Yucca

Fifty-five mg per kg live weight of crystallized Yucca schidigera saponins, corresponding to 26 mg/kg live weight of sapogenins, was given daily intraruminally to two lambs for 11 consecutive days. Neither of the lambs showed any sign of toxicity throughout the experimental period. One lamb was killed 5 h after the last dose and GC-MS analysis of the free and conjugated sapogenin content samples of liver, and of the contents of the rumen, omasum, abomasum, duodenum, jejunum, ileum, colon and rectum, of faecal samples collected before dosing started, and of parts of the administered Yucca saponin were performed. The Yucca material contained mainly sarsasapogenin and smilagenin saponins. Ingested saponins were quickly hydrolysed in the rumen to free sapogenins and, in part, epimerized at C-3 to afford episapogenins. The absorption of free sapogenins appeared to occur in the jejunum. The metabolism of Yucca saponins was identical to that of Narthecium ossifragum saponins, and it is sug...

Groundwater data from 73 wells in Yucca Mountain region were analyzed to better understand geochemical conditions and to make reducing/oxidizing (Redox) environment comparisons. Major ion chemistry, silica, fluoride and associated saturation indices, determined with PHREEQC, were sequentially examined using the multivariate statistical methods of principal component factor analysis and k means cluster analysis. Analysis of both major ion concentration data and their saturation indices allow simultaneous consideration of arithmetic (raw concentrations) and logarithmic (saturation indices) variables that describe the hydrochemical system and therefore can provide further insight into the system's behavior. The factor analysis of the major ion and saturation indices transforms the variables into a tractable number of descriptive factors that are rotated to summarize the chemical groundwater system and better interpret system variation. Results obtained from these analyses show a good agreement with literatures results. Literature indicates that the saturated zone (SZ) located to the east and south of the Yucca Mountain has reducing conditions, and oxidizing conditions are found elsewhere in the SZ flow system.

The present study was designed to determine the protective effects of Yucca schidigera (Ys) against oxidative damage induced by acute nitrite intoxication as well as the histopathological evaluation of Ys in rats. The rats were divided into three groups each containing 12 rats: control (C); nitrite intoxication (N); Ys + nitrite intoxication (NY). C and N groups were fed standard rat feed (SRF). The NY group was fed SRF + 100 ppm Ys powder for 4 weeks. Acute nitrite intoxication was induced by subcutaneous (s.c.) administration of sodium nitrite (60 mg/kg) 1 day after the feeding period. Fifty minutes after sodium nitrite administration, blood samples and tissues including lung, liver, and kidney were collected for clinical biochemistry and histopathological investigations. Ys treatment was found to decrease methemoglobin, blood and tissue malondialdehyde, and tissue nitric oxide concentrations, and to increase the glutathione in blood and various tissues. However, plasma nitric oxide, total antioxidant activity, β-carotene, and vitamin A did not differ between N and NY groups. While the N group rats showed distinct pathology in various tissues (compared with controls), the NY group had similar lung and liver pathology to the control. Only moderate or mild hemorrhage and hyperemia were seen in kidneys of NY group rats. Consequently, the natural compounds found in Ys, such as polyphenols, steroidal saponins, and other phytonutrients, could be used to substantially protect the organism from nitrite-induced oxidative damage and its complications.

Yucca queretaroensis es una especie endémica de la región denominada “Semidesierto Queretano-Hidalguense” en los estados de Guanajuato, Querétaro e Hidalgo, México. Se considera rara por su baja densidad poblacional, distribución restringida y su especificidad de hábitat, además de estar en la Norma Oficial Mexicana como sujeta a protección especial (Pr). Al momento de su descripción como nueva especie fue ubicada en la serie Rupicolae, sección Chaenocarpa. La siguiente propuesta la situó en la serie Gracilifoliae, sección Yucca. Ninguno de los dos planteamientos toma en cuenta la posición filogenética de la especie y tampoco contiene información morfológica completa. Los objetivos de este trabajo fueron proporcionar una descripción completa de la especie, incluyendo frutos y semillas; elaborar la ilustración botánica; compilar y discutir su historia taxonómica y presentar una propuesta sobre su posición taxonómica con base en la información morfológica y los estudios filogenéticos previos. Se propone ubicar a Yucca queretaroensis Piña en la serie Treculeanae, sección Yucca (ex Sarcocarpa) sensu McKelvey

The U.S. Department of Energy (DOE) is considering the possible recommendation of a site at Yucca Mountain, Nevada, for the potential development of a geologic repository for the disposal of high-level radioactive waste and spent nuclear fuel. To facilitate public review and comment, in May 2001 the DOE released the Yucca Mountain Science and Engineering Report (S&ER) (1), which presents technical information supporting the consideration of the possible site recommendation. The report summarizes the results of more than 20 years of scientific and engineering studies. Based on internal reviews of the S&ER and its key supporting references, the Total System Performance Assessment for the Site Recommendation (TSPA-SR) (2) and the Analysis Model Reports and Process Model Reports cited therein, the DOE has recently identified and performed several types of analyses to supplement the treatment of uncertainty in support of the consideration of a possible site recommendation. The results of...

Yucca queretaroensis es una especie endémica de la región denominada “Semidesierto Queretano-Hidalguense” en los estados de Guanajuato, Querétaro e Hidalgo, México. Se considera rara por su baja densidad poblacional, distribución restringida y su especificidad de hábitat, además de estar en la Norma Oficial Mexicana como sujeta a protección especial (Pr). Al momento de su descripción como nueva especie fue ubicada en la serie Rupicolae, sección Chaenocarpa. La siguiente propuesta la situó en la serie Gracilifoliae, sección Yucca. Ninguno de los dos planteamientos toma en cuenta la posición filogenética de la especie y tampoco contiene información morfológica completa. Los objetivos de este trabajo fueron proporcionar una descripción completa de la especie, incluyendo frutos y semillas; elaborar la ilustración botánica; compilar y discutir su historia taxonómica y presentar una propuesta sobre su posición taxonómica con base en la información morfológica y los estudios filogenéticos ...

The in vitro effect of a Yucca schidigera extract (YSE) and tannins from chestnut wood on composition and metabolic activity of canine and feline faecal microbiota was evaluated. Four treatments were carried out: control diet, chestnut tannins (CT), YSE and CT + YSE. The YSE was added to canine and feline faecal cultures at 0.1 g/l, while CT were added at 0.3 g/l for a 24-h incubation. A total of 130 volatile compounds were detected by means of headspace-solid phase microextraction gas-chromatography/mass spectrometry analyses. Several changes in the metabolite profiles of fermentation fluids were found, including a decrease of alcohols (-19%) and esters (-42%) in feline and canine inoculum, respectively, which was due to the antibacterial properties of tannins. In canine inoculum, after 6 h, YSE + CT caused lower cadaverine concentrations (-37%), while ammonia (-4%) and quinolone (-27%) were reduced by addition of CT. After 24 h, the presence of CT resulted in a decrease of sulphur...

The occurrence of steroidal saponins in the rhizomes of Yucca gloriosa has been detected by LC–MS. On the basis of the LC–MS analysis, five steroidal glycosides, including three spirostane, one furostane and one cholestane glycosides, along with seven known ...

Yucca queretaroensis es una especie endémica de la región denominada “Semidesierto Queretano-Hidalguense” en los estados de Guanajuato, Querétaro e Hidalgo, México. Se considera rara por su baja densidad poblacional, distribución restringida y su especificidad de hábitat, además de estar en la Norma Oficial Mexicana como sujeta a protección especial (Pr). Al momento de su descripción como nueva especie fue ubicada en la serie Rupicolae, sección Chaenocarpa. La siguiente propuesta la situó en la serie Gracilifoliae, sección Yucca. Ninguno de los dos planteamientos toma en cuenta la posición filogenética de la especie y tampoco contiene información morfológica completa. Los objetivos de este trabajo fueron proporcionar una descripción completa de la especie, incluyendo frutos y semillas; elaborar la ilustración botánica; compilar y discutir su historia taxonómica y presentar una propuesta sobre su posición taxonómica con base en la información morfológica y los estudios filogenéticos ...