• International Journal of Industrial Entomology and Biomaterials
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• 제5권2호
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• pp.183-188
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• 2002

Anti-fungal potential of 5 plant extracts viz., Eucalyptus citriodora, Allium sativum, Cassia sophera, Chromolaena odorata and Datura metel on the growth of mulberry brown leaf spot pathogen Myrothecium roridum were examined. Except fur the aqueous extract of Allium bulb, ethanolic leaf extract of all other plants more efficiently reduced the colony growth of the fungus on potato-dextrose-agar, Of which, Allium and Eucalyptus extracts were more effective. Initiation of radial growth of M. roridum on solid media was deferred maximum 6 days by ethanolic Eucalyptus extract and 4 days by aqueous Allium extract at $0.4 mg.ml^{-1}$. In the liquid media amended with Eucalyptus extract ($0.4 mg.ml^{-1}$) complete inhibition of sporulation was noticed upto 8 days, and initial inhibition of mycelial bio-mass generation was considerably diminished with time and reduction was 1.3 fold 14 days after application. While, complete inhibition of mycelial growth for 6-14 days was recorded with $\geq$0.1 mg.ml$^{-1}$ commercial eucalyptus oil. However, rejuvenation of growth appeared when fungus was re-inoculated in fresh media. Post-inoculate application of different doses Of Eucalyptus and Allium extracts significantly (p < 0.05) reduced the disease severity in pot-ted mulberry. However, persistence of the effect up to 28 days was apparent at $\geq$ 1.0 mg.ml$^{-1}$ and effectively was on par with carbendazim (1 mg.ml$^{-1}$ ). Almost equal control ability of 1.0 mg.ml$^{-1}$ Eucalyptus extracts can be achieved by ca. 10 times lowered dose of commercial eucalyptus oil. It seems, the toxic principle of E. citrodora to M. roridum is fungistatic in nature and may have essential oil based origin.

• Biotechnology and Bioprocess Engineering:BBE
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• 제8권6호
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• pp.349-353
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• 2003

The physiological characteristics of cultures of very high cell mass (e.g. 10g cell mass/L), termed“ultrahigh cell density cultures”is reviewed. A close relationship was found between the length of the optical path (OP) in flat-plate reactors and the optimal cell density of the culture as well as its areal (g m$\^$-2/ day$\^$-1/) productivity. Cell-growth inhibition (GI) unfolds as culture density surpasses a certain threshold. If it is constantly relieved, a 1.0cm OP reactor could produce ca. 50% more than reactors with longer OP, e.g. 5 or 10cm. This unique effect, discovered by Hu et al. [3], is explained in terms of the relationships between the frequency of the light-dark cycle (L-D cycle), cells undergo in their travel between the light and dark volumes in the reactor, and the turnover time of the photosynthetic center (PC). In long OP reactors (5cm and above) the L-D cycle time may be orders of magnitude longer than the PC turnover time, resulting in a light regime in which the cells are exposed along the L-D cycle, to long, wasteful dark periods. In contrast, in reactors with an OP of ca. 1.0 cm, the L-D cycle frequency approaches the PC turnover time resulting in a significant reduction of the wasteful dark exposure time, thereby inducing a surge in photosynthetic efficiency. Presently, the major difficulty in mass cultivation of ultrahigh-density culture (UHDC) concerns cell growth inhibition in the culture, the exact nature of which is awaiting detailed investigation.

• 산업기술연구
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• 제3권
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• pp.33-38
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• 1983

The effect of various environmental conditions on the growth kinetics of Zymomonas mobilis were studied and the kinetic parameters were evaluated. The value of ${\mu}m$ was $0.45hr^{-1}$ and Ks was 0.23 g/L. Inhibition of growth at high glucose concentration was found to follow the threshold substrate inhibition. Threshold substrate concentration was 102 g/L and substrate inhibition constant was 196 g/L. The effects of yeast extract concentrations were found to follow the Monod equation. ${\mu}m$ value was $0.45hr^{-1}$ and Ks was 0.3 g/L at 20 g/L of glucose and $0.24hr^{-1}$ and 0.24 g/L respectively at 200 g/L of glucose. The optimum temperature was found to be $35^{\circ}C$ and the activation energy of growth was 7.7 Kcal/mole below $35^{\circ}C$ and -29 Kcal/mole above $35^{\circ}C$.

• Advances in Traditional Medicine
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• 제6권2호
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• pp.102-107
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• 2006

The methanol extract and residual methanol fraction of Excoecaria agallocha L. (Euphorbiaceae) stem bark was investigated in this study by wheat rootlet and shoot growth inhibition, and antimicrobial bioassay. The methanol extract and residual methanol fraction showed high inhibitory effect on both the wheat rootlet (82-89%) and shoot growth (85-90%) compared to control. The methanol extract showed a better and dose related inhibition on both the rootlet and shoot growth compared to residual methanol fraction. The $IC_{50}$ value of methanol extract for rootlet and shoot were $2.88\;{\mu}g/ml$ and $2.32\;{\mu}g/ml$, and of residual methanol fraction for rootlet and shoot were $7.91\;{\mu}g/ml$ and $4.45\;{\mu}g/ml$. The methanol extract and residual methanol fraction did not show any antibacterial activity against the tested microorganisms of clinical isolates Escherichia coli, Staphylococcus aureous, Pseudomonas aeruginosa, Proteus vulgaris and Bacillus subtilis. The plant has the potential to be a source of novel cytotoxic compound(s).

• 한국환경과학회지
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• 제1권1호
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• pp.1.1-11
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• 1992

To find heavy metal-specific effects on the photosynthetic apparatus of higher plants, we investigated effects of $CuCl_2$, HgCl_2$ and $ZnCl_2$ on electron transport activity and chlorophyll fluorescence induction kinetics of chloroplasts isolated from barley seedlings. Effects on some related processes such as germination, growth and photosynthetic pigments of the test plants were also studied. Germination and growth rate were inhibited in a concentration-dependent manner by these metals. Mercury was shown to be the most potent inhibitor of germination, growth and biosynthesis of photosynthetic pigments of barley plants. In the inhibition of electron transport activity, quantum yield of PS II, and chlorophyll fluorescence induction kinetics of chloroplasts isolated from barley seedlings, mercury chloride showed more pronounced effects than other two metals. Contrary to the effects of other two metals, mercury chloride increased variable fluorescence significantly and abolished qE in the fluorescence induction kinetics from broken chloroplasts of barley seedlings. This increase in variable fluorescence is due to the inhibition of the electron transport chain after PS ll and the following dark reactions. The inhibition of qE could be attributed to the interruption of pH formation and do-epoxidation of violaxathin to zeaxanthin in thylakoids by mercury. This unique effect of mercury on chlorophyll fluorescence induction pattern could be used as a good indicator for testing the presence and/or the concentration of mercury in the samples contaminated with heavy metals.

• 한국식품조리과학회지
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• 제20권3호
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• pp.287-291
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• 2004

The growth inhibitory effect of germanium, or soybean sprouts cultured with germanium, on cancer cells was determined in the cultured gastric cancer cell line, AGS. The growth of AGS was significantly inhibited by the addition of 0.01-1％ organic germanium (Ge-132) and germanium stone powder in MTT cytotoxicity assays. The juice from germanium treated soybean sprouts (GTS) inhibited the growth of AGS gastric cancer cells by 78-88％ at concentrations of 2.5 or 5${\mu}\ell$. The juice from Seomoktae GTS revealed an especially higher growth inhibitory effect than that from the control soybean sprouts (germanium non-treated soybean sprouts, GNTS) in AGS. The results suggest that soybean sprouts cultured with germanium may exert an anticancer effect against gastric cancer cells.

• 한국잡초학회지
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• 제18권4호
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• pp.314-324
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• 1998

신규로 합성한 cyclohexanedione계 화합물 EK3143과 EK3150의 제초작용 발현의 특성을 기존약제와 비교조사하고, 이들이 ACCase에 대해 어떠한 저해활성을 가지는지를 알아보고자 제반실험을 수행하였다. Sethoxydim은 화본과식물에만 제초효과를 가지며 생육정지와 함께 조직의 황화, 괴사가 나타난다, 반면에 Ek3143과 EK3150은 화본과식물에 대한 활성은 상대적으로 감소되었으나 까마중, 어저귀 등의 광엽잡초에 대해서는 보다 강한 활성을 가졌다. EK3143은 저농도의 보다 폭넓은 범위에서는 백화증상이, 고농도에서는 sethoxydim과 동일한 증상을 나타내었고 EK3150은 모든 농도에서 식물체의 백화를 유기시켰으며 광엽잡초의 경우 분열조직에서 그 증상이 뚜렷하였다. 이들 화합물의 화본과식물에 대한 생육저해 활성과 옥수수 ACCase에 대한 저해정도간에는 일치된 경향을 보였으나 광엽잡초인 어저귀와 까마중에 대한 ACCase 활성과 전식물체(intact plant)에서의 제초활성간에는 일치된 경향을 보이지 않았다. 즉 EK3143과 EK3150은 어저귀와 까마중의 ACCase에 대한 저해활성이 sethoxydim보다 전반적으로 높은 특징을 보이지만, 광엽잡초에 대한 제초활성이 상대적으로 높았던 EK3150이 ACCase에 대해서는 EK3143보다 오히려 낮은 저해활성을 나타내었다. 한편 색소감소 정도가 신장저해보다 빨리 나타나는 norflurazon 및 EK3140 처리에서와는 달리, EK3143과 EK3150 처리에서는 색소감소 보다 신장저해가 보다 빠르게 나타나 다른 저해양상을 보였다. 이상의 결과로 보아 EK3143 EK3150은 ACCase 이외에 다른 작용점을 추가로 저해하는 것으로 생각되며, 약간의 구조변경에따라 제초작용점간의 결합정도에 차이가 생김으로써 생육저해 또는 백화증상이 서로 비중을 달리하여 나타나는 것으로 추정된다.

• 한국자원식물학회지
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• 제26권5호
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• pp.645-651
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• 2013

시설오이로 많이 재배되고 있는 4 품종을 선발하여 생육단계별로 총 페놀 및 플라보노이드 함량, 피부염증과 가려움증 관련 Staphylococcus aureus, Staphylococcus epidermidis, Malassezia furfur균에 대한 항균효과 그리고 tyrosinase 억제 활성에 대하여 비교 분석하였다. 총 페놀 함량은 장죽청장과 장형낙합 품종에서 늘푸른청장과 신조은백다다기 품종에 비해 상대적으로 다소 높게 나타났으며, 생육단계별로는 대부분 수확기에 이른 5단계에서 높은 함량을 보였다. 총 플라보노이드 함량은 조사된 오이 4품종 모두 생육단계별로 큰 차이를 나타내지는 않았다. 항균활성은 Staphylococcus aureus균에서는 장형낙합 품종이 모든 생육단계에서 상대적으로 높은 활성을 보였으며, Staphylococcus epidermidis균에서는 생육단계 및 품종에 따라 저해환이 8~12 mm로 항균성에 차이를 나타냈다. 또한 Malassezia furfur균에서는 장죽청장에서 항균활성이 높게 나타났으며, 특히 생육 3, 4단계에서는 저해환이 14 mm로 형성되어 가장 높은 항균효과를 보였다. 전체적으로 오이의 항균성은 Staphylococcus aureus균에서 비교적 높은 것을 확인할 수 있었다. 오이 추출물의 tyrosinase 억제 활성은 장축청장과 신조은백다다기 품종에서 상대적으로 높은 활성을 보였으며, 다음으로 장형낙합 품종에서 비교적 높게 나타났지만, 늘푸른청장의 경우는 상대적으로 낮은 활성을 보였다. 또한 생육초기보다 수확기에 이르렀을 때 모든 품종에서 tyrosinase 억제 활성이 다소 높게 나타났다. 본 실험의 결과, 피부상재균 및 비듬균에 대한 오이의 항균성과 미백효능을 확인함으로서 향후 고부가가치 향장소재로서의 이용성을 더욱 증대시킬 수 있을 것으로 기대된다.

• Ecology and Resilient Infrastructure
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• 제9권3호
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• pp.183-193
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• 2022

초음파 (ultrasonic) 조사시간 (irradiation time)에 따른 Microcystis aeruginosa (M. aeruginosa)의 성장억제 (growth inhibition) 효과를 대용량 (10 L) 조류 시료를 활용해 다양한 초음파 조사시간 동안 (0.5, 1, 1.5, 2, 2.5, 3 hr) 실험실 규모 (lab-scale) 실험을 진행하였다. Chl-a와 M. aeruginosa 개체수 (cell number) 분석 결과, 초음파 조사 종료 이후 모든 실험군에서 Chl-a와 개체수가 감소되어 조류 성장억제가 관찰되었으며, 초음파 조사시간이 2시간 미만인 실험군 (T_B, T_C, T_D)은 저감 이후 조류의 급격한 재성장 (regrowth)이 관측되었으나, 조사시간이 2시간 이상인 실험군 (T_E, T_F, T_G)은 2시간 미만 조사한 실험군 대비 조류성장억제가 1 - 2일 더 지속되는 것을 확인하였다. 또한, 조류의 개체수가 초기 개체수까지 회복 시간 (recovery time)을 검토한 결과 조사시간 2시간을 기준으로 실험군 T_B (0.5 hr)는 7일, T_C (1 hr)와 T_D (1.5 hr)는 약 20일, T_E, T_F, T_G (≥ 2 hr)는 약 30일이 소요되어 초음파 조사 종료 후 초기 개체수까지의 회복 시간의 차이를 확인하였다. 비성장속도 (𝜇)와 일차분해속도(𝜅)를 도출한 결과, 실험군은 성장억제 기간 동안 초음파 조사시간과 비례하여 높은 일차분해율이 도출되었으며, 조사시간이 2시간 이상인 실험군의 재성장 시 비성장속도 (𝜇)는 2시간 미만인 실험군 대비 비성장속도 (𝜇)가 상대적으로 낮은 것으로 확인되었다. 따라서 정체수역 내 장기적인 (30일) 조류 성장억제를 위해서는 최소한 2시간 이상의 초음파 조사가 필요한 것으로 판단되나, 조류 성장억제를 위한 적정 초음파 조사시간은 정체수역의 규모, 수심, 흐름속도, 조류 농도 등의 다양한 현장조건에 따라 결정돼야 하며, 실제 적용 가능성을 높이기 위한 추가 연구가 필요한 것으로 판단된다. 초음파의 영향으로 인한 M. aeruginosa의 세포 표면 및 내부형질 변화를 관찰한 결과, 조류 세포 표면 및 세포막의 손상이 명확히 관측되었으며, 대조군 대비 실험군의 M. aeruginosa의 기낭 파괴 및 교란이 확인되었다.

• 대한약침학회지
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• 제20권3호
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• pp.207-212
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• 2017

Objectives: Study of the mechanisms involved in cancer progression suggests that cyclooxygenase enzymes play an important role in the induction of inflammation, tumor formation, and metastasis of cancer cells. Thus, cyclooxygenase enzymes could be considered for cancer chemotherapy. Among these enzymes, cyclooxygenase 2 (COX-2) is associated with liver carcinogenesis. Various COX-2 inhibitors cause growth inhibition of human hepatocellular carcinoma cells, but many of them act in the COX-2 independent mechanism. Thus, the introduction of selective COX-2 inhibitors is necessary to achieve a clear result. The present study was aimed to determine the growth-inhibitory effects of new analogues of chalcone epoxide as selective COX-2 inhibitors on the human hepatocellular carcinoma (HepG2) cell line. Methods: Estimation of both cell growth and the amount of prostaglandin E2 (PGE2) production were used to study the effect of selective COX-2 inhibitors on the hepatocellular carcinoma cell. Cell growth determination has done by MTT assay in 24 h, 48 h and 72 h, and PGE2 production has estimated by using ELYSA kit in 48 h and 72 h. Results: The results showed growth inhibition of the HepG2 cell line in a concentration and time-dependent manner, as well as a reduction in the formation of PGE2 as a product of COX-2 activity. Among the compounds those analogues with methoxy and hydrogen group showed more inhibitory effect than others. Conclusion: The current in-vitro study indicates that the observed significant growth-inhibitory effect of chalcone-epoxide analogues on the HepG2 cell line may involve COX-dependent mechanisms and the PGE2 pathway parallel to the effect of celecoxib. It can be said that these analogues might be efficient compounds in chemotherapy of COX-2 dependent carcinoma specially preventing and treatment of hepatocellular carcinomas.