• 대한화학회지
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• 제15권5호
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• pp.256-265
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• 1971

An ESR study has been made on free radicals produced in frozen aqueous solutions (ices) of glycine, DL-${\alpha}$-alanine, DL-serine, L-cysteine, DL-leucine and DL-isoleucine by gamma-irradiation at dry ice temperature. All free radicals induced were decayed concomitant to the successive annealing but the radical species which is believed to be dominant seems to be stable even near the melting point of the ice. These dominant species were found to be identical to those resulted from direct action of radiation in the solid at room temperature. Small but significant changes in the spectra of glycine and DL-${\alpha}$-alanine were observed by varying the microwave power. These results seem to support the view that the spectra obtained were composite consisting of more than two different resonances having different power saturation characteristics. The relative contribution of unidentified resonances to the composite spectra was greater for solutions of low concentration. These resonances are assumed to be induced by indirect effects, mainly hydrogen abstraction by radiation produced hydroxyl radicals and also C-N bond cleavage by hydrated electrons.

• Mycobiology
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• 제28권4호
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• pp.165-170
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• 2000

This study was carried out to obtain the basic data for artificial culture of veiled lady mushroom (Dictyophora spp). The optimal conditions for the mycelial growth were $25^{\circ}C$ and pH 5.0 for all isolates except the optimal temperature of $30^{\circ}C$ for D. echinovolvata ASI 32002 and Phallus rugulosus. The optimal medium for Dictyophora spp. was PBA (potato bamboo sawdust extract agar) medium. The strain ASI 32002, D. echinovolvata, grew faster than. D. indusiata ASI 32003 and Phallus rugulosus ASI 25007 on the medium. Carbon sources such as glucose, maltose and inuline were favorable for stimulating a mycelial growth of the two strains of ASI 32002 and ASI 32003. Asparagine and glutamine appeared to be favorable to the strain ASI 32002 and ASI 32003, where as alanine, one of nitrogen source also favorable to the strain ASI 32002. The optimum C/N ratio of the two isolates of ASI 32002 and ASI 32003 was about 25 : 1 when 2% glucose as carbon source was mixed with the basal medium. While, in the case of 4% as carbon source, the optimum C/N ratio was about 30 : 1.

• Preventive Nutrition and Food Science
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• 제6권1호
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• pp.79-81
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• 2001

Deoxynucleoside kinases exist as heterodimeric pairs specific for deoxyadenosine/deoxyguanosine kinase (dAK/dGK) and deoxyadenosine/deoxycytidine kinase (dAK/dCK). The aspartic acid-84 in dGK was mutated to alanine, asparagine and glutamic acid by site-directed mutagenesis. The mutation resulted in a drastic decease in dGK activity compared to the unmodified cloned enzyme while it increased production of dAK activity. The mutated dak/dgk genes, which synthesize tandem deoxyadenosine/deoxyguanosine kinase, were inserted back to the Lactobacillus acidophilus and Lactococcus lactis by electroporation to determine the effect of site-directed mutation of he enzymes on the microbial growth. However, no significant change was observed in cell growth and lactic acid production between wild type and mutant lactic acid bacteria.

• Journal of Animal Science and Technology
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• 제63권3호
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• pp.531-544
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• 2021

Heat stress (HS) damages health and decreases performance variables in pigs, and if severe enough, causes mortality. However, metabolic changes under HS and recovery following HS are poorly understood. Therefore, this study was aimed to expose the essential mechanisms by which growing pigs respond to HS and the temporal pattern of plasma concentrations (PC) of amino acids (AAs) and metabolites. Crossbred male growing pigs were penned separately and allowed to adapt to thermal-neutral (TN) conditions (20℃ and 80% relative humidity; TN[-1D]). On the first day, all pigs were exposed to HS for 24 h (36℃ and 60% relative humidity), then to TN conditions for 5 days (TN[2D] to TN[5D]). All pigs had ad libitum access to water and 3 kg feed twice daily. Rectal temperature (RT) and feed intake (FI) were determined daily. HS pigs had higher RT (40.72℃) and lower (50%) FI than TN(-1D) pigs (p < 0.01). The PC of indispensable (threonine, valine, and methionine) and dispensable (cysteine and tyrosine) AAs were higher (p < 0.05) in HS than TN(-1D) pigs and remained increased during recovery time. Nonprotein α-aminobutyric acid and β-alanine concentrations were higher (p < 0.05) in HS than TN(-1D) pigs. The metabolite concentration of creatinine was higher (p < 0.01) under HS treatment than other treatments, but that of alanine and leucine remained increased (p < 0.05) through 5 d of recovery. In summary, some major differences were found in plasma AA profiles and metabolites between HS- and TN-condition pigs. This indicates that the HS pigs were forced to alter their metabolism, and these results provide information about mechanisms of acute HS responses relative to the recovery time.

• Natural Product Sciences
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• 제19권2호
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• pp.173-178
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• 2013

The protective effect of SAPP, an extract from a novel herbal complex, on acute liver injury was investigated using mouse animal model in this study. The content of total phenol in SAPP was increased at dose dependent manner. Consistent with the content of total phenol, SAPP showed the significant anti-oxidative effects on 1, 1-diphenyl-2-picrylhydrazyl (DPPH) method. Acute liver injury was induced by D-galactosamine (D-GalN) in mouse. Treatment with SAPP significantly reduced the level of alanine transaminase (ALT) and aspartate transaminase (AST) in serum. Histological observation revealed that whereas D-GalN treated mouse showed vacuolization of hepatocytes, sinusoidal dilation and congestion, loss of cell boundaries and ballooning degeneration, loss of architecture and cell necrosis, treatment with SAPP improved D-GalN-induced liver injury. These results suggest that SAPP shows protective effects against D-GalN-induced hepatotoxicity in vivo acute mouse model.

• Toxicological Research
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• 제14권3호
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• pp.365-370
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• 1998

To evaluate the renal toxicity of the antitumor agent, p-{N,N,-Bis(2-chloroethyl)amino}-4-phenyl acetyl-amino-2,6-piperidinedione(CK-15), rats were treated with CK-15 (acute: 50mg/kg. i.p., single and subacute: 5mg/kg, i.p., daily for 7 days). The changes in the body weight, water consumption, kidney weights and urine volume after and during the treatment were observed. The concentrations of urinary creatinine and portein, the activities of N-acetyl-${\beta}$-D-glucosaminidase (NAG), alanine aminopeptidase (AAP), ${\gamma}$-glutamyl transpeptidase (${\gamma}$-GT) and lactate dehydrogenase (LDH) in 24hr urine were also determined. The body weight, water consumption, and urine volume were decreased after the acute and subacute administration. However the weights of kidney were not changed after the treatments. The excretion of creatinine was significantly decreased 1 day after acute administration but, returned to the control value. In subactute administration, the excretion of creatinine was gradually decreased. However, the protein excretion did not changed in both treatment. Those indicate that CK-15 might decrease the metabolic rate of muscle. THe urinary activities of NAG, AAP, ${\gamma}$-GT, and LDH were significantly affected bythe drug treatment. The urinary activities of NAG, AAP and ${\gamma}$-GT were significantly increased 1 day after the acute administration and then returned to the control value. However, the urinary activities of LDH were not changed in acute treatment. In subacute treatment, although the urinary activities of NAG were not changed, those of AAP and ${\gamma}$-GT were significantly increased 2.3 times at 3 days during the subacute administration. Also the urinary activities of LDH were significantly increased at 7 day after the administration. These results indicate that the high and subacute administration might induce a damage in the kidney cells. Furthermore the present results suggest that the toxic effects of CK-15 might be due to the accumulation of the metabolites.

• 대한화장품학회지
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• 제30권4호
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• pp.499-502
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• 2004

장미과 식물(에탄을 추출)의 항산화력을 측정하기 위하여 1,1-diphenyl-2-picrylhydrazyl (DPPH) 자유 라디칼 생성 시스템을 이용하여 하였다. 또한 산화 환원 과정을 통하여 피부의 과잉 색소 생성에 관련된 멜라닌 생합성 과정의 조절 가능성을 조사하였다. 장미과 식물중에서 Prunus sargentii, Rubus coreanus, Chaenomeles sinensis, Photinia glabra와 Pyrus pyrifolia은 생합성 과정에서 dopa [3-(3,4-dihydroxyphenyl) alanine]를 도파크롬으로 변환시켜 주는 tyrosinase 저해 효과를 나타내었다. MTT 실험법은 장미과 에탄올 추출물의 사람 섬유아세포에 미치는 독성정도를 실험하기 위해 사용되었다. 장미과 식물중 특히 Prunus sargentii의 껍질, Phorinia glabra의 껍질과 나무 그리고 Chaenomeles sinenis의 잎, 껍질, 나무 모든 부분에서 mushroom tyrosinase에 대해 $100{\;}{\mu}g/mL$에서 50\%$ 이상의 저해 활성을 보였으며, $10{\;}{\mu}g/mL$ 농도에서 강한 라디칼 소거 효과를 나타내었다. 또한 이들 추출물은 사람 섬유아 세포에 대해 높은 생존율을 나타냄으로써 멜라닌 형성 과정을 조절할 수 있을 것으로 기대한다.

• 한국식품저장유통학회지
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• 제17권6호
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• pp.820-825
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• 2010

본 연구에서는 경제적 측면에서 일반 소금보다 우수한 해양심층수 소금을 이용하여 간장을 제조한 후 발효기간에 따른 품질특성을 조사하였다. pH와 완충능은 발효가 진행됨에 따라 점차 감소하였다. 순추출물의 함량은 점차 증가하여 발효 120일째에 7.5%로 나타났다. 간장의 갈색화는 발효 30일 째에 대부분의 갈색화가 진행되었다. 총질소와 아미노태 질소는 발효가 진행됨에 따라 점차 증가하여 발효 12일째 각각 1.4%와 0.75%를 나타내었다. 유리아미노산의 함량은 179.8~315.7 mg%가 검출되었으며, 발효기간이 증가함에 따라 점차 함량이 증가하였다. 발효 전 기간에 걸쳐 glutamic acid가 가장 많았으며, alanine, lysine 및 leucine의 순으로 많았다. 총 유리 아미노산에 대한 glutamic acid의 비율은 21.0~23.2%였으며, 필수아미노산의 함량은 발효 30일째에 78~142.3 mg%가 검출되었으며, 발효가 진행됨에 따라 그 함량도 증가하였다.

• 한국식품과학회지
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• 제13권2호
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• pp.121-126
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• 1981

Brevibacterium ammoniagenes ATCC 6872를 변이하여 얻은 adenine-guanine 및 $\beta$-alanine 영양요구성(營養要求性)이고 5'-XMP를 다량 생산하는 변이주 D-1550-40을 사용하여 발효배지성분(醱酵培地成分)의 최고농도(最高濃度)와 각 성분간의 상호작용효과(相互作用效果)를 검토하였다. 5'-XMP 축적(蓄積)에 필요한 adenine 및 guanine의 최적(最適) 농도(濃度)는 각각 75mg/l이었으나 생육(生育)에 대한 최적농도(最適濃度)는 이 보다 높은 100mg/ml이었고 그 이상의-농도에서는 5'-XMP 축적에 심한 저해를 초래하였다. 이러한 현상은 biotin을 $100{\mu}g/l$ 이상 첨가하거나 casamino acid를 0.3% 이상 첨가함으로서 배제할 수 있었다. 5'-lMP 발효의 경우와 마찬가지로 무기인산염(無機燐酸鹽)과 마그네슘은 5'-XMP 축적에도 $1.0{\sim}1.5%$1.5%가 적당(適當)하였다. $MnSO_4$의 농도가 $0{\sim}5mg/l$의 범위안에서 증가함에 따라 균증식과 5'-XMP의 축적은 촉진되었으나 그 이상의 농도에서는 변화가 없었고 정상상태를 나타내었다. Adenine과 guanine 각 100 mg/l, $MnSO_4\{cdot}7H_2O5mg/l 및 biotin $100{\mu}g/lg$가 함유된 발효배지에서 배양한 결과 4일후 60.5mg/ml의 5'-XMP가 측적되었으며, 5'-XMP의 생성활성(生成活性)은 균체량(菌體量)에 비례하여 배양 2일 내지 3일에서 가장 높았다.

• 한국버섯학회지
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• 제6권1호
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• pp.13-19
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• 2008

본 시험의 볏짚버섯속(Agrocybe) 2균주 ASI19003(A. cylindracea; 버들송이)와 '차신고'로 불려지는 ASI19016(A. chaxingu)의 배양생리 및 재배적 특성 비교에서 종간에는 많은 차이가 있었다. 균사생장 최적온도는 ASI19003이 28, ASI19016이 30 이었으며 배지산도는 고체배지 평판배양의 경우 ASI19003과 ASI19016 균주 공히 pH 5.5~7.0 범위에서 잘 자랐다. 그러나 액체배지 정치배양에서는 ASI19003이 pH 5.5에서, ASI19016이 pH 5.0에서 잘 자랐으며 ASI19016 균주의 경우 액체배지의 pH 6.0~7.5 범위에서는 균사생장이 매우 저조한 특이적 현상을 나타내었다. 탄소원으로는 ASI19003이 lactose, ASI19016 균주가 fructose에서 잘 자라고, 질소원으로 ASI19003이 asparagine > alanine > glycine, ASI19016이 ammonium tartrate > asparagine > glycine > alanine 순이었다. 봄재배 시 ASI19003은 배양기간이 27일, 초발이소요일수 13일로 ASI19016의 29일과 17일보다 총재배기간이 6일 빨랐으며, 850 $m{\ell}$ PP병당 자실체 수량도 ASI19003이 114 g으로 ASI19016의 100g보다 15%가 많았다. 한편 여름재배 시 ASI19003은 배양기간이 29일, 초발이소요일수 11일로 ASI19016의 30일과 12일보다 총재배기간이 3일 빨랐다. 그러나 버섯 생육기에 온도가 상승하면 ASI19003 균주는 자실체 색이 옅어지고 조직이 물러지는 등 상품성이 낮아지는 단점이 있으나, ASI19016은 고온기에 오히려 버섯 발생이 빨라지고 자실체의 갓 색깔도 짙게 유지되는 장점이 있다. 따라서 봄, 가을과 겨울철에는 다수성인 ASI19003(버들송이)을, 여름철 고온기에는 상품성이 좋은 ASI19016(차신고) 균주를 재배품종으로 선택함으로써 버들송이류 버섯의 상품성을 연중 내내 유지하면서 안정적인 공급이 가능할 것으로 본다.