IE902384A1 - Substituted polysaccharides, processes for their preparation¹and their use for the prophylaxis and treatment of virus¹diseases - Google Patents

Abstract

Polysaccharides which have a certain degree of sulphation and are further substituted by a group of the formula -X-B-Y, where this substituent has the stated meanings, are suitable for the prophylaxis and treatment of viral diseases, especially of diseases caused by HIV.

Description

Substituted polysaccharides, processes for their preparation and their use for the prophylaxis and treatment of virus diseases The present invention relates to substituted polysaccharides, processes for their preparation and their use for the prophylaxis and treatment of virus diseases. It is already known that sulfated polysaccharides are suitable for the treatment of virus diseases (compare, for example, WO 88/05,301 and EP 0,240,098). Although these compounds exhibit an activity, they have the disadvantage, for example, that they influence blood coagulation (compare, for example, Ryde et al. in Throm15 bosis Research 23 (1981) 435-445). With the intention of obtaining better compounds for the treatment of virus diseases, it has now been found, surprisingly, that polysaccharides in which the OH groups are only partly sulfated and a further portion of the OH groups is etherified or esterified have a greater activity against viruses than merely sulfated polysaccharides and at the same time influence blood coagulation less. Some of the compounds which can be ueed according to the invention are already known from Japanese Patent Application Sho25 46-36,277, in which, however, only their activity for completely different applications is described. The activity of the compounds mentioned against viruses was not to be expected in view of the already known actions of the compounds - such as, for example, dilation of the peripheral vessels and improvement in the blood circulation.

The activity described for the compounds according to the invention is also surprising because, for example, the most diverse neutral polysaccharides, such as xylofuran, ribofuran and various dextrans, exhibit no anti-HIV activity at all (H. Nakashima et al., Jap. J. Cancer - 2 Res./Gaun 78 (11), 1164-68, 1987), and because many of the cationic and neutral derivatives thereof are in the same way inactive (P. Ebbesen, Brit. J. Cancer, 30 (1), 68-72, 1974).

The discovery of pharmaceutically active polymeric compounds is moreover particularly difficult, because the pharmaceutical activity of low molecular weight compounds in no way allows conclusions to be drawn on the pharmaceutical activity of polymers. It is thus known, for example, that some low molecular weight active compounds are modified in respect of their cell membrane permeability by introduction of lipophilic groups, whereas such a change does not occur in high molecular weight substances on introduction of lipophilic groups (Advanced Drug Delivery Reviews 1, 1987, 235-248, Elsevier).

The invention accordingly relates to substituted polysaccharides, which can be linear or branched, and which are composed of uniform or different naturally occurring or synthetic monomers which can also contain one sub20 stituted or unsubstituted amino group per monomer unit and in which the OH groups are on average between 5 and 80% substituted by a group of the formula -X-B-Y, in which X denotes an oxy group or a group of the formula I -C^ (I) 0the carbon atom of which is bonded to B, B denotes a non-aromatic hydrocarbon radical having 2 to 30 carbon atoms, in the alkyl chain of which up to 3 methylene units can be replaced by oxy groups, in which up to three C-C double bonds can be present and which can be substituted by up to three Cj-C^alkyl radicals and Y - if X is an oxy group - can be hydrogen, COOR or OSO3R1. in which R is a physiologically tolerated mono- or divalent cation, or represents a hydro35 - 3 carbon radical having up to 20 carbon atoms or a mono- or bisether radical having 3 to 10 carbon atoms, and R1 represents a physiologically tolerated cation, or 5 Y - if X is a radical of the formula I - represents hydrogen or COOR, in which R has the abovementioned meanings, and in which the OH groups of the abovementioned polysaccharides are between 10 and 95% substituted by a group of the formula OSO3M, in which M represents a physiologically tolerated cation, and between 0 and 40% of the OH groups are unsubstituted, excluding the palmitic acid esters of chondroitin sulfate and the lauric acid esters of dextran sulfate, which are already mentioned in the abovementioned Japanese Specification Sho-46-36,277.

Preferred substituted polysaccharides are those which have a polysaccharide matrix which is built up from uniform or different monomer units chosen from the following group of compounds or is composed of the following compounds: xylose, arabinose, rhamnose, fucose, glucose, mannose, galactose, fructose, glucosamine, galactosamine, mannosamine, glucuronic acid, galacturonic acid, mannuronic acid, carrageenans, fucoidan, laminaran, alginate, lentinan, pluran, xylan, dextran, heparin, keratan sulfate, chondroitin 4- and 6-sulfate, dermatan sulfate, heparin sulfate, hyaluronic acid, teichuronic acid and partial hydrolysates of starch, cellulose, glycogen, chitin or pectin. The compounds mentioned can be of either synthetic or natural origin, i.e. in particular of vegetable or microbial origin.

The compounds which already occur in nature in sulfated form can be used either with their naturally occurring sulfate content or after additional sulfation. Particularly preferred polysaccharides are xylan and dextran.

The OH groups of the polysaccharides according to the invention are preferably 5 to 80%, particularly preferIE 902384 - 4 ably 5 to 50% and especially 10 to 40% substituted by a group of the formula -X-B-Y, and furthermore 10 to 95%, particularly preferably 45 to 95% and in particular 50 to 90% substituted by a group of the formula OSO3M, prefer5 ably between 0 and 40%, particularly preferably between 0 and 20% and in particular between 0 and 10% of the OH groups being unsubstituted.

Preferred radicals B have 2 to 20 carbon atoms, have one or no double bond and are unsubstituted or monosubstitu10 ted by a Ci-C^-alkyl group.

If X is an oxy group, Y is preferably H, COOR or OSOaR1, in which R is an alkali metal cation, in particular potassium or sodium, or a branched or unbranched Cj-Cealkyl group and R1 is preferably an alkali metal cation, in particular sodium.

If X is a radical of the formula I, Y preferably denotes H or a radical of the formula COOR, in which R is an alkali metal cation, preferably sodium or potassium, a branched or unbranched Cj-Cg-alkyl group or a mono- or bisether radical having 6 to 9 carbon atoms.

Examples of radicals of the formula -X-B-Y are ethoxy, propoxy, isopropoxy, butoxy, hexyloxy, octyloxy, decyloxy, dodecyloxy, propionyloxy, butyryloxy, valeryloxy, hexanoyloxy, octanoyloxy, decanoyloxy, dodecanoyloxy, palmitoyloxy, stearoyloxy, 2-methylbutyryloxy, 9-octadecenoyloxy, linoloyloxy, linolenoyloxy, cholesteryloxy, hydroxyoxalyloxy, hydroxymalonyloxy, hydroxysuccinyloxy, hydroxyglutaryloxy, hydroxyadipoyloxy, crotonoyloxy, mesaconoyloxy and the esters of the dicarboxylic acids mentioned with unbranched C1-C8-alcohols, or [(1,3-diisopropoxy)-propyl-2-oxycarbonyl]-propanoyloxy.

The dodecanoyloxy and the stearoyloxy radicals are of particular importance, especially on a xylan polysaccharide matrix. - 5 The substituted polysaccharides according to the invention can have an average molecular weight which extends over a wide range. The substituted polysaccharides preferably have an average molecular weight of up to 100 kD, particularly preferably of up to 40 kD and in particular between 1 and 22 kD. Substituted polysaccharides according to the invention in which the polysaccharide matrix is composed of xylan or dextran and which have an average molecular weight of 1 to 22 kD are of particular importance.

The present invention furthermore includes a process for the preparation of substituted polysaccharides in which X is an oxy group, which comprises partly etherifying the polysaccharides with an alkyl halide or an ω-halogeno carboxylic acid salt, under basic catalysis, and then completely or partly sulfating the products directly or after alkoxylation. In this process, the alkylation is carried out, for example, with an alkyl halide or ωhalogeno carboxylic acid salt in an anhydrous solvent, such as, for example, DMF, dioxane, DMSO and the like, it being possible to use, for example, an alkali metal hydroxide as the basic catalyst. Particularly suitable alkyl halides are the alkyl bromides and iodides. A particularly preferred variant of this process is described in the general working instructions I.

The present invention furthermore relates to a process for the preparation of the substituted polysaccharides in which X is a group of the formula I, which comprises partly acylating the polysaccharides with a mono- or dicarboxylic acid or with a dicarboxylic acid monoester and completely or partly sulfating the OH groups which remain in the polysaccharides. Various methods can be used for the acylation (compare, for example, Organikum, VEB, Verlag der Wissenschaften, Berlin 1977, Chapter 7 or Houben-Weyl, Volume 8, page 503, Georg-Thieme-Verlag Stuttgart (1952)). - 6 A preferred process comprises reacting a solution of the carboxylic acid or derivative thereof to be introduced into the polysaccharide with an equimolar amount of N,N'carbonyldiimidazole in an organic solvent, such as, for example, anhydrous DMF or DMSO, at a temperature of about 20 to 60 °C and acylating the particular polysaccharide with the acylimidazole formed, which can be effected at about 20 to 60°C by addition of the particular polysaccharide in the solvents already mentioned. The degree of acylation is determined here by the ratio of the amounts of the acylimidazole to the particular polysaccharide. A preferred process for the acylation of the polysaccharides is described in the general working instructions II.

The substituted polysaccharides can be sulfated in various ways (compare, for example, Whistler et al. in Carbohydr. Chem. 2, 298 (1963), US 2,715,091 or CH 293,566). A preferred process comprises taking up the polysaccharide to be sulfated in an organic solvent, preferably DMF, and then adding complexed sulfur trioxide, preferably complexed with pyridine, at a temperature of about 30 to 60eC. Experience has shown that about 1.5 to 3 equivalents of sulfur trioxide complex are required for sulfation of one OH group. When the sul25 fation has taken place, the reaction product can be taken up in water, and the mixture can preferably be neutralized with NaOH and then worked up by known methods. A particularly preferred process for the sulfation of the polysaccharides according to the invention is described in the general working instructions III.

Polysaccharides in which an amino function is present should be provided, before the sulfation, with a protective group which can be split off again when the reaction has taken place. Suitable protective groups are des35 cribed, for example, by E.Wunsch in Houben-Weyl, Volume 15, I/II, Georg Thieme Verlag Stuttgart (1974). - 7 The present invention furthermore relates to the use of substituted polysaccharides for combating diseases caused by viruses. The substituted polysaccharides are active against a number of viruses which are pathogenic to humans, such as, for example, herpes viruses; however, their activity against retroviruses, in particular against HIV, is of particular importance. The compounds according to the invention can be administered in various ways for combating, i.e. for treatment or prophylaxis, of diseases caused by viruses - in particular by retroviruses. For example, they can be administered intravenously, intramuscularly, intraperitoneally, subcutaneously, as a continuous intravenous drip, rectally or orally. For acute disease states, administration as a continuous intravenous drip is to be preferred. Oral administration, for example, is indicated for long-term medication.

The present invention furthermore relates to pharmaceuticals which contain substituted polysaccharides according to the invention. The pharmaceuticals according to the invention are prepared by bringing at least one substituted polysaccharide into a suitable presentation form, if appropriate with other auxiliaries and/or excipients. The auxiliaries and excipients originate from the group of carrier agents, preservatives and other customary auxiliaries.

For example, auxiliaries such as starches, for example potato, maize or wheat starch, cellulose or derivatives thereof, in particular microcrystalline cellulose, silicon dioxide, various sugars, such as lactose, magnesium carbonate and/or calcium phosphates can be used for oral presentation forms. It is furthermore advantageous for auxiliaries which improve the tolerability of the medicaments, such as, for example, mucilage-forming agents and resins, to be added to the oral presentation forms. The medicaments can also be administered in the form of capsules which are insoluble in gastric juice, - 8 for the purpose of better tolerability. It may furthermore be advantageous to add a retarding agent, if appropriate in the form of permeable membranes, such as, for example, those based on cellulose or polystyrene resin, or ion exchangers, to the presentation form or a component of the combination preparation.

The dosage to be used for the pharmaceuticals according to the invention depends on various factors, such as the presentation form of the medicament and condition, weight and nature of the disease of the patient. However, a daily dose of about 5000 mg of a substituted polysaccharide should be exceeded only in the short term. About 10 to 2500 mg of substituted polysaccharide is the preferred daily dose for a human being weighing about 70 kg. The daily dose of the substituted polysaccharides can be administered in the form of a single administration or in several small doses. Administration in 3 to 8 doses per day is preferred. In some cases, continuous administration of the substituted polysaccharides, for example in a form of a continuous intravenous drip, is indicated.

The antiviral properties of the substituted polysaccharides according to the invention in vitro and in vivo are demonstrated in the following experiments: 1. Activity against HIV, testing in cell cultures Description of the method: Medium RMPI pH 6.8 Complete medium additionally contains 20% of fetal calf serum and 20 I.U./ml of recombinant interleukin 2.

Cells Lymphocytes isolated from fresh donor blood by means - 9 of Ficoll gradient centrifugation are cultured in complete medium, with the addition of 2 pg/ml of phytohemagglutinin (Wellcome), under 5% of C02 at 37eC for 36 hours. After addition of 10% of DMSO, the cells are frozen at a cell density of 5 χ 106 and stored in liquid nitrogen. For the experiment, the cells are thawed, washed in RPMI medium and cultured in complete medium for 3-4 days.

Mixture The test preparations are dissolved in complete medium, usually in a concentration of 1.2 mg/ml. In each case 0.5 ml of complete medium is introduced into a 24-well multiwell dish. After addition of 0.1 ml of the dissolved preparation, dilution is performed in a geometric dilution series of factor 5 by transfer of in each case 0.1 ml of the preparation. 0.4 ml of a suspension containing 5 χ 105 lymphocytes per ml is added to each mixture. 0.1 ml of a supernatant of HIV I (D 34, Georg Speyer Haus, Frankfurt/Main) or HIV II (ROD) infected lymphocytes, which is adjusted so that the cytopathogenic effect can be detected in the mixture after 3 to 4 days, is added to the mixtures. The multiplicity of the infectious unit here is 0.01 - 0.02.

The experimental mixture thus contains the following components in complete medium: 0.5 ml of preparation at 200 pg/ml to 1.6 pg/ml 0.4 ml of cells at about 1 x 106/ml 0.1 ml of HIV (1:20 - 1:50 dilute cell culture 1.0 ml supernatant of HIVinfected lymphocytes) The experimental mixtures also contain preparationfree infection controls or standard preparations, for example 3'-azido-3'-deoxythymidine at 0.2 pg/ml or - ίο pentosan polysulfate at 25 pg/ml.

Evaluation The evaluation is by microscopic examination of the mixtures on the 4th day after infection. The virus multiplication and the minimum inhibitory concentration (MIC) is determined with the aid of the virusrelated syncytia formation. The results of this test are shown in Table 1.

Table 1 Activity against HIV-1 in the lymphocyte culture Preparation MIC (pg/ml) Compound according to Example 1 2 < 0.8 4 < 0.8 Comparison: dextran sulfate from dextran 10,000 D xylan sulfate - 11 Table 2 Activity against HIV-II (ROD) in the lymphocyte culture Preparation MIC (pg/ml) J Compound according to Example 6 25 7 25 10 25 11 25 10 12 50 Comparison: dextran sulfate from dextran 1,000 D 75 from dextran 5,000 D 50 15 from dextran 10,000 D 100 Reverse transcriptase inhibition test with recombinant HIV RT The test is carried out in 96-well microtiter plates. A 100 pi mixture contains 100 mM tris-HCl, pH 8.0, 80 mM KC1, 10 mM MgCl2, 5 mM dithiothreitol, 10 pi (3H)dTTP (deoxythymidine triphosphate) (121 Ci/mmol, 1.0 mCi/ml), 1.5 pg poly(rA)oligo(dT) 12-18 (Deutsche Pharmacia GmbH, Freiburg FRG) and 10 pi HIV RT (diluted 1j200, DEAE/PC/Aga(rC) fraction) (Hansen, J., Schulze, T., Moiling, K.s RNase H activity associated with bacterial expressed reverse transcriptase of Human T-cell Lymphotropic Virus III/Lymphadenopathyassociated Virus. J. Biol. Chem., 262, 12393 - 12396 (1987)).

After incubation at 41*C for 90 minutes, the labeled nucleic acid is precipitated by freezing (-80°C) and rethawing in the presence of 50 pi of 10% strength TCA (trichloroacetic acid) and 50 pi of Na pyrophosphate. Absorption of the mixture on (R>Whatman GF/C filter, is followed by washing with about 2 ml each of 10% strength TCA/10 mM Na pyrophosphate (1:1), then with - 12 10 mM Na pyrophosphate, H20 and 70% strength ethanol, and the bound radioactivity is subsequently determined after the filter has been dried at 120’C. 3H cpm incorporated into the DNA in the absence of the 5 inhibitor is defined as 100%. This corresponds to incorporation of 80,000 to 200,000 cpm per reaction.

Different concentrations of an inhibitor are investigated in the test. The final concentrations in the batch are stated in pg/ml.

Table 3: HIV reverse transcriptase inhibition test Preparation IC 50 (pg/ml) Compound according to Example 9 0.159 13 0.041 Comparison: xylan sulfate 0.497 Antiviral activity against herpes in cell cultures The test substances are dissolved in cell culture medium (Dulbecco's MEM) and introduced into 100 pi of cell culture medium in standard microtiter plates in a geometric dilution series of factor 3. 100 pi of a suspension of Hela or Vero cells in medium containing 5% of fetal calf serum in a cell density of 2 χ 105 cells/ml are then added. The mixtures are infected with 50 pi of a suspension of the particular test virus, which is adjusted so that the cells exhibit a cytopathogenic effect (CPE) within 72 hours. The evaluation is by microscopic assessment of the cell lawn and photometric measurement of the neutral red absorption (color test after filter). The concentration of the preparation (pg/ml) at which about 50% of the cells survive the infection is assumed to be the MIC. - 13 Table 4: Action against herpes Preparation MIC (pg/mi) Compound according to Example 2 4.94 4 4.94 6 4.94 7 4.94 10 4.94 10 11 <0.18 12 1.65 13 4.94 24 4.94 26 1.65 15 27 1.65 Comparison: xylan sulfate 4.94 2. In vivo experiments in mice using retroviruses Since no convincing model infection of laboratory animals exists for HIV infection of humans, infections with other retroviruses must be resorted to for testing of chemotherapeutics. In the present case, the infection of mice with the Friend leukemia virus was chosen.

Normal laboratory mice (NMRI = Naval Medical Research Institute) were infected by intravenous injection with mouse serum containing Friend virus. In the untreated control animals, a significant enlargement of the spleen and liver develops within 2 weeks or 3 weeks as a symptom of the infection. The treatment is carried out over 10 days by intraperitoneal administration and over 16 days by oral administration of the test substances. The treatment starts 48 hours after the infection in the case of intraperitoneal administration of the test substances, and 4 days before the - 14 infection in the case of oral administration. On the 14th day after infection, the animals are sacrificed by luxation of the cervical vertebrae and opened. The spleen is removed and weighed. The spleen weight of the treated animals is set in relation to that of the untreated infection control as a parameter for measuring the therapeutic activity.

For oral administration, the test substances are dissolved in drinking water. The drinking water containers, each of 100 ml capacity, are changed every hours. The average dose administered to one mouse per 24 hours is calculated from the consumption of drinking water per experimental group determined daily.

Whereas the spleen of uninfected adult laboratory mice (20 - 24 g body weight) weighs less than 1% of the body weight, the spleen of infected animals reaches up to about 10% of the body weight at the end of the experiment.

The comparison preparations used are suramin (= 3,3'ureylene-bis-(8-(3-benzamido-4-methylbenzamido) naphthalene-1,3,5-trisulfonic acid) for intraperitoneal administration and pentosan polysulfate for intraperitoneal and oral administration.

The results are shown in Table 5 and 6.

Start of treatments Duration of treatment: Virus dilutions Mode of administrations Spleen removal: Table 5 - 15 FLV model of mice days after infection days 1:5,000 intraperitoneal 14 days after infection Preparation Dosage Relative Compound mg/mouse spleen weight according in % of Number of Significance surviving (p) mice to body weight n Control — 6.41 ± 3.11 10 1.0000 Suramin 10 X 1.0 4.96 + 1.45 10 0.0985 XS 10 X 0.5 5.67 + 2.31 9 0.2883 15 XS 10 X 1.0 5.07 + 3.19 6 0.2141 Example 14 10 X 0.1 3.79 + 1.50 6 0.0372 Example 13 10 X 1.0 2.95 + 0.95 5 0.0156 Example 15 10 X 1.0 2.42 + 1.00 6 0.0046 20 Control — 7.25 + 2.91 10 1.0000 Suramin 10 X 0.1 5.68 ± 2.57 10 0.1069 XS 10 X 0.5 5.40 + 1.53 8 0.0601 XS 10 X 1.0 5.60 ± 2.62 5 0.1532 Example 16 10 X 1.0 4.94 ± 1.81 10 0.0223 25 Example 11 10 X 1.0 4.60 ± 1.83 9 0.0152 Example 17 10 X 0.5 3.79 ± 1.92 9 0.0038 XS: xylan sulfate Table 6s FLV model of mice Start of treatments 4 days before infection Duration of treatments 16 days Virus dilutions 1:5,000 Mode of administrations orally via the drinking water Spleen removal: 14 days after infection - 16 Preparation Dosage Relative Number of Significance Compound mg/mouse spleen weight surviving (p) according in % of mice to body weight n Control — 7.34 ± 2.36 9 1.0000 XS 16 x 49.0 6.43 ± 3.25 10 0.2548 Example 18 16 X 42.4 4.54 ± 1.11 10 0.0019 Example 19 16 X 22.3 3.58 ± 2.05 10 0.0010 Example 20 16 X 41.4 5.91 ± 1.94 10 0.0835 XS: xylan sulfate 3. Action against VISNA virus in cell cultures The VISNA virus and the HIV virus (virus of human immune deficiency) both belong to the retrovirus subfamily of the Lentiviruses (Haase A.T. Nature (1986) 322, 130-136). The two viruses have a similar genome organization and a complex transcription pattern compared with other retroviruses (Sonijo P. et al., Cell (1985), 42, 369 - 382; Davis J.L. et al., Journal of Virology (1987) 61 (5) 1325-1331).

The VISNA virus test is carried out in accordance with the method of O. Narayan et al., Journal of Infectious Diseases 135, 5, 1977, 800-806. For this, the com25 pounds according to the invention are diluted in culture medium in a non-cytotoxic concentration in 96well microtiter plates. Fibroblast cells from sheep (5 x 10* cells per well) in production medium are then added to each well. Each well then contains 50 pi of a VISNA virus solution with a titer of about 2.5 x 10* TCID50 (TCID = tissue culture infectious dose). This virus dose corresponds to an MOI (multiplicity of the infection) of about 0.05.

Under these infection conditions, a virus-induced cytopathic effect results between day 5 and day 10 in an infection control without substance. The infected - 17 and treated cells and the control cells are Incubated at 37°C under 5% C02 for 7 days.

On occurrence of the virus-induced cytopathogenic effect in the untreated virus control, the cultures are fixed with formalin and then stained with a Giemsa solution.

The action potency is evaluated in three stages with 1 meaning about 20% inhibition, ”2 about 70 - 80% inhibition and 3 complete inhibition of the virus multiplication, measured by the syncytia formation.

Table 7 Action against the VISNA virus Concentration (pl/ml) Compound according to Example 1 Example 2 Example 3 Xylan sulfate 500 250 125 62.5 31.3 2 2 2 2-1 1 2-3 2 2 2 2-1 2 2 2 2-1 2-1 2 2 2 2 2 4. Action of the substituted polysaccharides on blood coagulation The thrombin time (TT) and the partial thrombin time (PTT) are determined for evaluation of the influence of the substances on the course of coagulation. Heparin is used as the comparison substance, in a concentration of 6 I.U./ml. In each case concentrati25 ons of the substituted polysaccharides according to the invention which correspond in weight to the 6 I.U. of heparin are employed.

The substances are weighed and dissolved in a concentration of 6 mg/ml in a physiological saline solution containing 1% of albumin. In each case 10 pi of this are added to 1 ml of citrated plasma. After incubation at room temperature for 15 minutes, the TT - 18 and PTT are determined.

The results of the experiments are recorded in Table 8. The results show that the substituted polysaccharides according to the invention influence blood coagulation far less than heparin and xylan sulfate.

Table 8 Action on blood coagulation Compound according to TT (seconds) PTT (seconds) Example 21 18.1 61.5 22 19.4 55.2 23 21.7 72.4 24 24.9 124.3 25 19.5 67.2 15 Xylan sulfate 28.4 >400 Heparin (6 IU/ml) >400 >400 Control 18.3 41.8 General working instructions I: Alkylation and sulfation of polysaccharides The carbohydrate is dissolved in anhydrous DMSO to give an approximately 5% strength solution and stirred, with exclusion of oxygen (nitrogen or argon atmosphere), with the amounts of potassium hydroxide and alkyl bromide or alkyl iodide necessary for the desired degree of ether25 ification (ratio of base to alkylating agent 1.5:1) for hours, while heating. A 1.5- to 3-fold excess of sulfur trioxide-pyridine complex (based on the free OH groups) is then added and sulfation is carried out at 50 °C for a further 3 hours. The solution is then concentrated in vacuo, the residue is taken up in water and the mixture is neutralized with agueous NaOH. Purification and desalting are carried out by ultra-filtration through a suitable membrane. - 19 General working instructions II: Acylation of polysaccharides The equimolar amount of N,N'-carbonyldiimidazole (CDI) is added in portions to a solution of the carboxylic acid to be introduced in anhydrous DMSO at 50 eC, while stirring, escape of C02 indicating the formation of the reactive acylimidazole. The mixture is stirred at 50eC for another hour and a solution of the polysaccharide in DMSO is then added, the amount being chosen according to the desired degree of esterification. The reaction mixture is left at 50 °C for 3 hours and then concentrated in vacuo.

General working instructions III: Sulfation of polysaccharides The polysaccharide to be sulfated is taken up in DMF and sulfated with an excess of sulfur trioxidepyridine complex (1.5 - 3 equivalents per free OH group) at 50°C for 3 hours. After the solvent has been stripped off, the residue is taken up in water and neutralized with NaOH and the solution is concentrated again to remove pyridine and DMF. The residue is dissolved again in water and freed from salts and impurities by ultrafiltration through a membrane of suitable exclusion limit. Phosphate buffer pH 7, 2% strength by weight based on the dry matter, is added to the retained material and the mixture is spray- or freeze-dried.

Example 1 Propanoyl-xylan sulfate, Na salt In accordance with GWI (general working instruction) II 30 and III, 5 ml (4.97 g, 67 mmol) of propionic acid and g (67 mmol) of Ν,Ν'-carbonyldiimidazole (CDI) are reacted with 15 g (114 mmol) of xylan (molecular weight - 20 Μ ~ 4,000 D) in 200 ml of anhydrous DMSO and the product is then sulfated with 60 g (377 mmol) of SO3-pyridine complex in 300 ml of absolute DMF.

Working up, purification and freeze-drying give 26.7 g of 5 a yellowish amorphous powder.

Degree of acylation: 20% the Degree of sulfation: 75% Analysis: 26.7% C 4.5% H 12.9% S of the OH groups (according to 13C-NMR in D20) of the OH groups IR (KBr): 1740 cm1 (vs, ester CO) 13C-NMR (D20): δ = 176 - 178 (m, CO), - 103 (m, C-l), - 79 (m, C-2,3,4), - 64 (m, C-5, CO-CH2), 28.5 (s, CH2), 9.2 ppm (s, CH3).

The degree of acylation can be determined from the integral of the signals of CH3 (9.2 ppm) and C-l (95 103 ppm) in a quantitative 13C-NMR (INVGAT method).

Example 2 Propanoyl-dextran sulfate, Na salt, from dextran 6,000 D In accordance with GWI II and III, 9.2 ml (9.14 g, 25 123 mmol) of propionic acid and 20 g (123 mmol) of CDI are reacted with 20 g (123 mmol) of dextran (M ~ 6,000 D) in 200 ml of anhydrous DMSO and the product is then sulfated with 100 g (630 mmol) of SO3-pyridine complex in 300 ml of absolute DMF.

Working up, purification and drying gives 35.9 g of a white amorphous powder.

Degree of acylation: 29% of the OH groups (according to 13C-NMR) Degree of sulfation: 56% Analysis: 26.2% C 4.5% H 13.6% S IR (KBr): 1742 cm'1 (vs, ester CO) 13C-NMR (D2O): 5 = 177 (bs, CO), 95.5 - 99.5 (m, C-l), 65 - 80 (m, C-2,3,4,5,6, COCH2), (s, CH2), 8.7 ppm (s, CH3).

Example 3 Hexanoyl-dextran sulfate, Na salt, from 15 dextran 6,000 D .0 -X-B-Y = -O-C \ch2)4-ch3 In accordance with GWI II and III, 14 ml (13 g, 111 mmol) of hexanoic acid, 18.1 g (111 mmol) of CDI and 20 g (123 mmol) of dextran (M ~ 6,000 D) are reacted in 200 ml of absolute DMSO and the reaction product is then sulfated with 90 g (566 mmol) of SO3-pyridine complex in 300 ml of absolute DMF.

Yield: 44.2 g of slightly yellowish amorphous powder Degree of acylation: 20% of the OH groups (according to the 13C-NMR in D2O) Degree of sulfation: 65% Analysis: 26.4% C 4.3% H 13.6% S IR (KBr): 1740 cm1 (vs, ester CO) 13C-NMR (D20): S (bs, CO), (m, C-l), (m, C-2,3,4,5,6,CO177.5 - 19.5 - 79 - 22 £H2), 33.5, 32.2, 25.6, 23.2 (s, 4 x CH2), 5.0 ppm (s, CH3) .

Example 4 Dodecanoyl-dextran sulfate, Na salt, from 5 dextran 3,500 D -X-B-Y = -0-C (0¾) 10“ ^3 In accordance with GWI II and III, 14.8 g (0.074 mol) of dodecanoic acid, 12 g (0.074 mol) of CDI and 20 g (0.123 mol) of dextran (M ~ 3,500) are reacted in 200 ml of absolute DMSO and the reaction product is sulfated with 90 g (0.57 mol) of SO3-pyridine complex in 300 ml of absolute DMF.

Yield; Degree of Degree of 42.3 g of white amorphous powder acylation: 6% of the OH groups (according to 13C-NMR) sulfation: 83% Analysis: 21.3% C 3.1% H 17.3% S IR (KBr): 1741 cm'1 (s, ester-CO) 13C-NMR (D20) ; δ 177.3 97 - 99 66 - 78.5 35.5, 33.3 x CH2), .5 ppm (s, CH3). (bs, CO), (bs, C-1), (m, C-2,3,4,5,6,CO-£H2) , 31.4, 26.0, 24.3 (s, Example 5 Dodecanoyl-xylan sulfate, Na salt In accordance with GWI II and III, 9.1 g (0.045 mol) of dodecanoic acid, 7.36 g (0.045 mol) of CDI and 15 g (0.114 mol) of xylan are reacted in 200 ml of absolute - 23 DMSO and the reaction product is sulfated with 60 g (0.38 mol) of SO3-pyridine complex in 300 ml of absolute DMF.

Yield: 30.5 g of pale brownish amorphous powder 5 Degree of acylation: 20% of OH groups (according to 13CNMR) Degree of sulfation: 72.5% Analysis: 30.4% C 4.4% H 12.0% S IR(KBr): 1740 cm'1 (s, ester CO) 13C-NMR (D2O): δ 174 - 178.5 94.5 - 106 57 - 83.5 35.3, 33.4, 9 x CH2), 15 (bs, CO), (bs, C-l), (m, C-2,3,4,5,CO-CH2), 31.5, 26.0, 24.1 (bs, . 7 ppm (s, CH3).

Example 6 Hexanoyl-dextran sulfate, Na salt, from dextran 10,000 D In accordance with GWI II and III, 1.1 ml (1,08 g, 20 9 mmol) of hexanoic acid, 1.5 g (9 mmol) of CDI and 5 g (31 mmol) of dextran (M ~ 10,000 D) are reacted in 50 ml of absolute DMSO and the reaction product is sulfated with 30 g (189 mmol) of SO3-pyridine complex in 100 ml of absolute DMF.

Yield: 10.7 g of white amorphous powder Degree of acylation: 10% of the OH groups (according to 13C-NMR) Degree of sulfation: 51% Analysis: 27.0% C 4.2% H 14.1% S IR (KBr) : 1738 cm*1 (m, ester CO) 13C-NMR (D20): δ = 175.5 - 178 (m, CO), — 24 - 96 - 99 (nt, C-l), 66 - 81 (m, C—2,3,4,5,6 £H2), 35.7, , 32.1, 25.5, 23.4 (s, 4 : 15.0 ppm (s , CH3).

Example 7 Hexanoyl-dextran sulfate, dextran 10,000 D Na salt, from In accordance with GWI II and III, 2.2 ml (2.16 g, 18 mmol) of hexanoic acid, 3.0 g (18 mmol) of CDI and 5 g (31 mmol) of dextran (M ~ 10,000 D) are reacted in 50 ml of absolute DMSO and the reaction product is sulfated with 30 g (189 mmol) of SO3-pyridine complex in 100 ml of DMF.

Yield: 11.8 g of white amorphous powder 15 Degree of acylation: 20% of the OH groups (according to 13C-NMR) Degree of sulfation: 57% Analysis: 29.1% C 4.3% H 13.8% S IR (KBr): 1740 cm'1 (s, ester CO) 13C-NMR (D20): 8 = 176 - 178.5 (bs, CO), 96.5 - 99.5 (bs, C-l), - 82 (m, C-2,3,4,5,6, CO25 £H2), .6, 32.1, 25.8, 23.5, (s, 4 x CH2), .2 ppm (s, CH3).

Example 8 Hexanoyl-dextran sulfate, Na salt, from dextran 10,000 D In accordance with GWI II and III, 5.8 ml (5.38 g, 46 mmol) of hexanoic acid, 7.5 g (46 mmol) of CDI and 5 g (31 mmol) of dextran (M ~ 10,000 D) are reacted in 50 ml - 25 of absolute DMSO and the reaction product is then sulfated with 20 g (126 mmol) of SO3-pyridine complex in 100 ml of absolute DMF.

Yield: 12.2 g of white amorphous powder Degree of acylation: 44% of the OH groups (according to 13C-NMR) 10 Degree of Analysis: sulfation: 33.6% C 5.2% H 9.7% S 50% IR (KBr): 1741 cm1 (vs, ester CO) 1513C-NMR (D2O): δ = 172.5 - 179 (m, CO), 96.2 - 99.7 (m, C-l), 65 - 79 (m, C-2,3,4,5,6, C0- £H2), 35.6, 32.2, 25.7, 23.8, (s, 4 x ch2), 14.8 ppm (s, CH3).

Example 9 Hexadecanoyl-dextran sulfate, Na salt, from dextran 6,000 D /° -X-B-Y = -O-C^ ^(^2)14-¾ In accordance with GWI II and III, 1.9 g (7.4 mmol) of hexadecanoic acid, 1.2 g (7.4 mmol) of CDI and 2 g (12.3 mmol) of dextran (M ~ 6,000 D) are reacted in 20 ml of absolute DMSO and the reaction product is then sulfated with 10 g (63 mmol) of SO3-pyridlne complex in 100 ml of absolute DMF.

Yield: 4.3 g of white amorphous powder Degree of acylation: 20% of the OH groups (according to 13C-NMR) Degree of sulfation: 70% Analysis: 26.9% C 4.8% H 12.6% S IR (KBr ) : 1740 cm'1 (s, ester CO) 2860, 293 0 cm'1 (s, CH2)13C-NMR (D2o): δ = 174 - 179.5 (m, CO), 98.5 - 100.5 (m, C-1), 62 - 83 (m. C-2,3,4,5,6, CO- CH2) 9 39.0, 34.9, 32.8, 25.5 (bs, 14 x CH2), 16.8 ppm (s, CH3) .

Example 10 Dodecanoyl-dextran sulfate, Na salt, from dextran 6,000 D In accordance with GWI II and III, 15 g (75 mmol) of 15 dodecanoic acid, 12 g (75 mmol) of CDI and 20 g (123 mmol) of dextran (M ~ 6,000 D) are reacted in 200 ml of absolute DMSO and the reaction product is sulfated with 90 g (566 mmol) of SO3-pyridine complex in 300 ml of absolute DMF.

Yield: 47.4 g of pale yellowish amorphous powder Degree of acylation: 20% of the OH groups (according to13C-NMR) Degree of sulfation: 48% IR (KBr): 1740 cm1 (m, ester CO)13C-NMR (D20): δ = 175.5 - 180 (m, CO), 97 - 100.5 (m, C-1), 65.5 - 79.5 (m, C-2,3,4,5,6, CO- CH2), .6, 33.8, 31.0, 26.2, 24.0 (bs, 10 x CH2), 15.5 ppm (s, CH3). - 27 Hexanoyl-dextran sulfate, Na salt, from dextran 6,000 D Example 11 Degree of acylations 14% of the OH groups (according to 13C-NMR) Degree of sulfation: 66% Analysis: 22.9% C 3.9% H 14.1% S Example 12 Propanoyl-dextran sulfate, Na salt, from dextran 6,000 D Degree of acylation: 22% of the OH groups Degree of sulfation: 59% Analysis: 23.7% C 4.0% H 13.9% S Example 13 Hexanoyl-xylan sulfate, Na salt Degree of acylation: 25% of the OH groups Degree of sulfation: 70% Analysis: 24.5% C 20 2.8% H 13.8% S Example 14 [(1,3-Di-isopropoxyl)-propyl-2-oxycarbony1]-propanoyl-dextran sulfate, Na salt, from dextran 10,000 D -X-B-Y = XC ii // •0- C-CH2-CH2-C CHI * CH,-O-CH I z I CH0-CH CHCH,-O-CH Z I Hr |E 902384 - 28 Degree of acylation: Degree of sulfation: % of the OH groups 66% Analysis: 25.0% C 4.1% H 13.3% S Example 15 Hexanoyl-dextran sulfate, Na salt, hydrogenated dextran 3,500 D Degree of acylation: 20% of the OH groups Degree of sulfation: 78% Analysis: 23.8% C 3.4% H .9% S Example 16 Propanoyl-dextran sulfate, Na salt, dextran 10,000 D Degree of acylation: 38% of the OH groups Degree of sulfation: 53% Analysis: 24.7% C 4.0% H 11.2% S Example 17 Hexanoyl-dextran sulfate, Na salt, dextran 20,000 D Degree of acylation: 8% of the OH groups Degree of sulfation: 55% from from from Analysis: 27.2% C 3.1% H 16.0% S - 29 Example 18 Propanoyl-dextran sulfate, Na salt, from dextran 3,500 D Degree of acylation: 21% of the OH groups Degree of sulfation: 65% Analysis: 23.0% C 4.1% H .2% S Example 18 Dodecanoyl-dextran sulfate, Na salt, from dextran 10,000 D Degree of acylation: 17% of the OH groups Degree of sulfation: 80% Analysis: 25.9% C 4.6% H 14.6% S Example 20 Hexanoyl-xylan sulfate, Na salt Degree of acylation: 10% of the OH groups Degree of sulfation: 78% Analysis: 21.7% C 3.9% H 14.6% S Example 21 Propanoyl-xylan sulfate, Na salt Degree of acylation: 20% of the OH groups Degree of sulfation: 72% Analysis: 22.5% C 3.1% H 12.7% S Example 22 Propanoyl-xylan sulfate, Na salt - 30 Example 22 Propanoyl-xylan sulfate, Na salt Degree of acylations 39% of the OH groups Degree of sulfations 54% Analysis: 26.6% C 3.5% H .4% S Example 23 Hexanoyl-xylan sulfate, Na salt Degree of acylation: 16% of the OH groups Degree of sulfation: 56% Analysis: 26.65% C 3.65% H 11.4 % S Example 24 Dodecanoyl-xylan sulfate, Na salt Degree of acylation: 12% of the OH groups 15 Degree of sulfation: 81% Analysis: 24.5% C 3.7% H 13.4% S Example 25 Hexadecanoyl-xylan sulfate, Na salt g (152 mmol) of xylan are reacted in accordance with GWI II with 15.5 g (60.5 mmol) of palmitic acid and 9.8 g (60.5 mmol) of Ν,Ν'-carbonyldiimidazole in 200 ml of anhydrous DMSO at 70°C for 3 hours. The solvent is then stripped off in vacuo and the residue is sulfated in accordance with GWI III with 80 g (0.5 mol) of sulfur trioxide-pyridine complex in 200 ml of DMF at 50’C for 3 hours.

Working up, ultrafiltration and freeze-drying gives 46.2 g of a yellowish amorphous powder. - 31 Degree of acylation: 20% of the OH groups Degree of sulfation: 50% Analysis: 38.65% C .95% H 9.1% S IR (KBr): 1742 cm'1 (vs, ester CO) 13C-NMR (D2O) : 6 = 171-178.5 (m, CO), 92.5-100.5 (m, C-l), 47-81 (m, C-2,3,4,5, CO-CH2), 34.1, 31.8, 26.5, 24.4 (m, 14 x CH2), .2 ppm (s, CH3) .

Example 26 Hexyl-dextran sulfate, Na salt, from hydrogenated dextran 6,500 D -X-B-Y = -O-(CH2)5-CH3 In accordance with GWI I, 5 g of hydrogenated dextran (M ~ 6,500 D) are dissolved in 100 ml of anhydrous DMSO and reacted with 1.2 g of powdered sodium hydroxide and 3.9 ml of 1-bromohexane (corresponding to an equivalence of 30%, based on the OH groups) at 50°C for 8 hours under a nitrogen atmosphere. 22 g of sulfur trioxide-pyridine complex are then added, with vigorous stirring, and sulfation is carried out at 50eC for 3 hours. Working up, ultrafiltration and freeze-drying give 8.9 g of a yellowish amorphous powder.

Degree of alkylation: 12% of the OH groups Degree of sulfation: 83% Analysis: 20.1% C 2.9% H 16.4% S - 32 13C-NMR (D2O): 8 = 97 - 99.5 (m, C-1), 65.5 - 81 (m, C-2,3,4,5,6, O-CH2), 32.4, 30.7, 26.3, 23.5 (4s, 4 x CH2) .1 ppm (s, CH3) .

Example 27 Butyl-dextran sulfate, Na salt, from dextran 10,000 D -X-B-Y = -O-(CH2)3-CH3 In accordance with general working instructions I, 5 g of dextran (M ~ 10,000 D) are reacted with 2 ml of 1-bromo10 butane and 1 g of powdered potassium hydroxide in 100 ml of absolute DMSO at 50 °C for 8 hours under a nitrogen atmosphere. The reaction product is then sulfated with 22 g of sulfur trioxide-pyridine complex at 50 “C for 3 hours. Working up, purification and freeze-drying give 8.1 g of a pale yellowish-colored amorphous powder.

Degree of alkylation: 8% of the OH groups Degree of sulfation: 72% Analysis: 20.1% C 3.1% H 16.8% S 13C-NMR (D2O): 6 = 98.2 - 99.5 (m, C-1), 65.5 - 84.5 (m, C-2,3,4,5,6, O-CH2), 33.2, 20.5 (bs, 2 x (CH2), .3 ppm (bs, CH3) .

Example 28 Octyl-dextran sulfate, Na salt, from dextran 10,000 D -X-B-Y = -O-(CH2)7-CH3 In accordance with general working instructions I, 5 g of dextran (M ~ 10,000 D) are reacted with 3.4 ml of ΙΒΟ iodooctane and 1 g of powdered NaOH under nitrogen and - 33 the reaction product is then sulfated with 22 g of sulfur trioxide-pyridine complex.

Yield: 10.2 g of pale brownish amorphous powder Degree of alkylation: 7% of the OH groups Degree of sulfation: 89% Analysis: 18.7% C 2.7% H 17.6% S 13C-NMR (D2O): 6 = 96.5 - 99.5 (m, C-l), - 78.5 (m, C-2,3,4,5,6, O-CH2), 33.6, 31.0, 27.5, 24.2 (bs, 6 x (CH2), .8 ppm (s, CH3).

Example 29 Hexyl-dextran sulfate, Na salt, from hydrogenated dextran 6,500 D In accordance with general working instructions I, 5 g of hydrogenated dextran (M ~ 6,500 D) are reacted with 5.2 ml of 1-bromohexane and 1.6 g of powdered sodium hydroxide in 100 ml of absolute DMSO under a nitrogen atmosphere and the reaction product is then sulfated with 22 g of sulfur trioxide-pyridine complex.

Yield: 8.8 g of beige amorphous powder Degree of alkylation: 7% of the OH groups Degree of sulfation: 80% Analysis: 18.3% C 2.9% H 16.1% S 13C-NMR (D20): δ = 98.5 (bs, C-l), 67.0 - 80.5 (m, C-2,3,4,5,6, O-CH2), 32.5, 30.5, 26.2, 23.8 (bs, 4 x (CH2), 14.9 ppm (s, CH3). - 34 Example 30 Hexyl-dextran sulfate, Na salt, from hydrogenated dextran 10,000 D In accordance with general working instructions I, 5 g of hydrogenated dextran (M ~ 6,500 D) are reacted with 7.8 ml of 1-bromohexane and 2.4 g of sodium hydroxide in 100 ml of anhydrous DMSO at 70 °C under a nitrogen atmosphere and the reaction product is then sulfated with 22 g of sulfur trioxide-pyridine complex.

Yield: 7.2 g of a brownish amorphous powder Degree of alkylation: 17% of the OH groups Degree of sulfation: 64% Analysis: 26.7% C 3.9% H .2% S 13C-NMR (D20): δ = 97.2 - 99.5 (m, C-l), 66.0 - 80.5 (m, C-2,3,4,5,6, O-CH2), 32.5, 30.7, 26.2, 23.9 (bs, 4 x CH2), .0 ppm (s, CH3).

Claims (19)

1. Patent. Claims:

1. A substituted polysaccharide, which can be linear or branched, and which is composed of uniform or different naturally occurring or synthetic monomers which can also contain one substituted or unsubstituted amino group per monomer unit and in which the OH groups are on average between 5 and 80% substituted by a group of the formula -X-B-Y, in which X denotes an oxy group or a group of the formula I 0the carbon atom of which is bonded to B, B denotes a non-aromatic hydrocarbon radical having

2. To 30 carbon atoms, in the alkyl chain of which up to 3 methylene units can be replaced by oxy groups, in which up to three C-C double bonds can be present and which can be substituted by up to three Cx-C^-alkyl radicals and Y - if X is an oxy group - can be hydrogen, COOR or OSO3R 1 . in which R is a physiologically tolerated mono- or divalent cation, or represents a hydrocarbon radical having up to 20 carbon atoms or a mono- or bisether radical having 3 to 10 carbon atoms, and R 1 represents a physiologically tolerated cation, or Y - if X is a radical of the formula I - represents hydrogen or COOR, in which R has the abovementioned meanings, and in which the OH groups of the abovementioned polysaccharide are between 10 and 95% substituted by a group of the formula OSO 3 M, in which M represents a physiologically tolerated cation, and between 0 and 40% of the OH groups are unsubstituted, excluding the palmitic acid esters of chondroitin sulfate and the lauric acid esters of dextran sulfate. - 36 2. A substituted polysaccharide as claimed in claim 1, in which X is an oxy group and Y can be hydrogen, COOR or OSOaR 1 , in which R is a physiologically tolerated cation or represents a hydrocarbon radical having up to 20 carbon atoms and R 2 represents a physiologically tolerated cation.

3. A substituted polysaccharide as claimed in claim 1, in which X is a group of the formula I and Y represents hydrogen or COOR, in which R has the meanings given.

4. A substituted polysaccharide as claimed in one or more of claims 1 to 3, in which the polysaccharide matrix is built up from uniform or different monomer units chosen from the following group of compounds or is composed of the following compounds: xylose, arabinose, rhamnose, fucose, glucose, mannose, galactose, fructose, glucosamine, galactosamine, mannosamine, glucuronic acid, galacturonic acid, mannuronic acid, carrageenans, fucoidan, laminaran, alginate, lentinan, pluran, xylan, dextran, heparin, keratan sulfate, chondroitin 4- and 6sulfate, dermatan sulfate, heparin sulfate, hyaluronic acid, teichuronic acid and partial hydrolysates of starch, cellulose, glycogen, chitin or pectin.

5. A substituted polysaccharide as claimed in one or more of claims 1-4, which has an average molecular weight of up to 100 kD.

6. A substituted polysaccharide as claimed in one or more of claims 1 to 5, in which the polysaccharide matrix is composed of xylan or dextran having an average molecular weight of 1000 to 22,000.

7. A process for the preparation of a substituted - 37 polysaccharide in which X is an oxy group as claimed in one or more of claims 1, 2 or 4 to 6, which comprises partly etherifying the polysaccharide with an alkyl halide or an ω-halogenocarboxylic acid salt, under basic catalysis, and then completely or partly sulfating the product directly or after alkoxylation.

8. A process for the preparation of a substituted polysaccharide in which X is a group of the formula I as claimed in one or more of claims 1, 3 or 4 to 6, which comprises partly acylating the polysaccharide with a carboxylic acid or carboxylic acid derivative and completely or partly sulfating the OH groups which remain in the polysaccharide.

9. The use of a substituted polysaccharide as claimed in one or more of the preceding claims, not excluding the palmitic acid esters of chondrointin sulfate and the lauric acid esters of dextran sulfate, for combating diseases caused by viruses, in particular diseases caused by HIV.

10. A pharmaceutical containing a compound as claimed in claim 1.

11. A pharmaceutical containing a compound as claimed in one or more of the preceding claims for combating viral diseases, in particular for combating diseases caused by HIV.

12. The use of a compound as claimed in one or more of claims 1 to 6 for the preparation of pharmaceuticals for combating virus diseases, in particular for combating diseases caused by HIV.

13. A process for the treatment of virus diseases, which comprises administering one or more compounds as claimed in one of more of claims 1 to 6 . *E 902384 - 38

14. . A process for the preparation of a pharmaceutical for combating viral diseases, which comprises bringing one or more compound(s) as claimed in one or more of claims 1-6 into a suitable presentation form with suitable auxiliaries and/or excipients.

15. A substituted polysaccharide according to claim 1, substantially as hereinbefore described and exemplified.

16. A process for the preparation of a substituted polysaccharide according to claim 1, substantially as hereinbefore described and exemplified.

17. A substituted polysaccharide according to claim 1, whenever prepared by a process claimed in any one of claims 7, 8 or 16.

18. Use according to claim 9, substantially as hereinbefore described.

19. A pharmaceutical according to claim 10, substantially as hereinbefore described.