Interaction of the Laburnum anagyroides lectin with fucoantigens

We studied interaction of the lectin from the bark of Golden Rain shrub (Laburnum anagyroides, LABA) with a number of basic fucose-containing carbohydrate antigens by changes in its tryptophan fluorescence. The strongest LABA binding was observed for the trisaccharide H of type 6 [alpha-L-Fucp-(1-2)-beta-D-Galp-(1-4)-D-Glc, Ka= 4.2 x 10(3) M(-1)]. The following antigens were bound with a weaker affinity: H-disaccharide alpha-L-Fucp-(1-2)-D-Gal, a glucoanalogue of tetrasaccharide Ley alpha-L-Fucp-(1-2)-beta-D-Galp-(1-4)-[alpha-L-Fucp-(1-3)]-D-Glc, and 6-fucosyl-N-acetylglucosamine, a fragment of core of the N-glycans family (Ka 1.1-1.7 x 10(3) M(-1)). The lowest binding was observed for L-fucose (Ka = 2.7 x 10(2) M-1) and trisaccharide Lea, (3-Galp-(1-3)-[a-L-Fucp-(1-4)]-GlcNAc (Ka = 6.4 x 10(2) M(-1)). The Lea, Lea, and Lex pentasaccharides and Leb hexasaccharide were not bound to LABA.     

Interaction of the Laburnum anagyroides lectin with fucoantigens

We studied interaction of the lectin from the bark of Golden Rain shrub (Laburnum anagyroides, LABA) with a number of basic fucose-containing carbohydrate antigens by changes in its tryptophan fluorescence. The strongest LABA binding was observed for the trisaccharide H of type 6 [α-L-Fucp-(1-2)-β-D-Galp-(1-4)-D-Glc, K _a = 4.2 × 10³ M^?1]. The following antigens were bound with a weaker affinity: H-disaccharide α-L-Fucp-(1-2)-D-Gal, a glucoanalogue of tetrasaccharide Le^y α-L-Fucp-(1-2)-β-D-Galp-(1-4)-[α-L-Fucp-(1-3)]-D-Glc, and 6-fucosyl-N-acetylglucosamine, a fragment of core of the N-glycans family (K _a 1.1?1.7 × 10³ M^?1). The lowest binding was observed for L-fucose (K _a = 2.7 × 10² M^?1) and trisaccharide Le^a, (β-Galp-(1-3)-[α-L-Fucp-(1-4)]-GlcNAc (K _a = 6.4 × 10² M^?1). The Le^d, Le^a, and Le^x pentasaccharides and Le^b hexasaccharide were not bound to LABA.     

Oligosaccharide specificity of the fucolectin from the bark of laburnum Laburnum anagyroides

A comparative study of thin carbohydrate specificity of the lectin from the bark of laburnum Laburnum anagyroides (LABA) and fucolectin from asparagus pea Tetragonolobus purpureus (TPA) was performed using inhibition of agglutination of the complex formed by H-active neoglycoprotein and nanoparticles of colloidal gold. Both lectins bound most strongly the H type 2 oligosaccharides comprising O-glycanes; however, TPA was almost unable to discriminate between them. LABA bound more weakly the H type 6 trisaccharide (Fuc alpha 1-2Gal beta 1-4Glc) and difucosyllactose (Fuc alpha 1-2Gal beta 1-4[Fuc alpha 1-3]Glc), a glucoanalogue of the Le(y) antigen, and, even more weakly, the Le(a) pentasaccharide lacto-N-fucopentaose II (Gal beta 1-3[Fuc alpha 1-4]GlcNAc beta 1-3Gal beta 1-4Glc). However, LABA did not bind the antigens Le(b), Le(c), and Le(d), very poorly interacted with the terminal Le(x), and somewhat more strongly bound the internal Le(x). The lectin also had a hydrophobic binding site. Both lectins exhibited a cluster effect with polymeric ligands (neoglycoproteins).     

N-Methylation of quinolizidine alkaloids: an S-adenosyl-l-methionine: cytisine N-methyltransferase from Laburnum anagyroides plants and cell cultures of L. alpinum and Cytisus canariensis

An S-adenosyl-l-methionine (SAM): cytisine N-methyltransferase could be demonstrated in crude enzyme preparations from Laburnum anagyroides plants and cell cultures of L. alpinum and Cytisus canariensis. The transferase specifically catalyzes the transfer of a methyl group from SAM to cytisine. The apparent K_m values are 60 mol l^-1 for cytisine and 17 mol l^-1 for SAM. Other quinolizidine alkaloids, e.g. angustifoline and albine, are N-methylated by only 10–15%. The transferase shows a pH optimum at pH 8.5. It is activated by dithioerythritol and inhibited by thiol reagents and Fe²⁺ and Fe³⁺. The reaction product S-adenosylhomocysteine is a powerful inhibitor of the transferase reaction. Cell cultures of L. alpinum which have an active SAM: cytisine N-methyltransferase and which are able to N-methylate exogenous cytisine in vivo, do not accumulate cytisine or N-methylcytisine to a detectable degree.Abbreviations GLC gas-liquid chromatography - SAM S-adenosylmethionine - TLC thin-layer chromatography     

Structure of carbohydrate chains of fucolectin from the bark of golden rain shrub Laburnum anagyroides

A reductive LiBH4-ButOH cleavage of N-glycosylamide carbohydrate-peptide bond allowed splitting off of oligosaccharide chains of the fucolectin, the bark agglutinin from the shrub golden rain Laburnum anagyroides (LABA). Four N-glycans were isolated by HPLC, and their structures were elucidated by monosaccharide analysis and 1H NMR (500 MHz) spectroscopy: Man2Fuc1XyllGlcNAc2 (M2FX), Man3XyllGlcNAc2 (M3X), Man3FuclXyllGlcNAc2 (M3FX), and Man3XyllFucIGlcNAc3 (NM3FX). All the N-glycans contain D-xylose and three of them, L-fucose; they were found to be in a 1 : 8 : 1 : 3 ratio.     

A taxonomic study of Jamesia (Hydrangeaceae)

Jamesia (Hydrangeaceae) is endemic to western North America from the southern Rocky Mountains in southeastern Wyoming and Colorado west across the Great Basin to the southern Sierra Nevada and south through New Mexico and southeastern Arizona to Chihuahua and Nuevo León. Its distinctiveness and Oligocene fossil record suggest that it is an old genus. The genus comprises five geographically distinct taxa that can be grouped into two species. One of these,Jamesia americana, is further divided into four varieties, the second of which is new, and the fourth of which assumes a name older than that in current use:J. americana var.americana, var.zionis, var.macrocalyx, and var.rosea. The second species,J. tetrapetala, is new.     

Numerical taxonomic studies on Solarium L. section Solarium (Maurella)

Population differentiation was studied in 32 accessions belonging to Solarium L. section Solarium (Maurella); these accessions represented 20 species of four differing ploidy levels. A study of discordance demonstrated that the species exhibit considerable inherent discordant variation; it also provided an estimate of the relative variabilities of characters within these populations, and the consistency with which they differentiate populations.
Hierarchic clusters, obtained using the single-link cluster method, confirmed the relative importance of the different classes of characters used for differentiation within this section. Similarly, the hierarchic clusters generally supported earlier taxonomic decisions.
The use of a non-hierarchic cluster method provided the most interesting data on differentiation within the section Solarium, particularly for genome relationships of the polyploid taxa. This clustering pattern fitted well with known genome relationships, while also suggesting putative ancestors for other allopolyploids; suggestions deriving retrospective support from the hierarchic dendrograms. The progenitors suggested by tliese two clustering methods supported data derived from orthodox taxonomy, comparative morphology, hybridisation studies, the artificial synthesis of polyploids and seed protein band patterns.     

Numerical taxonomic study of some tribes of Brassicaceae from Egypt

 A systematic study of 45 taxa belonging to 23 genera of tribes Arabideae, Euclidieae, Hesperideae, Lunarieae, Matthioleae and Sisymbrieae of Brassicaceae from Egypt was conducted by means of numerical analysis based on sixty two morphological characters, including vegetative parts, pollen grains and seeds. On the basis of UPGMA clustering and PCO analysis, four main groups are recognised: Lunarieae, Euclidieae, Matthioleae and a mixed group. Representatives of these groups are clustered together based on characters with high factor loading in the PCO analysis. The tribe Euclidieae is the most homogeneous group, and the tribe Arabideae is the most heterogeneous one. Received November 9, 2001; accepted February 21, 2002 Published online: October 14, 2002 Addresses of the authors: K. Abdel Khalik, (e-mail: kadry.elsayedabdelkhalik@wur.nl), L. J. G. van der Maesen (e-mail: jos.vandermaesen@ wur.nl), W. J. M. Koopman, R. G. van der Berg, Group of Biosystematics, Gen. Foulkesweg 37, NL-6703 BL Wageningen, The Netherlands.     

Trametes fumoso-avellanea (Aphyllophorales): a taxonomic study

The morphology, cultural features, sexuality, nuclear behavior and dolipore/parenthesome apparatus of Trametes fumoso-avellanea were studied in an attempt to settle its taxonomic position. Data provided by the micromorphology, biological (non-morphological) characters and the non-perforate parenthesomes sustain its redisposition in the genus Trichaptum Murr.     

A taxonomic study of Salix section Longifoliae (Salicaceae)

Salix section Longifoliae occurs from Alaska to Guatemala and from the Atlantic to the Pacific. Nine taxa are here accepted as five species with one of the species including two subspecies and four varieties. the holotype of Salix taxifolia Humb., Bonpl. & Kunth represents the same taxon as the lectotype of Salix microphylla Schltdl. & Cham. Material recently called S. taxifolia is given a new name. Salix exilifolia Dorn. The name Salix fluviatilis Nutt is considered to be synonymous with S. melanopsis Nutt. One new variety is described and two new combinations are made under Salix exigua Nutt.     

A taxonomic study of theCalamagrostis tashiroi group (Poaceae)

TheCalamagrostis tashiroi group was taxonomically revised by examination of population samples from four areas and herbarium specimens. Results of the morphological examination, coupled with observations of the habitats, showed that three taxa with distinct morphological features and definite geographical ranges can be recognized in this group. They were disposed asCalamagrostis tashiroi subsp.tashiroi, C. tashiroi subsp.sikokiana, stat. nov. andC. onibitoana, sp. nov.     

Numerical taxonomic studies of the genus Notholca

The genus Notholca has been subjected to taxonomic analysis, using cluster analysis and ordination by principal coordinates analysis, based on 67 phenetic characters. All analyses converge on essentially identical groupings, but fail to inject new hypotheses to remedy the confusing and overlapping taxonomy of the genus. This shortcoming is ascribed to the incompleteness of the character set which currently lacks biochemical and genetic parameters. We suggest to invalidate the subspecies' of N. striata into a single species and consider the pros and cons combining N. haueri and N. latistyla.     

A taxonomic study of Plantago subgenus Psyllium (Miller) Harms

ANDRZEJEWSKA-GOLEC, E., 1992. A taxonomic study of Plantago subgenus Psyllium (Miller) Harms . The result of studies on hairs and iridoid glycosides provide evidence for heterogeneity of the subgenus Psyllium. The division of the subgenus into four series is undertaken.     

A taxonomic study of the subantarctic Piptoporus (Polyporaceae, Basidiomycetes) I

Ryvardenia gen. nov. is proposed to accommodate Polyporus cretaceus (as type species) and Polyporus campylus . The new genus is characterized by: medium to large fruit bodies that may be solitary or imbricate; monomitic context with clamped generative hyphae with thin to thickened walls that are not metachromatic in cresylblue; dimitic dissepiments with unbranched skeletal hyphae; obovate or broad-ellipsoid, uninucleated, thick walled spores; bipolar sexuality; astatocoenocytic nuclear behavior and simple-septated generative hyphae in the advancing mycelium in culture. Mating tests between specimens from Australia/New Zealand and Argentina of R. cretacea and R. campyla are presented. Tyromyces falcatus is considered a synonym of R. campyla only differing in the greater amount of sclerified generative hyphae and skeletal hyphae present in the fruit bodies.     

A taxonomic study of the Subantarctic Piptoporus (Polyporaceae, Basidiomycetes) II

Morphological and cultural studies of Polyporus maculatissimus and P. portentosus are presented. Neolentiporus gen. nov. is proposed to accommodate P. maculatissimus , a species with a striking macromorphological similarity with the north temperate P. squamosus . The new genus is characterized by medium to large stipitate fruitbodies with a poroid hymenophore, circular to flabellate pilei with a scaly surface and an excentric or lateral stipe that sometimes is reduced to a short, robust umbo. The hyphal system is dimitic with clamped, irregularly thick-walled generative hyphae that do not react with cresyl-blue, and terminal, unbranched, thick-walled skeletal hyphae that are strongly metachromatic in cresyl-blue. Spores are cylindric, hyaline, thin-walled, inamyloid and binucleate. The sexuality is bipolar, the nuclear behavior is astatocoeno-cytic and the associated wood-rot is brown. The new genus is regarded as the poroid counterpart of the agaricoid Neolentinus. Polyporus portenrosus is included in Laetiporus on the basis of its yellowish fruitbodies, its soft, punky context, its hyphal system composed of simple septate generative hyphae and binding hyphae, its holocoenocytic nuclear behavior and its associated brown wood-rot. A new code symbol, i.e. '9s' is proposed to codify the presence, in cultures, of simple-septate generative hyphae with irregularly thickened walls.     

The genus Cabomba (Cabombaceae)–a taxonomic study

The genus Cabomba (Cabombaceae) is revised. Five species and three varieties are recognized: C. aquatica, C. palaeformis, C. furcata, C. haynesii and C. caroliniana including var. caroliniana , var. pulcherrima , and var. flavida var. nov. A basic chromosome number of x = 13 is proposed. Special emphasis has been given to pollen and seed morphology as revealed by SEM studies.