• Biotechnology and Bioprocess Engineering:BBE
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• v.11 no.3
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• pp.240-244
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• 2006

To develop a health-aid preparation of Chinese yam (Dioscorea batatas Decne), lactic acid fermentation was attempted using a mixed starter comprising of Lactobacillus acidophilus, Streptococcus thermophilus, and Bifidobacterium bifidus. The anaerobic fermentation of a 5% Chinese yam flour suspension gave a uniform suspension of pH 4.35, containing $7.76{\times}10^6 CFU/mL$ lactic acid bacteria (LAB), and which was found to be acceptable to the panel from a sensory assessment. During the administration of the lactic acid fermented (LAF) Chinese yam to Sprague Dawley rats for 6 weeks, a smaller body weight gain, but greater excretion of feces were observed, implying the creation of a healthy gastrointestine on the administration of LAF Chinese yam, which was also confirmed by the gastrointestinal motility of the feed in rats fed on LAF Chinese yam. The constipation induced by loperamide was further suppressed in a rat group fed on a LAF Chinese yam diet, which was qualified from healthy gastrointestinal flora established by LAB. A serochemical analysis revealed a slight improvement in the blood glucose, neutral lipid and total cholesterol concentrations on administration of LAF Chinese yam, suggesting LAF Chinese yam could be served as a healthy-aid preparation, even for hyperglycemia or hyperlipidemia patients.

• Archives of Pharmacal Research
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• v.29 no.5
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• pp.348-353
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• 2006

In this study, a 40% ethanol extract of Chinese yam flour (Dioscoreae rhizoma), containing $177{\pm}58{\mu}g/mL$ of dioscin, was tested in order to evaluate its pharmacological effects on the gastrointestinal tracts of Sprague-Dawley rats. Via the ingestion of the Chinese yam extract, the secretion of gastric acid was suppressed in the rats, and gastrointestinal motility increased by as much as 10%. The fecal quantity of rats fed on the Chinese yam extract also increased, by more than 40% as compared with that of the controls. The Chinese yam extract was found not to affect the growth of normal intestinal bacteria. However, a great deal of lactose-fermenting bacteria was observed in the fecal samples of rats fed for 6 weeks on 2% Chinese yam extract. This finding would appear to suggest that Chinese yam extract not only induces an improvement in digestive capability, but also affects the conversion of some intestinal flora to helpful bacteria. Our serochemical analyses indicated that serum glucose, neutral lipid, and total cholesterol levels were reduced to some degree by long-term feeding on Chinese yam extract. This finding bolsters the notion that Chinese yam extract may prove helpful as a digestion-aiding agent for patients suffering from hyperglycemia or hyperlipidemia.

• Research in Plant Disease
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• v.22 no.3
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• pp.194-197
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• 2016

Chinese yam necrotic mosaic virus (CYNMV) is one of the most widespread viruses in Chinese yam (Dioscorea opposita Thunb.) and causes serious yield losses. Currently, genetic information of CYNMV is very restricted and complete genome sequences of only two isolates (one from Japan and another from China) have been reported. In this study, we determined complete genome sequence of the CYNMV isolate AD collected from Andong, Korea. Genetic analysis of the polyprotein amino acid sequence revealed that the Korean isolate AD has high similarity with the Japanese isolate PES3 (97%) but relatively low similarity with the Chinese isolate FX1 (78%). Phylogenetic analysis using the CYNMV 3' proximal nucleotide sequences harboring the coat protein and 3' untranslated region further supported genetic relationship among the CYNMV isolates. Based on comparative analysis of the CYNMV genome sequences determined in this study and other previous studies, we generated molecular detection primers that are highly specific and efficient for CYNMV diagnosis.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.54 no.2
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• pp.198-202
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• 2009

The starch properties of two chinese yams were evaluated in this study. Amylose content ranged 13.5% to 19.3%. The swelling power of starches varied 10.98% to 11.43%. Water binding capacity in chinese yam starches ranged 93.46% to 107.21%, high WBC was observed in Ma 1. The onset temperature (To) of two chinese yam starches ranged 62.9 to $75.0^{\circ}C$, peak temperature (Tp) ranged 76.2 to $84.7^{\circ}C$. The PHI(peak height index) was about 4-fold higher in Anwon cultivar than in Ma 1 cultivar. SEM revealed that starches has a presence of large oval or spherical to small irregular-shape granules. Starch granule size ranged 15.23 to 15.52 ${\mu}m$, showing a typical C-type X-ray pattern.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.151.1-151
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• 2003

Chinese yam(D. opposita Thunb. cv. Jang-Ma) plants showing necrotic mosaic symptom were collected from their growing fields in Andong, Korea. Electron microscoptic examination of negatively stained preparations showed filamentous particles of 660nm in length. The virues purified partially were used to isolate Viral RNA as template for RT-PCR to amplify the CP gene with ChYNMV specific and oligo dT primers. Amino acids sequeces revealed that the viruses shared 99.3％ similarity with ChYNMV(AB044386) which was known as the member of macluravirus. So the viruses from Chinese yam(D. opposita Thunb. cv. Jang-Ma) plants were identified as ChYNMV. Comparing the amino aced sequences of ChYNMV strains with other macluraviruses such as CdMV, NLV and MacMV revealed that N-terminal was the most variable region and conserved regions were present within the genus Macluravirus.

• Journal of Plant Biotechnology
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• v.6 no.2
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• pp.97-102
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• 2004

This study was carried out to establish The regeneration of healthy seedlings from the nodal segment culture of Chinese yam (Dioscorea opposita cv. Danma), cultivated in Korea. Different explants such as leaves, petioles, roots and nodal pieces, excised from the in vitro grown seedlings of Chinese yam, were cultured on MS medium supplemented with various combinations of growth regulators. All the growth regulators used induced plantlet regeneration from the nodal segments at a high frequency, while there was no induction of shoot or callus from leaf, petiole or root tissues. The medium supplemented with 0.01mg/L NAA, 0.5mg/L BA, 0.5-1.0mg/L kinetin and without plant growth regulator was effective for shoot development of buds from the nodal segment culture. The concentration of BA and NAA was an important factor in the bud induction of buds from the nodal segments of Chinese yam. Nodal segments cultured on the medium containing 1.0mg/L NAA and 0.5-1.0mg/L BA gave the best response to bud formation. The addition of GA$_3$ to the culture medium suppressed shoot induction and growth, while it increased microtuber formation. The shoot growth and microtuber formation were also affected by medium strength and solidity. The MS basal medium containing 1 g/L gelrite was suitable for microtuber formation from the nodal segment of Chinese yam.

• Preventive Nutrition and Food Science
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• v.4 no.3
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• pp.193-196
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• 1999

To investigate the effect of yam on the activity of benzo[a]pyrene hydroxylase(BPH), the key enzyme associated with polycyclic aromatic hydrocarbons(PAHs) metabolism, rats were fed a fiber free diet for 7 days, whereupon they were switched to experimental diets for another 7 days. Diets contained benzo[a] pyrene(BP, 400 mg/kg diet) and 25% or 50% yam powder (freezer dried and hot air dried ). Diets containing pectin and cellulose were compared with diets containing yam. BPH activities were assessed in the liver, lung, kidney, stomach, small intestine and large intestine of rats. BP induced BPH activities in various tissues ; 8 fold in liver, 28 in lung and stomach , and 32 in large intestine. The addition of yam significantly lowered BPH activity in liver, lung and stomach and hot air dried yam was nmor eeffectivie than freeze dried yams. These data suggested that yam containing diet may influence carcinogen metabolism in liver and extrahepatic target tissues by altering activities of BPH and may reduce exposure of these tissues to dietary carcinogens.

• Journal of Plant Biotechnology
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• v.6 no.2
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• pp.103-106
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• 2004

Plantlet regeneration from the shoot apex was studied in three different genotypes of the chinese yam (Dioscorea opposita Thunb) cv. Jnagma and Danma, Dunggunma. The effects of plant growth regulators and inorganic salts concentration of the culture medium on bud induction and shoot growth were examined. The combinations of 0.2 mg/L BAP + 0.2mg/L kinetin, 0.01mg/L NAA + 0.2 mg/L kinetin and a single treatment of 0.2mg/L BAP were equally effective for bud and shoot formation from the shoot apices in the three cultivars. Auxin (2,4-D, NAA) treatment enhanced calli formation from the cultured apices. Also, the shoot apices of the cv. Dunggunma produced more callus and buds on the culture medium (MS) containing 0.05mg/L NAA and 0.5-1.0mg/L SAP. Lower salt strength of medium inhibited shoot elongation but did not have much effect on the shoot and bud induction from the shoot apices. These results will be useful to obtain disease-free plants of the Chinese yam.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.47 no.4
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• pp.297-300
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• 2002

Endogenous ABA and batatasins were first quantified in the stored tubers and bulbils of the Chinese yam, Dioscorea opposita Thunb. cv. 'Tsukune' by GC-MS with comparison of internal standard, and sugar content was also analyzed by HPLC with comparison of external standard. Endogenous ABA content in stored tubers and bulbils was rapidly decreased as storage period prolonged. ABA content of the bulbils was always higher than that of tuber during storage periods. All batatasins of stored tubers and bulbils at 30 days after storage decreased steadily compared to 120 days after storage. On the contrary, batatasin-Ⅲ of the stored tuber and bulbils was only decreased at 60 days after storage. In Dioscorea opposita Thunb. cv. 'Tsukune' like D. japonica, D. alata, and D. bulbifera, may be controlled by endogenous batatasins and ABA, In these compounds, batatasins rather than ABA might be closely related to dormancy-inducing compound during dormancy of the Chinese yam, Dioscorea opposita Thunb. cv. Tsukune.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2014.05a
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• pp.829-832
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• 2014

This study was conducted to investigate antioxidative and physiological activities of ethanol extracts concentration from Monascus-Fermented Chinese Yam (MFCY). The ethanol extracts from MFCY were measured to examine pigments, DPPH radical scavenging activity, reducing power and monacolin K contents. As a results show that Monascus sp. MK805, with Dioscorea japonica as the substrate can produce pigments (yellow, orange and red), DPPH radical scavenging activity, reducing power and monacolin K content at 29.6 (yellow), 15.1 (orange), 20.4 (red), 72.8%, 1.74(OD at 700nm), 480.6 mg/kg in EtOH extract, respectively. Therefore, fermented chinese yam (Dioscorea japonica) was estimated to be effective biological activity material.