• Journal of Microbiology and Biotechnology
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• v.20 no.6
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• pp.1011-1017
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• 2010

A novel dioscin-glycosidase that specifically hydrolyzes multi-glycosides, such as 3-O-${\alpha}$-L-($1{\to}4$)-rhamnoside, 3-O-${\alpha}$-L-($1{\to}2$)-rhamnoside, 3-O-${\alpha}$-L-($1{\to}4$)-arabinoside, and ${\beta}$-D-glucoside, on diosgenin was isolated from the Absidia sp.d38 strain, purified, and characterized. The molecular mass of the new dioscin-glycosidase is about 55 kDa based on SDS-PAGE. The dioscin-glycosidase gradually hydrolyzes either 3-O-${\alpha}$-L-($1{\to}4$)-Rha or 3-O-${\alpha}$-L-($1{\to}2$)-Rha from dioscin into 3-O-${\alpha}$-L-Rha-${\beta}$-D-Glc-diosgenin, further rapidly hydrolyzes the other ${\alpha}$-L-Rha from 3-O-${\alpha}$-L-Rha-${\beta}$-D-Glc-diosgenin into the main intermediate products of 3-O-${\beta}$-D-Glc-diosgenin, and subsequently hydrolyzes these intermediate products into aglycone as the final product. The enzyme also gradually hydrolyzes 3-O-${\alpha}$-L-($1{\to}4$)-arabinoside, 3-O-${\alpha}$-L-($1{\to}2$)-rhamnoside, and ${\beta}$-D-glucoside from [3-O-${\alpha}$-L-($1{\to}4$)-Ara, 3-O-${\alpha}$-L-($1{\to}4$)-Rha]-${\beta}$-D-Glc-diosgenin into diosgenin as the final product, exhibiting significant differences from previously reported glycosidases. The optimal temperature and pH for the new dioscin-glycosidase is $40^{\circ}C$ and 5.0, respectively. Whereas the activity of the new dioscin-glycosidase was not affected by $Na^+$, $K^+$, and $Mg^{2+}$ ions, it was significantly inhibited by $Cu^{2+}$ and $Hg^{2+}$ ions, and slightly affected by $Ca^{2+}$ ions.

• Korean Journal of Pharmacognosy
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• v.24 no.3
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• pp.187-191
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• 1993

Three compounds were isolated from the rhizomes of Dioscorea quinqueloba and identified as $diosgenin\;3-O-{\alpha}_-L-rhamnopyranosyl(1{\rightarrow}2)-{\beta}-_D-glucopyranoside$, dioscin and gracillin by chemical and spectroscopic means.

• Proceedings of the PSK Conference
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• 2003.04a
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• pp.234.1-234.1
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• 2003

Spicatoside A and spicatoside B were isolated from Liriopis tuber. Spicatoside A has anticancer activity and it is composed of 1 ${\beta}$-hydroxy diosgenin and trisaccharides. Spicatoside B has the preventive effect of diabetes mellitus and also has 1 ${\beta}$-hydroxy derivatives, which is clevaged the ether linkage of F ring of diosgenin. Therefore, selective synthesis of 1 ${\beta}$-hydroxydiosgenin is required. (omitted)

• Korean Journal of Plant Resources
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• v.18 no.1
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• pp.161-168
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• 2005

Tuber yield and content of general component and diosgenin which is a main bioactive property were investigated in order to determine the growth characteristics of round typed yam(Dioscorea opposita L.) and the potential of artificial culture at Suwon, Korea. Tubers of round yam were initiated to form at 60 days after planting and then enlargement of tubers lasted by 160 days after planting. Compared to short typed yam(108g), tuber weight of round yam was higher(127g) on the basis of dry weight at 200 days after planting. In comparison of general component between round yam and short yam, protein of round yam$(3.62\%)$ was higher than short yam$(2.10\%)$. Water content in round yam$(64.5\%)$ was lower in short yam$(79.4\%)$, indicating a higher dry weight ratio of round yam. Hardness of round yam was 2787.6 while short yam showed about two times higher hardness(4946.9). Lightness was higher in round yam(77.4). In tuber extracts analysis, diosgenin content was respectively $3.32\%$ in round yam and $2.61\%$ in short yam.

• Journal of Practical Agriculture & Fisheries Research
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• v.6 no.1
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• pp.50-62
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• 2004

Tuber yield and content of general component and diosgenin which is a main bioactive property were investigated in order to determine the growth characteristics of round typed yam(Dioscorea opposita L.) and the potential of artificial culture at Suwon, Korea. Tubers of round yam was initiated to form at 60 days after planting and then enlargement of tubers lasted by 160 days after planting. Compared to short typed yam(108g), tuber weight of round yam was higher(127g) on the basis of dry weight at 200 days after planting. In comparison of general component between round yam and short yam, protein of round yam(3.62%) was higher than short yam(2.10%). Water content in round yam(64.5%) was lower in short yam(79.4%), indicating a higher dry weight ratio of round yam. Hardness of round yam was 2787.6 while short yam showed about two times higher hardness(4946.9). Lightness was higher in round yam(77.4). In tuber extracts analysis, diosgenin content was respectively 3.32% in round yam and 2.61% in short yam.

• YAKHAK HOEJI
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• v.44 no.6
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• pp.534-538
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• 2000

A phenolic glucoside and two steroidal sapogenins were isolated from the aerial part of Solanum Iyratum (Solanaceae). They were identified as 2-hydroxy-3-methoxybenzoic acid glucose ester (1), ${\Delta}^{3,5}$-deoxytigogenin ((25R)-spirosta-3,5-diene) (2), diosgenin (($3{\beta}$, 25R)-spirost-5-en-3-ol) (3), respectively by several spectroscopic methods including IR, MS and NMR. Compound 1 has not been previously isolated from Solanaceae plants. Compounds 2 and 3 are isolated from S. Iyratum for the first time in the present study.

• Journal of Dairy Science and Biotechnology
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• v.30 no.2
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• pp.69-74
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• 2012

This study was performed to determine by the ability of the mixed culture of Lactobacillus bulgaricus and Streptococcus thermophilus to ferment Dioscorea opposita Thunb. (yam) and to evaluate the nutraceutical value of fermented yam. The titratable acidity (TA) value increased from 2 to 6% with increased concentrations in both raw yam and extracted lactic acid bacteria (LAB) fermented yam (LFY). The viable cell counts and the allantoin and diosgenin contents were higher in raw LFY at large concentrations (6%) than in extracted LFY samples at all fermentation periods up to 32 h. Based on these data, it confirmed that raw yam fermented by the combination culture of L. bulgaricus and S. thermophilus for various fermentation periods favors the symbiotic growth of LAB and results in higher nutraceutical content.

• Archives of Pharmacal Research
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• v.14 no.4
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• pp.305-310
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• 1991

In order to find out the values of the steroid resources for the future use, the compositions and contents of steroidal sapogenins from 13 domestic plants have been investigated. As a result Dioscorea nipponica, D. quinqueloba and Smilax china were found to have large amount of diosgenin. And pennogenin in Trillium kamtschaticum and Paris verticillata, yuccagenin in Allium fistulosum, hecogenin in Agave americana and neochlorogenin in Solanum nigum were appeared to be major steroidal sapogenins.

• Food Science of Animal Resources
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• v.31 no.1
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• pp.66-73
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• 2011

Physicochemical and sensory properties of Dioscorea opposita Thunb. (yam) powder-added yogurts (1, 3, 5, and 7%, w/v) were examined when stored at $4^{\circ}C$ for 16 d. When the yam concentration increased, the pH increased with 16 d storage. The lactic acid bacteria counts in all yogurt samples showed an increase during storage period, and the highest counts were appeared with 7% yam powder addition. The dramatic decrease was found in viscosity with higher concentrations of yam powder-added yogurt samples. No change was found in allantoin and diosgenin contents for 16 d storage periods. A significantly strong bitterness and astringency and decreased viscosity were found with 5 and 7% yam powder addition. However, less than 3% yam powder-added yogurt samples did not show a significant difference compared with the control (p>0.05) and overall acceptability score was the highest in 3% yam powder-added yogurt throughout the storage. The present study indicated that the concentrations (1 and 3%, w/v) of yam powder could be used to produce yam powder-added yogurt without significant adverse effects on physicochemical, microbial and sensory properties, and enhance functional components from the supplementation.

• Journal of Society of Preventive Korean Medicine
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• v.7 no.1
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• pp.133-138
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• 2003

It is well known that Dioscoreae Rhizoma tonifies and benefits the Spleen and Stomach, benefits the Lung and nourishes the Kidney. A major component isolated from this herb consist of dioscin, diosgenin, allantoin, starch, alanin, mucilage, choline, amylase, and glycoprotein. In this study, we aimed to measure the content of allantoin, one of major component, to determine the quality of Dioscoreae Rhizoma.