• 한국환경보건학회지
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• 제31권6호
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• pp.498-503
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• 2005

Stability of soybean isoflavone isomers according to extraction conditions such as temperature, pH, and extracting solvents was investigated. Heating induced three chemical reactions to occur for malony1 derivatives of isoflavones, namely decarboxylation of malony1 groups into acety1 derivatives, deesterification of malony1 residues, and hydrolysis of $\beta$-glycosidic bonds. Among the twelve isoflavone isomers, change in concentrations of acety1glycosides were most pronounced: Acety1 derivatives were present only in trace amounts in unheated hypocotyls, but the content increased dramatically during heating. As for the glycosides, concentrations of daidzin and glycitin increased due to heat treatment, though that of genistin remained almost unchanged. Heat decomposition rates and the patterns differed among the three malony1 derivatives. After 120 min at $80^{circ}C$, the relative concentrations of daidzin, glycitin and genistin were increased from $9.2\%$, $12.4\%$ and $3.3\%$ to $19.3\%$, $21.9\%$ and $6.2\%$, respectively. When crude isoflavones were solubilized in glycine buffer (pH 10.0) and incubated at $80^{circ}C$, deesterification occurred faster than at pH 7.0. When the pH of isoflavone solution was increased, the malony1glycosides were hydrolyzed to their respective glycosides at increased rate. Both acetyl and aglycone forms were unchanged and only de-esterification reactions occurred. At the acidic pH, malonylglycosides were much stable both at 60 and $80^{circ}C$. However at pH 10, $80^{circ}C$ and 1 hr, $75-80\%$ of malonylglycosides were transformed to their deesterified glycosides. When isoflavones were extracted with $60\%$ aqueous ethanol at $60^{circ}C$, isoflavone isomers were stable and the deesterification reactions did not occur in these conditions. However, at $80^{circ}C$ deesterification of malonyiglycosides occurred significantly with $15-20\%$ of malonylglycosides being hydrolyzed into their respective glycosides. This experiment showed that malonylglycosides undergo decomposition when heated or exposed to alkaline conditions. Also, aqueous ethanol was preferred to aqueous methanol as solubilizing media for obtaining extract with minimum degradation of malonylglycosides.

• Food Science and Biotechnology
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• 제15권1호
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• pp.24-27
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• 2006

A simple HPLC quantification method was developed for genistein, genistin, daidzein, and daidzin in soybeans and soybean products. The procedure used a $4.6{\times}100\;mm$ $Chromolith^{(R)}$ RP-18e column with a mobile phase of 1% HOAc in 20% MeOH to 1% HOAc in 80% MeOH for 10 min. The injection volume was $2\;{\mu}L$ at a flow rate of 2 mL/min. Detection was carried out under UV at 254 nm. Under these conditions, the major isoflavones daidzein, daidzin, genistein, and genistin in soybean and soybean pastes were eluted within 7 min with baseline separation. Optimal extraction of the above four major isoflavones was achieved when 40 g of soybean or soybean paste was refluxed in 100 mL of 95% ethanol for 2 hr. Ten different soybean cultivars and nine commercial soybean pastes were analyzed by this method. The total isoflavone content was highest in the cultivar Somyung ($2,497\;{\mu}g/g$ dry weight). The isoflavone content in soybean pastes varied widely from manufacturer to manufacturer (an almost five-fold difference between the highest and lowest values). Such variations were presumably due to differences in fermentation conditions, type of soybeans used, and levels of such additives as starch and salt.

• Journal of Microbiology and Biotechnology
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• 제25권4호
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• pp.469-478
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• 2015

In spite of the reported probiotic effects, Bifidobacterium bifidum BGN4 (BGN4) showed no βglucosidase activity and failed to biotransform isoflavone glucosides into the more bioactive aglycones during soy milk fermentation. To develop an isoflavone-biotransforming BGN4, we constructed the recombinant B. bifidum BGN4 strain (B919G) by cloning the structural β-glucosidase gene from B. lactis AD011 (AD011) using the expression vector with the constitutively active promoter 919 from BGN4. As a result, B919G highly expressed β-glucosidase and showed higher β-glucosidase activity and heat stability than the source strain of the β-glucosidase gene, AD011. The biotransformation of daidzin and genistin compounds using the crude enzyme extract from B919G was completed within 4 h, and the bioconversion of daidzin and genistin in soy milk during fermentation with B919G also occurred within 6 h, which was much faster and higher than with AD011. The incorporation of this β-glucosidase-producing Bifidobacterium strain in soy milk could lead to the production of fermented soy milk with an elevated amount of bioavailable forms of isoflavones as well as to the indigenous probiotic effects of the Bifidobacterium strain.

• 한국식품과학회지
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• 제34권5호
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• pp.916-918
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• 2002

산가수분해시 산의 농도가 탈지대두박의 isoflavone 양에 미치는 영향을 조사하였다. 측정한 isoflavone은 daidzin, genistin 등 glucosides와 daidzein, genistein 등 aglycons이었다. 산가수분해는 탈지대두박 분말에 0.25 N-3.00 N HCl을 가하고 $95^{\circ}C$에서 4시간 가열하였다. 그 결과 총 isoflavone은 0.25 N-1.0 N HCl의 범위에서 가열이 진행되면서 증가하여 2시간 후에는 약 40% 증가함을 보였다. 그러나 그 이상의 농도에서는 현저한 감소가 있어 4시간 후에는 52%의 감소가 있었다. 이 결과는 낮은 HCl 농도에서의 증가는 isoflavone isomer가 isoflavone으로 전환되었음을 보여주고 높은 농도에서의 감소는 isoflavone이 분해됨을 보여주고 있다. 가열 중 각각의 isoflavone의 변화는 전체적으로 glucosides는 감소하고 aglycons는 증가하는 경향이었다. 특히 2 N HCl에서의 60분 반응시 daidzin과 genistin, glycitin 등 glucosides는 검출되지 않았다.

• 한국식생활문화학회지
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• 제30권1호
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• pp.77-85
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• 2015

This study investigated the physicochemical properties and antioxidative activity of soymilk added with buckwheat sprout (SBS), and sensory properties of SBS were analyzed with control soymilk (CS). Moisture content decreased while protein, ash, and lipid contents increased according to content of buckwheat sprout. Solids content and viscosity tended to increase with addition of buckwheat sprout from 0% (CS) to 2.5% (2.5SBS), 3.5% (3.5SBS), and 4.5% (4.5SBS). SBS was found the significant pH drop from 7.08 to 6.43, 6.34, and 6.21. Suspension stability of soymilk slightly decreased with addition of buckwheat sprout. Hunter's color value L of SBS decreased while a and b values increased in comparison with CS. Rutin content was measured 23.78 mg/100 g (2.5SBS), 39.68 mg/100 g (3.5SBS), and 44.80mg/100 g (4.5SBS). Vitamin C content in SBS was higher than CS. Daidzin content increased as buckwheat sprout was added. Total phenolic content increased from 100.95 mg/100 g (CS) up to 315.71 mg/100 g (4.5SBS). For free radical scavenging activity, SBS was significantly higher than CS. In conclusion, SBS can be used as a functional food with higher amounts of rutin, vitamin C, total phenolics, and daidzin. 2.5SBS and 3.5SBS also showed better overall quality characteristics.

• Food Science and Biotechnology
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• 제17권2호
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• pp.228-233
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• 2008

Considerable progress has been made in functionalization of the soy isoflavones through enzymatic modification of daidzin, genistin, and glycitin. After hydrolysis of $\beta$-glucosides into their corresponding aglycones, these compounds were structurally modified via biotransformations such as regioselective hydroxylation, enantioselective reduction, regioselective methylation, and polymerization. These reactions often resulted in an increase of the biological activities (e.g., anti oxidative activity, antiproliferative activity) and/or improvement of the physico-chemcial properties (e.g., water solubility, bioavailability). This review briefly summarizes on-going research activities on the biofunctionalization of the soy isoflavones.

• Preventive Nutrition and Food Science
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• 제14권2호
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• pp.134-141
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• 2009

The changes in components and biological activities of doenjang samples prepared with black soybeans and fermented with Bacillus subtilis SCB were investigated. The amino nitrogen (A-N) contents of samples increased with increasing black soybean content. A doenjang product made using a 1:1 ratio of soybeans-black soybeans showed a maximum level of genistein and daidzein isoflavones ($1111.6{\mu}g/g$) at 110 days of fermentation, along with decreasing contents of genistin and daidzin due to the conversion to aglycones. The black soybean-only doenjang sample showed higher protease activity, including caseinolytic and fibrinolytic enzyme activities, than the other samples, and had relatively higher polyphenol content and DPPH radical scavenging activity. Therefore, doenjang made with additions of black soybeans and fermented by B. subtilis SCB may have improved physiological properties, suggesting this to be a valuable method of preparation.

• 생약학회지
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• 제30권2호
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• pp.216-221
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• 1999

The NAD(P)-linked $3{\alpha}-Hydroxysteroid$ $dehydrogenase(3{\alpha}-HSD)$ of rat liver cytosol is powerfully inhibited by the non-steroidal anti-inflammatory drugs in rank-order of their therapeutic potency, and this observation has now been developed into a rapid screen for predicting the potency of products that show anti-inflammatory effect. Five-plants were screened by using this method. Among them, BuOH-fraction of Mucuna birdwoodiana showed strong inhibitory effect on $3{\alpha}-HSD$, and three isoflavone compounds were isolated. Inhibitory activates of isolated compounds were compared.

• Natural Product Sciences
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• 제10권4호
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• pp.152-167
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• 2004

Traditional Chinese Medicines (TCM) have attracted great interest in recent researchers as alternative medicines for incurable diseases. This review focuses on qualitative and quantitative analytical approaches for bioactive metabolites of components flavonoids and saponins of traditional Chinese medicines by TLC system, although various methods have been introduced. Emphasis will be put on the processes of metabolite extraction from intestinal bacterial cultures or urines, separation (mobile phase) and detection. The identified metabolites by selection of extraction solvent and detection methods are also discussed. In addition, metabolite determinations of flavonoids (baicalin, apiin, rutin, quercetin, quercitrin, kaempferol, diosmin, hesperidin, poncirin, naringin, puerarin, daidzin, daidzein, tectoridin) and saponins (ginsenosides, kalopanaxsaponins, glycyrrhizin, chiisanoside, saikosaponins, soyasaponins) in culture fluid, in urine and in some herbal formula extracts are summarized. These bioactive metabolites of these components by intestinal microflora should be connected to pharmacological actions.

• 생약학회지
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• 제28권1호
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• pp.42-47
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• 1997

The prescription of Gal Gun Tang, which has been used for treatment of cold, fever, and muscular pain in Chinese herb medicine, is produced in the form of decoction However, the storage problem for this dosage form remains unsettled. Using HPLC and GC, we examined quantitative change of major constituents caused by time-progress and temperature-change. Nine major constituents, such as cinnamaldehyde, cinnamic acid, ephedrine, puerarin, paeoniflorin, daidzin, benzoic acid, glycyrrhizin and liquiritin, were selected as references. The content of cinnamaldehyde significantle decreased by the increase of temperature. While that of cinnamic acid increased. Benzoic acid showed the most significant change of the content in three months at $40^{\circ}C$. It is suggested that most of constituents are considerably stable when kept frozen.