Data on the composition and structure of the O-specific polysaccharides (O-antigens) of the lipopolysaccharides of the genus Proteus are summarized and discussed as the molecular basis for serotyping of these medically important bacteria.

The mode of coordination of the complexes formed in the systems Cu/spermine/nucleoside (or nucleotide) was proposed on the basis of the equilibrium and spectral studies. Significant differences were found in the coordination character of nucleosides and nucleotides. In the systems with adenosine or cytidine, mixed-ligand complexes are formed with the N5 type coordination. On the other hand, in the systems with their monophosphates, molecular complexes are formed with metal ions coordinated through oxygen atoms from the phosphate groups. Spermine, left outside the inner coordination sphere, is involved in non-covalent interactions with nitrogen atoms from the nucleotide bases.

A synthetic procedure has been developed for the preparation of new salen (2,2'- [1,2-ethanediyl bis (nitriloethylidyne)] bis (1-naphthalenol)). The thermodynamics and kinetics of complexation reaction between the new salen and Cu²⁺ ion were investigated spectrophotometrically in different dimethylsulfoxide-acetonitrile mixtures. Formation constant of the resulting 1:1 complex was determined from the absorbance-mole ratio data and found to increase with increasing acetonitrile content of the solvent mixtures. Enthalpy and entropy data for complexation were determined from the temperature dependence of the formation constant. In all solvent mixtures, the salen–copper complex is entropy stabilized but enthalpy destabilized. Order of reaction, rate constants and activation parameters for the complexation reaction in different solvent mixtures were also investigated. The Arrhenius plots showed a distinct isokinetic temperature at about 88°C, at which the reaction rate is approximately independent of the solvent composition. Activation parameters are strongly solvent dependent.

Computer analysis of potentiometric titration data was applied for determination of stability constants of Cd(II) and Hg(II) complexes in binary systems with polyamines (PA), nucleosides (Nuc) and nucleotides (NMP). For the systems of Hg(II) and PA an untypical increase in the complex stability with increasing ring size was observed and interpreted as the mercury preference to formation of linear complexes. Results of the potentiometric and 13C NMR studies for the complexes of both metals indicate the involvement of all donor nitrogen atoms of di- and triamines in the coordination, leading to formation of N2 and N3 type chromophores, respectively. Monodentate complexes of Hg(II) with Cyd are formed already at very low pH (complexes with Cd from pH of about 4). In the systems with AMP apart from nitrogen donor atoms, also the phosphate groups are involved in coordination. In the solid complexes of Cd(II) and Hg(II) with PA all donor atoms from the polyamines were found to be involved in the coordination and the presence of nitrate ions was established both in the inner and in the outer coordination spheres.

The synthesis of glycosphingolipid Lewis Y (1) could be efficiently carried out, based on the connection of building blocks 2–7. Reaction of fucosyl donor 2 with azidoglucose derivative 4 as acceptor gave a(1–3)-linked disaccharide 8, which was transformed to acceptor 9; ensuing reaction with galactosyl donor 3 furnished Lewis X trisaccharide derivative 10. This compound could be transformed into the LeY hexasaccharide 16 either via transformation into glycosyl donor 12, connection with lactose moiety 5, and then reaction with fucosyl donor 2a, or, alternatively by transformation of 10 into acceptor 18, reaction with fucosyl donor 2, and then attachment of lactose moiety 5. Application of the azidosphingosine glycosylation procedure to 16, i.e. first transformation into O-acyl protected hexaosyl donor 33, then reaction with azidosphingosine 6 and fatty acid (7), and finally O-acyl deprotection, afforded target molecule 1 in high purity.

Synthesis of mono- and ditrityl ethers of mannobiosides and mannotriosides as precursors for higher mannooligosaccharides is described. Advantage is taken of selective glycosylation of primary-secondary ditrityl ethers and selective removal of O-acetyl protective groups in the presence of O-benzoyl protective groups.

Per(6-bromo-6-deoxy)cyclomalto-hexaose, -heptaose, and -octaose and the corresponding per(6-chloro-6-deoxy) derivatives were prepared in high yield by reaction of bromomethylenemorpholinium bromide or chloromethylenemorpholinium chloride, respectively, with cyclomaltohexaose, cyclomaltoheptaose and cyclomaltooctaose in dimethylformamide.

A new direct route to the stereospecific construction of aglycosides and adisaccharides of ulosonic acids is presented. Addition reaction of alcohols and/or "sugar alcohols" to the quaternary double bond of sugar ketene dithioacetal 1 mediated by trimethylsilyl triflate led to the corresponding O-glycosides. Subsequent hydrolysis of dithianyl residue afforded the title compounds.

The methodology for the preparation of various derivatives of sucrose modified at C1', C6, and C6'-positions is presented. 6-Amino-, 6'-amino-, and 6,6'-diamino-penta-O-benzylsucroses (16, 17 and 18 respectively), as well as appropriate uronic acids (characterized as methyl esters: 19–22), have been obtained from 2,3,4,3'4'-penta-O-benzyl-sucrose (1). The usefulness of this approach was exemplified by the preparation of 1'-O-benzyloxymethyl-6-deoxy-6-C-(2-furyl)-2,3,4,3'4'-penta-O-benzylsucrose (26).

1,3,4-Tri-O-acetyl-2,6-anhydro-2-thio-D-manno- and -D-altropyranose as well as 1,4-di-O-acetyl-2,6-anhydro-3-azido-3-deoxy-2-thio-D-mannopyranose were synthesized and used as donors in the synthesis of the corresponding 4-cyano- and 4-nitrophenyl-thioglycosides, which showed significant oral antithrombotic activity in rats.

The magnesium hydride based reagent in THF solution is an excellent tool for the stereoselective reduction of different uloside derivatives. Sugar azides, sulfonyl esters give aminosugars and methylose derivatives without affecting other functionalities. Halogenated sugars or methylene derivatives are stable under these conditions. The reagent can be applied in the presence of a wide variety of blocking groups (acetals, benzyl and allyl ethers, imides, C=C bonds) generally used in the carbohydrate chemistry.

N,N'-Bis(methyl 3,4,6-tri-O-acetyl-2-deoxy-b-D-glucopyranosid-2-yl)urea 1 and its N'-nitroso derivative 2 were synthesized from methyl 2-amino-3,4,6-tri-O-acetyl-2-deoxy-b-D-glucopyranoside and di(4-nitrophenyl)carbamate. The nitrosation was carried out using N₂O₃ in dichloromethane. The structure of compounds was analyzed by ¹H , ¹³C, ¹⁵N NMR in CDCl₃ and ¹³C CP MAS in the solid state. The assignments of resonances were done by COSY ¹H, ¹³C, HETCOR and the ¹H, ¹⁵N 2D correlation spectroscopy. Compound 1 gives one set of ¹H/¹³C resonances in solution, but exhibits polymorphism in the solid state.

2-[(2-Acetoxyethoxy)methyl]indazole (3), a kinetic product formed in the reaction of indazole (1) with 2-acetoxyethyl acetoxymethyl ether (2), undergoes an irreversible, acid-catalyzed isomerization of the 2 -> 1 transglycosylation type to the respective 1-regioisomer (4). In contrast to the purine acyclonucleosides series, however, product 4 undergoes a further rearrangement to the dimer 5. On the basis of products distribution and kinetics of their formation, a mechanism of these conversions has been proposed and compared to the facile anomerization reactions of indazole ribofuranosides.

C-13 isotope effect in the decarboxylation of phenylpropiolic acid in diluted aqueous sulphuric acid and in its concentrated solution has been studied in vacuum reaction vessels. The (k₁₂/k₁₃) KIEs are located in the range 1.0042–1.0046 in the temperature interval 90–110^oC in the case of decarboxylation of PPA in H₂SO₄ diluted with water. C-13 KIEs in the decarboxylation of PPA in the concentrated H₂SO₄ were found to be 1.060–1.050 between 16–60^oC. A discussion of the negligible C-13 KIE in the decarboxylation of PPA in diluted aqueous sulphuric acid (1:4/V:V/H₂SO₄:H₂O) has been given and the discussion of the large C-13 KIE, exceeding the values of C-13 KIE calculated for this temperature interval, assuming the "full" C–*C bond rupture in the T.S., has been presented. The kinetic parameters, deduced from the temperature dependence of the absolute rate constants of decarboxylation reaction and the C-13 KIE data, have been interpreted as the result of the loose T.S. in the case of decarboxylation of PPA in aqueous solution of H₂SO₄ and as the result of the "chelate-like" T.S. in the decarboxylation of PPA in concentreted sulphuric acid. The protonation of the triple bond and/or formation of he Ca–H bond are the rate and the C-13 KIE determining processes in 3.75 M H₂SO₄, while in the case of decarboxylation of PPA in concentrated H₂SO₄, the phenylpropiolic acid is fully protonated and the rupture of the C–*C bond, preceded by preequilibria, determines the large C-13 isotope effect observed.