• Journal of Environmental Health Sciences
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• v.33 no.3
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• pp.195-201
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• 2007

The objective of present study was to examine the composition of functional components (isoflavones, phytic acid, and saponin) in hypocotyls and cotyledons of six traditional Korean soybeans, namely Cheongtae, Seoritae, Jinjoori, Subaktae, Yutae, and Huktae. Three 'family' of isoflavones, as four chemical structures were present in hypocotyls and cotyledons of six soybean cultivars: the aglycones genistein, daidzein, and glycitein; the glycosides genistin, daidzin, and glycitin; the acetylglycosides 6"-O-acetylgenistin, 6"-O-acetyldaidzin, and 6"-O-acetylglycitin; and the malonylglycosides 6"-O-malonylgenistin, 6"-O-malonyldaidzin, and 6"-O-malonylglycitin. Isoflavone contents of hypocotyls and cotyledons differed among the cultivars, and glucosides and malonylglucosides accounted for more than 90% of the total phytoestrogens, with the remaining $1\sim7%$ taken up by aglycones. Concentrations of isoflavones in cotyledons were approximately about $10\sim20%$ of respective hypocotyls. Contents of phytic acids in hypocotyls and cotyledons of the selected soybean cultivars were $1.21\sim1.70%$ and $2.59\sim3.01%$, respectively. Hypocotyls of Seoritae showed the lowest content of phytic acid with 1.21%, while cotyledons of Cheongtae showed the highest content with 3.01%. The sapogenol concentrations ranged from $13.58mg/100g\sim20.82mg/100g$ for hypocotyls and $0.95mg/100g\sim2.55mg/100g$ for cotyledons showing that concentrations of saponin are $7\sim10$ times higher in hypocotyls than in cotyledons of respective soybeans. For both hypocotyls and cotyledons the sapogenol A were present in higher concentrations than soyasapogenol B.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.51 no.spc1
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• pp.166-173
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• 2006

Soyasaponins are phytochemicals of major interest fur their health benefits. Chemical investigation of a soybean phytochemical concentrate resulted in the isolation and identification of triterpenoid saponins. The MeOH extraction of defatted hypocotyl separated from soybeans was peformed by the automated solvent extractor (ASE). Fractionation was performed on a flash column ($150mm{\times}40mm$ i.d.) packed with a preparative $C_{18}$ reverse phase bulk packing material $(125\AA,\;55-105{\mu}m)$ and monitored at 210 nm, and collected 14 fractions. Consequent Fsat preparative column liquid chromatography (Fast PCLC) was performed for the purification of Fraction-I (Fr-I) collected from the fraction 8 and 9 of flash chromatography. Fsat PCLC was performed on a Luna $C_{18}\;10{\mu}m,\;100{\AA}$, semipreparative reverse phase column ($250cm{\times}50mm$ i.d.) for the purification of isolated unknown compound (Fr-I-2). Chemical structure of acetyl soyasaponin $A_1\;(MW:1436.6,\;C_{67}H_{104}O_{33})$ was identified and determined by a combination of extensive NMR ($^1H-NMR$, 400 MHz; $^{13}C-NMR$, 100 MHz; DEPT), IR, UV, and ESI-MS analysis.

• Journal of Plant Biotechnology
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• v.50
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• pp.70-75
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• 2023

In legumes, soyasaponins, one of triterpenoid saponins, are major components of secondary metabolites with a more diverse array of bioactive chemicals. Although the biosynthetic pathway of soyasaponins has been largely studied in soybean, the study on the soyasaponin contents and biosynthesis-related gene expression in pea (Pisum sativum L.) is poorly understood. Here, we found the accumulation of only soyasaponin Bb component in the sprouts of two Korean domestic pea cultivars (Dachung and Sachul). This pattern was consistent with our observation that increased expression of PsUGT73P2 and PsUGT91H4 genes, but not PsCYP72A69, could be responsible for biosynthesis of only soyasaponin Bb in pea by examining their gene expression. However, gradual accumulation of soyasaponin Bb at developmental stages was not consistent with the expression of PsUGT73P2 and PsUGT91H4, suggesting that the changes of their protein activities may affect the accumulation patterns of soyasaponin Bb. We also revealed that the increased expression levels of PsUGT73P2 and PsUGT91H4 during light to dark transition led to increase of soyasaponin Bb contents. Collectively, our results provided a molecular basis of metabolic engineering for enhancing useful soyasaponin Bb metabolites in Korean domestic pea cultivars.