• Journal of Nutrition and Health
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• v.38 no.7
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• pp.512-520
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• 2005

Phytoestrogens, especially Yak-kong or soybean-derived isoflavones have been traditionally used as a supplement of estrogen for preventing postmenopausal osteoporosis in oriental folk medicine. In a previous study, we demonstrated that as Yak-kong and soybean increased MG-63 human osteoblastic cell proliferation, the expression of estrogen receptor $\alpha\;and\;beta\;(ER\;\alpha:\;ER\;\beta$) both were increased. However, the increased level of ER $\alpha$ is much higher than that of ER$\beta$. To determine whether the altered level of ER $\alpha$ expression affects Yak-kong or soybean induced MG-63 cell proliferation, we established cell lines stably expressing either ER $\alpha$ or antisense ER $\alpha$ RNAs. Increased expression of ER a in MG- 63 cells (ER $\alpha$-MG63) enhanced Yak-kong or soybean induced proliferation which paralleled with the enhanced expression of IGF-I. Inhibition of ER $\alpha$ expression by antisense $ER\;\alpha\;RNAs\;(As-ER\;\alpha-MG63$) caused these cells to insensitize Yak- kong or soybean induced proliferation and IGF-I expression. Furthermore, the comparable effects between Yak-kong and the combined treatment of genistein and daidzein at $0.5\;{\times}\;10^{-8}M$, which is a concentration of these two isoflavones similar to Yak-kong at 0.001 mg/ml, on cell proliferation and IGF-I expression in $ER\;\alpha-MG63\;or\;As-ER\;\alpha-MG63$ cells demonstrate that ER $\alpha$ plays an important, active role in MG-63 cell proliferation induced by phytoestrogens, especially Yak-kong or soybean derived isoflavones.

• KSBB Journal
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• v.16 no.2
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• pp.174-178
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• 2001

Soybeans contain the phytoestrogens genistein and daidzein, their glucosides genistin and daidzin and coumesterol. These isoflavonoid compounds are capable of producing an estrogenic response in a number of diverse species. This study determined optimum conditions for the extraction of the main isoflavones(daidzin, genistin, daidzein, genistein) in defatted soybean meal using high-performance liquid chromatography. The best optimum extraction was achieved at 75% ethanol, $80^{circ}C$, pH4 and a three hour contact time. In addition, isoflavones with high purity were separated by adding up to 4%(w/v) of calcium chloride dihydrate. Most soybean extracts were composed of $beta$-glucosidic conjugate(daidzin, genistin) which is difficult to adsorb in body. Therefore, $beta$-glucosidase was used to convert as conjugate to aglycone form (daidzein, genistein) which is easy to adsorb. The optimal conditions of enzyme reaction involved to be 8.4 units of enzyme concentration, pH5.0, $40^{circ}C$ and 40 minutes.

• Proceedings of the Korean Society of Crop Science Conference
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• 2000.04a
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• pp.332-333
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• 2000

• 한국생물공학회:학술대회논문집
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• 2002.04a
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• pp.508-509
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• 2002

• Proceedings of the Korean Society of Crop Science Conference
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• 2001.05a
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• pp.76-77
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• 2001

• Korean Journal of Food Science and Technology
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• v.32 no.1
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• pp.25-30
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• 2000

Phytoestrogen has been used as a suppliment of estrogen in order to treat osteoporosis. The representative phytoestrogens, isoflavones, are daidzein, genistein and formononetin which were present highly in our traditional soybean foods. The quantitative analysis of the isoflavone was done with a high performance liquid chromatography(HPLC) using a UV/VIS detector for the contents of the isoflavones in Astragali Radix, soybean sprouts, bean-curd(Tofu), soybean, soybean oil, pea, kidney pea, black bean(Yak-kong), soybean sauce(Ganjang). soybean paste(Doenjang), and fermented soybean(Maejoo). The content of free daidzein in soybean sprouts was $43.49{\pm}3.41\;mg/kg$$ which was much higher than that in soybean, $14.52{\pm}0.58\;mg/kg$, although total daidzein of fermented soybean was lower than that in soybean (Table 2. P<0.01). The amounts of free genistein in soybean sprouts, fermented soybean. and soybean paste were $27.63{\pm}1.66\;mg/kg,\;291.52{\pm}6.81\;mg/kg,\;and\;18.75{\pm}1.33\;mg/kg$, respectively. The level of free formononetin in soybean paste was the highest among the soybean products (P<0.01). The content of formononetin in Aatragali Radix, $9629.73{\pm}0.57\;{\mu}g/kg$, was about 160 times higher than that in soybean. Thus Korean traditional soybean products, black bean(Yak-Kong) and Astragali Radix can be a good choice of phytoestrogens.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2020.08a
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• pp.101-101
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• 2020

Soybean is known as to have a several healthy ingredients. Among them, isoflavones are effective in reducing obesity, menopausal symptom. Isoflavones consist of 12 isomers, including Aglycon, Glucoside, Malonyl glucoside, Acetyl glucoside, and are usually found in soybean seeds. The content is determined by the sum of 12 isomers, and the content value difference between the varieties is huge. In this study, we investigated the agronomic traits, 12 isomer of isoflavone content and composition for 49 soybean germplasms. This germplasms were selected from the 23,000 germplasms with the highest total content of isoflavones possessed by the National Agrobiodiversity Center. Seed samples were cultivated in experimental field located in Jeonju City on April 04, 2019. Matured seeds were harvested and portions of each seed samples were oven-dried, pulverized, and analyzed for their isoflavone compositions using HPLC-DAD. The soybean samples showed distinction in their agronomic traits, isoflavone compositions and contents. The days to flowering ranged between 38 and 69 days while the days to maturity ranged between 103 and 156 days. The seed coat color of soybean germplasms was 24 in black, 10 in yellow, 2 in green, 5 in yellowish green, 4 in green with black spot, 4 in pale yellow. The germplasm with the highest total content of isoflavones was the IT178054(1257.61±7.98 ㎍/g), but the germplasms containing the largest number of isoflavone isomers were IT274592, IT275005, both germplasms had 11 isoflavone isomers excluding Malonyl glycitin. The largest source of Aglycon, the most easily absorbed isoflavone form in the human body, was IT274592(DZ: 8.83±0.30 ㎍/g, GL: 11.14±0.81 ㎍/g, GE: 8.16±0.26 ㎍/g), while only IT274592, IT275005, IT308619 contained all three components of Aglycon. In Principal Component Analysis(PCA), the first two principal components showed more than 3.5 Eigen value and accounted for 58.2% of variability. The total content value had strong relationship with Malonyl genistin content value. Acetyl isomers had strong relationship, but Malonyl isomers were only related to isomers except Malonyl glycitin. These results will help in research on soybean varieties to enhance isoflavone ingredients.

• 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.

• 한국생물공학회:학술대회논문집
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• 2000.11a
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• pp.640-643
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• 2000

Soybeans contain the phytoestrogens genistein and daidzein, their glucosides genistin and daidziin and coumesterol. These isflavonoid compounds are capable of producing an estrogenic response in a number of diverse species. This study determined optimum conditions for extraction of isoflavones in defatted soybean meal. Extraction of isoflavones was conducted at various conditions such as difference concentrations of extraction solvent, temperature, time and pH to extact. The most optimum extraction conditions was achieved at 75% ethanol, $80^{\circ}C$, pH4 and extract for three hours. In addition. isoflavones with high purity were separated by adding up to 4%(w/v) of calcium chloride dihydrate.

• Proceedings of the Korea Society of Poultry Science Conference
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• 2005.11a
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• pp.31-43
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• 2005

Isoflavones are naturally occurring plant chemicals belonging to the 'phytoestrogen' class. The isoflavones are strikingly similar in chemical structure to natural estrogens. The phenolic ring is a key structural element of most compounds that bind to estrogen receptors. Dietary components that recently have received attention for their action as phytoestrogens are soy isoflavones. Soy products are the most significant dietary sources of isoflavones. Recently It is concerned clinical nutrition of isoflavone that is driven by reason of alternative sources of exogenous estrogen are constantly being needed. Estrogen therapy after the menopause offers protection from cardiovascular disease, reduces the extent of osteoporosis and relieves menopausal symptoms. Exogenous estrogen treatment is a fear of possible increased risk of developing breast cancer and because of side effects. Daily intake of soybean or soy food can affirmative effect to disease occurrence, that is based on mechanical investigation, experimental results of animals and human. Research into isoflavone is going on various field to relieve hormone - dependent disease such as cancer, menopausal symptom, cardiovascular disease and osteoporosis. Isoflavone is plenty in soybean meal, soy by-product, but only limited information is available on isoflavone efficacy into animal husbandry. Thus we conducted three experiments to investigate the effects of dietary isoflavone on productivities, antioxidative responses and bone metabolism in poultry. Dietary supplementation of isoflavone resulted in preventing the lipid oxidation of plasma and egg yolk. Dietary isoflavone improved bone development in egg-type growing chicks and broilers in terms of tibial strength. It was suggested that the proper use of feed additives such as isoflavone might provide means of improving antioxidative effect, skeletal strength, egg and eggshell quality.