One-step isolation of sappanol and brazilin from Caesalpinia sappan and their effects on oxidative stress-induced retinal death

Caesalpinia sappan is a well-distributed plant that is cultivated in Southeast Asia, Africa, and the Americas. C. sappan has been used in Asian folk medicine and its extract has been shown to have pharmacological effects. Two homoisoflavonoids, sappanol and brazilin, were isolated from C. sappan by using centrifugal partition chromatography (CPC), and tested for protective effects against retinal cell death. The isolated homoisoflavonoids produced approximately 20-fold inhibition of N-retinylidene-N-retinyl-ethanolamine (A2E) photooxidation in a dose-dependent manner. Of the 2 compounds, brazilin showed better inhibition (197.93 ± 1.59 μM of IC50). Cell viability tests and PI/Hoechst 33342 double staining method indicated that compared to the negative control, sappanol significantly attenuated H2O2-induced retinal death. The compounds significantly blunted the up-regulation of intracellular reactive oxygen species (ROS), and sappanol inhibited lipid peroxidation in a concentration-dependent manner. Thus, both compounds represent potential antioxidant treatments for retinal diseases.The RGC-5 cells were kindly gifted by Alcon Research, Ltd. This work was financially supported by an intramural grant (2Z04381) from the Korea Institute of Science and Technology (KIST), Republic of Korea.OAIID:RECH_ACHV_DSTSH_NO:220152015000794002RECH_ACHV_FG:RR00200001ADJUST_YN:EMP_ID:A079994CITE_RATE:2.782DEPT_NM:국제농업기술학과EMAIL:[email protected]_YN:YCONFIRM:

大學修學能力試驗의 採擇過程 分析硏究

학위논문(석사)--서울大學校 大學院 :敎育學科 敎育行政專攻,1996.Maste

파킨슨병과 치매의 초기 진단을 위한 뇌전도 분석 및 뇌파 청진기의 가능성 연구

학위논문(석사) - 한국과학기술원 : 바이오및뇌공학과, 2013.8, [ iii, 52 p. ]Parkinson’s disease (PD) is a neurodegenerative disorder that leads to motor disability and cognitive impairment. It is important to distinguish PD from other forms of dementia, including Alzheimer’s disease (AD), but differential diagnosis is difficult because PD-D is accompanied with AD and vice versa. Besides, their symptoms are similar. Electroencephalography (EEG) can be useful for quick and simple diagnosis. Few studies have compared the EEG characteristics of PD and AD because EEG measurement is difficult, as PD lesions are located in the substantia nigra and subcortical regions and EEG patterns show similar slowing activity in both PD and AD patients. In this study, two methods were suggested for the diagnosis of PD.First, non-linear dynamics and the regularity of EEG were examined using Approximate Entropy (ApEn). One time delay selected by Auto Mutual Information (AMI) and 2 embedding dimensions selected by False Nearest Neighbors (FNN) were used as features of ApEn. ApEn values were decreased in patients in most channels, and ApEn values in PD patients were significantly lower than those in AD patients in channels F3-C3 and C3-P3. These results showed that EEG patterns are simple and regular in the cognitively impaired brain. In particular, the difference in ApEn values between PD and AD patients in frontocentral channels might have resulted from motor disability in PD patients because the frontocentral cortex is related to the motor area. An increase in regularity in patients might be correlated with slowing brain activity, as seen in the results from spectral analysis. This method can be used to differentiate between PD patients and controls as well as to differentiate between PD patients and AD patients.Next, a Brain Stethoscope was designed by mapping low-alpha (8-10 Hz) power and low-beta (12-20 Hz) into low-pitched sound and high-pitched sound. Low-alpha power was dominant in PD patients, and low-beta power was dominant in controls. This resul...한국과학기술원 : 바이오및뇌공학과

Current research status and analysis methods on the effects of food surface properties on particulate matter adsorption

Air pollution caused by particulate matters (PM) has become a global issue. PM is known to threaten human health by causing respiratory and cardiovascular disease. PM can be introduced to human gastrointestinal track through food intake, causing inflammation and changes in gut microbiota. Even at low PM concentrations, prolonged exposure to PM can cause significant accumulation of PM in food products. The adsorption of PM onto food surfaces is expected to be strongly influenced by the properties of food surfaces, but few studies have been reported. This paper examines several important food surface properties that may affect the interactions between PM and food surfaces, including surface wettability, surface charge, and surface microstructure. Understanding the adsorption of PM onto food surfaces can provide useful guidance for classifying PM-sensitive foods and controlling food chains, including cultivation, processing, preservation, and cooking, to ensure food safety against PM.N

Characterization of fish gelatin-gum arabic complex coacervates as influenced by phase separation temperature

he rheological and structural characteristics of fish gelatin (FG)–gum arabic (GA) complex coacervate phase, separated from an aqueous mixture of 1% FG and 1% GA at pH 3.5, were investigated as influenced by phase separation temperature. Decreasing the phase separation temperature from 40 to 10 °C lead to: (1) the formation of a coacervate phase with a larger volume fraction and higher biopolymer concentrations, which is more viscous, more structural resistant at low shear rates, more shear-thinning at high shear rates, and more condensed in microstructure, (2) a solid-like elastic behavior of the phase separated at 10 °C at a high oscillatory frequency, (3) the increase in gelling and melting temperatures of the coacervate phase (3.7−3.9 °C and 6.2−6.9 °C, respectively), (4) the formation of a more rigid and thermo-stable coacervate gel. The coacervate phase is regarded as a homogeneously networked biopolymer matrix dispersed with water vacuoles and its gel as a weak physical gel reinforced by FG–GA attractive electrostatic interactions.This research was supported by the Korea Sea Grant Program (Gangwon Sea Grant) funded by the Ministry of Oceans and Fisheries in Korea.OAIID:RECH_ACHV_DSTSH_NO:220152015000794001RECH_ACHV_FG:RR00200001ADJUST_YN:EMP_ID:A079994CITE_RATE:3.138DEPT_NM:국제농업기술학과EMAIL:[email protected]_YN:YCONFIRM:

One-step isolation of sappanol and brazilin from Caesalpinia sappan and their effects on oxidative stress-induced retinal death

Caesalpinia sappan is a well-distributed plant that is cultivated in Southeast Asia, Africa, and the Americas. C. sappan has been used in Asian folk medicine and its extract has been shown to have pharmacological effects. Two homoisoflavonoids, sappanol and brazilin, were isolated from C. sappan by using centrifugal partition chromatography (CPC), and tested for protective effects against retinal cell death. The isolated homoisoflavonoids produced approximately 20-fold inhibition of N-retinylidene-N-retinyl-ethanolamine (A2E) photooxidation in a dose-dependent manner. Of the 2 compounds, brazilin showed better inhibition (197.93 ± 1.59 μM of IC(50)). Cell viability tests and PI/Hoechst 33342 double staining method indicated that compared to the negative control, sappanol significantly attenuated H(2)O(2)-induced retinal death. The compounds significantly blunted the up-regulation of intracellular reactive oxygen species (ROS), and sappanol inhibited lipid peroxidation in a concentration-dependent manner. Thus, both compounds represent potential antioxidant treatments for retinal diseases. [BMB Reports 2015; 48(5): 289-294

Enhanced production of xylitol from xylose by expression of Bacillus subtilis arabinose:H+ symporter and Scheffersomyces stipitis xylose reductase in recombinant Saccharomyces cerevisiae

Inefficient transport of xylose into Saccharomyces cerevisiae is a major hurdle for production of xylitol, a natural sweetener with five carbons. To facilitate the xylose transport and hence increase xylose conversion to xylitol, the araE gene encoding an arabinose:H+ symporter (AraE) from Bacillus subtilis and the XYL1 gene from Scheffersomyces stipitis were expressed in Saccharomyces cerevisiae EBY.VW4000, a hxt null mutant. The resulting strain of EXHA exhibited 4.1 fold increases in xylose consumption rate and xylitol productivity, relative to the control strain without AraE. Also, overexpression of AraE in wild type S. cerevisiae D452-2 having all hexose transporters and the XYL1 gene increased both xylose consumption and xylitol production considerably. In a glucose -limited fed-batch culture with intermittent addition of xylose, the DXXA strain with multiple copies of araE and XYL1 produced 177.8 g/L xylitol with 2.47 g/L-h productivity, which were 26.9 and 17.6 times higher than those for a batch culture of the DX strain expressing the XYLI gene only, respectively. It was concluded that B. subtilis AraE might be a potent xylose transporter and conferred much higher xylose-consuming and xylitol-producing abilities to S. cerevisiae.OAIID:RECH_ACHV_DSTSH_NO:T201737392RECH_ACHV_FG:RR00200001ADJUST_YN:EMP_ID:A079994CITE_RATE:2.932DEPT_NM:국제농업기술학과EMAIL:[email protected]_YN:YN

Optimization of manufacturing conditions for improving storage stability of coffee-supplemented milk beverage using response surface methodology

This study aimed at optimizing the manufacturing conditions of a milk beverage supplemented with coffee, and monitoring its physicochemical and sensory properties during storage. Raw milk, skim milk powder, coffee extract, and emulsifiers were used to manufacture the beverage. Two sucrose fatty acid esters, F110 and F160, were identified as suitable emulsifiers. The optimum conditions for the beverage manufacture, which can satisfy two conditions at the same time, determined by response surface methodology (RSM), were 5,000 rpm primary homogenization speed and 0.207% sucrose fatty acid emulsifier addition. The particle size and zeta-potential of the beverage under the optimum condition were 190.1 nm and 25.94 +/- 0.06 mV, respectively. In comparison study between F110 added group (GF110) and F160 added group (GF160) during storage, all samples maintained its pH around 6.6 to 6.7, and there was no significant difference (p<0.05). In addition, GF110 showed significantly higher zeta-potential than GF160 (p<0.05). The particle size of GF110 and GF160 were approximately 190.1 and 223.1 nm, respectively at initial. However, size distribution of the GF160 tended to increase during storage. Moreover, increase of the particle size in GF160 was observed in microphotographs of it during storage. The L* values gradually decreased within all groups, whereas the a* and b* values did not show significant variations (p<0.05). Compared with GF160, bitterness, floating cream, and rancid flavor were more pronounced in the GF110. Based on the result obtained from the present study, it appears that the sucrose fatty acid ester F110 is more suitable emulsifier when it comes to manufacturing this beverage than the F160, and also contributes to extending product shelf-life.OAIID:RECH_ACHV_DSTSH_NO:T201707034RECH_ACHV_FG:RR00200001ADJUST_YN:EMP_ID:A079994CITE_RATE:.484DEPT_NM:국제농업기술학과EMAIL:[email protected]_YN:YY