Intracellular sites of the synthesis of sweet potato mitochondrial F1ATPase subunits

Summary Five subunits (-, -, -, - and -subunits) of the six -and -subunits) in the F₁ portion (F₁ATPase) of sweet potato (Ipomoea batatas) mitochondrial adenosine triphosphatase were isolated by an electrophoretic method. The - and -subunits were not distinguishable immunologically but showed completely different tryptic peptide maps, indicating that they were different molecular species. In vitro protein synthesis with isolated sweet potato root mitochondria produced only the -subunit when analyzed with anti-sweet potato F₁ATPase antibody reacting with all the subunits except the -subunit. Sweet potato root poly(A)⁺RNA directed the synthesis of six polypeptides which were immunoprecipitated by the antibody: two of them immunologically related to the -subunit and the others to the - and -subunits. We conclude that the -subunit of the F₁ATPase is synthesized only in the mitochondria and the -, - and -subunits are in the cytoplasm.     

Tumor necrosis factor α modifies resistance to interferon α in vivo: First clinical data

Summary Patients with Philadelphia-positive chronic-phase chronic myelogenous leukemia (CML) resistant to interferon (IFN) were treated in a phase I/II study with recombinant human tumor necrosis factor to overcome IFN resistance. Doses of 40, 80, 120 or 160 µg/m² TNF were given as 2-h infusions on 5 consecutive days every 3 weeks. IFN (4 × 10⁶ IU/m² s.c., daily) treatment was continued. Six patients were treated, completing 1–24 (median, 12) treatment cycles. Five of the six patients achieved partial hematological remission, while the remaining patient had to stop treatment because of WHO grade 4 thrombocytopenia following the first TNF cycle. No complete hematologic remission or cytogenetic improvement was seen. Side-effects were similar to those described for both substances alone. Maximum tolerable TNF doses usually varied between 80 µg/m² and 160 µg/m². To examine possible pathways of TNF activity in these patients, interferon receptor status and (2–5)-oligoadenylate synthetase levels were examined in peripheral blood mononuclear cells. Both parameters remained unchanged during TNF treatment. These preliminary data point to significant clinical efficacy of additionally applyed TNF in IFN-resistant CML patients.     

Interactions of Aβ(1–40) with Glycerophosphocholine and Intact Erythrocyte Membranes: Fluorescence and Circular Dichroism Studies

Deposition of amyloid peptide in human brain in the form of senile plaques is a neuropathological hallmark of Alzheimers disease (AD). Levels of a phospholipid breakdown product, glycerophosphocholine (GPC), also increase in AD brain. The effect of GPC on amyloid (1–40) peptide (A) aggregation in PBS buffer was investigated by circular dichroism and fluoresence spectroscopy; interactions of A and GPC with the intact erythrocyte membrane was examined by fluoresence spectroscopy. Fluorescamine labeled A studies indicate GPC enhances A aggregation. CD spectroscopy reveals that A in the presence of GPC adopts 14% more -sheet structure than does A alone. Fluorescamine anisotropy measurements show that GPC and A interact in the phospholipid head-group region of the erythrocyte membrane. In summary, both soluble A and GPC insert into the phospholipid head-group region of the membrane where they interact leading to -sheet formation in soluble A which enhances A aggregation.     

ε-caprolactam,a new powerful inducer for the formation of Rhodococcus rhodochrous J1 nitrilase

We found that -caprolactam is a new powerful inducer for the formation of Rhodococcus rhodochrous J1 nitrilase. When Rhodococcus rhodochrous J1 cells were cultivated at 28°C for 120 h in a nutrient medium supplemented with 0.5% (w/v) -caprolactam, an enormous amount of nitrilase was formed in the cells which corresponded to approximately 30% of all soluble protein. The level of -caprolactam in the culture broth barely decreased in the course of cultivation. -Butyrolactam and -valerolactam also caused effective induction. The induction of nitrilase formation by -caprolactam was also observed in some other Rhodococcus strains.     

Inheritance of resistance to the bean-pod weevil (Apion godmani Wagner) in common beans from Mexico

The bean-pod weevil (BPW), Apion godmani Wagner, often causes heavy losses in crops of common bean (Phaseolus vulgaris L.). Farmers need resistant bean cultivars to minimize losses, cut production costs, stabilize seed yield, and reduce pesticide use and consequent health hazards. To design effective breeding methods, breeders need new and better sources of resistance and increased knowledge of their modes of inheritance. We therefore: (1) compared sources of resistance to BPW, (2) studied the inheritance of resistance, and (3) determined whether the sources possess similar or different genes for BPW resistance. The following sources of resistance, originating from the Mexican highlands, were evaluated for 3 years at INIFAP-Santa Lucía de Prias, Texcoco, Mexico: Amarillo 153, Amarillo 169, Hidalgo 58, J 117, Pinto Texcoco, Pinto 168, and Puebla 36. All except Puebla 36 were crossed with the susceptible cultivar Jamapa. Amarillo 153 and Puebla 36 were crossed with another susceptible cultivar, Bayo Mex. The parents, F₁ hybrids, and F₂ populations were evaluated for BPW damage in 1992. Backcrosses of the F₁ of Jamapa/Pinto 168 to the respective susceptible and resistant parents were also evaluated in 1992. All seven resistant accessions were crossed in all possible combinations, excluding reciprocals. The resulting 21 F₁ hybrids and 21 F₂ populations were evaluated for BPW damage in 1994. J 117 had the highest level of resistance to BPW. Pinto Texcoco and Puebla 36 had the highest mean damage score of all seven sources of resistance. The F₁ hybrids between susceptible parents and resistant sources were generally intermediate. Two genes segregating independently controlled the BPW resistance in each accession. One gene, Agm, has no effect when present alone, whereas the other gene, Agr, alone conferred intermediate resistance. When both genes were present, resistance to BPW was higher. Based on mean BPW damage scores, all 21 F₁ hybrids and their F₂ populations, derived from crosses among seven resistant accessions, were resistant. However, data from individual plant damage scores in F₂ populations of Amarillo 169/Pinto 168 and Pinto Texcoco/Pinto 168 suggested that at least one gene in each of the three accessions was non-allelic. Data also indicated that Amarillo 169 had a dominant gene that conferred high levels of BPW resistance, irrespective of the alleles at the other locus; and that Pinto Texcoco and Pinto 168 possessed two different genes for intermediate resistance.     

The effect of monoterpenes on astaxanthin production by a mutant ofPhaffia rhodozyma

Summary The total pigment and astaxanthin content ofPhaffia rhodozyma increased with increasing concentrations -pinene up to 500 l -pinene/l. Above this concentration the total pigment and astaxanthin content as well as the biomass production decreased. The addition of 500 l -pinene/l increased the total pigment content from 1652 g/g to 2201 g/g and the astaxanthin content from 1554 g/g to 1883 g/g. A sharp decrease in maximum specific growth rate occurred above 150 l -pinene/l.     

Variations in the rate of synthesis of beta and beta'' RNA polymerase polypeptides under the influence of certain factors.

Summary In merodiploid cells containing a double dose of structural genes of RNA polymerase subunits-rpoBand rpoC-the rate of and subunits synthesis is 2 times higher than in haploidcells. Missence mutation rpoC1 (tsX) alters polypeptide and inducesthe and subunits synthesis at increased rate, particularly at a nonpermissive temperature. When rpoBCoperon carrying mutation rpoC1 is duplicated no dosage effect is observed. In the rpoC ⁺/rpoC1 heterodiploid the rpoC1 mutation does not significantly accelerate RNA polymerase subunits synthesis i.e. is recessive with respect to rpoC ⁺ Rifampicin causes 6-fold stimulation of RNA polymerase subunits synthesis in a sensitive wild-type strain. The rpoC1 mutation itself accelerates the synthesis of these subunits 3-fold. In the presence of rifampicin the mutant strain produces 13–22-fold faster as compared to wild-type strain without the drug. Thus, the effects of rifampicin and the mutation are multiplied suggesting that these factors act independently. Similar data have also been obtained with rifampicin-treated cells of rpoB22 (ts22) amber-mutant.After UV-irradiation of cells and synthesis is depressed much stronger than the total protein synthesis. Infection with a transducing phage rif ^d-47 which carries rpoB gene provokes a higher rate of synthesis. When pre-irradiated cells (500 erg/mm²) are infected with this phage, the rate of synthesis grows 20-fold compared to irradiated, non-infected cells and 6.5-fold compared to intact cells.The data are discussed in terms of the possible regulatory mechanisms of RNA polymerase subunit synthesis.     

Memorization and delayed expression of regulatory messages in plants

Plantlets of Bidens pilosus L., considered to be basically symmetrical, can be lateralized (A/B) by being administered a symmetry-breaking signal such as puncturing one of the plant cotyledons. The induced asymmetry remains latent as long as the plants have not been made permissive, i.e. as long as the plant apex is left functioning. When the apex has been removed (plant decapitation), the latent asymmetry is expressed by one of the cotyledonary buds (a/b) statistically beginning to elongate before the other. The interval of time between delivering the symmetry-breaking signal and making the plant permissive is the memorization-time, t. Memorization can be quantified by using a precedence index, q, the values of which range from 0 (no detectable asymmetry with regard to bud growth) to ±1 (bud growth perfectly asymmetric in favour of either bud b or a). Even for memorization times, t, up to 14 d, q-values up to 0.4 (or even larger) are observed. Various experimental characteristics (e.g. light, temperature, presence or absence of the root system) but not the plant age can affect the q-values, at the moment when the treatments are performed, at least in the range of 6 to 25 d. Combining several puncturing treatments either increases or decreases the q-values, depending on the nature of these treatments and the time-intervals, t, between them. Symmetrically removing both cotyledons in the minutes following the puncturing of one of them does not significantly alter the results, which means that the symmetry-breaking message is rapidly transported and memorized within the plant. Non-traumatic asymmetrical treatments (droplets of saline solutions, light-gradients) can also act as symmetry-breaking signals and be memorized. Plants other than Bidens are likely to possess similar memorization ability, although the q-values observed up to now have not been very large.     

Evidence that α-dihydrograyanotoxin II does not bind to the sodium gate

Summary The basis for the ability of -dihydrograyanotoxin II (-2HG-II) to promote Na⁺ conductance in axons was sought. The apparent binding of tritiated -2HG-II to neural and other preparations was studied, using equilibrium dialysis, with lobster axon membranes,Torpedo electroplax, housefly head, and rat brain, liver and kidney. In every case the binding was nonsaturating and was suggested to involve nonspecific partitioning into the tissue. Supporting evidence was the similarity of extent of binding in all tissues and its relative insensitivity to neuropharmacological agents. -2HG-II did not affect the Na⁺ conductance of phospholipid bilayers, nor did it permit transport of²²Na into a bulk organic phase. It was concluded that -2HG-II did not bind to the sodium gate, but possibly to a sodium permease present at a frequency of less than one per ² of cell membrane.     

Effect of 17β-estradiol on calcium response to phytohaemagglutinin in human lymphocytes

Pre-treatment of human lymphocytes with 17-estradiol diminishes the increase in concentration of cytosolic free calcium after stimulation with phytohaemagglutinin. The effect is dependent on 17-estradiol concentration and on the preincubation time. The effect is not due to an interaction between 17-estradiol and phytohaemagglutinin, but appears to be a consequence of the binding of the hormone to the cell surface. The effect is specific for 17-estradiol, since the isomer and other steroid hormones (progesterone, testosterone, diethylstilbestrol and 5-androstan), have no effect. Since the effect of the 17-estradiol can be suppressed by treatment of lymphocytes with ouabain, it appears that the effect of estradiol on the rise of cytosolic calcium induced by phytohaemagglutinin is mediated by the (Na, K)-ATPase.     

Transglycosylation reactions by exoglycosidases from the termite Macrotermes subhyalinus

The ability of four exoglycosidases (-galactosidase, -glucosidase, -glucosidase and invertase) from the termite Macrotermes subhyalinus to catalyse tranglycosylation reactions was tested using lactose, cellobiose, maltose and sucrose as glycosyl donors and 2-phenylethanol as glycosyl acceptor. The experimental conditions were optimized in relation to the time course of the reaction, pH and concentrations of glycosyl donor and acceptor. Whereas the hydrolytic activity was largely predominant over the transferase activity with -galactosidase and -glucosidase, the transglycosylation activity represented 68% with -glucosidase. In addition, as demonstrated by the transglycosylation product formed, the hydrolysis of sucrose was catalysed by -glucosidase and not by invertase. On the basis of this work, -glucosidase from M. subhyalinus appears to be a valuable tool for the preparation of neoglycoconjugates.     

Identification of a complete set of isogenic wheat/rye D-genome substitution lines by means of Giemsa C-banding

Summary A complete set of isogenic wheat/rye D-genome substitutions were produced by crossing an inbred line of spring rye Secale cereale L. cv. Prolific to a tetraploid wheat, the A-and B-genomes of which had previously been extracted from hexaploid wheat, Triticum aestivum L. em Thell. cv. Thatcher. After chromosome doubling, the derived hexaploid triticale (x Triticosecale Wittmack) was backcrossed to 6x Thatcher and selection for wheat/rye substitution lines was carried out in BCF₃ to BCF₆ families by using Giemsa C-banding. Five fertile disomic wheat/rye D-genome substitution lines were obtained and their chromosomal constitution was determined to be 1D/1R, 2D/2R, 7D/4R, 6D/6R, 7D/7R. The two remaining 3R and 5R substitutions are at the moment in a monosomic condition. Another 1D/7R substitution was detected but this plant was very weak and sterile, indicating that only substitutions between homoeologous chromosomes result in fertile, vigorous plants. Furthermore, many rye telocentrics as well as rye-rye and rye-wheat translocations were selected. Since all lines selected in this program share the same genetic background of Thatcher wheat, genetic heterogeneity is excluded. The material is very useful, therefore, for analyzing the effects of different rye chromosomes or chromosome segments in an otherwise homozygous background.Contribution No. 797     

Effect of liquid culture on the growth and development of miniature rose (Rosa chinensis Jacq. ‘Minima’)

The growth of miniature rose (Rosa chinensis Jacq. Minima) shoots cultured on liquid medium was greater relative to those cultured on two-phase (solid + liquid) medium or solid medium alone. Shoot multiplication ratio (number of multiple shoots per explant per subculture) on liquid medium was higher with 17.8–26.6 M 6-benzyladenine at compared to that at 0–8.9 M. Shoots grown on 30 ml or more of liquid medium had a higher multiplication ratio than those grown on 10 or 20 ml. The growth and multiplication ratio increased when the culture period was extended from 3 to 6 weeks, although plantlets began to exhibit some chlorosis by the 6^th week. These conditions were maintained over four subcultures for cultivars Baby Katie, Lavender Jewel, Red Sunblaze and Royal Sunblaze, with no significant change in multiplication ratio over time.Abbreviations BA 6-benzyladenine - NAA 1-naphthaleneacetic acid     

The relation of proton motive force,adenylate energy charge and phosphorylation potential to the specific growth rate and efficiency of energy transduction inBacillus licheniformis under aerobic growth conditions

The magnitude of the proton motive force (p) and its constituents, the electrical () and chemical potential (-ZpH), were established for chemostat cultures of a protease-producing, relaxed (rel ^–) variant and a not protease-producing, stringent (rel ⁺) variant of an industrial strain ofBacillus licheniformis (respectively referred to as the A- and the B-type). For both types, an inverse relation of p with the specific growth rate was found. The calculated intracellular pH (pH_in) was not constant but inversely related to . This change in pH_in might be related to regulatory functions of metabolism but a regulatory role for pH_in itself could not be envisaged. Measurement of the adenylate energy charge (EC) showed a direct relation with for glucose-limited chemostat cultures; in nitrogen-limited chemostat cultures, the EC showed an approximately constant value at low and an increased value at higher . For both limitations, the ATP/ADP ratio was directly related to .The phosphorylation potential (G'p) was invariant with . From the values for G'p and p, a variable H⁺/ATP-stoichiometry was inferred: H⁺/ATP=1.83+0.52µ, so that at a given H⁺/O-ratio of four (4), the apparent P/O-ratio (inferred from regression analysis) showed a decline of 2.16 to 1.87 for =0 to _max (we discuss how more than half of this decline will be independent of any change in internal cell-volume). We propose that the constancy of G'p and the decrease in the efficiency of energy-conservation (P/O-value) with increasing are a way in which the cells try to cope with an apparent less than perfect coordination between anabolism and catabolism to keep up the highest possible with a minimum loss of growth-efficiency. Protease production in nitrogen-limited cultures as compared to glucose-limited cultures, and the difference between the A- and B-type, could not be explained by a different energy-status of the cells.Abbreviations CCCP carbonylcyanide-p-trichloromethoxyphenylhydrazone - DW dry weight of biomass - F Faraday's constant, 96.6 J/(mV × mol) - Fo chemostat outflow-rate (ml/h) - FCCP carbonylcyanide-p-trifluoromethoxyphenylhydrazone - G'p phosphorylation potential, the Gibbs energy change for ATP-synthesis from ADP and P_i - G'⁰p standard Gibbs energy change at specified conditions - H⁺/ATP number of protons translocated through - ATP synthase in synthesis of one ATP - H⁺/O protons translocated during transfer of 2 electrons from substrate to oxygen - specific growth rate (1/h) - _H+ transmembrane electrochemical proton potential, J/mol - M_b molar weight (147.6 g/mol) of bacteria with general cell formula C_6.0H_10.8O_3.0N_1.2 - pH_out,in extracellular, intracellular pH - P_i (intracellular) inorganic phosphate - p proton motive force, mV - pH transmembrane pH-difference - transmembrane electrical potential, mV - P/O number of ADP phosphorylated to ATP upon reduction of one O^2– to H₂O by two electrons transferred through the electron transfer chain - P/O (H⁺/O) × (H⁺/ATP)^–1 - P/O_F, P/O_N P/O with the two electrons donated by resp. (NADH + H⁺) and FADH - q specific rate of consumption or production (mol/g DW × h) - rel ⁺,rel ^– stringent, relaxed genotype - R universal gas constant, 8.36 J/(mol × degree) - T absolute temperature - TPMP⁺ triphenylmethylphosphonium ion - TPP⁺ tetraphenyl phosphonium ion - Y growth yield, g DW/mol - Z conversion constant=61.8 mV for 310 K (37 °C) - ZpH transmembrane proton potential or chemical potential, mV     

Proteolysis alters the spectral properties of 124 kdalton phytochrome from Avena

Native phytochrome from Avena sativa L. is homogeneous with a monomeric molecular weight of 124 kdalton; 6–10 kdalton larger than the heterogeneous 120 kdalton preparations previously considered to be undegraded (Vierstra and Quail, 1982, Proc. Natl. Acad. Sci. USA, 79: 5272–5276). The phototransformation difference spectrum (Pr-Pfr) of 124 kdalton phytochrome measured in crude extracts has a minimum in the farred region at 730 nm, the same as that observed in vivo. These spectral properties contrast with those of 120 kdalton phytochrome purified by column immunoaffinity chromatography where the difference minimum is at 724 nm. When 124 kdalton phytochrome is incubated as Pr in crude extracts, the difference minimum shifts progressively to shorter wavelengths (from 730 to 722 nm) concomitant with the proteolytic degradation of the chromoprotein to the mixture of 118 and 114 kdalton species that comprise 120 kdalton phytochrome preparations. These two effects are inhibited in concert by the serine protease inhibitor, phenylmethylsulfonylfluoride, and or maintenance of the phytochrome in the Pfr form. These results provide further evidence that 124 kdalton phytochrome is the native molecule in Avena and indicate that the peptide segments removed by proteolysis of the Pr form are important to the pigment's spectral integrity. The present data thus resolve the previously unsettled question of why the Pfr form of 120 kdalton phytochrome isolated by various procedures from Avena has been found to absorb at shorter wavelengths than that observed in vivo. Previous spectral studies with 120 kdalton phytochrome preparations are open to reexamination.Abbreviations, symbols PMSF phenylmethylsulfonylfluoride - SDS-PAGE sodium dodecyl sulfate polyacrylamide gel electrophoresis - Ig immunoglobulin - A_minimum, A_maximum phototransformation difference spectrum (Pr-Pfr) minimum and maximum - A_r/A_fr ratio spectral change ratio     

Purification and characterization of aspartate aminotransferase from developing embryos of the camel tick Hyalomma dromedarii

Aspartate transaminase (AST) activity in the camel tick Hyalomma dromedarii was followed throughout embryogenesis. During purification of AST to homogeneity, ion exchange chromatography lead to four separate forms (termed I, II, III and IV). AST II with the highest specific activity was pure after chromatography on Sephacryl S-300. The molecular mass of AST II was 52KDa for the native enzyme, composed of one subunit of 50KDa. AST II had a Km value of 0.67mM for -ketoglutarate and 15.1mM for aspartate. AST II had a pH optimum of 7.5 with heat stability up to 50°C for 15min. The enzyme was activated by MnCl₂, and inhibited by CaCl₂, MgCl₂, NiCl₂, and ZnCl₂.     

Polymorphism of the HLA DR1 haplotype in the Israeli population investigated at the serological,cellular, and genomic levels

In the present report, we used serological, cellular, and restriction fragment length polymorphism (RFLP) to investigate the DR1 haplotype in the Israeli population. We describe an Israeli homozygous typing cell (HTC), HLA-DwLVA, which defines a new lymphocyte-activating determinant associated with Bw65, DR1 and distinct from Dwl. The parents of this donor, non-Ashkenazi Algerian Jews, are first cousins and share HLA-Cw8, Bw65, BfS, DR1, DQw1, DPw4. No specificity could be assigned to HLA-DwLVA using the 91 Ninth Workshop HTCs. Two families and forty unrelated DR1 individuals were studied with DwLVA and a panel of DR1/Dw1 HTCs. HLA-DwLVA showed segregation as a single determinant within families. This new specificity was present in 24 out of 40 (60%) unrelated DR1 individuals, indicating that in the Israeli population DwLVA is the main lymphocyte-defined determinant associated with the serologically defined DRI specificity, in contrast to non-Jewish Caucasoids where DR1 is significantly associated with Dw1. The vast majority of DwLVA-positive carriers were also Bw65 carriers, indicating that Bw65, DR1, DwLVA may represent a typical allele combination in the Israeli population. The RFLP analysis established the correlation of certain RFLPs with Dw1 and DwLVA. In addition, we describe a cluster of RFLPs that may correspond to a new Dw subtype associated with DR1, for which no serological and cellular reagents have been described so far.     

Meiotic studies ofElymus nutans andE. jacquemontii (Poaceae,Triticeae) and their hybrids withPseudoroegneria spicata and seventeenElymus species

Hybridizations ofElymus nutans andE. jacquemontii were carried out with one species ofPseudoroegneria (S genome), and 20Elymus species, each containing either of the SH, SY, SYH, or SYW genomes. Chromosome configurations were analysed at metaphase I of the two target taxa and their interspecific hybrids. It is concluded that (i)E. nutans is an allohexaploid containing the SYH genomes, andE. jacquemontii is an allotetraploid having the SY genomes; (ii) the genomic affinity is associated with the geographic distance between the species studied; (iii) minor genomic structural rearrangements have occurred within the hexaploid taxon ofE. nutans.     

Adrenergic regulation of ion transport by primary cultures of canine tracheal epithelium: Cellular electrophysiology

Summary We examined the effect of adrenergic agents on the cellular electrical properties of primary cultures of canine tracheal epithelium. Both isoproterenol and epinephrine stimulated Cl secretion, as evidenced by an increase in transepithelial voltage and a fall in transepithelial resistance. Moreover, both agents appear to increase the conductance of apical and basolateral membranes. However, the pattern of response was different. Isoproterenol initially depolarized apical voltage _a and decreased the fractional resistance of the apical membranef _R. These changes are consistent with an initial increase in apical Cl conductance. In contrast, epinephrine acutely hyperpolarized _a and increasedf _R, changes consistent with an initial increase in basolateral K conductance. Following the acute effect of epinephrine, _a depolarized andf _R decreased to values not significantly different from those observed with isoproterenol. The acute increase in basolateral K conductance produced by epinephrine appeared to result from stimulation of adrenergic receptors because it was reproduced by addition of the agonist phenylephrine, and blocked by the antagonist phentolamine. The ability of prazosin but not yohimbine to block the acute epinephrine-induced increase in K permeability indicates the presence of ₁ adrenergic receptors. The acute adrenergic-induced increase in basolateral K conductance may be mediated by an increase in cell Ca because the response was mimicked by addition of the Ca ionophore A23187. In contrast, the response to isoproterenol was similar to that observed with addition of 8-bromo-cAMP and theophylline. These results indicate that both and adrenergic agents mediate the ion transport processes in canine tracheal epithelium. adrenergic agents have their primary effect on the apical Cl conductance, probably via an increase in cAMP. adrenergic agents exert their primary effect on the basolateral K conductance, possibly via an increase in cell Ca.     

Synthesis of an H type 2 and a Y (Ley) glycoside from thioglycoside intermediates

The trisaccharide 2-(p-trifluoroacetamidophenyl)ethyl 2-acetamido-2-deoxy-4-O-[2-O-(-l-fucopyranosyl)--d-galactopyranosyl]--d-glucopyranoside 1 and the tetrasaccharide 2-(p-trifluoroacetamidophenyl)ethyl 2-acetamido-2-deoxy-3-O-(-l-fucopyranosyl)-4-O-[2-O-(-l-fucopyranosyl)--d-galactopyranosyl]--d-glucopyranoside 2 were synthesized. Thioglycosides, suitably protected, activated directly with methyl trifluoromethanesulfonate or dimethyl(methylthio)sulfonium tetrafluoroborate or activated after bromine treatment with halophilic reagents, were used as glycosyl donors in the construction of the glycosidic linkages.Abbreviations DMTSB dimethyl(methylthio)sulfonium tetrafluoroborate - Phth phthaloyl - MBn p-methoxybenzyl - ClBn p-chlorobenzyl