A new prenylisoflavone from Ulex jussiaei

A new naturally occurring isoflavone, derrone, was isolated from Ulex jussiaei (Leguminosae) together with the isoflavones ulexins A-C, lupalbigenin, isolupalbigenin, 7-O-methylso-lupalbigenin, isoderrone, ulexone A and isochandalone, the pterocarpans (6aR,11aR)-(-)-maackiain, (6aR,11aR)-(-)-2-methoxymaackiain and (6aR,11aR)-(-)-4-methoxymaackiain, the chalcone 4-hydroxylonchocarpine and the dihydrochalcone crotaramosmine. The antifungal activity of the new compound was tested by a bioautographic method against Cladosporium cucumerinum, and as expected from structural features it proved to have no activity.     

Ulex europaeus agglutinin-I binds to developing gastrin cells

 We have previously reported that antropyloric gastrin (G) and somatostatin (D) cells derive from precursor (G/D) cells that coexpress both hormones. We have now analyzed this endocrine cell pedigree for binding of Ulex europaeus agglutinin-I (UEA-I), which previously has been reported to represent a useful marker for cell differentiation. Subpopulations of G/D, D, and G cells were all found to express UEA-I binding. Labelling with bromodeoxyuridine showed that UEA-I positive G cells possessed a higher labelling index than UEA-I negative G cells. These data suggest that the UEA-I positive G cells represent maturing cells still involved in DNA synthesis and cell division. Electron microscopically, specific UEA-I binding sites were localized to the secretory granules and the apical cell membrane of G cells. We conclude that UEA-I represents a differentiation marker for G cells. Moreover, the presence of UEA-I binding sites in these cells may be relevant for Helicobacter pylori-mediated disturbances of gastric acid secretion and gastrin hypersecretion. Accepted: 19 August 1997     

Chemotaxonomy of Portuguese Ulex: quinolizidine alkaloids as taxonomical markers

Six species of Portuguese Ulex L. in a total of nineteen populations were studied by GC-EIMS as to their content in quinolizidine alkaloids. Sparteine, beta-isosparteine, jussiaeiine A, N-methylcytisine, cytisine, 5,6-dehydrolupanine, rhombifoline, lupanine, jussiaeiine B, N-formylcytisine, N-acetylcytisine, anagyrine, jussiaeiine C, jussiaeiine D, pohakuline, baptifoline, and epibaptifoline were detected. Analysis of the chromatograms showed that the chemical profile of all species was mainly composed of N-methylcytisine, cytisine, anagyrine, and jussiaeiines A, B, C and D. Therefore a quantification study of these alkaloids in all the populations studied was done by GC. These data were then submitted to cluster analysis and principal component analysis, which allowed the definition of five chemotypes and the recognition of hybrids. N-methylcytisine, cytisine, and jussiaeiines A, C and D are recognized as markers of this genus in Portugal.     

Binding sites of Ulex europaeus-lectin I in human parotid gland

Summary Twenty non-neoplastic parotid glands (removed during neck dissection for regional tumours) were examined for cellular and subcellular binding sites of Ulex europaeus-lectin I (UEA-I), a lectin reported to be specific for -L-fucose. For light microscopy, an extended peroxidase-antiperoxidase method was applied; for the evaluation of the subcellular localization of bound lectin, three of these glands were examined following immunocryoultramicrotomy and staining by the protein A-gold technique.In addition to the known cytoplasmic affinity of UEA-I for capillary endothelium, acinar cells bound the lectin within the cytoplasmic compartment; the number and distribution of stained acinar cells varied among individuals. Furthermore, cytomembrane-bound labelling that occurred most markedly at the luminar surface was observed in striated-duct epithelium.Using the electron microscope, protein A-gold particles were seen in zymogen granules and in Golgi cisternae of serous acinar cells; primary saliva secreted in the lumina exhibited strong labelling; serous acinar cells had binding sites on their cell membranes, striated-duct epithelium had binding sites on its surface membrane and in the vicinity of apical vesicles. Our results show that UEA-I is a useful tool for the study of the structure and functional states of the parotid gland epithelium and its associated pathological alterations.Dedicated to Prof. Dr. med. G. Seifert on the occasion of his 65th birthday     

On the identity of Ulex gallii Planchon (Leguminosae)

On the basis of the study of the original material used by Planchon, the typification previously made by other authors is discussed, and an interpretation of the U. minor-galli group is presented. We conclude that the name U. galli must continue in use in its traditional sense, and, therefore, U. cantabricus Alvarez Martínez el al. must become a mere synonym. The new combinations U. breoganii (Castroviejo & Valdés-Bermejo) Castroviejo & Valdés-Bermejo, stat. nov. and U. minor subsp. gallii (Planchon) Castroviejo & Valdés-Bermejo, comb. nov. are proposed.     

Ecological mechanisms involved in dormancy breakage in Ulex parviflorus seeds

Dormancy in the hard seed coats of Mediterranean species is considered a strategy that enables persistent seed banks to be formed in the soil. An important factor related to seed coat fracture and dormancy breakage in Mediterranean ecosystems is heat. Nevertheless, the effect of factors other than heat on dormancy breakage in these species has hardly been studied. To investigate the different ecological factors involved in germination, in the laboratory we applied several scarification treatments to seeds with chromatic polymorphism. We evaluated the effect of soil seed depth during experimental burns by sowing seeds at −1, −3 and −5 cm in the soil profile, and we also studied the effect of seed origin on the posterior germination of seeds from 4 and 10 year-old shrubs as well as from the soil seed bank. U. parviflorus shows clear chromatic polymorphism: its brown seeds present higher dormancy levels than its yellow seeds. The different techniques of dormancy breakage result in different degrees of germination; the highest degree of germination is generated by the mechanical treatment, followed by the acid and the heat treatments, in that order. The depth of the seeds in the soil determines the temperature thresholds and the residence times of these temperatures and whether they stimulate a massive germination at the −1 cm soil profile or only a slight germination at the −5 cm depth. Seeds recently produced by the plant show higher dormancy levels than seeds extracted from soil seed banks. Dormancy levels also depend on the shrubland age used for extracting the soil samples (3>9 years old). In effect, from the point of view of dormancy, the germination behaviour of U. parviflorus seeds seems to follow a multiresponse strategy based on different seed populations and involving both biological and abiotic processes to break dormancy.     

Properties of Ulex europaeus II lectin isolated by affinity chromatography.

A lectin was isolated from Ulex europaeus seeds by affinity chromatography on affinity adsorbent prepared by copolymerization of acrylamide, N,N'-methylene bisacrylamide and maleylated hog stomach peptone. The lectin is homogeneous as judged by ultracentrifugation (s20,w = 6.4 S), electrophoretic and gel chromatography criteria; it contains 4.2% neutral sugar and 1.4% glucosamine. Its molecular weight is approx. 110,000 and the molecule consists of two noncovalently linked protomers which are formed by two covalently bound basic subunits (Mr = 30,000). The preparation contains three isolectins differing in the strength of interaction with specific sugars (cellobiose, N-acetyl-D-glucosamine) under the conditions of affinity electrophoresis. The lectin is non-specific with human ABO blood group system, the agglutination is inhibited by partial chitin hydrolysate, hog stomach peptone and high concentration of cellobiose.     

Identification of novel small-molecule Ulex europaeus I mimetics for targeted drug delivery

Lectin mimetics have been identified that may have potential application towards targeted drug delivery. Synthetic multivalent polygalloyl constructs effectively competed with Ulex europaeus agglutinin I (UEA1) for binding to intestinal Caco-2 cell membranes.     

The primary structures of two types of the Ulex europeus seed lectin

The complete amino acid sequences of the Ulex europeus anti-H(O) lectins I and II were determined by using a protein sequencer. After digestion with endoproteinases Lys-C and Asp-N of the lectins reduced with 2-mercaptoethanol and modified with iodoacetamide, the resulting peptides were purified by reversed-phase high-performance liquid chromatography and subjected to sequence analysis. The complete primary structures of these two Ulex lectins I and II were compared with those of nine lectins already determined, including that of Lotus tetragonolobus anti-H(O) lectin which we have determined. Extensive homologies were found among them.     

Population responses of Ulex shrubs to fire in a lowland heath community

Question: How does the frequency of heathland fire events affect population growth rates of two woody shrub species, Ulex gallii and U. minor? Location: Dry heathland on the south coast of England, UK. Methods: The population dynamics of U. gallii and U. minor were modelled at each phase of the heathland cycle — pioneer, building, mature and degenerate — using periodic matrix products to investigate the response to different fire regimes. Results: Population growth rates of both Ulex species declined under annual burning. Initially, as the time between burns increased, population growth rate increased for both species. Maximum population growth rates for each Ulex species were achieved under a 16‐yr fire return interval. Fire return intervals > 16 yr resulted in declining population growth rates. Conclusions: A species‐specific critical fire frequency can be predicted, the minimum fire return intervals permitting persistence were 4 yr for U. minor and 3 yr for U. gallii. These patterns are similar to those reported for a range of woody plant species within savanna environments.     

Factors influencing pathogenicity of Fusarium tumidum on gorse (Ulex europaeus)

Factors promoting pathogenicity of Fusarium tumidum on gorse (Ulex europaeus) were determined to develop a novel strategy for delivering this potential mycoherbicide using insects as vectors of inoculum. Fusarium tumidum sprayed as a suspension of 1×10⁶ conidia mL^?1 on at least 50% of a gorse plant reduced shoot dry weight by 45% (P<0.05). A minimum of 910 viable conidia were required to cause a lesion on leaves. The leaves and flowers were more susceptible to infection than stems, spines and pods. Generally, wounding of gorse leaves and stem increased F. tumidum infection, most likely through releasing nutrients that enhanced conidial germination and hyphal growth. We showed in a separate experiment that conidial germination (93%) and germ tube length (407 µm) were greater when incubated in 0.2% gorse extract solution for 24 h than in water (62% germination, germ tube length 42 µm). Inoculation of gorse with a F. tumidum conidial suspension supplemented with 0.2% gorse extract resulted in a shoot dry weight reduction (P=0.012) equivalent to that of plants that were wounded and inoculated. It is concluded that wounding of older tissues (which mimics insect damage) is required to facilitate F. tumidum infection of mature gorse plants.     

Effects of root dehydration on biomechanical properties of woody roots of Ulex europaeus

Plant and Soil - Effects of root water status on root tensile strength and Young’s modulus were studied in relation to root reinforcement of slopes. Biomechanical properties of woody roots,...     

Chondrostereum purpureum and Fusarium tumidum independently reduce regrowth in gorse (Ulex europaeus)

An experiment was conducted in two gorse populations (Ulex europaeus) in which Chondrostereum purpureum was applied each month as mycelial-agar cultures to the wounds of decapitated stems of previously untreated gorse plants to determine its potential as a mycoherbicide. Summer-autumn (Feb-May) or late winter-early spring (Aug-Sept) applications were effective in both populations, halving stem stump survival (from an average of 56 to 29%). Another experiment in the same gorse populations evaluated the combined effects of C. purpureum applied in May to decapitated stems, and Fusarium tumidum applied as spores in an invert emulsion to regenerative shoots 5-6 months later. There was no evidence of synergism between the two fungi; each pathogen independently reduced the density of regenerative shoots on the decapitated stems by 39-63% averaged over the 12 months following their respective applications. It is concluded that both pathogens have potential as mycoherbicides for gorse regenerating after stem decapitation.     

Chromosome numbers and geographical distribution of Ulex europaeus subsp. europaeus (Leguminosae)

FERNANDEZ PRIETO, J. A., VERA, M. L., ALVAREZ MARTINEZ, M. J., DIAZ, T. E., FERNANDEZ CASADO, M. A., FERNANDEZ-CARVAJAL, M. C, GUTIERREZ VILLARIAS, M. I. & NAVA, H. S., 1993. Chromosome numbers and geographical distribution of Ulex europaeus subsp. europaeus (Leguminosae). Chromosome numbers are reported in Ulex europaeus subsp. europaeus (99 samples from northern Spain, France and Great Britain). Three levels of ploidy (diploid, tetraploid and hexaploid) have been detected; the diploid and tetraploid levels, hitherto unknown in this taxon, have been found exclusively in coastal areas of northern Spain and western France.