http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
茶 침출조건에 따른 Catechin, 무기질 및 Vitamin C 함량 변화
이순재,김미지,윤연희,박규영,최원경,방진숙,부용출 대구효성가톨릭대학교 응용과학연구소 1994 응용과학연구논문집 Vol.3 No.-
본 연구에서는 실제 상용하고 있는 각 차음료가 온도, 시간 및 추출 횟수에 따른 성분의 함량의 차이를 관찰코져 시판되고 있는 한국산 녹차, 우롱차 및 홍차를 대상으로 추출방법을 달리한 후 茶浸出液중의 주요성분인 catechin, vitamin C 및 여러가지 무기질의 함량을 측정하여 다음과 같은 결과를 얻었다. 1. 차침출온도에 따른 침출액중의 catechin과 vitamin C 함량의 차이를 볼 때 온도가 높을수록 많이 추출되었다. 2. 같은 온도라는 침출시간에 따른 차이를 관찰한 결과 시간이 길수록 침출액중의 catechin과 vitamin C의 함량이 증가되었다. 3. 녹차는 우려낸 횟수에 따른 catechin의 함량 차이는 처음에 비하여 2회 추출시약 51%, 3회추출시는 71% 감소하였다. 4. 차의 각 무기원소에 따른 함량을 비교시 Mg은 우롱차가 가장 높고 K, Mn은 녹차가, Zn, Cu 그리고 Fe는 홍차가 가장 높게 나타났다. 5. 녹차, 우롱차의 경우 대체로 무기질의 침출정도가 온도가 높을수록 오히려 감소하는 경향을 나타내었고 홍차는 Mg, K을 제외하고 모두 증가하였다. 6. 각 침출액중의 대부분의 무기질 함량은 추출횟수가 증가할수록 감소하였다. 7. 시료로 사용한 녹차, 우롱차, 홍차의 vitamin C 함량은 녹차, 우롱차, 홍차의 순으로 높게 나타났다. 8. 녹차를 추출한 횟수에 따른 vitamin C 함량은 1회에 비해 2회 추출시 약 36%, 3회 추출시 약 62% 감소되었다. 9. 5g의 녹차를 80℃에서 2분간 침출한 액중에서는 catechin은 100ml당 0.34g, Mg은 2.229mg, Ca은 0.365mg, K은 39.77mg, Zn은 0.037mg, Cu은 0.010mg, Fe는 0.001mg, Mn은 0.581mg이며, vitamin C는 9.65mg이 함유되어 있었다. This study was to compare the ingredients which are contained in usual Korean teas in-depednence on leaching temperature, time and number. The main contents i.e. catechin, vi-tamin C and other minerals extracted from Korean commercial green tea, oolong tea and black tea were measured. The resluts are as follows; According to extracting temperature, the higher temperature made catechin and vitamin C extracted more. For the same leaching temperature, the longer time the more catechin and vitamin C. In case of extracting number, the contents of catechin was decreased a-bout 50% and 70% at second time and third, respectively in comparasion to the first time. For minerals from teas, management(Mg) was most in oolong tea, potassium(K)and manganease(Mn) and in green tea and iron(FEe) was in black tea respectively. Most min-erals from greentea and oolong tea were extracted less as leaching temperature was in-creased. But in black tea minerals other than Mg and K were more at increased tempera-ture. Most minerals in extractions were decreased as leaching number was increased. The content of vitamin C in the experimental samples(tea) was most in green tea, next in oo-long tea and third in black tea. In comparasion with the first extraction vitamin C was de-creased about 35% and 60% at 2nd and 3rd leach, respectively.
Boo, Yong-Chool,Cho, Moon-jae,Jung, Jin 제주대학교 방사능이용연구소 1999 연구보고 Vol.13 No.-
Effects of the enhanced level of L-ascorbic acid (AA) on the water deficit-induced oxidative damage were studied in rice (Oryza sativa L.) seedlings. The seedlings splayed with 20 to 80 mM L-galacono γ - lactone (GL), a putative precursor of AA, showed 2 to 5-fold higher levels of AA compared with controls. Pretreatment of the seedlings with GL prior to water stress imposition caused virtually no effect on dehydration of tissues during water deficit but substantially mitigated oxidative injury, as accessed by 2-thiobarbituric acid-reactive substances, α-tocopherol, chlorophylls and β -carotene. Proline accumulation during water stress was also significantly lowered in the treated seedlings. In a complementary exptriment, AA retarded photodegradation of α -tocopherol in isolated thylakoids far more efficiently than glutathione. GL in itself did not show any noticeable reactivity toward α -tocopheroxyl radical. The results demonstrate the antioxidative function of AA in rice seedlings encountering water-limited environments, suggesting a critical role of AA as a defense against oxidative stress in plants.
Detection of low levels of nitric oxide using an electrochemical sensor.
Boo, Yong Chool,Mun, Gyeong In,Tressel, Sarah L,Jo, Hanjoong Humana Press 2011 Methods in molecular biology Vol.704 No.-
<P>Nitric oxide produced from nitric oxide synthases mediates various physiological and pathological events in biological systems. However, quantitative assessment of nitric oxide from biological sources remains a difficult task. Here we describe a procedure for the quantification of low levels of nitric oxide using a nitric oxide - selective electrochemical sensor. Nitric oxide is oxidized to nitrite and/or nitrate and accumulated in the aqueous media. First, nitrate in biological fluids or culture media is converted to nitrite by an enzymatic method. Nitrite is then chemically converted to equimolar NO in an acidic iodide bath, where nitric oxide is detected by the sensor. Using this method, the present study demonstrates siRNA -mediated suppression of nitric oxide synthase 3 leading to a significant decline of basal nitric oxide production in human umbilical vein endothelial cells. Basal nitric oxide production from HUVECs is also shown to be inhibited by N (G)-nitro-L: -arginine methyl ester but not by N (G)-nitro-D: -arginine methyl ester (D-NAME) D-NAME . The analytical method presented here provides a sensitive and convenient tool for measuring basal and stimulated nitric oxide production from biological sources.</P>
Boo, Yong-Chool The Korean Society for Applied Biological Chemistr 2005 Journal of Applied Biological Chemistry (J. Appl. Vol.48 No.3
Endothelial nitric oxide synthase (eNOS) plays a critical role in vascular biology and pathophysiology. Its activity is regulated by multiple mechanisms such as calcium/calmodulin, protein-protein interactions, sub-cellular locations and phosphorylation at various sites. Phosphorylation of eNOS-Ser1177 (based on mouse sequence) has been identified as an important mechanism of eNOS activation. However, signaling pathway leading to it phosphorylation remains controversial. The regulation of eNOS-Ser1177 phosphorylation by Src and protein kinase A (PKA) was investigated in the present study using cultured mouse aorta endothelial cells. Expression of a constitutively active Src mutant in the cells enhanced phosphorylation of eNOS and protein kinase B (Akt). The Src-stimulated phosphorylation was not attenuated by the expression of a dominant negative PKA regulatory subunit. Neither activation nor inhibition of PKA activity had any significant effect on tyrosine phosphorylation of activation or inactivation site in Src. Based on the results of this study, it is suggested that Src/Akt pathway and PKA signaling may regulate eNOS phosphorylation independently. The existence of multiple mechanisms for eNOS phosphorylation may guarantee endothelial nitric oxide production in various cellular contexts which is essential for maintenance of vascular health.
Stimulation of eNOS-Ser617 Phosphorylation by Fluid Shear Stress in Endothelial Cells
Boo, Yong-Chool The Korean Society for Applied Biological Chemistr 2005 Journal of Applied Biological Chemistry (J. Appl. Vol.48 No.4
Nitric oxide (NO) produced from endothelial cells plays a critical role in vascular physiology. The regulation of endothelial NO synthase (eNOS) involves various mechanisms including multiple Ser/Thr phosphorylations. Recently, eNOS-Ser617 was newly recognized to be phosphorylated in response to humoral factors including vascular endothelial growth factor. However, it remains unknown whether and how eNOS-Ser617 phosphorylation is stimulated by shear stress, the primary stimulus of endothelial NO production. This issue was explored in the present study using cultured bovine aortic endothelial cells (BAECs). Over-expression of a constitutively active protein kinase B(Akt) mutant in BAECs increased Ser617 phosphorylation while constitutively active protein kinase A mutant had no effect. When BAECs were subjected to an arterial level of laminar shear stress, eNOS-Ser617 phosphorylation was clearly increased in a time-dependent manner. Shear stress also stimulated Akt phosphorylation at Thr308, one of the key regulatory sites. The time courses of eNOS-Ser617 and Akt-Thr308 phosphorylations appeared to be very similar. These results suggested that eNOS-Ser617 phosphorylation, mediated by Akt, is a physiological response to the mechanical shear stress, involved in the regulation of NO production in endothelial cells.
Boo, Yong-Chool,Lee, Keum-Pyo,Jung, Jin Korean Society of Photoscience 1998 Journal of Photosciences Vol.5 No.3
Occurrence of an electron (or H atom equivalent to one electron plus H+) transfer from $\alpha$- tocopherol $\alpha$(TOH) to a number of photosensitizers in theri triplet states were investigated by monitoring the ESR signal of $\alpha$-chromaoxyl radical ($\alpha$(TO.) in ethanolic solutions of $\alpha$TOH and the sensitizers under continuous illumination. Every sensitizer molecule examined, such as protocholorophyllide (Pchl), hematoporphyrin and rose bengal which are generally regarded as efficient type II photosensitizers and thus have long-lived triplet states, was found to actively participate in an electro transfer reaction with $\alpha$TOH even under air-saturation conditions, generating $\alpha$TOH complex as an intermediate in a fashion of Michaelis-Menten type of reaction. For the reaction of $\alpha$TOH with triplet Pchl, the rate law was derived by applying the steady approximation for the binary complex, triplet Pchl-$\alpha$TOH , which turned out to be well consistent with the kinetic data.