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PubMedDate not supplied

Analysis of bisdesmosidic saponins in Saponaria vaccaria L. by HPLC-PAD-MS: identification of new quillaic acid and gypsogenin 3-O-trisaccharides.

A high-performance liquid chromatographic method using photodiode array and single quadrupole electrospray mass detection for analysis and profiling of bisdesmosidic saponins in Saponaria vaccaria seed was developed. Profiles of seed extract from three different plant sources were obtained and found to contain the same saponins, albeit in different proportions. Several known saponins were identified by selected ion extraction of quasi-molecular ions from the total ion chromatogram and confirmed by their mass spectra. Application of high cone voltages afforded mass spectra containing key diagnostic fragments and relatively strong singly charged quasi-molecular ions. In addition to previously identified saponins, several new quillaic acid and gypsogenin bisdesmosides could be detected via mass spectral analysis. Five of these were tentatively identified as pentose homologues of known saponins, having an added xylosyl residue linked to the 3-O-glucuronyl group (1 --> 3). The stereochemistry and identity of the xylosyl linkage in the new saponins was determined by chemical means. Previously reported vaccaric or segetalic acid-type bisdesmosides could not be detected in any of the extracts.

Carbohydrate Conformation↗
PubMed2003

Environmental risk evaluation of chemicals: achievements of the project and seeds for future--development of metrics for evaluating risks.

Achievements of the research project entitled "Establishment of a scientific framework for the management of toxicity of chemicals based on environmental risk-benefit analysis" supported by the JST were introduced and reviewed, focusing on the development of the methodology for estimating risks; human health risks and ecological risks. The usefulness of loss of life expectancy as a metric for evaluating cancer and noncancer risks was demonstrated. To evaluate ecological risks, three metrics, 1/T, logT and T, developed based on the mean extinction time (T) of species were proposed. Then, their implication and feasibility were examined in terms of what ecological system should be conserved and how easily people can understand the implications of metrics. Protocols for estimating human health risks and ecological risks are illustrated.

Animals↗
PubMed1999

Soil, seed and climate: developing a strategy for prevention and management of infections in UK nursing homes.

Most studies of nursing home (NH) infections come from the USA and very few from the UK. USA studies lead us to anticipate a rate of 7 infections per 1000 patient days with a point prevalence as high as 16% in UK NH residents. Pneumonia, skin and urine infections would be the most frequent, followed by enteric infection and bacteraemia. Colonization with resistant organisms is increasing in UK NH residents (e.g., MRSA in 4-17%). Surveillance studies are needed in UK NHs to report incidence of infection, residents' characteristics, existence of and adherence to above standards and policies. Trials of effectiveness of different infection control programmes and of NH vs hospital management are required. Management of infection may be a useful marker of quality of care in NHs and therefore of interest to health and local authorities.

Aged↗
PubMed2003

RHM2 is involved in mucilage pectin synthesis and is required for the development of the seed coat in Arabidopsis.

Pectins are major components of primary plant cell walls and the seed mucilage of Arabidopsis. Despite progress in the structural elucidation of pectins, only very few enzymes participating in or regulating their synthesis have been identified. A first candidate gene involved in the synthesis of pectinaceous rhamnogalacturonan I is RHM2, a putative plant ortholog to NDP-rhamnose biosynthetic enzymes in bacteria. Expression studies with a promoter beta-glucuronidase construct and reverse transcription PCR data show that RHM2 is expressed ubiquitously. Rhm2 T-DNA insertion mutant lines were identified using a reverse genetics approach. Analysis of the rhm2 seeds by various staining methods and chemical analysis of the mucilage revealed a strong reduction of rhamnogalacturonan I in the mucilage and a decrease of its molecular weight. In addition, scanning electron microscopy of the seed surface indicated a distorted testa morphology, illustrating not only a structural but also a developmental role for RGI or rhamnose metabolism in proper testa formation.

Adhesives↗
PubMed1995

Suborganellar Localization and Molecular Characterization of Nonproteolytic Degraded Leukoplast Pyruvate Kinase from Developing Castor Oil Seeds.

Plastid pyruvate kinase (PKp) activity and anti-(castor oil seed [COS] PKp) immunoglobulin G immunoreactive polypeptides were recovered in the stroma but not from envelope membranes of purified COS leukoplasts that had been subfractionated by sucrose density gradient centrifugation. The PKp was highly purified from isolated leukoplasts using anion-exchange and ADP-agarose chromatographies. Proteolysis of PKp was almost entirely eliminated by including 2,2[prime]-dipyridyl disulfide in purification buffers. The final preparation contained 63.5-kD ([alpha] subunit) and 54-kD ([beta] subunit) polypeptides that stained for protein and cross-reacted with anti-(COS PKp) immunoglobulin G with similar intensities. These two polypeptides co-eluted following gel-filtration chromatography and co-migrated during nondenaturing isoelectric focusing-polyacrylamide gel electrophoresis. The enzyme's native Mr was estimated to be 334,000. This PKp thus appears to exist as an [alpha]3[beta]3-heterohexamer. Comparison of the respective N-terminal sequences of the [alpha] and [beta] subunits with the deduced amino acid sequences for several PKp cDNAs indicated that (a) the [alpha] and [beta] subunits are encoded by COS genes previously designated as PKpA and PKpG, respectively, and (b) respective transit peptides of 4.8- and 5.5-kD are cleaved from the [alpha] and [beta] subunit preproteins following their translocation into the leukoplast.

Journal Article↗
PubMed1975

Mitochondrial Arginase Activity from Cotyledons of Developing and Germinating Seeds of Vicia faba L.

Differential and sucrose density gradient centrifugation established that about 80% of the total arginase activity (EC 3.5.3.1) in cotyledons of germinating broad bean seeds (Vicia faba L.) was present in the mitochondrial fraction. The mitochondrial arginase activity was enhanced considerably by exposure to osmotic shock, by freezing and thawing, or by Triton X-100 treatment. About 10% of the total arginase activity was recovered from the 40,000g supernatant fraction. During seed maturation, arginase activity in the cotyledons decreased to about one-third of its maximal activity, while increasing over 10-fold during subsequent germination. The time courses of mitochondrial arginase, succinate oxidase, and succinate dehydrogenase activities differed considerably during germination.

Journal Article↗
PubMed1984

Gene Expression and Synthesis of Phytohemagglutinin in the Embryonic Axes of Developing Phaseolus vulgaris Seeds.

Phytohemagglutinin (PHA), the major seed lectin of the common bean (Phaseolus vulgaris), is found largely in the cotyledons, but is also present in the embryonic axis. At mid-maturation, the percentage of total protein synthesis which is directed towards making PHA is 5 to 10 times greater in the cotyledons than in the axes. This lower rate of synthesis in the axes is correlated with a lower abundance of mRNA for PHA, as determined by dot blot hybridization using a cDNA clone for PHA. Manen and Pusztai (Planta 1982 155: 328-334) have claimed on the basis of immunocytochemical evidence that, in the axis, PHA is found in the cytosol although it is present in protein bodies in the cotyledons. In the cotyledons, PHA is synthesized on rough endoplasmic reticulum, and its transport to the protein bodies via the Golgi complex is associated with specific posttranslational processing steps (Vitale and Chrispeels, J Cell Biol 1984 In press). A cytosolic localization of axis PHA would be an indication of a different site of synthesis and transport pathway. The results presented here indicate that the site of synthesis of PHA and the posttranslational modifications of PHA are the same in the axes as in the cotyledons. Since in the cotyledons these modifications take place in the endoplasmic reticulum, the Golgi, and the protein bodies, it appears that the transport pathway and the site of accumulation of PHA in the axes is similar to that in the cotyledons. On the basis of our evidence, we suggest that the subcellular localization of PHA in the axes should be reexamined.

Journal Article↗
PubMed2004

A tutorial of recent developments in the seeding of local alignment.

We review recent results on local alignment. We begin with a review of classical methods and early heuristic methods, and then focus on more recent work on the seeding of local alignment. We show that these techniques give a vast improvement in both sensitivity and specificity over previous methods, and can achieve sensitivity at the level of classical algorithms while requiring orders of magnitude less runtime.

Algorithms↗
PubMed1986

Effects of precocenes on ovarian development of the seed bug, Oxycarenus lavaterae (F.).

Antigonadotropic activities of Precocene 1 (P1), Precocene 2 (P2) and Ethoxyprecocene 2 (EP2) on the seed bug Oxycarenus lavaterae (F.) (Heteroptera, Lygaeidae), are reported. EP2 proved to be the most active compound followed by P2 and P1, which agrees with the structure-activity relationships reported for these compounds thus far. Mortality in both sexes was furthermore studied. In this context, compound P2 showed the highest degree of toxicity. Males, interestingly, appeared to be more sensitive to the toxic effects of Precocenes.

Animals↗