• Journal of Microbiology and Biotechnology
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• v.25 no.4
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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.

• Korean Journal of Food Science and Technology
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• v.34 no.5
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• pp.916-918
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• 2002

The effect of acid hydrolysis on isoflavone contents of defatted soybean flour (DSF) was investigated in this study. Isoflavone analyzed were daidzein, genistein, glycitein, daidzein, genistein and glycitein with using HPLC. The DSF suspension was heated at $95^{\circ}C$ for 4 hour with addition of HCl (0.25-3.00 N) and analyzed isoflavone. The results showed that the total isoflavone was increased as the HCl concentration increased up to 1.0 N HCl during heating, indicating conversion of glucoside isomers of isoflavone to its aglycons. However, higher concentration than 1.0 N HCl caused a relatively fast decrease in isoflavone after 4 hour of heating. These results were probably caused by degradation of isoflavone by high concentration of acid during heating. The glucosides of isoflavone were steadily decreased while its aglycons were rather increased during $1.0{\sim}2.0$ hour of heating.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.58 no.2
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• pp.149-160
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• 2013

The objective of present study was to simultaneously isolate of isoflavone and soyasaponin compounds from the germ of soybean seeds. Soy germ flours were defatted with hexane for 48h at room temperature, and methanolic extracts were prepared using reflux apparatus at $90^{\circ}C$ for 6h, two times. After extraction, extracts were separated with preparative RP-$C_{18}$ packing column ($125{\AA}$, $55-105{\mu}m$, $40{\times}150mm$), and collected 52 fractions were identified with TLC plate (Kieselgel 60 F-254) and HPLC, respectively. Among the identified isoflavone and soyasaponin fractions, isoflavone fractions were re-separated using a recycling HPLC with gel permeation column (Jaigel-W252, $20{\times}500mm$). Final fractions were air-dried, and the purified compounds of two isoflavones (ISF-1-1, ISF-1-2) and four soyasaponins (SAP-1, SAP-2, SAP-3, SAP-4) were obtained. Two isoflavone compounds (ISF-1-1, ISF-1-2) were acid-hydrolyzed for the identification of their aglycones, and confirmed by comparing with 12 types of isoflavone isomers. While the four kinds of soyasaponins were identified by using a micro Q-TOF mass spectrometer in the ESI positive mode with capillary voltage of 4.5kV, and dry temperature of $200^{\circ}C$. Base on the obtained results, it was conclude that ISF-1-1 is the mixture isomers of daidzin (43.4%), glycitin (47.0%), and genistin (9.6%), but ISF-1-2 is the single compound of genistin (99.8% <). On the other hand, soyasaponin SAP-1 is the mixture compounds of soyasaponin A-group (Aa, Ab, Ac, Ae, Af); SAP-2 is soyasaponin B-group (Ba, Bb, Bc) and E-group (Bd, Be); SAP-3 is soyasaponin B-group (Ba, Bb, Bc), E-group (Bd, Be), and DDMP-group (${\beta}g$); SAP-4 is soyasaponin B-group (Ba, Bb, Bc), E-group (Bd, Be), and DDMP-group (${\beta}g$, ${\beta}a$), respectively.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.5
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• pp.680-689
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• 2016

The present study evaluated the validation method for isoflavone contents of fermented soybean extracts by bioconversion as well as their antioxidant activities. Our results show that the total isoflavone contents of non-fermented and fermented soybean extract ranged between 119.8 to $637.7{\mu}g/g$ and between 567.3 to $2,074.6{\mu}g/g$, respectively. Moreover, fermented soybean extracts had higher contents of isoflavone aglycones, including daidzein, glycitein, and genistein than non-fermented soybean extracts as well as lower contents of isoflavone glucosides such as daidzin, glycitin, and genistin. FRAP and ORAC values ranged between 0.15 to 0.22 and between 195.24 to $753.79{\mu}M$ Trolox equivalents/g in non-fermented and fermented soybean extracts, respectively. These results indicate that fermented soybean extracts had higher total isoflavone contents and antioxidant activities than non-fermented soybean extracts. Bioconversion process in this study may have the potential to produce isoflavone-enriched natural antioxidant agents with high added value from soybean matrices.

• Food Science and Biotechnology
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• v.17 no.2
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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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• v.14 no.2
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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.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.46 no.2
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• pp.139-144
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• 2001

To analyze their isoflavones contents by HPLC analysis during two years on 60 collected old local traditional soybean varieties from various districts of Korea was conducted. There was a yearly variation in the seed isoflavon concentrations. The total contents on 5 isoflavones were in the range from 16.21mg/g to 25.21 mg/g and from 6.47 mg/g to 15.44 mg/g, in 1997 and 1998, respectively. Collected soybean from Gunsnsi-1(25.21 mg/g) in 1997 and from Gangjingun-3 (16.50 mg/g) in 1998 showed the highest amount of isoflavones as compared with other collected soybean varieties. The highest amount among 5 isoflavones was genistin as 48.45% and 49.73%, in 1997 and 1998, respectively, indicating the genotypic variation in seed isoflavon contents of local soybean cultivar. Our data suggest that it may be feasible for improving soybean variety with higher antioxiadtive activity and substances.

• Proceedings of the Plant Resources Society of Korea Conference
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• 1999.10a
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• pp.110-117
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• 1999

A new lignan named as hibiscuside, (+) pinoresinol 4-O-[-glucopyranosyl (12) -rhamnoside] (1), and a known lignan, syringaresinol (2) were isolated from the root bark of Hibiscus syriacus together with two feruloyltyramines (3,4) and three known isoflavonoids (5,6,7). The structures of these compounds have been established on the basis of their NMR, Mass, UV spectra. Among these phenolic compounds,6-O-acetyl daidzin (5), 6-O- acetyl genistin (6), and 3-hydroxy daidzein (7) with IC50 values of 8.2, 10.6, and 4.1 M, respectively, significantly inhibited lipid peroxidation in rat liver microsomes Hibiscuside (1), E and Z-N-feruloyl tyramines (3,4) exhibited moderate antioxidant activity.

• Preventive Nutrition and Food Science
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• v.12 no.1
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• pp.29-34
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• 2007

The production of mevinolin, a potent hypocholesterolemic drug, and the bioconversion of isoflavones were investigated in soybeans fermented with Monascus pilosus KFRI-1140. The highest yields of 2.94 mg mevinolins and 1.13 mg isoflavone aglycones per g dry weight of soybean were obtained after 20 days of fermentation. Mevinolin was present in the fermentation substrate predominantly in the hydroxycarboxylate form (open lactone, 94.8$\sim$96.7%), which is currently being used as an hypocholesterolemic agent. The significant (p<0.01) bioconversion (96.6%) of the glucoside isoflavones (daidzin, glycitin, genistin) present in the soybean to the bioactive aglycones (daidzein, glycitein, genistein), with a 15.8-fold increase of aglycones was observed. The results suggest that Monascus-fermented soybean has potential as a novel medicinal food or multifunctional food supplement.

• Proceedings of the PSK Conference
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• 2003.10b
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• pp.193.2-193.2
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• 2003

Phytochemical examination of Sophorae Fructus yielded six phenolic compounds. The structures were elucidated as genistein(1), genistin(2) and genistein 7-O-${\alpha}$- L-rhamnopyranoside(3) by phytochemical and spectral evidences. The other compounds(4, 5, 6) are understudied by 2D-NMR. Nitric Oxide and PGE$_2$ production inhibitory activities in INF-${\gamma}$, LPS stimulated RAW 264.7 cell were examined. Compound 2 and 4 showed significant nitrogen monoxide(NO) production inhibitory activity in IFN-${\gamma}$, LPS stimulated RAW 264.7 cell. (omitted)