No full-text available
To read the full-text of this research,
you can request a copy directly from the author.
Health effects of Dioscorea Bulbifera of aerial-potato (Yam)
Abstract
Dioscorea spp. (yam) is a rich source of carbohydrate crop in the diet and also resource of different phytohormones. Among Dioscorea spp, especially, Dioscorea bulbifera of aerial-potato has widely been used as their traditional folklore medicines for their treatments such as thyroid disease, tumor, diretic disturbance and inflamation in the tropical and subtropical areas. The diverse compounds in Dioscorea bulbifera have been found and their functionality has been examined in various researches such as their antibacterial and antitumor activity. The purpose of this review paper is to focus and describe their compositions found and functional activities.
ResearchGate has not been able to resolve any citations for this publication.
The determination of the nutritive and anti- nutritive principles in the uncooked and cooked wild species of Dioscorea bulifera and Dioscorea dumentorum showed that the wild yams contain all the food nutrients within the reported and acceptable values for root and tuber crops. The presence of alkaloids, oxalates, and saponins at high concentrations are responsible for the qualification of the yam species as wild (poisonous) and inedible. However, the cooking of these yam species reduced these principles to values that may earn the wild yams consideration as food for consumption. (Keywords: wild yams, wild foods, nutrients, anti- nutrients, Dioscorea bulifera, Dioscorea dumentorum)
a b s t r a c t From the bulbils of Dioscorea bulbifera L. var sativa, two clerodane diterpenoids, Bafoudiosbulbins F (1) and G (2), together with five known compounds: Bafoudiosbulbins A–C, 3,5,4 0 -trihydroxy-3 0 -methoxy-bibenzyl, and kaempferol were isolated. Their structures were established by spectroscopic techniques, including 1 H, 13 C NMR, NOESY, ROESY, COSY, TOCSY, HSQC, and HMBC. The relative stereochemistry of compounds 1 and 2 was assigned on the basis of X-ray crystallographic diffraction analysis. Furthermore, the structure of Bafoudiosbulbin B was revised using extensive 2D NMR techniques as well as chemical transformation.
Plumbagin (5-hydroxy-2-methyl-1,4-naphthaquinone), a compound derived from the root of thePlumbago zeylanica plant, was effective in selectively eliminating stringent, conjugative, multidrug-resistant plasmids fromEscherichia coli strains. Simultaneous loss of resistance to antibiotics in plumbagin-treated cells indicated loss of plasmid. However, such R plasmids are refractory to treatment with acridine orange and sodium dodecyl sulfate, which are widely used in curing techniques.
Three nonsteroidal compounds, named diosbulbins A, B and C, were isolated from the root tubers of Dioscorea bulbifera L. forma spontanea MAKINO et NEMOTO (a wild type of D. bulbifera L.) in which scarcely steroid sapogenin was found. Diosbulbin A, C20H24O7, mp 265°(decomp.), [α]20D+26.7°, B, C19H20O6, mp 285°(decomp.), [α]20D+92.0°and C, C19H22O7, mp 247-250°(decomp.), [α]20D+64.7°, all having bitter taste, were assigned the partial structural formulae III, I, II, respectively, and regarded as a series of novel type of furanoid norditerpenes. These are first terpenoids reported in Dioscoreaceae and first furanoid diterpenoids in Monocotyledoneae.
Methyl 2α,3β,4β-trihydroxy-neo-clerodan-15-oate was isolated from the acid fraction of Cistus populifolius and its structure determined by semisynthesis and confirmed by X-ray diffraction. Three other triols (2, 3 and 4) and an intermediate diol (5) were also synthesized as potential antifeedants. The functional groups and stereochemistry for antifeedancy are discussed.
2′,3-Dihydroxy-5-methoxybibenzyl (Batatasin IV), its demethyl derivative and 3,5-dihydroxybibenzyl (dihydropinosylvin) were isolated only from flesh of Dioscorea rotundata infected with Botryodiplodia theobromae and may therefore be considered phytoalexins. These compounds were found to be antifungal using bioassays with Cladosporium cladosporioides, Botryodiplodia theobromae, Aspergillus niger and Penicillium schlerotgenum. Dihydro-pinosylvinin also exhibited strong antibacterial activity against Bacillus cereus, Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia coli.
The bulbils and tubers of a wild variety of Dioscorea bulbifera L. contained an alkaloid, dihydrodioscorine. When crystallized in its hydrochloride form and incorporated into potato dextrose agar at a final concentration of 0.1%, it was found to slow down the rate of growth of five plant pathogenic fungi namely: Sclerotium rolfsii, Curvularia lunata, Fusarium moniliforme, Macrophomina phaseolina and Botryodiplodiatheobromae. Also sclerotia formation in S. rolfsii was delayed and the number was reduced. Conidia formation in C. lunata and F. moniliforme was also delayed and reduced but pycnidia formation in M. phaseolina and B. theobromae was not affected. There was no significant difference between the rate of growth of the fungi on PDA incorporated with 0.01% final concentration of dihydrodioscorine and on control plates. Abbreviations: PDA = potato dextrose agar, D.D. = dihydrodioscorine dihydrochloride.
From the bulbils of Dioscorea bulbifera L. var. sativa, three new clerodane diterpenoids, bafoudiosbulbin C (-methyl (2 beta,8 alpha,12S)-17-oxo-2,19:8,19:12,17:15,16-tetraepoxycleroda-3,13(16), 14-triene- I 8-carboxyl ate; 1), bafoudiosbulbin D (-methyl (2 beta,6 beta,12R)-17,19-dioxo-2,19:6,17: 8, 12 :15,1 6-tetraepoxycleroda- 13 (16),14-diene- 18-carboxylate; 2), and bafoudiosbulbin E (-methyl (2 alpha,3 alpha.4 alpha.6 beta,12R)-17,19-dioxo-2,19:3,4:6,17:8,12:15,16-pentaepoxycleroda-13(16),14-diene-18-carboxy- late: 3) were isolated, together with the known compounds bafoudiosbulbins A and B, 3-O-beta-Dglucopyranosyl- -sitosterol, and 6'-stearoyl-3-O-beta-D-glucopyranosyl-beta -sitosterol. Their structures were established by high-field NMR techniques (H-1,H-1-COSY, C-13-DEPT, HSQC, HMBC, and NOESY), MS analyses. as well as by comparison of their spectral data with those of related compounds.
Ten cultivars of five edible yam species were examined for o-dihydroxyphenoloxidase (o-DPOase) activity against yam extracts containing phenolic compounds, and for their propensity to brown when cut slices are exposed to air. (+)-Catechin levels in Dioscorea cayenensis (260 mg kg−1) and D. bulbifera (240 mg kg−1) were similar to those in D. dumetorum (270 mg kg−1), but the latter contained less o-DPOase and showed less tendency to browning. D. alata contained more (+)-catechin than other yams, and one cultivar with a higher (+)-catechin content (660 mg kg−1) showed more browning than another cultivar containing 430 mg kg−1 (+)-catechin. Five cultivars of D. rotundata showed less tendency to brown, and had lower (+)-catechin content (90–190 mg kg−1) than the other yams examined, but showed marked variation in o-DPOase activity. o-DPOase activity, assayed by recording the rate of oxygen consumption, varied between 75 units (1 unit=μmol O2 consumed min−1 100 g−1 fresh yam tissue) in D. dumetorum and 2380 units in one D. rotundata cultivar when a crude extract of phenolic compounds diluted to contain 10 mM (+)-catechin was used as substrate and from 60 to 3480 units for these same two enzyme extracts when assayed using crude extracts of phenolic compounds (also adjusted to contain 10 mM (+)-catechin) prepared from the same yam as the enzyme extract. However, in general, the o-DPOase activities recorded using the D. alata extract showed little correlation with the activity when the phenolic extract was prepared from the same yam as the enzyme extract. Incubation of crude extracts containing phenolics with crude extracts of o-DPOase at 20°C for 24 h resulted in a decrease in the quantity of (+)-catechin estimated by h.p.l.c. Cyanidin released by hydrolysis with HCl under mild conditions was also measured. The level in D. alata was sufficiently high to account for ‘pinking’ when this species is boiled. It is concluded that the o-DPOase-catalysed oxidation of (+)-catechin is largely responsible for the browning of yams. The possible influence of other factors, including the reducing agent ascorbic acid in moderating the rate and extent of browning observed, is discussed.
It is generally agreed that the administration of amphetamine ("benzedrine") facilitates the reduction of weight. This effect of the drug was first reported in 1937, when patients receiving amphetamine for other purposes were observed to lose weight.¹ Since that time a number of papers have appeared in which the drug has been reported to be of value in the management of obesity.² However, it has not been demonstrated by controlled experiments that the drug actually causes a reduction of body weight.
The mechanism by which the drug apparently facilitates the loss of weight has not been settled. All the possible mechanisms have been suggested in the literature and are summarized in the following outline.
The drug acts to facilitate the loss of weight:
• By increasing the expenditure of energy
• by increasing the basal metabolism as does dinitrophenol or
• by increasing muscular activity by
Two new furanoid norditerpenes (1, 2) were isolated from the root tubers of Dioscorea bulbifera L. Their structures were established on the basis of extensive spectroscopic analysis.
Bitter and related nonbitter compounds were extracted from tubers of Dioscorea bulbifera, purified by column chromatography, and separated on thin layers of silica gel. Color reactions to spray reagents, solubilities, and uv absorption peaks show the compounds to be terpenoid, and they appear to be related to previously described furanoid norditerpenes. Varieties of D. bulbifera vary in bitterness, either cooked or uncooked, but all contain some of the bitter and nonbitter compounds.
The individual activity of antibiotics such as ampicillin, tetracycline, erythromycin and gentamicin in combination with compounds known to modify bacterial resistance to given antibiotics was studied using the checkerboard method. The combination of promethazine with either ampicillin, tetracycline or erythromycin or the combination of methylene blue and erythromycin produced significant synergistic activity against Escherichia coli. Verapamil, however, in combination with ampicillin reduced the activity of ampicillin against E. coli. Combinations of clomipramine with either tetracycline or erythromycin, promethazine and erythromycin or verapamil and ampicillin were synergistic against Staphylococcus epidermidis that was resistant to these antibiotics. The only synergy against Pseudomonas aeruginosa was shown by the combination of methylene blue and gentamicin.
A patient case report describes an Enterococcus faecium strain isolated from a blood culture that was resistant to linezolid (MIC, 8 microg/mL; G2576U mutation of 23S rRNA). Co-resistances were identified for vancomycin, ampicillin, macrolides, fluoroquinolones, chloramphenicol, rifampin, gentamicin (high-level), nitrofurantoin and trimethoprim/sulfamethoxazole. Etest (AB BIODISK, Solna, Sweden) and disk diffusion results also detected the oxazolidinone resistance pattern. Laboratories should be aware of the rare possibility of these strains occurring during linezolid therapy or spontaneously (this case) in contemporary practice, and have in vitro susceptibility methods available capable of detecting oxazolidinone resistance.
A new furoclerodane, croblongifolin, together with one known clerodane, crovatin and one known labdane, nidorellol, were isolated from the stem bark of Croton oblongifolius. Structures were established based on spectroscopic and X-ray analysis. Croblongifolin showed a significant cytotoxicity against various human tumor cell lines including HEP-G2, SW620, CHAGO, KATO3 and BT474.
To study the chemical constituents of Dioscorea bulbifera.
Column chromatography with silica gel was employed for the isolation and purification of constituents. The structures were elucidated by UV, IR, MS, 1H NMR and 13C NMR analyses.
Three compounds were obtained and elucidated as 3,7-dimethoxy-5,4'-dihydroxyflavone; 3,7-dimethoxy-5,3',4'-trihydroxyflavone and emodin.
These compounds were separated from D. bulbifera for the first time.
A complete section through the forebrain through and just anterior to the orbital sulcus and directed well anterior to the caput of the caudate nucleus was not seen to primarily reduce the water intake of dogs or to cause any reduction in the amount of water drunk by the animals subsequent to the intravenous injection of a certain amount of hypertonic saline. The latter was temporarily the case in one animal where the lesion was extended in ventro‐caudal direction to involve the preoptic area on both sides.
Amphetamine (1 mg per kg of body weight) completely inhibited the drinking of water after an intravenous injection of 20 cc of a 20 % NaCl solution in 4 of 5 normal dogs tested. This was no longer the case in 3 of these animals after “prefrontal lobotomy”.
An incomplete section through the forebrain in 5 out of 8 dogs made that the dose of amphetamine necessary to inhibit, the food intake of the animals completely had to be increased by 50 to 100 %.
Promethazine has been recognised as an effective antiplasmid agent in cultures containing a single bacterial species such as Escherichia coli, Yersinia enterocolitica, Staphylococcus aureus and Agrobacterium tumefaciens. The objective of this study was to examine the effect of heterogenity of the microbial flora on plasmid elimination by promethazine in a laboratory based model system of mixed bacterial infection. F'lac plasmid elimination of E. coli K12 LE140 was studied in the presence of a numerically predominant Gram-positive species (Bacillus cereus, Staphylococcus epidermidis) by promethazine (0-120 mg/l) at 23, 37 and 39 degrees C. Growth kinetics of different bacterial species were studied at various temperatures without drug treatment in mixed bacterial cultures and it was found that the small number of added bacteria overgrew the pre-existing flora during the incubation period. We observed that bacterial-bacterial interactions modified the growth rate of individual bacterial species and gave selective advantages to some bacterial species of the microbial community. Some interactions between coexisting bacterial species enhanced the frequency of plasmid curing by promethazine in mixed cultures with S. epidermidis. In our experiments the plasmid curing action of promethazine was more effective at elevated temperature than at lower temperatures.
Five new triterpenoid saponins, pursaethosides A-E (1-5), were isolated from the n-BuOH extract of the seed kernels of Entada pursaetha along with the known phaseoloidin. The structures of 1-5 were elucidated mainly by spectroscopic data interpretation and chemical degradation. Pursaethosides C-E (3-5) possess as a common structural feature entagenic acid as aglycon, which is rare among triterpene saponins. Compounds 2-4 and phaesolidin were found to be not cytotoxic when tested against HCT 116 and HT-29 human colon cancer cells.