0001 The invention relates to anthracycline glycosides, to a process for their preparation and to pharmaceutical compositions containing them. 0002 The invention provides a compound which is an anthracycline glycoside of the formula I: 1

0003 wherein R is hydrogen, hydroxy or methoxy, R1 and R2, which are the same or different, are independently hydrogen or hydroxy, or a pharmaceutically acceptable salt thereof. 0004 In preferred compounds of formula I R is methoxy, R1 is hydroxy and R2 is hydrogen; or R is methoxy, R1 is hydrogen and R2 is hydroxy. These compounds are 0005 daunorubicin 14-sulfonic acid (Ia) and 0006 4 epi daunorubicin 14-sulfonic acid (Ib). 0007 The compounds of formula (I) may exist as zwitterions, i.e. as internal salts of a 14-SO3-group with the amino group on the sugar residue; such salts are also part of the present invention. 0008 The pharmaceutically acceptable salts are, for example, alkali metal and alkaline earth metal salts (e.g. sodium, potassium, lithium, calcium and magnesium salts), ammonium salts and salts with an appropriate organic amine or amino acid (e.g. arginine, procaine salts), and the addition salts formed with suitable organic or inorganic acids (e.g. hydrochlorides, hydrobromides, sulfates, phosphates) or carboxylic and sulfonic organic acids (e.g. acetates, citrates, succinates, malonates, lactates, tartrates, fumarates, maleates, methanesulphonates, p-toluenesulphonates). 0009 The compounds of the formula I may be prepared by reacting the anthracycline of the formula II 2

0010 wherein R, R1 and R2 are as defined above, R3 is hydroxy or a leaving group, and R4 is hydrogen or a nitrogen protecting group, with a sulfiting agent in a polar solvent or a mixture of polar solvents, and, if desired, removing the protecting groups from the resulting compound. The resulting compound may be converted into a pharmaceutically acceptable salt thereof. Suitable leaving group which R3 may represent include halogen atoms, such as bromine, iodine or chlorine, or mesyl, trifluoromesyl or p-toluensulfonyl groups. Suitable nitrogen protecting groups include, for instance, a trifluoroacetyl group. Examples of suitable solvents include acetone, water and mixtures of acetone and water. The reaction is preferably conducted at a temperature below 50 C., more preferably at room temperature. The desired resultant derivative may be isolated by precipitation from appropriate solvent mixtures. The starting material for the preparation of the new anthracycline glycosides is an optionally protected daunorubicin or 4-demethoxy daunorubicin, that may be easily converted into the compounds of the formula II as described in Antitumor Anthracyclines, Chim. Oggi, April 1990, p. 9-19. 0011 The invention further provides a pharmaceutical composition comprising an anthracycline glycoside of formula I in admixture with a pharmaceutically acceptable diluent or carrier. Conventional carriers and diluents may be used. The composition may be formulated and administered in conventional manner. 0012 The suspension or solutions for intramuscular injections may contain, together with the active compound, a pharmaceutically acceptable carrier, e.g. sterile water, olive oil ethyl oleate, glycols, e.g. propylene glycol and, if desired, a suitable amount of lidocaine hydrochloride. The solutions for intravenous injections or infusions may contain as carrier, for example, sterile water or preferably they may be in the form of sterile, aqueous, isotonic saline solutions or they may contain as a carrier propylene glycol. 0013 The compounds according to the invention are useful in methods of treatment of the human or animal body by therapy. They are useful as anti-tumor agents. They are useful in the treatment of leukemia and solid tumors, such as colon, colon-rectal ovarian, mammary, prostate, lung, kidney and also melanoma tumors. A human can therefore be treated by a method comprising administering thereto a therapeutically effective amount of a compound of the invention. The condition of the human patient can thus be improved. The dosage to be given can be ascertained using known dosage ranges in the field of anthracyclines, modified by reference to the activity shown by the present compounds in in vitro and in vivo anti-tumor tests. Suitable dosages are generally in the range of 1 to 200 mg/m2 body surface, preferably from 1 to 100 mg/m2, depending on the nature and severity of the disease being treated and on the general condition of the patient. 0014 The compounds of formula I were tested and found active in vivo against a tumor cell lines, and in vivo on murine leukemia. 0015 On tumor cell lines, the compounds of the present invention were shown to present high cytotoxicity. The in vivo tests were carried on murine leukemia.

EXAMPLE 1 0016 Daunorubicin 14-sulfonic Acid (Ia) 0017 14-bromo-daunorubicin hydrochoride (II, ROCH3, R1OH, R2H, R3Br, 2 mmol) were dissolved in acetone-water (3030 ml). The solution was added with an aqueous solution of sodium sulfite (570 mg, 4.38 mmol), and the pH was adjusted to about 7.6 with aqueous ammonia 100%. After stirring 3 hours at room temperature, the reaction mixture was concentrated to dryness. The residue was suspended in methanol and the methanolic suspension was dropped in acetone at 4-5EC. The precipitate was filtered, washed on the filter and dried under vacuum. The product has been identified by MS and NMR analysis. 1ESI () Mass spectrumm/zIntensityAttribution608100M H59012M H2O H 46110

44312

3814

3636

3212

0018 High resolution mass spectrometry. 0019 An exact mass determination has been performed on the protonated molecular ion at m/z 608, with the following result 0020 Calculated for C27H29NO13SH: 608.14379 Found: 608.14374 0.0 ppm 21H NMR chemical shifts and coupling constants (ppm)Multiplicity*J (Hz)Proton1.11d6.5CH3-61.62dd12.5, 4.2H-2eq1.83ddd12.5, 12.5, 3.4H-2ax2.03dd14.8, 5.3H-82.36d14.8H-82.73d18.0H-102.99d18.0H-103.25dd12.5, 4.2H-33.50sH-43.86d10.9H-14a3.99sOCH34.18d10.9H-14b4.33q6.5H-54.90d5.3H-75.30d3.4H-16.13sOH-97.66mH-37.92mH-2, H-1*s singlet, d-doublet, t triplet, q quartet, m-multiplet H2O signal overlaps this resonance; chemical shift was detected in 2D experiments and coupling constants were measured on J-coupled signals.

0021

313C NMR chemical shifts* (ppm)Carbon (ppm)Carbon17.1C-699.5C-129.3C-2C-5a, C-11a33.2C-10119.5C-136.7C-8120.2C-3, C-4a47.2C-3135.0, 136.0C-10a, C-6a57.0OCH3135.1C-12a61.5C-14136.7C-266.6C-5C-11, C-667.2C-4161.1C-469.5C-7C-5, C-12C-9208.6C-13*Carbon chemical shift were detected in the HSQC and GHMBC experiments no correlations were observed in the GHMBC experiment for these carbons