Interactions glycanne-protéine. Synthése des 4-méthylombelliféryl-(2-acétamido-2-désoxy-β-D-glucopyranoside), -DI-N-acétyl-β-chitobioside et -tri-N-acétyl-β-chitotrioside. Interaction de ces osides avec le lysozyme

4-Methylumbelliferyl 2-acetamido-2-deoxy-β-D-glucopyranoside, 2-acetamido-4-O-(2-acetamido-2-deoxy-β-D-glucopyranosyl)-2-deoxy-β-D-glucopyranoside (di-N-acetyl-β-chitobioside), and O-(2-acetamido-2-deoxy-β-D-glucopyranosyl)-(1→4)-O-(2-acetamido-2-deoxy-β-D-glucopyranosyl)-(1→4)-2-acetamido-2-deoxy-β-D-glucopyranoside (tri-N-acetyl-β-chitotrioside) were obtained in good yield from the corresponding peracetylated glycosyl chlorides by condensation with the sodium salt of 4-methylumbelliferone in N,N-dimethylformamide. The trisaccharide glycoside is hydrolyzed by lysozyme and is, therefore, a convenient substrate for this enzyme; the 4-methylumbelliferone produced can be determined by the increase of the fluorescence intensity at 442 nm. The intensity of the fluorescence of 4-methylumbelliferyl tri-N-acetyl-β-chitotrioside is enhanced upon binding with lysozyme without modification of the position of the absorption maximum. The binding constant and the rate of hydrolysis of the trisaccharide glycoside by lysozyme are higher than those obtained with p-nitrophenyl tri-N-acetyl-β-chitotrioside.     

Enzymatic synthesis of N-acetylglucosaminobioses by reverse hydrolysis: characterisation and application of the library of fungal β-N-acetylhexosaminidases

The regioselectivity of 20 extracellular β-N-acetylhexosaminidases of fungal origin was screened in the reverse hydrolysis with 2-acetamido-2-deoxy- -glucopyranose. Most of the enzymes used yielded 2-acetamido-2-deoxy-β- -glucopyranosyl-(1→4)-2-acetamido-2-deoxy- -glucopyranose (3) and 2-acetamido-2-deoxy-β- -glucopyranosyl-(1→6)-2-acetamido-2-deoxy- -glucopyranose (4). So far unknown product of enzymatic condensation, 2-acetamido-2-deoxy-β- -glucopyranosyl-(1→3)-2-acetamido-2-deoxy- -glucopyranose (2) was synthesised using the β-N-acetylhexosaminidases from Penicillium funiculosum CCF 1994, P. funiculosum CCF 2325 and Aspergillus tamarii CCF 1665. Addition of salts ((NH₄)₂SO₄ or MgSO₄ (0.1–1.0 M)) to the reaction increased the yields and also enhanced the β-N-acetylhexosaminidase regioselectivity.     

Synthesis of methyl O-(3-deoxy-3-fluoro-β- -galactopyranosyl)-(1→6)-β- -galactopyranoside and methyl O-(3-deoxy-3-fluoro-β- -galactopyranosyl)-(1→6)-O-β- -galactopyranosyl-(1→6)-β- -galactopyranoside

Condensation of 2,4,6-tri-O-acetyl-3-deoxy-3-fluoro-α- -galactopyranosyl bromide (3) with methyl 2,3,4-tri-O-acetyl-β- -galactopyranoside (4) gave a fully acetylated (1→6)-β- -galactobiose fluorinated at the 3′-position which was deacetylated to give the title disaccharide. The corresponding trisaccharide was obtained by reaction of 4 with 2,3,4-tri-O-acetyl-6-O-chloroacetyl-α- -galactopyranosyl bromide (5), dechloroacetylation of the formed methyl O-(2,3,4-tri-O-acetyl-6-O-chloroacetyl-β- -galactopyranosyl)-(1→6)- 2,3,4-tri-O-acetyl-β- -galactopyranoside to give methyl O-(2,3,4-tri-O-acetyl-β- -galactopyranosyl)-(1→6)-2,3,4-tri-O-acetyl-β- -galactopyranoside (14), condensation with 3, and deacetylation. Dechloroacetylation of methyl O-(2,3,4-tri-O-acetyl-6-O-chloroacetyl-β- -galactopyranosyl)-(1→6)-O-(2,3,4-tri-O-acetyl- β- -galactopyranosyl)-(1→6)-2,3,4-tri-O-acetyl-β- -galactopyranoside, obtained by condensation of disaccharide 14 with bromide 5, was accompanied by extensive acetyl migration giving a mixture of products. These were deacetylated to give, crystalline for the first time, the methyl β-glycoside of (1→6)-β- -galactotriose in high yield. The structures of the target compounds were confirmed by 500-MHz, 2D, ¹H- and conventional ¹³C- and ¹⁹F-n.m.r. spectroscopy.     

Saponins from Albizzia lucida

Three main saponins were isolated from the seeds of Albizzia lucida. Their structures were established by spectral analyses and chemical and enzymatic transformations as 3-O-[β- -xylopyranosyl(1→2)-α- -arabinopyranosyl (1→6)] [β- -glucopyranosyl (1→2)] β- -glucopyranosyl echinocystic acid; 3-O-[α- -arabinopyranosyl (1→6)][β- -glucopyranosyl (1→2)]-β- -glucopyranosyl echinocystic acid and 3-O-[β- -xylopyranosyl (1→2)-β- -fucopyranosyl (1→6)-2-acetamido-2-deoxy-β- -glucopyranosyl echinocystic acid, characterized as its methyl ester.     

Synthesis of trisaccharides containing 3-deoxy- -manno-2-octulosonic acid residues related to the KDO-region of enterobacterial lipopolysaccharides

Glycosylation of methyl (allyl 7,8-O-carbonyl-3-deoxy-α- -manno-2-octulopyranosid)onate with an α-(2→4) linked per-O-acetylated KDO-disaccharide bromide derivative under Helferich conditions afforded a 2:1 mixture of the α- and β-linked trisaccharide derivatives in 50% yield. Removal of the protecting groups gave sodium O-[sodium (3-deoxy-α- -manno-2-octulopyranosyl)onate]-(2→4)-O-[sodium (3-deoxy-α- and -β- -manno-2-octulopyranosyl)onate]-(2→4)-sodium (allyl 3-deoxy-α- -manno-2-octulopyranosid)onate. Radical copolymerization of the allyl glycosides afforded artificial antigens, suitable for defining antibody specificities directed against the KDO-region of enterobacterial lipopolysaccharides.     

An approach to branched-chain amino sugars, particularly derivatives of -vancosamine (3-amino-2,3,6-trideoxy-3-C-methyl- -lyxo-hexose) and its enantiomer, via the cyanohydrin route

Methyl 4,6-O-benzylidene-2-deoxy-α- -erythro-hexopyranosid-3-ulose reacted with potassium cyanide under equilibrating conditions to give, initially, methyl 4,6-O-benzylidene-3-C-cyano-2-deoxy-α- -ribo-hexopyranoside (7), which, because it reverted slowly to the thermodynamically stable -arabino isomer, could be crystallised directly from the reaction mixture. The mesylate derived from the kinetic product 7 could be converted by published procedures into methyl 3-acetamido-2,3,6-trideoxy-3-C-methyl-α- -arabino-hexopyranoside, which was transformed into methyl N-acetyl-α- -vancosaminide on inversion of the configuration at C-4. A related approach employing methyl 2,6-dideoxy-4-O-methoxymethyl-α- -erythro-hexopyranosid-3-ulose gave the kinetic cyanohydrin and thence, via the spiro-aziridine 27, methyl 3-acetamido-2,3,6-trideoxy-3-C-methyl-α- -arabino-hexopyranoside, a known precursor of methyl N-acetyl-α- -vancosaminide.     

Studies on the koenigs-knorr reaction : Part V. Synthesis of 2-acetamido-2-deoxy-3-O-α-L-fucopyranosyl-α-D-glucose

Optically pure 2-acetamido-2-deoxy-3-O-α-L-fucopyranosyl-α-D-glucose was synthesized by the Koenigs-Knorr reaction of 2-O-benzyl-3,4-di-O-p-nitrobenzoyl-α-L-fucopyranosyl bromide with benzyl 2-acetamido-4,6-O-benzylidene-2-deoxy-α-D-glucopyrainoside. Reaction of 2,3,4-tri-O-acetyl-α-L-fucopyranosyl bromide gave the β-L-fucopyranosyl anomer. In contrast to the stereospecificity shown in this reaction by these two bromides, 2,3,4-tri-O-benzyl-α-L-fucopyranosyl bromide afforded a mixture of α-L and β-L anomers in almost equimolar proportions. The disaccharides synthesized were crystallized and characterized, and their optical purity demonstrated by g.l.c. of the per(trimethylsilyl) ethers of the corresponding alditols.     

Sequential synthesis and C-N.m.r. spectra of methyl β-glycosides of (1→4)-β-d-xylo-oligosaccharides

The reaction of 2,3-di-O-acetyl-4-O-benzyl-α,β-d-xylopyranosyl bromide (2) with methyl 2,3-di-O-acetyl-β-d-xylopyranoside gave methyl O-(2,3-di-O-acetyl-4-O-benzyl-β-d-xylopyranosyl)-(1→4)-2,3-di-O-acetyl-β-d-xylopyranoside (22). Catalytic hydrogenolysis of 22 exposed HO-4′ which was then condensed with 2. This sequence of reactions was repeated three more times to afford, after complete removal of protecting groups, a homologous series of methyl β-glycosides of (1→4)-β-d-xylo-oligosaccharides. ¹³C-N.m.r. spectra of the synthetic methyl β-glycosides (di- to hexa-saccharide) are presented together with data for six other, variously substituted, homologous series of (1→4)-d-xylo-oligosaccharides.     

Circular dichroism studies on α- and β-ketosides of 5-acetamido-3,5-dideoxy- -glycero- -galacto-nonulopyranosonic acid (N-acetylneuraminic acid) and of some of its derivatives

The circular dichroism spectra of a number of N-acetylneuraminic acid derivatives in aqueous solution were studied. For all compounds, the Cotton effects were found to be in the spectral range of the acetamido and carboxyl chromophores. The c.d. curves of the methyl, ethyl, and allyl α- -ketosides are characterized by a broad, positive band centered at λ ≈ 195 nm with a slight skew towards the higher wavelengths and weak bands between λ 225 and 255 nm, whereas the methyl β- -ketoside and the corresponding methyl ester show only an intense positive band with a broad shoulder in the same spectral range. 5-Acetamido-3,5-dideoxy- -glycero-β- -galacto-nonulopyranose, its methyl β- -ketoside, and 5-acetamido-3,5-dideoxy- -glycero- -galacto-nonulopyranosonamide containing only the acetamido chromophore showed one single positive Cotton effect centered at λ ≈ 192 nm. The c.d. spectrum of 5-acetamido-3,5-dideoxy- -glycero- -galacto-nonulopyranosonic acid confirms the β- configuration of the free acid in aqueous solution, whereas the shape of the c.d. curve of O-(N-acetyl-α- -neuraminopyranosyl)-(2→3)-O-β- -galactopyranosyl-(1→4)- -glucopyranose resembles that of the methyl, ethyl, and allyl α- -ketosides 2-4.     

Synthetic studies on amino-α-glycosides of aminocyclitols. Synthesis of kanamycin analogues

A diastereoisomer of Kanamycin C has been synthesized by a modified Koenigs—Knorr reaction of 3,4,6-tri-O-acetyl-2-(2,4-dinitroanilino)-2-deoxy-α-D-glucopyranosyl bromide with 4-O-(3-acetamido-2,4,6-tri-O-benzyl-3-deoxy-α-D-glucopyranosyl)-N,N′-di[(benzyloxy)carbonyl]-2-deoxystreptamine. Several Kanamycin analogues were synthesized by a similar condensation reaction. Each of the condensed products was isolated as its crystalline tetra-N-acetyl derivative and was proved by n.m.r. spectroscopy in D₂O to have the α-configuration.     

β-N-Acetylhexosaminidase-catalysed synthesis of non-reducing oligosaccharides

A large panel of fungal β-N-acetylhexosaminidases was tested for the regioselectivity of the β-GlcNAc transfer onto galacto-type acceptors ( -galactose, lactose, 2-acetamido-2-deoxy- -galactopyranose). A unique, non-reducing disaccharide β- -GlcpNAc-(1→1)-β- -Galp and trisaccharides β- -GlcpNAc-(1→4)-β- -GlcpNAc-(1→1)-β- -Galp, β- -Galp-(1→4)-β- -Glcp-(1→1)-β- -GlcpNAc and β- -Galp-(1→4)-α- -Glcp-(1→1)-β- -GlcpNAc were synthesised under the catalysis of the β-N-acetylhexosaminidase from the Aspergillus flavofurcatis CCF 3061 with -galactose and lactose as acceptors. The use of 2-acetamido-2-deoxy- -galactopyranose as an acceptor with the β-N-acetylhexosaminidases from A. flavofurcatis CCF 3061, A. oryzae CCF 1066 and A. tamarii CCF 1665 afforded only β- -GlcpNAc-(1→6)- -GalpNAc.     

Synthesis of 4-O-α- -galactopyranosyl- -rhamnose and 4-O-α- -galactopyranosyl-2-O-β-glucopyranosyl- -rhamnose using dioxolane-type benzylidene acetals as temporary protecting-groups

The Halide ion-catalysed reaction of benzyl exo-2,3-O-benzylidene-α- -rhamnopyranoside with tetra-O-benzyl-α- -galactopyranosyl bromide and hydrogenolysis of the exo-benzylidene group of the product 2 gave benzyl 3-O-benzyl-4-O-(2,3,4,6-tetra-O-benzyl-α- -galactopyranosyl)-α- -rhamnopyranoside (6). Compound 2 was converted into 4-O-α- -galactopyranosyl- -rhamnose. The reaction of 6 with tetra-O-acetyl-α- -glucopyranosyl bromide and removal of the protecting groups from the product gave 4-O-α- -galactopyranosyl-2-O-β- -glucopyranosyl- -rhamnose.     

Synthesis and biological activity of O-(N-acetyl-β-muramoyl-l-alanyl-d-isoglutamine)-(1→6)-2-acylamino-2-deoxy-d-glucoses

Benzoylation of benzyl 2-acetamido-2-deoxy-4,6-O-isopropylidene-α-d-glucopyranoside, benzyl 2-deoxy-2-(dl-3-hydroxytetradecanoylamino)-4,6-O-isopropylidene-α-d-glucopyranoside, and benzyl 2-deoxy-4,6-O-isopropylidene-2-octadecanoylamino-β-d-glucopyranoside, with subsequent hydrolysis of the 4,6-O-isopropylidene group, gave the corresponding 3-O-benzoyl derivatives (4, 5, and 7). Hydrogenation of benzyl 2-acetamido-4,6-di-O-acetyl-2-deoxy-3-O-[d-1-(methoxycarbonyl)ethyl]-α-d-glucopyranoside, followed by chlorination, gave a product that was treated with mercuric actate to yield 2-acetamido-1,4,6-tri-O-acetyl-2-deoxy-3-O-[d-1-(methoxycarbonyl)ethyl]-β-d-glucopyranose (11). Treatment of 11 with ferric chloride afforded the oxazoline derivative, which was condensed with 4, 5, and 7 to give the (1→6)-β-linked disaccharide derivatives 13, 15, and 17. Hydrolysis of the methyl ester group in the compounds derived from 13, 15, and 17 by 4-O-acetylation gave the corresponding free acids, which were coupled with l-alanyl-d-isoglutamine benzyl ester, to yield the dipeptide derivatives 19–21 in excellent yields. Hydrolysis of 19–21, followed by hydrogenation, gave the respective O-(N-acetyl-β-muramoyl-l-alanyl-d-isoglutamine)-(1→6)-2-acylamino-2-deoxy-d-glucoses in good yields. The immunoadjuvant activity of these compounds was examined in guinea-pigs.     

Synthesis of 2,3-di-O-glycosyl derivatives of methyl α- and β- -glucopyranoside

The syntheses are described of 2,3-di-O-glycosyl derivatives of methyl α- and β- -glucopyranoside having α- -manno-, β- -galacto-, α- -rhamno-, α- -fuco-, and β- -fuco-pyranosyl substitutents at O-2 and O-3. The syntheses involved glycoslation of methyl 4,6-O-(benzylidene-α- (24) and β- -glucopyranoside (21), and substituted derivatives of 21 bearing 2-O-(2,3,4,6-tetra-O-benzyl-α- -mannopyranosyl)-, -(2,3,4,6-tetra-O-acetyl-β- -galactopyranosyl)-, -(2,3,4-tri-O-benzyol-α- -rhamnopyranosyl)-, and-(2,3,4-tri-O-benzoyl-β- -fucopyranosyl) groups.     

Mēthylation de dērivēs n-acylēs du 2-amino-2-dēsoxy-D-glucose en prēsence de sels d'argent: observations sur le comportement du groupement ambident acetamido (ou benzamido)

The behavior of the acetamido (and benzamido) ambident, nucleophilic group under methylation with methyl iodide and silver oxide has been studied for several 2-acetamido-2-deoxy-D-glucose derivatives. When silver perchlorate was added, alkylation occurred at the oxygen atom, giving methyl imidates that were labile in acidic medium. Benzyl 2-acetamido-3,4,6-tri-O-acetyl-2-deoxy-β-D-glucopyranoside was converted into N-(benzyl 3,4,6-tri-O-acetyl-2-deoxy-β-D-glucopyranoside-2-yl) methyl acetimidate (83%), which was subsequently hydrolyzed quantitatively in acidic medium into the corresponding amine salt. Similar results were obtained with benzyl 3,4,6-tri-O-acetyl-2-benzamido-2-deoxy-β-d-glucopyranoside, methyl 2-acetamido-2-deoxy-3,4,6-tri-O-methyl-β-D-glucopyranoside, and benzyl 2-acetamido-3,4,6-tri-O-benzyl-2-deoxy-β-D-glucopyranoside. Under Kuhn's methylation conditions (methyl iodide-silver oxide-N,N-dimethylformamide), alkylation of the just mentioned derivatives occurred at both oxygen and nitrogen atoms.     

Unsaturated sugars I. Decarboxylative elimination of methyl 2,3-di-O-benzyl-α-D-glucopyranosiduronic acid to methyl 2,3-di-O-benzyl-4-deoxy-β-L-threo-Pent-4-enopyranoside

Decarboxylative elimination of methyl 2,3-di-O-benzyl-α-D-glucopyranosiduronic acid (1) with N,N-dimethylformamide dineopentyl acetal in N,N-dimethylformamide gave methyl 2,3-di-O-benzyl-4-deoxy-β-L-threo-pent-4-enopyranoside (3). Debenzylation of 3 was effected with sodium in liquid ammonia to give methyl 4-deoxy-β-L-threo-pent-4-enopyranoside (4). Hydrogenation of 3 catalyzed by palladium-on-barium sulfate afforded methyl 2,3-di-O-benzyl-4-deoxy-β-L-threo-pentopyranoside (5), whereas hydrogenation of 3 over palladium-on-carbon gave methyl 4-deoxy-β-L-threo-pentopyranoside (6). An improved preparation of methyl 4,6-O-benzylidene-α-D-glucopyranoside is also described.     

Synthesis, and carbon-13 n.m.r. study, of O-α- -rhamnopyranosyl-(1→3)-O-α- -rhamnopyranosyl-(1→2)- -rhamnopyranose and O-α- -rhamnopyranosyl-(1→3)-O-α- -rhamnopyranosyl (1→3)- -rhamnopyranose, constituents of bacterial, cell-wall polysaccharides

O-α- -Rhamnopyranosyl-(1→3)- -rhamnopyranose (19) and O-α- -rhamnopyranosyl-(1→2)- -rhamnopyranose were obtained by reaction of benzyl 2,4- (7) and 3,4-di-O-benzyl-α- -rhamnopyranoside (8) with 2,3,4-tri-O-acetyl-α- -rhamnopyranosyl bromide, followed by deprotection. The per-O-acetyl α-bromide (18) of 19 yielded, by reaction with 8 and 7, the protected derivatives of the title trisaccharides (25 and 23, respectively), from which 25 and 23 were obtained by Zemplén deacetylation and catalytic hydrogenolysis, With benzyl 2,3,4-tri-O-benzyl-β- -galactopyranoside, compound 18 gave an ≈3:2 mixture of benzyl 2,3,4-tri-O-benzyl-6-O-[2,4-di-O-acetyl-3-O-(2,3,4-tri-O-acetyl-α- -rhamnopyranosyl)-α- -rhamnopyranosyl]-β- -galactopyranoside and 4-O-acetyl-3-O-(2,3,4-tri-O-acetyl-α- -rhamnopyranosyl)-β- -rhamnopyranose 1,2-(1,2,3,4-tetra-O-benzyl-β- -galactopyranose-6-yl (orthoacetate). The downfield shift at the α-carbon atom induced by α- -rhamnopyranosylation at HO-2 or -3 of a free α- -rhamnopyranose is 7.4-8.2 p.p.m., ≈1 p.p.m. higher than when the (reducing-end) rhamnose residue is benzyl-protected (6.6-6.9 p.p.m.). α- -Rhamnopyranosylation of HO-6 of gb- -galactopyranose deshields the C-6 atom by 5.7 p.p.m. The 1 2-orthoester ring structure [O₂,C(me)OR] gives characteristic resonances at 24.5 ±0.2 p.p.m. for the methyl, and at 124.0 ±0.5 p.p.m. for the quaternary, carbon atom.     

Synthesis of Neu5Ac- and Neu5Gc-α-(2→6′)-lactosamine 3-aminopropyl glycosides

In order to prepare 3-aminopropyl glycosides of Neu5Ac-α-(2→6′)-lactosamine trisaccharide 1, and its N-glycolyl containing analogue Neu5Gc-α-(2→6′)-lactosamine 2, a series of lactosamine acceptors with two, three, and four free OH groups in the galactose residue was studied in glycosylations with a conventional sialyl donor phenyl [methyl 5-acetamido-4,7,8,9-tetra-O-acetyl-3,5-dideoxy-2-thio- -glycero-α- and β- -galacto-2-nonulopyranosid]onates (3) and a new donor phenyl [methyl 4,7,8,9-tetra-O-acetyl-5-(N-tert-butoxycarbonylacetamido)-3,5-dideoxy-2-thio- -glycero-α- and β- -galacto-2-nonulopyranosid]onates (4), respectively. The lactosamine 4′,6′-diol acceptor was found to be the most efficient in glycosylation with both 3 and 4, while imide-type donor 4 gave slightly higher yields with all acceptors, and isolation of the reaction products was more convenient. In the trisaccharides, obtained by glycosylation with donor 4, the 5-(N-tert-butoxycarbonylacetamido) moiety in the neuraminic acid could be efficiently transformed into the desired N-glycolyl fragment, indicating that such protected oligosaccharide derivatives are valuable precursors of sialo-oligosaccharides containing N-modified analogues of Neu5Ac.     

N-Acetylhexosamine triad in one molecule: Chemoenzymatic introduction of 2-acetamido-2-deoxy-β-d-galactopyranosyluronic acid residue into a complex oligosaccharide

A complex trisaccharide β-d-GalpNAcA-(1 → 4)-β-d-GlcpNAc-(1 → 4)-d-ManpNAc (3) was prepared in a good yield (35%) in a transglycosylation reaction catalyzed by β-N-acetylhexosaminidase from Talaromyces flavus using p-nitrophenyl 2-acetamido-2-deoxy-β-d-galacto-hexodialdo-1,5-pyranoside (1) as a donor followed by the in situ oxidation of the aldehyde functionality by NaClO₂. The disaccharide β-d-GlcpNAc-(1 → 4)-d-ManpNAc (2) was used as galactosyl acceptor. A disaccharide β-d-GalpNAcA-(1 → 4)-d-GlcpNAc (4; 39%) originated as a by-product in the reaction. Oligosaccharides comprising a carboxy moiety at C-6 are shown to be very efficient ligands to natural killer cell activation receptors, particularly to human receptor CD69. Thus, oxidized trisaccharide 3 is the best-known oligosaccharidic ligand to this receptor, with IC₅₀ = 2.5 × 10⁻⁹ M. The presented method of introducing a β-d-GalpNAcA moiety into carbohydrate structures is versatile and can be applied in the synthesis of other complex oligosaccharides.     

Conversion of amylose into a (1→4)-2-amino-2-deoxy-α-D-glucopyranuronan and its 2-N-sulfo derivative, a heparin analog

By a modification of a previously established reaction-sequence involving successive oxidation with methyl sulfoxide-acetic anhydride, oximation, and reduction with lithium aluminum hydride, 6-O-tritylamylose (1) was converted into a 6-O-tritylated (1→4)-α-D-linked glucan (3) containing 2-amino-2-deoxy-D-glucose residues and some O-(methylthio)methyl groups. Removal of the ether groups from this product gave a 2-aminated amylose (4) of degree of substitution (d.s.) by amine of 0.54 that underwent cleavage by fungal alpha-amylase to give oligosaccharides containing amino sugar residues. N-Trifluoroacetylation of 3 followed by removal of the ether groups, oxidation at C-6 with oxygen-platinum, and removal of the N-substituent, gave a (1 →4)-2-amino-2-deoxy-α-D-glucopyranuronan 7 having d.s. by amine of up to 0.65, and by carboxyl, of 0.46. Sulfation of this product with sulfur trioxide-pyridine and then with chlorosulfonic acid-pyridine gave a (1→4)-2-deoxy-2-sulfoamino-α-D-glucopyranuronan, isolated as its sodium salt 8, which showed appreciable blood-anticoagulant activity.