unigera were evaluated against postharvest pathogens of kiwifruits, Botrytis cinerea, Botryosphaeria dothidea, and Diaporthe actinidiae, to screen effective natural substances as an alternative to chemical fungicides. Methanol extract of the Eucalyptus trees showed strong antagonistic activity against the pathogenic fungi. Among them, E. unigera and E. darlympleana effectively inhibited mycelial growth of the pathogens. For chemical identification of the antifungal substances, the methanol extract of E. darlympleana leaves was successively partitioned with $CH_2Cl_2$, EtOAc, n-BuOH and $H_2O$. Among the fractions, $CH_2Cl_2$ and n-BuOH showed strong inhibitory activity of mycelial growth of the fungi. Five compounds were isolated from EtOAc and n-BuOH fractions subjected to $SiO_2$ column chromatography. Two phenolic compounds(gallic acid and 3,4-dihydroxybenzoic acid) and three flavonoid compounds(quercetin, quercetin-3-O-$\alpha$-L-rhamnoside, quercetin-3-O-$\beta$-glucoside) were identified by $^1H$-NMR and $^{13}C$-NMR spectroscopy. Among them, only gallic acid was found to be effective in mycelial growth and spore germination of B. cinerea at relatively high concentrations. The results suggest that gallic acid can be a safer and more acceptable alternative to current synthetic fungicides controlling soft rot decay of kiwifruit during postharvest storage.

• The Plant Pathology Journal
• /
• 제17권5호
• /
• pp.264-270
• /
• 2001

The effects of leaf extracts of 14 different non-host plant species on in vitro conidial germination of Phaeoisariopsis personata, the causal organism of late leaf spot(LLS) of groundnut were evaluated. Aqueous and ethanol leaf extracts of Datura metel, Lawsonia inermis and aqueous leaf extracts of Sphaeranthus indicus at 25%(w/v) concentration completely inhibited the conidial germination of P. personata both at 24h and 48h after incubation. Aqueous leaf extracts of Blumea bifoliata, Eucalyptus globules, Ocimum sanctum and Pongamia pinnata, and ethanol leaf extracts of Azadirachta indica and S. indicus inhibited the conidial germination by >90%. Aqueous and ethanol leaf extract of L. inermis and S. indicus were highly inhibitory to conidial germination up to 1% concentration. Aqueous and ethanol leaf extracts of D. metel and ethanol leaf extract of A. indica were highly inhibitory to P. personata even at 0.01% (100 ppm) concentration. Ethanol leaf extract of A. indica up to $80^{\circ}$, aqueous leaf extracts of D. metel and S. indicus up to $100^{\circ}$, and L. inermis up to $60^{\circ}$, were highly stable and retained their fungitoxic effects. Extract of D. metel was antifungal even after 180 days when it was stored both at room temperature and $4^{\circ}$. Aqueous leaf extract of D. metel at 2% concentration effectively reduced the development of LLS by >60%, under greenhouse conditions both in prophylactic and simultaneous applications. Extracts of D. metel could be a potential economical and an eco-frendly alternative for control of late leaf spot, and its efficacy under field conditions is further being evaluated.