Abstract: The present invention provides a ketoaldonic acid such as an octulosonic or nonulosonic acid having a formed stereogenic center of R configuration, as well as methods of synthesizing the same.

Abstract: This invention provides compositions for inhibiting the binding between two cells, one expressing P- or L-selectin on the surface and the other expressing the corresponding ligand. A covalently crosslinked lipid composition is prepared having saccharides and acidic group on separate lipids. The composition is then interposed between the cells so as to inhibit binding. Inhibition can be achieved at an effective oligosaccharide concentration as low as 106 fold below that of the free saccharide. Since selectins are involved in recruiting cells to sites of injury, these composition scan be used to palliate certain inflammatory and immunological conditions.

Abstract: The present invention is directed to novel compositions and their use in the treatment of inflammatory responses. Specifically, the invention is directed to novel synthetic oligosaccharide constructs and their use to block lymphocyte binding to correspondent oligosaccharides on the endothelial surface, and thus reduce or otherwise ameliorate an undesired inflammatory response. The invention is further directed to the use of such constructs in other disease states characterized by selectin binding, such as bacterial infections and metastatic cancers.

Abstract: Novel substituted liposaccharides useful as in the prophylactic and affirmative treatment of endotoxemia including sepsis, septicemia and various forms of septic shock and methods of using these agents are provided. Also provided are methods of preparing these agents and intermediates useful therein.

Abstract: Derivatives of the K5 polysaccharide having anticoagulant activity higher than heparin, obtained by a process including the steps of reacting: with an organic base a solution of K5 polysaccharide N-deacetylated, N-sulfated and epimerized at least to an iduronic acid content of 50% treating with a sulfating agent to obtain the N-resulfation of the possible N-desulfated groups.

Abstract: A method for the preparation of N-acetyl-D-neuraminic acid (NANA) N-acetyl-D-glucosamine (NAG) is described.

Abstract: The invention relates to carbohydrate mimetics, which inhibit the binding of selectin to carbohydrate ligands, of the formula I ##STR1## excluding the compounds sialyl-Lewis-X and -A and their derivatives which, instead of an N-acetyl group, carry the substituents N.sub.3, NH.sub.2 or OH or which, instead of fucose, carry glycerol,and pharmaceutical compositions and diagnostic agents containing these derivatives, and methods for using these pharmaceutical compositions and diagnostic agents.

Abstract: An unbranched polylactosamine comprising at least 6 monosaccharides and having terminal .alpha.2.fwdarw.3 sialylation and internal .alpha.1.fwdarw.3 fucosylation at various N-acetylglucosamine residues except for solely at the penultimate N-acetylglucosamine residue.

Abstract: The invention relates to compounds of formula Ix and Ia: ##STR1## wherein (Ix) comprises the regioisomeric form sLe.sup.X and (Ia) comprises the regioisomeric form sLe.sup.A, and R.sup.1 is a lipophilic radical formed from aliphatic or cycloaliphatic units, or a sugar residue which is capped by a .beta.1-O-linked aliphatic or cycloaliphatic unit at the reducing end of the terminal sugar. The compounds of the present invention are useful as inhibitors of increased cell-cell adhesion as well as useful in treating diseases associated with increased cell-cell-adhesion. The compounds of the present invention are also incorporated into pharmaceutical compositions.

Abstract: The present invention consists in methods of preparing derivatives either isolation or from glycopeptides or glycoproteins. The methods comprise producing sugar hydrazones, sugar pyrazoles, glycosylpyrazones, azoglycan dyes and hydrazoglycan dyes. The present invention also relates to the removal of O-glycans from glycopeptides or glycoproteins, immobilising reducing sugars onto solid supports and methods to obtain sugars from glycopeptide or glycoprotein comprising subjecting the glycopeptide or glycoprotein to solid-phase Edman degradation followed by separating and characterizing the sugars.

Abstract: A method is provided of inhibiting the narrowing of the vascular tubular walls of an animal by the proliferation of endothelial cells in the area of trauma after the vascular tubular walls have been traumatized, the method comprising the administration of a therapeutically effective non-toxic amount of a form of hyaluronic acid selected from the group consisting of hyaluronic acid and pharmaceutically acceptable salts thereof to the animal to inhibit the narrowing of the vascular tubular walls by the proliferation of endothelial cells into the area of trauma.

Abstract: The invention concerns a novel phosphoglycolipid compound. The compound of the subject invention is 2-Deoxy-6-O-[2-deoxy-4-O-phosphono-3-O-[(R)-3-tetradecanoyloxytetradecanoy l]-2-[(R)-3-octadecanoyloxytetradecanoylamino]-.beta.-D-glucopyranosyl]-2-[ (R)-3-hexadecanoyloxytetradecanoylamino]-D-glucopyranose and pharmaceutically acceptable salts thereof. The compound is not immunoreactive, not pyrogenic, not toxic but is active in ameliorating tissue damage due to ischemia/reperfusion injury. Methods for using the subject compound to protect against reversible and irreversible damage due to ischemia/reperfusion injury are also disclosed.

Abstract: A process for the preparation of azide derivatives useful as drugs, perfumes or intermediates of dyes by reacting an alcohol derivative with di-p-nitrophenyl phosphorazidate in the presence of 1,8-diazabicyclo[5.4.0]-7-undecene.

Abstract: This invention provides compositions for inhibiting the binding between two cells, one expressing P- or L-selectin on the surface and the other expressing the corresponding ligand. A covalently crosslinked lipid composition is prepared having saccharides and acidic group on separate lipids. The composition is then interposed between the cells so as to inhibit binding. Inhibition can be achieved at an effective oligosaccharide concentration as low as 10.sup.6 fold below that of the free saccharide. Since selectins are involved in recruiting cells to sites of injury, these composition scan be used to palliate certain inflammatory and immunological conditions.

Abstract: Compounds which bind to selectin receptors and thus may modulate the course of inflammation, cancer and related processes by intervening with cell-cell adhesion events. Further, such compounds can be used for identification and analysis of such receptors. In this regard the invention is directed to compounds of formula (I). ##STR1## wherein R.sup.1 is independently H, alkyl, aryl, an aryl alkyl, alkenyl or one or more additional saccharide residues; R.sup.2 =H or OH provided that when R.sup.2 is H, R.sup.3 is OH; R.sup.3 =H or OH provided that when R.sup.3 is H, R.sup.2 is OH; X=H, SO.sub.3.sup.- or PO.sub.4.sup.- ; Y is independently H, OH, OR.sup.4 or NHCOR.sup.4, wherein R.sup.4 is alkyl, and Z is an organic acid residue. .alpha.-L-Fucose residue can be modified or replaced with suitable bioisosters or a different saccharide residue such as D-mannose. Modification of L-fucose may include replacement of each or all of the hydroxyl groups with H or OR' wherein R' can be methyl, ethyl or allyl groups.

Abstract: The present invention relates to pharmaceutical compositions for the prevention and/or treatment of pathological processes involving the induction of TNF-.alpha. secretion comprising a pharmaceutically acceptable carrier and a low molecular weight heparin (LMWH). In the pharmaceutical compositions of the present invention, the LMWH is present in a low effective dose and is administered at intervals of about 5-8 days. Furthermore, the LMWH is capable of inhibiting in vitro TNF-.alpha. secretion by resting T cells and/or macrophages in response to T cell-specific antigens, mitogens, macrophage activators, disrupted extracellular matrix (dECM), laminin, fibronectin, and the like.

Abstract: The present invention provide a method of inhibiting an irregular binding of human cells caused by specific adhesion of Lewis.sup.x glycolipids by administering any of an oligosaccharide having a Lewis.sup.x sugar chain structure, CMP-sialic acid, and a sialidase inhibitor, into the lens, and an inhibitory agent for this purpose. This make it possible to prevent or improve cataract of the lens caused by aging.

Abstract: A composition of matter comprising a hyaluronate functionalized with a hydrazide at glucuronic acid sites of said hyaluronate, wherein the hydrazide is chosen from a group consisting of: monohydrazide and hydrazides comprising three or more amine groups.

Abstract: An analog of sialic Lewis antigen prepared from native capsular polysaccharide of Klebsiella 63 bacteria.

Abstract: Saccharopeptides and methods of using the novel saccharopeptides are described having the following structural formula I:W--?--Y--W--!.sub.m (I)wherein W is independently one or more saccharide(s); Y is independently --CO--NH-- or --NH--CO--; and m is an integer greater than or equal to one; or structural formula II:W--Y--?W--X--W--Y!.sub.n --W (II)wherein W is independently one or more saccharide(s); S is a difunctional or polyfunctional alkyl, aryl or aralkyl group, lipid, amino acid or peptide capable of covalently joining together said saccharides; Y is independently --CO--NH-- or --NH--CO--; and n is an integer greater than or equal to zero; or formula III:W--Y.sup.1 --X.sup.1 --Y.sup.2 --W (III)wherein W is independently one or more saccharide(s); X.sup.1 is a difunctional or polyfunctional alkyl, aryl or aralkyl group capable of covalently joining together said saccharides; Y.sup.1 is --NH--CO--; and Y.sup.2 is --CO--NH--.

Abstract: A method is provided of preventing arterial restenosis of an animal after the arteries have been traumatized. The method comprises the administration of a therapeutically effective non-toxic amount of hyaluronic acid and/or pharmaceutically acceptable salts thereof to the animal to prevent narrowing of the arteries. The form of hyaluronic acid is selected from hyaluronic acid and pharmaceutically acceptable salts thereof having a molecular weight less than 750,000 daltons.

Abstract: The present invention consists in methods of preparing sugar derivatives either in isolation or from glycopeptides or glycoproteins. The methods comprise producing sugar hydrazones, sugar pyrazoles, glycosylpyrazones, azoglycan dyes and hydrazoglycan dyes. The present invention also relates to the removal of O-glycans from glycopeptides or glycoproteins, immobilizing reducing sugars onto solid supports and methods to obtain sugars from a glycopeptide or glycoprotein comprising subjecting the glycopeptide or glycoprotein to solid phase Edman degradation followed by separating and characterizing the sugars.

Abstract: Compounds of the formulae I and II ##STR1## are suitable for the suppression of tumor growth and of tumor metastasis.

Abstract: A process for the purification of opacifying contrastographic agents, comprising chromatographic and nanofiltration techniques combined together, the subsequent chromatographic separation of the crude product solution and a nanofiltration step, with a final deionization on ion exchange resins.

Abstract: The present invention relates to analogues of sialyl Le.sup.x the inhibit cellular adhesion between a selectin and cell that express sialyl Le.sup.x on their surfaces, as well as methods and compositions using the same, intermediates and methods for the preparation of the celluar adhesion inhibitor compounds and their intermediates. A contemplated intermediate or inhibitor compound has a structure that corresponds to that of Formula A, ##STR1## wherein: Z is selected from the group consisting of hydrogen, C.sub.1 -C.sub.

Abstract: Aliphatic Nitrate esters having a sulfur or phosphorus atom .beta. or .gamma. to a nitrate group having efficacy as vasodilators are described. Preferred nitrate esters may be synthesized by nitration of a 3-bromo-1,2-propanediol, and subsequent reaction to yield the desired mono, di or tetra nitrate ester.

Abstract: Semisynthetic analogues of gangliosides selected from the group consisting of N-sulfo-, N-hydrocarbyl-sulfonyl- and N-hydrocarbyloxy-sulfonyl-N,N'-dilyso-gangliosides and the N'-acyl derivatives thereof, N'-sulfo-, N'-hydrocarbylsulfonyl- and N'-hydrocarbyloxy-sulfonyl-N,N'-dilyso-gangliosides and the N-acyl derivatives thereof, N,N'-di or polysulfo-N,N'-di- or poly-lyso-gangliosides, N,N'-di- or polyhydrocarbylsulfonyl-N,N'-di- or poly-lyso-gangliosides and N,N'-di- or polyhydrocarbyloxy-N,N'-di- or poly-lyso-gangliosides, and functional derivatives thereof, and salts of these compounds, have protective activity against neurotoxicity induced by excitatory amino acids and are foreseen to be used in therapy in the nervous system and in modulating of the expression of determinants such as CD.sub.4 on the surface of human cells in the immune system.

Abstract: The present invention relates to an organic solvent-soluble mucopolysaccharide consisting of an ionic complex of at least one mucopolysaccharide (preferably heparin or heparin derivative) and a quaternary phosphonium, an antibacterial antithrombogenic composition comprising said organic solvent-soluble mucopolysaccharide and an organic polymer material, an antibacterial antithrombogenic composition comprising said organic solvent-soluble mucopolysaccharide and an antibacterial agent (preferably inorganic antibacterial agent such as silver zeolite), and to a medical material comprising said organic solvent-soluble mucopolysaccharide.

Abstract: A Lewis-associated compound, represented by general formula (I), a process for producing the same, and an anti-inflammatory, wherein R.sup.1 and R.sup.3 represent each hydrogen, m SO.sub.3 H or CH.sub.2 COOH; R.sup.2 represents hydrogen, SO.sub.3 H, CH.sub.2 COOH or N-acetyl-neutraminic acid residue; R.sup.4 represents hydrogen; R.sup.5 represents O-lower alkyl, O-lower alkenyl, O-ceramide residue, O-mannose residue, O-galactose residue or O-lactose residue; R.sup.6 represents acetylamine; and R.sup.7 and R.sup.8 represent each hydrogen.

Abstract: The present invention is directed towards compositions and methods for reducing or controlling inflammation and for treating inflammatory disease processes and other pathological conditions mediated by intercellular adhesion. The compositions of the invention include compounds that selectively bind selectin receptors, the selectin binding activity being mediated by a carbohydrate moiety. The selectin-binding moieties of the invention are derivatives of a sialylated, fucosylated N-acetyllactosamine unit of the Lewis X antigen. Compounds containing a selectin-binding moiety in both monovalent and multivalent forms are included in the invention. The compounds of the invention are provided as pharmaceutical compositions which include, for example, liposomes that carry selectin-binding moieties of the invention. The invention further includes immunoglobulins capable of selectively binding an oligosaccharide ligand that is recognized by a selectin receptor.

Abstract: Novel substituted liposaccharides useful as in the prophylactic and affirmative treatment of endotoxemia including sepsis, septicemia and various forms of septic shock and methods of using these agents are provided. Also provided are methods of preparing these agents and intermediates useful therein.

Abstract: This invention relates to compounds prepared by linking glycosaminoglycan to phospholipid or lipid, which are expected to exert a pharmacological effect for inhibiting metastasis because of their excellent function to inhibit adhesion of cancer cells to blood vessel endothelial cells and extracellular matrix. This phospholipid- or lipid-linked glycosaminoglycan can be produced for example by: cleaving and oxidizing reducing terminal group of glycosaminoglycan, and allowing an aldehyde group or a lactone compound of the thus-formed derivative or a carboxyl group in the glycosaminoglycan chain to react with a primary amino group of a phospholipid; or linking a glycosaminoglycan derivative to a phospholipid or a lipid by allowing a primary amino group of the derivative to react with a carboxyl group of the phospholipid or lipid. This phospholipid- or lipid-linked glycosaminoglycan is useful as a metastasis inhibitor because it has no toxicity.

Abstract: Oligosaccharides derived from natural or supersulphated GAGS or their mixtures, with a heparin content less than 1% by wt. having average molecular weight between 2,500 and 15,000 dalton, at least 50% by wt. of said oligosaccharide having a molecular weight in the +20% range in respect of the average molecular weight, providing an exceptional bioavailability and an antithrombin activity equal or higher than the starting GAGS.

Abstract: Aldehyde cationic derivatives of galactose containing polysaccharides which are obtained by oxidizing galactose containing polysaccharides with the enzyme galactose oxidase. The enzyme oxidized products have an aldehyde function at a specific position of the polysaccharide, i.e., the C.sub.6 position, of the galactose unit, and the cationic derivatives thereof have unexpected and significantly improved properties when used as paper strength additives.

Abstract: The present invention relates to methods for the prevention and/or treatment of pathological processes involving the induction of TNF-.alpha. secretion comprising a pharmaceutically acceptable carrier and a low molecular Weight heparin (LMWH). In the pharmaceutical compositions of the present invention, the LMWH present in a low effective dose and is administered at intervals of about 5-8 days. Furthermore, the LMWH is capable of inhibiting in vitro TNF-.alpha. secretion by resting T cells and/or macrophages in response to T cell-specific antigens, mitogens, macrophage activators, disrupted extracellular matrix (dECM), laminin, fibronectin, and the like.

Abstract: Provided are new derivatives of neuraminic acid of formula (I), where Ac represents an acyl residue of an aliphatic, araliphatic, aromatic, alicyclic, or heterocyclic carboxylic acid, including carboxylic amides, their 2-hydrocarbyl-glycosides, and their peracylated derivatives at the hydroxy groups of both these series of amides. These compositions are therapeutically useful in providing a protective effect against the neurotoxicity induced by excitatory amino acids, and can therefore be used in therapies of the central nervous system.

Abstract: Inter and/or intramolecular cross-linked esters of acid polysaccharides are disclosed in which a part or all of the carboxy groups are esterified with hydroxyl groups of the same molecule and/or of different molecules of the acid polysaccharide. These inner cross-linked esters of polysaccharide acids are useful in the field of biodegradable plastic materials, to manufacture sanitary and surgical articles, in the cosmetic and pharmaceutical fields, in the food industry and in many other industrial fields.

Abstract: Disclosed herein is a new cationic starch and cationic starch paste or slurry. The starch paste or slurry has a low cation equivalent value despite its high nitrogen content and also has a low solution viscosity despite its high molecular weight. The cationic starch and cationic starch paste or slurry is formed by substitution with a one or both of quaternary ammonium salt or a tertiary amino group, characterized in that its nitrogen content (X) due to the quaternary ammonium salt and/or tertiary amino group is related to its cation equivalent value (Y) as defined below:Y<0.70097X-0.07978(in the case of natural terrestrial stem starch)Y<0.32936X-0.00495(in the case of natural subterranean stem starch having ester-type substituents)Y<0.40942X+0.

Abstract: A purified lipid A from Rhizobium leguminosarum biovar phaseoli CE3, as well as analogs and derivatives of the purified lipid A are provided. Compositions containing heterogenous mixtures of lipid A from R. leguminosarum bv. phaseoli CE3 are also provided. The lipid A provided herein can be combined with a pharmaceutically acceptable carrier. Methods of stimulating the immune system in a subject, treating or preventing toxic shock in a subject, and methods of treating and preventing a lipopolysaccharide mediated disorder in a subject using the novel lipid A are provided.

Abstract: An ionomer for an ion complex membrane useful for the separation of water-organic solvent by osmosis or low pressure osmosis as well as by pervaporation and a method for producing ion complex membrane therefrom are disclosed. The ionomer for producing ion complex membrane can be prepared by heat polymerization of an alkyl compound having pyridyl groups such as 1,3-di(4-pyridyl) propane at both terminal ends with a dihaloalkane compound such as dibromooctane and dichloroheptane having two halogen atoms at both terminal ends or with one or two halogen atoms affixed to intermediate carbon atoms in a polar solvent such as acrylonitrile. An ion complex membrane can be produced by preparing a membrane of a polycation or polyanion in a solution casting method and dipping the membrane in a solution of polycation or polyanion for 24 hours to give an ion complex membrane. This ion complex membrane may be a single membrane or composite membrane. Composite membrane includes a plain membrane and a hollow fiber membrane.

Abstract: Provided is a biomaterial comprising an interpenetrating polymer network (IPN), wherein one of the polymer components is an acidic polysaccharide or a semi-synthetic derivative thereof. The polysaccharide can be hyaluronic acid, and the second polymer component can be a non-toxic, non-carcinogenic synthetic chemical polymer. The derivative can be a total or partial hyaluronic acid ester or a hyaluronic acid salt. The ester or salt can be formed with a pharmacologically active molecule. Methods for preparing the IPN are also disclosed. The acidic polysaccharide or derivative thereof and the synthetic chemical polymer comprising the IPN can be cross-linked, or the synthetic chemical polymer can be grafted onto the acidic polysaccharide. The cross-linking or grafting can be achieved using compounds capable of generating radicals, or via functional groups on the acidic polysaccharide and the synthetic chemical polymer. The IPN can be formed prior to cross-linking or grafting.

Abstract: The present invention provides a composition of matter comprising a biosynthetic anti-inflammatory oligosaccharide, comprising the structure of: sugar - sugar - X - R; wherein said sugar is selected from the group consisting of N-acetylneuraminic acid, galactose, N-acetylglucosamine, N-acetylgalactosamine, fucose and mannose; wherein X is a bridging atom selected from the group consisting of oxygen, sulfur, nitrogen and carbon; and wherein R is an aglycone selected from the group consisting of naphthol, naphthalenemethane, indenol, a heterocyclic derivative of indenol, a heterocyclic derivative of naphthol and a heterocyclic derivative of naphthalenemethanol. Also provided is a method of treating an inflammatory disease in an individual comprising the step of administering to said individual a therapeutically effective dose of the novel composition of the present invention.

Abstract: Hepatocytes spheroids can be formed by culturing hepatocytes in a culture vessel using a lipid-bound glycosaminoglycan as a culture substrate. Floating spheroids of hepatocytes can be obtained efficiently, which are capable of maintaining liver-specific functions and of keeping the spheroid form stably for a prolonged period of time.

Abstract: Hyaluronate functionalized with dihydrazide is provided and may be cross-linked. A method for producing hyaluronate functionalized with dihydrazide includes mixing hyaluronate and dihydrazide in aqueous solution, then adding carbodiimide so that the hyaluronate and dihydrazide react to form functionalized hyaluronate.

Abstract: The inventive compounds are analogues of sialyl Le.sup.x that inhibit cellular adhesion between a selectin and cells that express sialyl Le.sup.x on their surfaces, and their synthetic intermediates. An inventive compound has structure A, ##STR1## wherein Z is hydrogen, C.sub.1 -C.sub.6 acyl or ##STR2## Y is C(O), SO.sub.2, HNC(O), OC(O) or SC(O); R.sup.1 is an aryl, a substituted aryl or a phenyl C.sub.1 -C.sub.3 alkylene group, wherein an aryl group has one five- or six-membered aromatic ring, a fused five/six-membered aromatic ring, or two fused six-membered aromatic rings, which rings are hydrocarbyl, monooxahydrocarbyl, monothiahydrocarbyl, monoazahydrocarbyl or diazahydrocarbyl rings, and a substituted aryl group is an aryl group having a halo, trifluoromethyl, nitro, C.sub.1 -C.sub.18 alkyl, C.sub.1 -C.sub.18 alkoxy, amino, mono-C.sub.1 -C.sub.18 alkylamino, di-C.sub.1 -C.sub.18 alkylamino, benzylamino, C.sub.1 -C.sub.18 alkylbenzylamino, C.sub.1 -C.sub.18 thioalkyl or C.sub.1 -C.sub.

Abstract: A sulfated acid amide having heparin-like properties of the formula:(R.sub.1)--NH--R--NH--(R.sub.1)whereR.sub.1 is a di-, tri- or tetra-saccharide acid selected from cellobiose, cellotriose, cellotetrose, maltose, maltotriose and maltotetrose or mixtures thereof, andR is an alkylene of from 3 to 12 carbons, and is optionally substituted with one or more hydroxyls.

Abstract: Disclosed are novel Lewis.sup.x and Lewis.sup.a analogues, pharmaceutical compositions containing such analogues, methods for their preparation and methods for their use.

Abstract: Simple lactose or lactosamine related compounds which behave as ligands for the ELAM-1 and related receptors are described. These compounds are useful in the treatment of conditions characterized by excess inflammation. These compounds are of the formula ##STR1## wherein each R.sup.1 is independently H or lower alkyl (1-4C); R.sup.2 is H, lower alkyl (1-4C), alkylaryl or one or more additional saccharide residues;R.sup.3 and R.sup.4 are each independently H, alkyl(1-6C), aryl or R.sup.3 and R.sup.4, taken together, form a five- or six-membered ring optionally containing a heteroatom selected from the group consisting of O, S, and NR.sup.1 ;wherein said five- or six-membered ring may further be substituted by one or more substituents selected from the group consisting of (CHOR.sup.1).sub.m H wherein m is 1-4, OR.sup.1, OOCR.sup.1, NR.sup.1.sub.2, NHCOR.sup.1, and SR.sup.1 ;Y is H, OR.sup.1, OOCR.sup.1, NR.sup.1.sub.2, NCOR.sup.1 or SR.sup.1 ; andX is --CHR.sup.5 (CHOR.sup.1).sub.2 CHR.sup.6 OR.sup.1 wherein R.

Abstract: The present invention relates to bivalent sialyl Lewis X saccharide compounds that inhibit cellular binding to a selectin receptor. Pharmaceutical compositions containing a compound of Formula I, and processes for making and using the same are disclosed. A contemplated bivalent sialyl Lewis X saccharide compound has a structure that corresponds to Formula I, below, ##STR1## wherein R is a directly linked divalent monosaccharide unit; Y is selected from the group consisting of C(O), SO.sub.2, HNC(O), OC(O) and SC(O);R.sup.2 is selected from the group consisting of a C.sub.1 -C.sub.6 hydrocarbyl, an aryl, a substituted aryl and a phenyl C.sub.1 -C.sub.3 alkylene group, wherein an aryl group has one six-membered aromatic ring or two fused six-membered aromatic rings, which ring or rings are hydrocarbyl, monoazahydrocarbyl, or diazahydrocarbyl rings, and a substituted aryl group is a before-mentioned aryl group having a substituent selected from the group consisting of halo, trifluoromethyl, nitro, C.sub.1 -C.

Abstract: A highly pure fraction of hyaluronic acid is disclosed which is non-inflammatory and avoids post-operative complications in ocular surgery. Also disclosed is a process for the preparation of hyaluronic acid characterized by converting hyaluronic acid into a corresponding quaternary ammonium salt and, following purification procedures, reconverting the quaternary ammonium salt into a sodium salt of hyaluronic acid.