• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.1
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• pp.27-35
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• 2005

This study was performed to determine the effect of three different concentrations of soy-isoflavones on excretions through urine and feces in either sham-operated or ovariectomized female rats. Seventy-two 16-week old Sprague-Dawley rats underwent sham operation or bilateral ovariectomy. They were provided diets containing different levels of soy isoflavones for 6 weeks: 50 ppm (low isoflavone intake; LI), 250 ppm (medium isoflavone intake; MI) and 500 ppm (high isoflavone intake; HI). The subsequent fecal and urinary excretions of daidzein and genistein were then measured. In the sham operated rats, body weight gains and food efficiency ratio of the MI and HI groups were significantly lower than control group, while food intake was not different. However, there was no significant difference in ovariectomized rats. The fecal excretion of daidzein was significantly higher in the HI group than the LI and MI groups, and that of genistein increased as dietary isoflavone intakes increased in both the sham operation and ovariectomy. The reverse tendency of fecal recovery was shown with dietary isoflavone dose only in genistein among ovariectomized rats. When dietary isoflavones were increased from 50 ppm to 500 ppm, the amounts of daidzein and genistein in the urine increased dose-dependently. The higher intakes of isoflavones leaded to lower recovery rates of daidzein and genistein in the urine in the sham-operated rats but not in the ovariectomized rats. The urinary recovery was significantly higher in the LI group than the MI and HI groups in the sham-operated rats. The excreted amounts and recovery of the two isoflavones in the urine were higher in the sham operated groups than in the ovariectomized groups, which implied an increased bioavailability of isoflavones by ovariectomy. Therefore, the results suggest that a more efficient use of soy isoflavones in ovariectomized conditions may occur, which indicates that a higher dose of soy isoflavones is necessary for the postmenopausal states.

• Food Science and Biotechnology
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• v.14 no.1
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• pp.89-93
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• 2005

Squalene synthase (SQS) inhibitors were screened from various plants and food extracts. Effective SQS inhibitor was purified from fermented soybean paste using ethanol extraction, HP-20 column chromatography, ethyl acetate extraction, silica gel column chromatography, and crystallization. Through UV spectrometry, $^1H$ NMR, $^{13}C$ NMR, and mass spectrometry, SQS inhibitor was identified as daidzein with molecular mass of 254 and molecular formula of $C_{15}H_{10}O_4$. Daidzein showed $IC_{50}$ value of 50 nmol/L against SQS, confirming its potential as therapeutic agent for hypercholesterolemia.

• YAKHAK HOEJI
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• v.54 no.3
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• pp.168-173
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• 2010

We investigated whether three flavonoids including daidzein, baicalein, hesperidin and ursolic acid, a triterpene acid, affect proliferation of MCF-7 human breast cancer cells stimulated by estrogenic compounds. Ursolic acid and baicalein inhibited proliferation of MCF-7 cells induced by PhIP, a food-derived carcinogen with estrogenic activity. Daidzein and hesperidin inhibited estradiol-induced proliferation of MCF-7 cells. These compounds should be further investigated for the possible involvement in signaling pathway after estrogen receptor binding in breast cancer cells.

• The Korean Journal of Food And Nutrition
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• v.17 no.2
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• pp.229-235
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• 2004

Chemical composition, total dietary fiber(TDF), oligosaccharide, isoflavone and phytic acid contents of seven domestic and three imported soybean cultivars were determined. TDF contents were ranged from 16.83 to 21.71％(w/w) without remarkable differences among soybean cultivars. Phytic acid contents of domestic cultivars such as Geomjongkong 1 (3.02％) and Dawonkong (2.92％) were higher than imported ones such as Canadian (2.07％) and American (2.22％) soybeans for soybean sprout and US No. 1 (2.16％). The phytic acid contents of cotyledon parts were 1.5 to 2 times higher than those of hypocotyl parts. Isoflavone contents in whole seed were wide ranged from 371 to 2,398 $\mu\textrm{g}$/g among cultivars and it were existed mainly as glucoside isomers. Profiles of isoflavone aglycones were composed of 52％ genistein, 36％ daidzein and 11％ glycitein. Hwanggumkong, Dawonkong, Geomjongkong 1 and American soybean for sprout contained lower isoflavone than others. Hypocotyl parts of soybeans contained from 6120.1 to 16921.1 $\mu\textrm{g}$/g isoflavone with ratio of 48％ glycitein, 35％ daidzein and 10％ genistein. Isoflavone contents of cotyledon parts were ranged 375-2393 $\mu\textrm{g}$/g, composition of which had no glycitein, 55％ genistein and 38％ daidzein. Oligosaccharide contents were similar among cultivars. Stachyose of 3.0-3.9％, raffinose of 0.8-1.2％, sucrose of 4.5-7.8％ and fructose of 0.3-0.8％ were determined.

• Korean Journal of Pharmacognosy
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• v.26 no.1
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• pp.13-17
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• 1995

From the EtOAc soluble parts of Lespedeza x nakaii T. Lee, three flavonoids and phytosterols have been isolated and identified as genistein, 4',7-dihydroxyflavone, daidzein and a mixture of campesterol, stigmasterol and ${\beta}-sitosterol$.

• Proceedings of the Korean Society of Life Science Conference
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• 2008.10a
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• pp.58.1-58.1
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• 2008

• Preventive Nutrition and Food Science
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• v.10 no.1
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• pp.52-57
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• 2005

Soy and soy foods are a rich source of isoflavones, which possess several biological activities. The effect of soy isoflavones, genistin and diadzin and their respective aglycones, on glucose uptake in adipocytes isolated from normal or high-fat fed rats was examined. As expected, insulin stimulated glucose uptake in a concentration-dependent manner. However, genistin and daidzin and their aglycones inhibited glucose uptake in a concentration-dependent (25-100μM) manner. In a time-course response, the aglycones significantly inhibited glucose uptake throughout 3 hr (after 30, 60, 120, 180 min), whereas the glycones only significantly inhibited the glucose uptake after 120 min and 180 min in the isolated rat adipocytes. Thus, the glucosides of genistein and daidzein, i.e. genistin and daidzin, were much less effective in inhibiting glucose uptake than their aglycones. In addition, genistin and daidzin did not significantly affect the insulin-stimulated glucose uptake, whereas genistein and daidzein did significantly inhibited glucose uptake compared to the vehicle control group by 47.5% and 24.8%, respectively (p < 0.05). The isoflavones also significantly inhibited glucose uptake in adipocytes isolated from rats fed a high-fat diet (50% of total calorie intake) when compared to the vehicle control. Finally, the isoflavones were found to enhance lipolysis in adipocytes isolated from high-fat fed rats, where the glycerol released by the aglycones was also higher than that released by the glycones. The current results showed that the inhibitory effect of daidzein on glucose uptake was very similar to that of genistein. The aglycones were more potent in inhibiting the uptake of glucose and a more potent stimulator of lypolysis than the glycones in adipocytes isolated from high-fat fed rats.

• Nutrition Research and Practice
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• v.7 no.5
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• pp.393-399
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• 2013

Asian populations are thought to receive significant health benefits from traditional diets rich in soybeans due to high isoflavone contents. However, available epidemiologic data only weakly support this hypothesis. The present study was carried out to assess the pharmacokinetics of isoflavones in South Korean women after ingestion of soy-based foods. Twenty-six healthy female volunteers (20-30 y old) consumed three different soy products (i.e., isogen, soymilk, and fermented soybeans) with different aglycone/glucoside ratios. Plasma and urine isoflavone concentrations were measured by high-performance liquid chromatography (HPLC) after ingestion of one of the soy products. Pharmacokinetic parameters were determined using the WinNonlin program. The area under the curve (AUC) for plasma daidzein levels of the soymilk group ($2,101{\pm}352ng{\cdot}h/mL$) was significantly smaller than those of the isogen ($2,628{\pm}573ng{\cdot}h/mL$) and fermented soybean ($2,593{\pm}465ng{\cdot}h/mL$) groups. The maximum plasma concentration ($C_{max}$) of daidzein for the soymilk group ($231{\pm}44$ ng/mL) was significantly higher than those of the isogen ($160{\pm}32$ ng/mL) and fermented soybean ($195{\pm}35$ ng/mL) groups. The half-lives of daidzein and genistein in the soymilk group (5.9 and 5.6 h, respectively) were significantly shorter than those in the individuals given isogen (9.6 and 8.5 h, respectively) or fermented soybean (9.5 and 8.2 h, respectively). The urinary recovery rates of daidzein and genistein were 42% and 17% for the isogen group, 46% and 23% for the fermented soybean group, and 33% and 22% for the soymilk group. In conclusion, our data indicated that soy products containing high levels of isoflavone aglycone are more effective for maintaining plasma isoflavone concentrations. Additional dose-response, durational, and interventional studies are required to evaluate the ability of soy-based foods to increase the bioavailability of isoflavones that positively affect human health.

• Molecules and Cells
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• v.37 no.2
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• pp.172-177
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• 2014

A glycosyltransferase, YjiC, from Bacillus licheniformis has been used for the modification of the commercially available isoflavonoids genistein, daidzein, biochanin A and formononetin. The in vitro glycosylation reaction, using UDP-${\alpha}$-D-glucose as a donor for the glucose moiety and aforementioned four acceptor molecules, showed the prominent glycosylation at 4' and 7 hydroxyl groups, but not at the $5^{th}$ hydroxyl group of the A-ring, resulting in the production of genistein 4'-O-${\beta}$-D-glucoside, genistein 7-O-${\beta}$-D-glucoside (genistin), genistein 4',7-O-${\beta}$-D-diglucoside, biochanin A-7-O-${\beta}$-D-glucoside (sissotrin), daidzein 4'-O-${\beta}$-D-glucoside, daidzein 7-O-${\beta}$-D-glucoside (daidzin), daidzein 4', 7-O-${\beta}$-D-diglucoside, and formononetin 7-O-${\beta}$-D-glucoside (ononin). The structures of all the products were elucidated using high performance liquid chromatography-photo diode array and high resolution quadrupole time-of-flight electrospray ionization mass spectrometry (HR QTOF-ESI/MS) analysis, and were compared with commercially available standard compounds. Significantly higher bioconversion rates of all four isoflavonoids was observed in both in vitro as well as in vivo bioconversion reactions. The in vivo fermentation of the isoflavonoids by applying engineered E. coli $BL21(DE3)/{\Delta}pgi{\Delta}zwf{\Delta}ushA$ overexpressing phosphoglucomutase (pgm) and glucose 1-phosphate uridyltransferase (galU), along with YjiC, found more than 60% average conversion of $200{\mu}M$ of supplemented isoflavonoids, without any additional UDP-${\alpha}$-D-glucose added in fermentation medium, which could be very beneficial to large scale industrial production of isoflavonoid glucosides.

• Journal of Microbiology and Biotechnology
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• v.27 no.11
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• pp.1952-1960
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• 2017

Recently, soybean isoflavone aglycones (i.e., daidzein and genistein) and ${\gamma}-aminobutyric$ acid (GABA) have begun to receive considerable consumer attention owing to their potential as nutraceuticals. To produce these ingredients, multiple microorganisms and their enzymes are commonly used for catalysis in the nutraceutical industry. In this work, we introduce a novel fermentation process that uses whole-cell biocatalysis to accelerate GABA and isoflavone aglycone production in doenjang (a traditional Korean soybean paste). Microbial enzymes transform soybean isoflavone glycosides (i.e., daidzin and genistin) and monosodium glutamate into soybean isoflavone aglycones and GABA. Lactobacillus brevis GABA 100 and Aspergillus oryzae KACC 40250 significantly reduced the production time with the aid of a protease. The resulting levels of GABA and daidzein were higher, and genistein production resembled the levels in traditional doenjang fermented for over a year. Concentrations of GABA, daidzein, and genistein were measured as 7,162, 60, and $59{\mu}g/g$, respectively on the seventh day of fermentation. Our results demonstrate that the administration of whole-cell L. brevis GABA 100 and A. oryzae KACC 40250 paired with a protease treatment is an effective method to accelerate GABA, daidzein, and genistein production in doenjang.