OBJECTIVETo characterize properties of Rhizoma Dioscoreae polysaccharide-Fe (III) complex (RDPC) and analyze its composition.

METHODPhysicochemical properties, such as character, solubility and stability of RDPC were studied. Surface structure of RDPC was studied by Infrared spectroscopic technique and transmission electron microscopy. The content of Fe (III) in RDPC was determined by o-phenanthroline spectrophotometry after being treated by ashing, wet digestion, or direct dissolution methods. Content of polysaccharide in RDPC was determined by sulphuric acid-phenol method.

RESULTRDPC was brownish red powder. It could dissolve in water, its aqueous solution was very stable at the pH from 3.8 to 11.6. RDPC was a surface complex in which polysaccharide combined with beta-FeOOH as core. The content of Fe (III) in RDPC was 17.05%, 16.53%, 17.10% respectively after being treated by 3 different pretreatment methods. Content of polysaccharide in RDPC was 16.27%.

CONCLUSIONThis is the first report of RDPC which was stable under physiological pH conditions and could be a new candidate for iron-supplementary.

Dioscoreaceae ; chemistry ; ultrastructure ; Drugs, Chinese Herbal ; chemistry ; Iron ; chemistry ; Microscopy, Electron, Transmission ; Polysaccharides ; chemistry

The underground cane of Schizocapsa plantaginea (Hance) has long been used by Chinese ethnic minority as a constituent of anti-cancer formulae. Saponins are abundant secondary metabolic products located in the underground cane of this plant. The potential therapeutic effects of total saponins isolated from Schizocapsa plantaginea (Hance) (SSPH) on human hepatocellular carcinoma (HCC) were tested in vitro in human liver cancer cell lines, SMMC-7721 and Bel-7404. Apoptosis and cell cycle arrest were determined using flow cytometry, caspase activation was determined by ELISA, and PARP, cleaved PARP, mitogen-activated protein kinase (MAPK) expression and phosphorylation were measured using Western blotting analysis. In vivo anti-HCC effects of SSPH were verified in nude mouse xenograft model. SSPH exerted markedly inhibitory effect on HCC cell proliferation in time- and concentration-dependent manner. Moreover, SSPH significantly induced apoptosis through caspase-dependent signaling and arrested cell cycle at G/M phase. These anti-proliferation effects of SSPH were associated with up-regulated phosphorylation of extracellular signal-regulated kinase-1/2 (Erk1/2) and c-jun-NH2-kinase-1/2 (JNK1/2) and reduced phosphorylation of p38MAPK. Furthermore, inhibitors of ERK, UO126, and JNK, SP600125 inhibited the anti-proliferation effects by SSPH, suggesting that Erk and JNK were the effector molecules in SSPH induced anti-proliferative action. During in vivo experiments, SSPH was found to inhibit xenograft tumor growth in nude mice, with a similar mechanism in vitro. Our study confirmed that SSPH exerted antagonistic effects on human liver cancer cells both in vitro and in vivo. Molecular mechanisms underlying SSPH action might be closely associated with MAPK signaling pathways. These results indicated that SSPH has potential therapeutic effects on HCC.
Animals ; Antineoplastic Agents ; isolation & purification ; pharmacology ; toxicity ; Apoptosis ; drug effects ; Caspases ; genetics ; metabolism ; Cell Cycle Checkpoints ; drug effects ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; Cell Survival ; drug effects ; Dioscoreaceae ; chemistry ; Heterografts ; drug effects ; growth & development ; Humans ; Inhibitory Concentration 50 ; Liver Neoplasms ; drug therapy ; metabolism ; pathology ; MAP Kinase Signaling System ; drug effects ; Mice ; Mice, Nude ; Phosphorylation ; drug effects ; Plant Tubers ; chemistry ; Poly (ADP-Ribose) Polymerase-1 ; metabolism ; Saponins ; isolation & purification ; pharmacology ; toxicity

A split-plot experiment was conducted to study the optimum planting density of Nuomi yam in directional groove shallow cultivation. Nuomi yam was the main local cultivar of Dioscorea. The study of this paper may help to give valuable instructions of local production. Three different planting densities and shallow groove diameter were designed in the experiment. The results showed that the fresh weight of aerial part per plant, yield and planting benefit of Nuomi yam tuber were the highest when the planting density was 12 000 plants/hm~2 and the diameter of shallow growth groove was 11.0 cm, while they were the lowest when the planting density was 22 500 plants/hm~2 and the diameter of shallow growth groove was 7.5 cm. Along with the increase of planting density, the fresh weight of aerial part, tuber, fresh yield, benefit and commercial tuber rate of Nuomi yam also decreased. The commercial tuber rate of Nuomi yam of 11.0 cm diameter in shallow growing pot was the highest, while it was the lowest with no shallow growing pot. On the contrary, the content of amylopectin and mucin was the highest when there was no shallow groove, and was the lowest when the diameter of shallow groove was 7.5 cm, although there was no significant difference between the two treatments. Therefore, Nuomi yam with the directional cultivation combination of planting density of 12 000 plants/hm~2 and shallow groove diameter of 11.0 cm showed high yield, good appearance quality, high planting benefit and no obvious adverse effect on internal quality.
Dioscorea

Leaf spot symptoms were frequently observed on yam plants grown in the Yeoju area in Korea during a disease survey in 2008. A total of five isolates of Pseudophloeosporella sp. were obtained from the infected leaves of yam plants. All of the isolates were identified as Pseudophloeosporella dioscoreae based on their morphological and cultural characteristics. A phylogenetic tree derived from the internal transcribed spacer sequences of the fungal isolates showed that the fungus is distinctly separated from species in other related genera. P. dioscoreae isolates caused very tiny spots on leaves of yam plants two weeks after artificial inoculation which were similar to those observed in the field. This is the first report that Pseudophloeosporella dioscoreae causes leaf spot in yams in Korea.
Cultural Characteristics ; Dioscorea ; Fungi ; Korea

During 2007 survey of post-harvest diseases of yam performed in May and June, severe tuber loss caused by blue mold was observed in Iksan, Cheonbuk Province. Two species of Penicillium were isolated from the infected tubers. Based on beta-tubulin gene sequence analysis, and cultural and morphological characteristics, the isolates were identified as Penicillium sclerotigenum and P. polonicum. P. sclerotigenum, which is a novel to Korea, is presently described and illustrated.
Dioscorea ; Fungi ; Korea ; Penicillium ; Sequence Analysis ; Tubulin

Animals ; Diabetic Nephropathies ; drug therapy ; Dioscorea ; chemistry ; Polysaccharides ; pharmacology ; Rats

OBJECTIVEIn order to find the new varieties with different horticultural characters, and investigate the mutation effects of seeds of Dioscorea zingerbrensis.

METHODThe seeds were carried by a satellite into space and recovered. The space mutation effect on the germination, seedling growth, chromosomes and rhizome diosgenin content of SP, populations of D. zingerbrensis were investigated.

RESULTStimulated by space environment, the seed possessed the fast germinating characteristics. Germination rate showed no change. It was also found that a few plants were aneuploid or tetraploid. Fresh rhizome weight and rhizome diosgenin content in the second year plant were remarkably higher than those of the control. However, the increasing of third year plant was slow down, and rhizome diosgenin content in the third year plant declined simultaneously.

CONCLUSIONThe space environment showed stimulating effects on seed germination, fresh rhizome weight and rhizome diosgenin content.

Dioscorea ; chemistry ; genetics ; physiology ; Extraterrestrial Environment ; Germination ; Mutation ; Plant Extracts ; chemistry ; Seedlings ; chemistry ; genetics ; physiology

OBJECTIVETo study the chemical constituents in the tubers of Dioscorea bulbifera.

METHODCompounds were isolated and purified with silica gel, ODS and Sephadex LH-20 column chromatography, their structures were determined by using spectroscopic methods including MS and NMR.

RESULTFourteen compounds were isolated and identified as stigmasterol (1), mono-arachidin (2), 1,7-bis-(4-hydroxyphenyl)-1E,4E,6E-heptatrien-3-one (3), behenic acid (4), demethyl batatasin IV (5), 2,3'-di-hydroxy-4',5'-dimethoxybibenzyl (6), diosbulbin B (7), diosbulbin D (8), docosyl ferulate (9), 7-bis-(4-hydroxyphenyl) -4E, 6E-heptadien-3-one (10), 5,3,4-trihydroxy-3,7-dimethoxyflavone (11), tristin(12), protocatechuic acid (13), adenosine (14).

CONCLUSIONCompounds 24, 6, 9, 10, 12, 14 were isolated from the genus Dioscorea for the first time.

Dioscorea ; chemistry ; Drugs, Chinese Herbal ; chemistry ; isolation & purification ; Plant Tubers ; chemistry

This article assessed the genetic relationship and genetic diversity in Dioscorea alata. Twenty samples were examined to identify their original plants, and analyzed by ISSR markers. The results showed that 20 samples were classified into three different plants, such as D. alata, D. persimilis, and D. fordii. There was significant difference in genetic similarity coefficient between D. alata and D. persimi as well as D. fordii. There was distinct differences in D. alata, the genetic similarity coefficient was resulted from 0.672 9 to 0.990 7. With UPGMA clustering method, 16 samples of D. alata could be divided into 4 groups. After comparing samples with the phenotypic characteristics of original plants, it showed that the color and the number of tuber were the most important characteristics of judging the genetic relationship of D. alata. It is concluded that the genetic variation of Dioscorea spp is significant, especially the genetic diversity in D. alata were in a high level. This article supplied a molecular biologic support for distinguishing Dioscorea spp, and also provided basis for breeding of D. alata.
DNA, Plant ; genetics ; Dioscorea ; classification ; genetics ; Genetic Variation ; Phylogeny ; Repetitive Sequences, Nucleic Acid

OBJECTIVETo study the production technology of extraction in combination hydrolysis in situ for isolating diosgenin from Dioscorea nipponica by orthogonal design.

METHODThe optimum production conditions were investigated with the recovery of diosgenin as an index by extraction in combination hydrolysis in situ, and were compared with the traditional method.

RESULTExtraction in combination hydrolysis in situ conducted in 1.5 mol x L(-1) sulfuric acid of water containing 75% isopropanol at 100 degrees C for 4.5 h could get higher recovery of diosgenin than traditional methods.

CONCLUSIONThis production technology can get higher recovery of diosgenin, and it is simple, time and money saving.

Dioscorea ; chemistry ; Diosgenin ; isolation & purification ; Hydrolysis ; Pressure ; Sulfuric Acids ; Technology, Pharmaceutical ; methods ; Temperature ; Time Factors