Biological activities of cheonggukjang prepared with several soybean cultivars

To select proper soybean cultivars for producing functional cheonggukjang, a comparison was made of the physiological activities of different cheonggukjang prepared with 30 different soybean cultivars. The isoflavone content was highest in the cheonggukjang made from ‘Daepung’ soybeans at 208.75 mg%. In general, the contents of glycone types (and derivatives) of isoflavone, specifically daidzin, glycitin, genistin, and malonylgenistin, were higher than that of aglycone types. The polyphenol contents ranged from 30.62 to 80.32 mg%. The DPPH radical scavenging activity and superoxide dismutase (SOD)-like activity of the cheonggukjang made from yellow soybeans had a higher activity than those of black soybeans. Although there are no consistent tendencies in the functional activity of cheonggukjang according to soybean color and size, the antioxidative activity is highest in the cheonggukjang made of yellow soybeans. Additionally, the fibrinolytic and inhibitory activities against angiotensin I-converting enzyme are highest in the cheonggukjang made of black soybeans. From these results, it can be concluded that the DPPH free radical scavenging activity and SOD-like activity in cheonggukjang depends on the phenolic compound content in soybean.     

Regulatory policy on genetically modified breeding stack in key countries and the current status in Korea

With an increasing interest and demand for biotechnology crops in agriculture worldwide, genetically modified (GM) breeding stacks produced by conventional breeding of previously approved GM single events remain popular for farmers in GM crop cultivation countries. However, regulations on stacks vary in each country. Currently, Korea requires approval for all breeding stacks intended for cultivation. To determine whether the stack is subject to a full safety assessment as a new GM crop, molecular characterization, protein expression, composition analysis, and agronomic characterization data are required. Korea’s regulatory policy on stacks has not adopted the high-covers-low concept; therefore, subcombinations of already approved higher combination events are subject to breeding stack review if any subcombination was purposefully bred for cultivation use. This review will help promote the efficient management of GM breeding stacks in Korea in the future.

     

Age-hardening characteristics of a dental low-carat gold alloy with dual hardener system of In and Cu

The age-hardening characteristics of a dental low carat gold alloy with a dual hardener system of indium (In) and Cu (33.9 Au–26.2 Ag–20.28 Cu–9.8 Pd–7.8 In–2 Zn (at%)) were examined by observing the age hardenability and related phase transformation, microstructural changes and elemental distribution during the aging process at 400°C. The dual hardener system by the use of both In and Cu provided more powerful hardening effect compared to a single-hardener system of In or Cu, without the formation of a AuCu type ordered phase. The alloy showed apparent initial hardening, which was attributed to the pre-precipitation or zone formation by the help of quenched in excess vacancies. During the constant increase in hardness, the single parent phase separated into three phases, Au–Ag-based phase, Au–Cu-based phase containing Pd and In, and InPd-based phase, through a metastable state. Indium which was added as one of the hardeners induced initial grain boundary precipitation, followed by an expansion of the lamellar structure, which was responsible for softening. The alternative lamellar structure was composed of a Cu-rich layer (Au–Cu-based phase containing Pd and In) and an Ag-rich layer (Au–Ag-based phase) replaced partly by the InPd-based phase. Separation of the Ag-rich layer from the Cu-rich layer is based on the miscibility limit of Ag and Cu due to their eutectic property.     

Measurements of Diacylglycerols in Skeletal Muscle by Atmospheric Pressure Chemical Ionization Mass Spectrometry

Diacylglycerol (DAG) is an intermediate lipid involved in the synthesis of phospholipids and triglycerides. As signaling regulators, DAG activate novel protein kinase C leading to decreased response to insulin in skeletal muscle. Alteration of DAG contents correlates with development of metabolic dysregulation in obese and diabetic conditions. Recent advances in lipidomics using mass spectrometry allow expanded measurements of various lipid species. This study describes a rapid measurement of DAG species using the triple quadrupole mass spectrometry using atmospheric pressure chemical ionization in a positive ion mode. DAG in the cells and muscle tissues were separated depending on differences in chain lengths and degree of unsaturation. The limit of detection and quantification for DAG was 0.2 to 17 pmol for this method. When C2C12 cells were treated with palmitate or oleate, we found a 12-fold and 2-fold DAG increase respectively compared to the no-treatment control. In the muscles of obese db/db mice, DAG levels were elevated by 6-fold compared to those of wild-type skeletal muscles. The present analytical method provides a rapid and sensitive quantification of DAG molecular species from various biological samples and can be used to correlate the degree of metabolic dysregulation with lipotoxic metabolites.     

Identification of bitter components from <Emphasis Type="Italic">Artemisia princeps</Emphasis> Pamp.

Identification of bitter components from the aerial parts of Artemisia princeps Pamp. was performed to search for a method to eliminate the bitter taste from A. princeps products. The aerial parts of A. princeps were extracted in an aqueous EtOH solution, and the obtained extracts were partitioned into essential-oil, flavonoid-rich, n-BuOH, and aqueous fractions. Two purified bitter sesquiterpenoids were identified through repeated column chromatography of the bitterest fraction, the flavonoid-rich fraction, through an activity-guided fractionation method. The compounds were identified to be 1α,6α,8α-trihydroxy-5α,7βH-guaia-3,9,11(13)-trien-12-oic acid and artecalin, respectively, based on the interpretation of NMR, MS, and IR spectroscopic data. Both compounds were 50 times bitterer than caffeine and had similar bitterness to quinine HCl. Neither eupatilin nor jaceosidin, the major active components of A. princeps, showed any bitterness.     

Improvement in Biocompatibility of Fluoridated Apatite with Addition of Resorbable Glass

The biocompatibility of fluoridated apatite (FHA) was significantly improved by the addition of a resorbable phosphate-based glass. With the addition of small amounts of the glass (up to 5%) to the FHA, a completely densified body was obtained after sintering at 1250°C. The resultant crystalline phase was composed of tricalcium phosphate (TCP) and FHA. The addition of the glass to the FHA significantly improved the viability and functional activity of osteoblastic cells, while these were only slightly improved when the glass was added to pure hydroxyapatite, demonstrating that the fluoridation and glass addition had a synergistic stimulatory effect. This finding suggests that the glass-added FHA bioceramic would be highly useful as a hard tissue reconstructive material.     

Tetracycline release from bioerodible hydrogels based on semiinterpenetrating polymer networks composed of poly(ε-caprolactone) and poly(ethylene glycol) macromer in vitro

Poly(ethylene glycol) (PEG) macromers terminated with acrylate groups and semiinter-penetrating polymer networks (SIPNs) composed of poly(ε-caprolactone) (PCL) and PEG macromer were synthesized and characterized with the aim of obtaining a bioerodible hydrogel that could be used to release tetracycline HCl for local antibiotic therapy administered peroperatively. Polymerization of PEG macromer resulted in the formation of crosslinked gels due to the multifunctionality of macromer. Noncrosslinked PCL chains were interpenetrated into the crosslinked three-dimensional networks of PEG. Glass transition temperature (T_g) and melting temperature (T_m) of PCL in the SIPNs were inner shifted, indicating interpenetration of PCL and PEG chains. It was found that water content increased with increasing PEG weight fraction due to the hydrophilicity of PEG. Drug release can be controlled by weight fraction of PEG in the PCL/PEG SIPNs, concentration of PEG macromer in the SIPNs preparation, and the nature of PEG. © 1996 John Wiley & Sons, Inc.