NZ505531A

NZ505531A - 7-Propyl-8-oxo-alpha or beta-L-guanine alpha or beta-L-nucleoside

Info

Publication number: NZ505531A
Application number: NZ505531A
Authority: NZ
Inventors: Robert Tam; Devron Averett; Kandasamy Ramasamy
Original assignee: Icn Pharmaceuticals
Priority date: 1996-10-16
Filing date: 1998-01-13
Publication date: 2001-08-31

Abstract

A nucleoside having the structure of formula (I) is disclosed. A pharmaceutical composition thereof is useful for enhancing an immune response in a mammal.

Description

<div class="application article clearfix" id="description"> NEW ZEALAND PATENTS ACT, 1953 No: Divided out of NZ 336350 Dated 13 January 1998 Date: COMPLETE SPECIFICATION NOVEL NUCLEOSIDES We, ICN PHARMACEUTICALS, INC., of 3300 Hyland Avenue, Costa Mesa, California 92626, United States of America, do hereby declare the invention for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: -1 - (followed by page la) IN'TELLFCT"" N.I -3 JUL 2000 RECEIVED - la - NOVEL NUCLEOSIDES This application is a divisional of New Zealand Specification No. 336350. FIELD OF THE INVENTION The piesent invention relates to the field of nucleosides BACKGROUND OF THE INVENTION Mammalian immune systems contain two major classes of lymphocytes B lymphocytes (B cells), which 01 iginate in the bone manow, and T lymphocytes (T cells) which originate in the thymus. B cells are largely responsible for humoral immunity (i e , antibody production), while T cells are largely responsible for cell-mediatcd immunity T cells are generally considered to fall into two subclasses, helper T cells and cytotoxic T cells Helper T cells activate other lymphocytes, including B cells and cytotoxic T cells, and macrophages, by releasing soluble protein mediators called cytokines which are involved in cell-mediated immunity As used herein, lymphokines are a subset of cytokines Helper T cells are also geneially considered to fall into two subclasses, Thl and Th2. Thl cells (also known as Type 1 cells) produce interleukin 2 (1L-2), tumor neciosis factor (TNFa) and interferon gamma (IFNy), and are responsible primarily for cell-mediated immunjty such as delayed type hypersensitivity and antiviral immunity In contrast, Th2 cells (also known as Type 2 cells) produce interleukins, 1L4, IL-5, IL-6, IL-9, IL-10 and IL-13, and are pnmarily involved in assisting humoral immune responses such as those seen in response to allergens, e g IgE and lgG4 antibody isotype switching (Mosmann, \9%9, Aumi Rev Immunol, 7 145-173) As used herein, the terms Thl and Th2 "responses" are meant to include the entire range of effects resulting from induction of Thl and Th2 lymphocytes, respectively Among other things, such responses include variation in production of the corresponding cytokines through transcription, translation, secretion and possibly other mechanisms, increased proliferation of the corresponding lymphocytes, and other effects associated with increased production of cytokines, including motility effects The mechanisms by which nucleosides and other compounds selectively modulate Thl and Th2 responses relative to each other are still unclear One possibility contemplated by the present inventors is that effective nucleosides alter the pool of guanosine triphosphate (GTP), which m turn affects the rate at which cytokines are pioduced In this theory, relatively large variations in available GTP are sufficieni to affect concentrations of both Thl and Th2 cytokines, while, jelatively smaller variations in available GTP lend to affect concentrations of Thl and Th2 cytokines io different extents ) These discoveries are especially significant because modern treatment strategies for many of the above-listed diseases have either limited effectiveness, significant side effects, or both Treatment of autoimmune disease, for example, is frequently limited to palliative measures, removal of toxic antibodies (as m myasthenia gravis), and administration of hazardous drugs including corticosteroids, chloroquine derivatives, and antimetabolic or antitumor drugs, and drugs such as cyclosporins which target immune system cells. SUMMARY OF THE INVENTION This application relates to novel nucleosides. Nucleosides contemplated are those nucleosides corresponding to Formula 1 Divisional specification No. NZ 505530 also divided out of NZ 336350, provides a method of reducing an administered dosage of a first drug in the treatment of a disease which is known to produce an abnormality in at least one cytokine m a patient, comprising: identifying a monotherapeutic dosage of the first drug which is effective to treat the disease; identifying a second drug which is known to exacerbate the abnormality when administered with a dosage range; and administering a combination therapy comprising the first drug at less than the monotherapeutic dosage and the second drug outside the dosage range. Also described is a controlled release preparation for oral administration including a compound effective to selectively modulate Thl and Th2 responses with respect to each other within a dosage range. DETAILED DESCRIPTION Where the following terms are used in this specification, they are used as defined below The terms "a" and "P" indicate the specific stereochemical configuration of a substituent at an asymmetric carbon atom in a chemical structure as drawn The term "aryl" refers to a monovalent unsaturated aromatic carbocyclic radical having a single ring (e g , phenyl) or two condensed nngs (e g , naphthyl), which can optionally be substituted with hydroxyl, lower alky, chloro, and/or cyano The term "enantiomers" refers to a pair of stereoisomers that are non-supenmposable mirror images of each other A mixture of a pair of enantiomers, in a 1.1 ratio, is a "racemic" mixture The term "heterocycle" refers to a monovalent saturated or unsaturated carbocyclic radical having at least one hctcro atom, such as N, 0 or S, within the ring each available position of which can be optionally substituted, independently, with, e g , hydroxy, oxo, amino, imino, lower alkyl, bromo, chloro and/or cyano Included within this class of substituents are punnes, pyrimidines The term "isomers" refers to different compounds that have the same formula. "Stereoisomers" are isomers that differ only in the way the atoms are arranged in space. The term "L-configuration" is used throughout the present invention to describe the chemical configuration of the nbofuranosyl moiety of the compounds that is linked to the nucleobases. The L-configuration of the sugar moiety of compounds of the present invention contrasts with the D-configuration of ribose sugar moieties of the naturally occurring nucleosides such as cytidine, adenosine, thymidine, guanosine and uridine. The term "lower alkyl" refers to methyl, ethyl, n-propyl, isopropyl, n-butyl, t-butyl, I-butyl or n-hexyl This term is further exemplified to a cyclic, branched or straight chain from one to six carbon atoms. The term "monocyclic" refers to a monovalent saturated carbocyclic radical having at least one hetero atom, such as 0, N, S, Se or P, within the ring, each available position of which can be optionally substituted, independently, with a sugar moiety or any other groups like bromo, chloro and/or cyano, so that the monocyclic ring system eventually aromatized The term "nucleoside" refers to a compound composed of any pentose or modified pentose moiety attached to a specific position of a heterocycle or to the natural position of a purine (9-position) or pyrimidine (1-position). The term "C-nucleosides" is used throughout the specification to describe the linkage type that formed between the ribose sugar moiety and the heterocyclic base. In C-nucleosides, the linkage originates from the C-l position of the ribose sugar moiety and joins the carbon of the heterocyclic base The linkage that forms in C-nucleosides is carbon-to-carbon type The term "D-nucleosides" refers to nucleoside compounds that have a D-ribose sugar moiety (e g., Adenosine). The term "L-nucleosides" refers to nucleoside compounds that have an L-ribose sugar moiety The term "N-nucleosides" is used throughout the specification to describe the linkage type that formed between the nbose sugar moiety and the heterocychc base. In N-nucleosides, the linkage originates from the C-l position of the nbose sugar moiety and joins the nitrogen of the heterocyclic base The linkage that forms in N-nucleosides is carbon to nitrogen type. The term "nucleotide" refers to a phosphate ester substituted on the 5-position of a nucleoside The term "Punne" refers to nitrogenous bicyclic heterocycles depicted in Figures 1 and 2 herein Examples of compounds contemplated to be effective in the invention are shown in Formula 1. Formula 2 is also disclosed but not claimed. Formula 1 has the structure: INTELLECTUAL PROPERTY OFFICE OF NZ. 1 4 JUN 2001 RECEIVED Formula 2 has the structure: 0 (followed by page -5a-) -5a- SYNTHESIS OF COMPOUNDS OF FOkMULA "0 oif McO 01I "0 Oil 2 0 N. *-< J T I N^nh, LovT-oh "0 on o N. UnX'n I N NIIAC UyOR RO OR 5 Kb Dl 6 R a II (^OsyT^OlI HO Oil (followed by page -5b-) 1-0-Methyl-L-ribofuranose 2 A cold solution of dry hydrogen chloride (4.4 g, 0.12 mol) in methanol (100 mL) was slowly added to the solution of L-(+)-ribose 1 (50 g, 0.33 mole in methanol (1000 mL) at room temperature. After addition, the solution was stirred for 2.5 h and quenched with pyridine (100 mL). The mixture was stirred for 10 min and the solvent was evaporated. The residue was dissolved in pyridine (100 mL) and the resulting solution was concentrated to dryness to give 1-O-methyl-L-ribofuranose 2 as a pale-yellow syrup. l-0-Methyl-2',3',5'-0-tribenzoyl-L-ribofuranose 3 Benzoyl chloride (154.5 g, 1.1 mol) was added dropwise during 10 min to a solution of l-O-methyl-L-ribofuranose 2 (0.33 mol) in pyridine (350 mL) at 0 °C. After addition, the solution stood at room temperature for 14 la and quenched by stirring with water (50 mL) at 0 oC for 1 h. The aqueous layer was extracted with CH2Cl2 (2 x 100 mL) and the combined organic layer concentrated. The residue was dissolved in CH2C12 (500 mL), washed successively with saturated NaHC03 (3 x 100 mL), water (200 mL), brine (200 mL), dried over Na2S04, filtered, and evaporated with toluene (2 x 300 mL). Further drying under vacuum afforded 1-0-methyl-2\3',5'-0-tribenzoyl-L-ribofuranose 3 as a yellow syrup (80 g, 0.17 mole). l-O-Acetyl-2',3 \5'-CJ-tribenzoyl-L-ribofuraaose 4 1 -O-Methyi-2' ,3 \51 -O-tribenzoyl-L-ribofuranose 3 (80 g, 0.17 mol) was dissolved at room temperature in a mixture of acetic acid (354 mL) and acetic anhydride (36 mL). The resulting solution was cooled to 0 oC and sulfuric acid (96%, 8.23 g, 0.084 mol) added dropwise. After addition, the reaction mixture stood at room temperature for 18 h, poured onto ice (500 g), and stirred until the ice had melt. EtOAc (1.2 L) was added followed by water (1 L). The organic layer was washed with water/brine mixture (4/1 ratio), saturated NaHC03 (500 mL), brine (500 mL), filtered through a silica gel pad, and concentrated to give the crude product as yellow solid. Recrystallization from hexanes/EtOAc (300 mL/100 mL ratio) afforded l-0-acelyl-2\3\5'-<9-tribenzoyl-L-ribofiiranose 4 as white needles (50 g, 59.6% overall yield from L-ribose). N^-Acetyl-2',3',5'-(9-triben2oyI-P-L-guanosme 5 N^-Acetylguanine (4.125g, 21.35mmol) was suspended in pyridine (50 mL) at 80 °C for 25 min. and then pyridine was evaporated under high vacuum. The same procedure was repeated once. The obtained material was dried under vacuum overnight and silylated by heating with excess of HMDS (50mL), pyridine (lOmL) and TMSC1 (150 mL) under argon for 2.5 hours. After the reaction mixture was cooled to RT, the solvents were evaporated under vacuum. The residual (followed by page -5c-) INTELLECTUAL PROPERTY OFFICE OF N.Z. 1 k JUN 2001 RECEIVED HMDS and pyridine were coevaporated with xylene (2 x 40mL). Tine silylated base was suspended in dichloroethane (70 mL) and combined with dichloroethane (182mL) solution of 1-aceiyl-2,3,5-0-tribezoyl-L-ribose (9.71g, 19.22 mmol). The obtained suspension was stirred under argon at reflux temperature for 10 min. and dichloroethanc (35 mL) solution of TMS-triflate (4.50 mL, 23.276 mmol) was added dropwise (20 min). The obtained reaction mixture was stirred under reflux for 1.5 h, cooled to RT and diluted with methylene chloride (500ml). The organic solution was washed with cold NaHCOj (5% aq., 2 x 150mL), brine (150 mL), dried (Na2S04) and evaporated to dryness. The reaction mixture was purified by flash chromatography (400 g of silica gel, eluent: 28% EtOAc, 2% EtOH in CH2C12, v/v) to give 5.60g (46%) of N2-Acetyl-2\3',5'-Otribenzoyl- (3 -L-guanosine 5. J3 -L-Guanosine 6 A solution of N2-acetyl-2',3',5'-C>-tribenzoyl-L-guanosine 5 in saturated ammonia-methanol stood at room temperature for two days. Ammonia and methanol were evaporated and the crude dissolved in water and chloroform (two layers). The aqueous layer was washed with chloroform three times and concentrated. The crude product was purified by crystallization from water-methanol to give (3 -L-Guanosine 6 as a colorless solid. 8-Bromo- -L-gnanosine 7 To a suspension of L-guanosine 6 (1.24 g) in water (7.5 mL) was added in portions 35 mL of saturated bromine-water containing 0.35 mL of bromine. The solid was filtered off, successively washed with cold water, cold acetone, and dried. Crystallization from water gave pure 8-Bromo-L-guanosine 7 as a colorless solid. 8-Alkyloxy- (3 -L-guanosine 8 To a stirred mixture of NaH (984 mg) in anhydrous DMSO (30 mL) was added dropwise alkyl alcohol (10 mL), followed by addition of 8-Bromo-L-guanosine 7 (1.78 g, 4.92 mmol) in DMSO (10 mL). The resulting reaction mixture was stirred at 60 °C overnight, cooled to room temperature, and diluted with ethyl ether (350 mL). The resulting precipitates were filtered, dissolved in water (18 mL), and neutralized with acetic acid. The resulting precipitates were filtered and recyrstallized from water/methanol to give 836 mg of 8-aUcyloxy-L-guanosine 8 as a slightly yellow solid. 7-Allyl-8-oxo- 3 -L-guanosine 9 A mixture of 8-alkyloxyguanosine 8 (560 mg) in methanol-water (50 mL, 1:1, v/v) was stirred under reflux and a clear solution formed after two hours. The solution was refluxed for additional (followed by page -5d-) INTELLECTUAL PROPERTY OFFICE OF N.Z. 1 i JUN 2001 RECEIVED 50 5531 5 h and cooled to room temperature. A brown precipitates (by product) was^ltlAd-aAd ^ r t filtrate concentrated to give a crude product Crystallization from watcr-ethanol gave 83 mg of " title compound as a slightly brown solid. The filtrate was concentrated and the residue chromatographed on silica with 5%Et3N and 20%MeOH in methylene chloride to give 260 mg of 7-alkyl-8-oxo- {3 -L-guanosine 9 as a colorless solid. Administration It is contemplated that compounds according to the present invention will be administered in any appropriate pharmaceutical formulation, and under any appropriate protocol. Preferred monotherapeutic dosages and protocols for such drugs are set forth in the PDR, or are at least available from the manufacturer or distributor. Of course, one of ordinary skill in the art will recognize that a therapeutically effective amount will vary with the infection or condition to be treated, its severity, the treatment regimen to be employed, the pharmacokinetics of the agent used, as well as the patient (animal or human) treated. Thus, effective dosages may range from 1 mg/kg of body weight, or less, to 25 mg/kg of body weight or more. This dosage range generally produces effective blood level concentrations of active compound ranging from about 0.04 to about 100 micrograms/cc of blood in the patient. It is contemplated, however, that appropriate patient-specific regimens will be developed by administering a small amount, and then increasing the amount until either the side effects become unduly adverse, or the intended effect is achieved Administration of compounds according to the present invention may take place orally, parenterally (including subcutaneous injections, intravenous, intramuscularly, by intrastemal injection or infusion techniques), by inhalation spray, or rectally, topically and so forth, and in dosage unit formulations containing conventional non-toxic pharmaceutically acceptable carriers, adjuvants and vehicles. It is contemplated that compounds according to the present invention can be formulated in admixture with a pharmaceutically acceptable carrier. For example, the compounds of the present (followed by page -6-) INTELLECTUAL PROPERTY OFFICE OF N.Z. 1 4 JUN 2001 RECEIVED -6- mvention can be administered orally as pharmacologically acceptable salts. Because the compounds of the present invention are mostly water soluble, they can be administered intravenously in physiological saline solution (e g., buffered to a pH of about 7.2 to 7 5) Conventional buffers such as phosphates, bicarbonates or citrates can be used for this purpose Of course, one of ordinary skill in the art may modify the formulations within the teachings of the specification to provide numerous formulations for a particular route of administration without rendering the compositions of the present invention unstable or compromising their therapeutic activity. In particular, the modification of the present compounds to render them more soluble in water or other vehicle, for example, may be easily accomplished by minor modifications (salt formulation, esterification, etc.) which are well within the ordinary skill in the art It is also well within the ordinary skill of the art to modify the route of administration and dosage regimen of a particular compound in order to manage the pharmacokinetics of the present compounds for maximum beneficial effect in patients. In addition, compounds included in combinations according to the present invention may be administered separately or together, and when administered separately this may occur in any order The amounts of the active mgredient(s) and pharmaceutically active agent(s) and the relative timings of administration will be selected in order to achieve the desired combined therapeutic effect Administration routes of compounds according to the present invention may range from continuous (intravenous drip) to several oral administrations per day (for example, QID ) and may include oral, topical, parenteral, intramuscular, intravenous, sub-cutaneous, transdermal (which may include a penetration enhancement agent), buccal and suppository administration, among other routes of administration. To prepare therapies according to the present invention, a therapeutically effective amount of a compound is preferably intimately admixed with a pharmaceutically acceptable carrier according to conventional pharmaceutical compounding techniques to produce a dose A carrier may take a wide variety of forms depending on the form of preparation desired for administration, e.g., oral or parenteral. In preparing pharmaceutical compositions in oral dosage form, any of the usual pharmaceutical media may be used. Thus, for liquid oral preparations such as suspensions, elixirs and solutions, suitable carriers and additives including water, glycols, oils, alcohols, flavoring agents, preservatives, coloring agents and the like may be used. For solid oral preparations such as powders, tablets, capsules, and for solid preparations such as suppositories, suitable carriers and additives including starches, sugar carrier, such as dextrose, mannitol, lactose and related carriers, diluents, -7- granulating agents, lubncants, binders, disintegrating agents and the like may be used. If desired, the tablets or capsules may be enteric-coated or sustained release by standard techniques. For parenteral formulations, the carrier will usually comprise sterile water or aqueous sodium chloride solution, though other ingredients including those which aid dispersion may be included. Of course, where sterile water is to be used and maintained as sterile, the compositions and carriers must also be sterilized. Injectable suspensions may also be prepared, in which case appropriate liquid carriers, suspending agents and the like may be employed It will also be appreciated that in general, the most preferred uses according to the present invention are those in which the active compounds are relatively less cytotoxic to the non-target host cells and relatively more active against the target While specific embodiments have been disclosed herein, the scope of the invention is not be limited except through interpretation of the appended claims. </div>

Claims

<div class="application article clearfix printTableText" id="claims"> 50 5 5.3 1 WHAT WE CLAIM IS:

1. A nucleoside having the structure of Formula 1:

2. A nucleoside having the structure of formula 1 substantially as herein described.

3. A use of the nucleoside as claimed in claim 1 in the manufacture of a medicament for enhancing the immune response in a mammal in need thereof.

4. A pharmaceutical composition comprising the compound of claim 1 together with a pharmaceutically acceptable carrier.

5. A use as claimed in claim 1 substantially as herein described or exemplified.

6. A pharmaceutical composition as claimed in claim 4 substantially as herein described or exemplified. INTELLECTUAL PROPERTY OFFICE OF N.Z. 1 < JUN 2001 RECEIVED </div>