Immunosuppressive cyclolignan derivatives

Abstract: Immunosuppressive cyclolignan derivatives are provided of formula (I) or (II): or in which R¹ is hydrogen, hydroxy, alkoxy; R² and R³ are hydrogen, alkyl, acyl, or together R² and R³ form a group -CHR⁴-; R⁴ is hydrogen, alkyl, alkenyl, hydroxyalkyl, (poly)haloalkyl, aryl, acyloxyalkyl, alkoxy, carboxyalkyl, alkoxycarbonyl, carbamoyl; R⁵ when present is hydrogen, alkyl, alkenyl, aryl, (poly)haloalkyl, acyl, carbamoyl, or thiocarbamoyl; R⁶ is alkyl, hydroxyalkyl, haloalkyl, acyl, acyloxyalkyl, carboxy or alkoxycarbonyl; Ar is 3,4,5-trialkoxyphenyl or 4-hydroxy-3,5-dialkoxyphenyl; and X is nitrogen or oxygen.

Description: This invention is concerned with cyclolignan derivatives, the preparation of such derivatives, and pharmaceutical compositions containing them. Podophyllotoxin is a known cyclolignan derivative with antimitotic and related activities, see for example the discussion in US 4,567,253. Many derivatives have been discovered or synthesised, see additionally for example Acta Chem. Scan. 1993 47:1190 and Arch. Pharm. (Weinheim) 327, 175 (1994). WO 86/04062 reports an effect against reactions of immunity and rejection in respect of podophyllotoxin. Helvetica Chimica Acta, 46 (1), 75(1963) and 47 (6), 164(1964) disclose the compounds hereinafter defined as AP-39 and AP-40 and a method for synthesising them. Chem.Pharm.Bull. 40 (10), 2720 (1992) discloses the compound hereinafter defined as AP-37 and other podophyllotoxin derivatives which are stated to have antitumour activity. However, according to this document, the compounds used in the present invention show neither inhibition of tubulin polymerisation nor inhibition of DNA topoisomerase II. DE-A-3612278 discloses epipodophyllotoxin and related compounds of use as antineoplastic agents. The definition in this publication for the group R 5 does not coincide with the compounds of the present invention. J.Pharm.Sci., 75 (11) 1076 (1986) relates to podophyllotoxin and this thermolysis products. J.Org.Chem., 54 (18), 4280 (1989) relates to intermediates for podophyllotoxin synthesis. Chem.Abs. 120 235424b (1996) relates to various podophyllotoxin derivatives with antineoplastic and antiviral activities. J.Chem.Soc.Perkin Trans. 1, 21, 2541 (1993) is concerned with the synthesis of various podophyllotoxin derivatives. It has now been found, in accordance with the present invention, that the above known cyclolignan derivatives, as hereinafter defined, possess immunomodulatory activity, as evidenced by both in vitro (MLR) and in vivo (GVHR and SG) tests. Accordingly, the invention provides the use of cyclolignan derivatives of the formula (I): in which: R 1 is hydrogen or hydroxy; and Ar is 3,4,5-trialkoxyphenyl, wherein each alkoxy moiety may be the same or different and each has from 1 to 6 carbon atoms; in the manufacture of an immunomodulatory pharmaceutical composition. PREFERRED EMBODIMENTS The alkoxy groups have from 1 to 6 carbon atoms, more preferably 1 to 4 carbon atoms. Examples include methoxy, ethoxy, propoxy, isopropoxy, butoxy, t-butoxy and other alkoxy groups. The present compounds can exist as optical isomers, and the invention embraces the individual isomers and mixtures thereof, including the diastereomeric or racemic mix. The stereochemistry of the substituents may be selected as desired, and for example the group R 1 can be α or β. Individual preferred compounds usable in this invention include AP-37, which is 3,4- O -demethylenedeoxypicropodophyllin; AP-39, which is 3,4- O -demethyleneepipodophyllotoxin; and AP-40, which is 3,4- O -demethylenepodophyllotoxin. Compounds of formula (I), as noted above, have immunomodulatory activity. Accordingly, immunosuppressive pharmaceutical compositions comprising compounds of formula (I) as defined above in association with a pharmaceutical carrier, can be readily envisaged by those skilled in the art. Such pharmaceutical compositions may, for example, be adapted for oral, parenteral, or rectal administration by the incorporation or appropriate pharmaceutical carriers and options adjuvants. The immunosuppressive activity of a compound in accordance with the invention is summarised below. Immunosuppressive effects of several representative cyclolignans Compound dose GVHR index SG index Cytotox. AP-37 0.1 58 -- >20 AP-39 1.5 -- 200 >10 AP-40 1.5 -- 229 0.5 Cyclophosphamide 200 79 -- -- Cyclosporin A 25 -- 178 -- The compounds in accordance with the invention may be prepared from podophyllotoxin and analogues formula: For example, see A.W. Fortschrite Chem. Org. Naturstoff 15 . 83 (1953) which describes podophyllotoxin where R is hydroxy and 8'-H is β; deoxypodophyllotoxin where R is hydrogen and 8'-H is β; and deoxypicropodophyllin where R is hydrogen and 8'-H is α. See also J.Med.Chem. 29 1547-1550 (1986) and Chem. Pharm. Bull. 40 2720-2727 (1992). For example, compounds of this invention can be made in accordance with the following reaction scheme, where partial structures are shown as appropriate: Other equivalent reaction conditions can be employed. EXAMPLE OF THE INVENTION In order that the invention may be further understood, the following example is given by way of illustration only. Example Preparation of AP-37: To a solution of boron trichloride in CH 2 Cl 2 (1M, 2 ml) precooled at -70° to -65° was added dropwise deoxypicropodophyllin (100 mg) in dry CH 2 Cl 2 (6 ml). After stirring at the same temperature for an additional 1 hour, the mixture was poured into ice-water and extracted with ethyl acetate. The residue obtained after evaporating the organic solvent was dissolved in a mixture of water:acetone:calcium carbonate (3ml:3ml:1g) and refluxed for 1 hour. The suspension was acidified with 2N HCl and extracted with ethyl acetate. Evaporation of the solvent afforded 80 mg of AP-37. [M+]: 386 mp: 226-228°C (MeOH) [α] D (CHCl 3 ): +46.8° UV λ max (EtOH)(ε): 222(23300), 288(7200) IR (KBr): 3400, 1740, 1600, 1510, 1300, 1110 cm -1 .

Claims: The use of a compound of the formula (I): in which: R 1 is hydrogen or hydroxy; and Ar is 3,4,5-trialkoxyphenyl, wherein each alkoxy moiety may be the same or different and each has from 1 to 6 carbon atoms, in the manufacture of an immunomodulatory pharmaceutical composition. The use according to claim 1, wherein the compound is 3,4- O -demethylenedeoxypicropodophyllin. The use according to claim 1, wherein compound is 3,4- O -demethyleneepipodophyllotoxin. The use according to claim 1, wherein the compound is 3,4- O -demethylenepodophyllotoxin.

Inventors: CASTRO MARIA ANGELES, DEL CORRAL JOSE MARIA MIGUEL, FAIRCLOTH GLYNN T, GORDALIZA MARINA, LOPEZ MARIA LUISA, SAN FELICIANO ARTURO, CASTRO, MARIA ANGELES, DEL CORRAL, JOSE MARIA MIGUEL, FAIRCLOTH, GLYNN T., GORDALIZA, MARINA, LOPEZ, MARIA LUISA, SAN FELICIANO, ARTURO, Faircloth, Glynn T. Pharma Mar S.A.
Applicants: UNIV SALAMANCA, UNIVERSIDAD DE SALAMANCA
Application year: 1995
Main classification: C07D307
IPC codes: A61K31, A61P37, C07D498, C07D491, C07D493, C07D261, C07D231, C07D307, C07D209