AU723707B2

AU723707B2 - Steroid sulphatase inhibitors

Info

Publication number: AU723707B2
Application number: AU71952/98A
Authority: AU
Inventors: Barry Victor Lloyd Potter; Michael John Reed
Original assignee: Sterix Ltd
Current assignee: Sterix Ltd
Priority date: 1991-08-29
Filing date: 1998-06-18
Publication date: 2000-09-07
Anticipated expiration: 2012-08-28
Also published as: AU7195298A

Description

AUSTRALIA

Patents Act COMPLETE SPECIFICATION

(ORIGINAL)

Class Int. Class Application Number: Lodged: Complete Specification Lodged: Accepted: Published: Priority Related Art: a.

to.

"0000 o** *to*0 to* Name of Applicant: Actual Inventor(s): Michael John Reed Barry Victor Lloyd Potter Address for Service: ilogy and medicin~e PHILLIPS ORMONDE FITZPATRtett Patent and Trade Mark Attorneys 367 Cllins Street Melbourne 3000 AUSTRALIA 'qsr& -rd~f LAAj' &m~2 oA Z10( 2 Invention Title: STEROID SULPHATASE INHIBITORS Our Ref 533426 POF Code: 1519/173677 The following statement is a full description of this invention, including the best method of performing it known to applicant(s): 1la STEROID SULPHATASE INHIBITORS This application is a divisional application of 58373/96 which in turn is a divisional of 24905/92. The entire disclosure of both applications is incorporated herein by reference.

FIELD OF INVENTION This invention relates to novel compounds for use as steroid sulphatase inhibitors, and pharmaceutical compositions containing them.

BACKGROUND AND PRIOR ART Steroid precursors, or pro-hormones, having a sulphate group in the 3-position of the steroid nucleus, referred to hereinafter simply as steroid sulphates, are known to play an important part as intermediates in steroid metabolism in the human body. Oestrone sulphate and dehydroepiandrosterone (DHA) sulphate, for example, are known to play an important role as intermediates in the production, in the body, of oestrogens such as oestrone and oestradiol. Oestrone sulphate, in particular, is known, for example, to represent one of the major circulating oestrogen precursors particularly in post-menopausal women and oestrone sulphatase activity in breast tumours is 100-1000 fold greater than that of other enzymes involved in oestrogen formation (James et al., Steroids, 50, 269-279 (1987)).

Not only that, but oestrogens such as oestrone and oestradiol, particularly the over-production thereof, are strongly implicated in malignant conditions, such as breast cancer, see Breast Cancer, Treatment and Prognosis: Ed. R.A. Stoll, pp. 156-172, Blackwell Scientific Publications (1986), and the control of oestrogen production is the specific target of many anticancer therapies, both chemotherapy and surgical, e.g. oophorectomy and adrenalectomy. So far as endocrine therapy is concerned, efforts have so far tended to concentrate on aromatase inhibitors, i.e. compounds which inhibit aromatase activity, which activity is involved, as the accompanying oestrogen 2 metabolic flow diagram (Figure 1) shows, in the conversion of androgens such as androstenedione and testosterone to oestrone and oestradiol respectively.

In recently published International Application W091/13083 a proposal has been made to target a different point in the oestrogen metabolic pathway, or rather two different points, that is to say the conversion of DHA sulphate and oestrone sulphate to DHA and oestrone, respectively, by steroid sulphatase activity, and using 3-monoalkylthiophosphonate steroid esters as a steroid sulphatase inhibitor, more especially oestrone-3-monomethylthiophosphonate.

OBJECTS OF THE INVENTION A first object of the present invention is to provide new compounds capable of inhibiting steroid sulphatase activity in vitro and in vivo.

A second object of the present invention is to provide new compounds having improved activity as steroid sulphatase inhibitors both in vitro and in vivo.

A third object of the invention is to provide pharmaceutical compositions effective in the treatment of oestrogen dependent tumours.

A fourth object of the invention is to provide pharmaceutical compositions effective in the treatment of breast cancer.

A fifth object of the invention is to provide a method for the treatment of oestrogen dependent tumours in mammals, especially humans.

A sixth object of the invention is to provide a method for the treatment of breast cancer in mammals and especially in women.

SUMMARY OF INVENTION The invention is based on the discovery of novel compounds having steroid sulphatase inhibitory activity, in some cases, with extremely high activity levels.

In its broadest aspect the present invention provides a ring system compound; wherein the ring system compound comprises a ring to which is attached a sulphamate group of the formula 3

R/

R2 O wherein each of R, and R 2 is independently selected from H, alkyl, alkenyl, cycloalkyl and aryl, or together represent alkylene optionally containing one or more hetero atoms or groups in the alkylene chain; wherein R, or R 2 is H; wherein said compound is an inhibitor of an enzyme having steroid sulphatase activity and a wherein if the sulphamate group of said compound is replaced with a sulphate group to form a sulphate compound it would be a substrate for a steroid sulphatase enzyme In a further aspect the present invention provides a ring system 20 compound; a wherein the ring system compound comprises a ring to which is attached a sulphamate group of the formula R 0

II

N-S-O

R/ II R2 O wherein each of R, and R 2 is independently selected from H, alkyl, alkenyl, cycloalkyl and aryl, or together represent alkylene optionally containing one or more hetero atoms or groups in the alkylene chain; wherein R, or R 2 is H; 4 wherein said compound is an inhibitor of an enzyme having steroid sulphatase activity and wherein if the sulphamate group of said compound is replaced with a sulphate group to form a sulphate compound and incubated with a steroid sulphatase enzyme at a pH 7.4 and 370C it would provide a Km value of less than 50 pM.

In an even further aspect the present invention provides a ring system compound; wherein the ring system compound has the formula R 0 II ,Poly cycle N-S-o R/

II

wherein each of R, and R 2 is independently selected from H, alkyl, 20 alkenyl, cycloalkyl and aryl, or together represent alkylene optionally containing one or more hetero atoms or groups in the alkylene chain; wherein R, or R 2 is H; wherein the group Poly cycle is a polycyclic ring structure wherein said compound is an inhibitor of an enzyme having steroid sulphatase activity and wherein if the sulphamate group of said compound is replaced with a sulphate group to form a sulphate compound it would be a substrate for a steroid sulphatase enzyme In yet an even further aspect the present invention provides a ring system compound; wherein the ring system compound has the formula R 0 II Poly cycle

N-S-O

II

R2 O wherein each of R, and R 2 is independently selected from H, alkyl, alkenyl, cycloalkyl and aryl, or together represent alkylene optionally containing S: one or more hetero atoms or groups in the alkylene chain; wherein R, or R 2 is H; wherein the group Poly cycle is a steroidal ring structure that wherein said compound is an inhibitor of an enzyme having steroid sulphatase activity and wherein if the sulphamate group of said compound is replaced with a sulphate group to form a sulphate compound it would be a substrate for a steroid sulphatase enzyme In a preferred aspect the compounds are the sulphamic acid esters of polycyclic alcohols, being polycyclic alcohols the sulphate of which is a substrate for enzymes having steroid sulphatase (EC 3.1.6.2) activity, the N-alkyl and N-aryl derivatives of those sulphamic acid esters, and their pharmaceutically acceptable salts.

Broadly speaking, the preferred compounds of this invention are compounds of the Formula (I) 6 FORMULA (I) R 0 II ,Poly cycle

N-S-O

R/ I 2 0 10 where: R 1 and R 2 are each independently selected from H, alkyl, cycloalkyl, alkenyl and aryl, or together represent alkylene optionally containing one or more hetero atoms or groups in the alkylene chain; and the group polycycle represents the residue of a polycyclic 15 alcohol, the sulphate of which is a substrate for enzymes having steroid sulphatase activity (EC 3.1.6.2).

As used herein the reference to polycyclic alcohols, the sulphate of which is a substrate for enzymes having steroid sulphatase activity refers to polycyclic alcohols, the sulphate of which, viz: the derivatives of the Formula:

O

II Polycycle HO -S 0 when incubated with steroid sulphatase EC 3.1.6.2 at pH 7.4 and 37 C, provides a Km value of less than 501pmoles.

Throughout the description and claims of the specification the word "comprise" and variations of the word, such as "comprising" and "comprises", is not intended to exclude other additives, components, integers or steps.

BRIEF DESCRIPTION OF DRAWINGS The activity of the present compounds as steroid sulphatase inhibitors is illustrated in the accompanying drawings: Figure 1 is a schematic chart showing the metabolic pathways, enzymes and steroid intermediates associated with the production of oestradiol in vivo.

Figure 2 is a histogram showing the dose-dependent inhibitory effect of oestrone-3-sulphamate on steroid sulphatase activity in human MCF-7 cells in vitro.

Figure 3 is a histogram showing the dose-dependent inhibitory effect of oestrone-3-N,N-dimethylsulphamate on steroid sulphatase activity in human .i MCF-7 cells in vitro.

Figure 4 is a graph comparing the log dose-response curves for oestrone-3-sulphamate and oestrone-3-N,N-dimethylsulphamate on steroid sulphatase activity in human MCF-7 cells in vitro.

Figure 5 is a graph showing the dose-dependent inhibitory effect of oestrone-3-sulphamate, together with its IC 50 value (concentration required to produce 50% inhibition), on steroid sulphatase activity in human placental microsomes in vitro.

DETAILED DESCRIPTION In a preferred aspect the present invention provides, as novel compounds, the sulphamic acid esters of polycyclic alcohols, being polycyclic alcohols the sulphate of which is a substrate for enzymes having steroid sulphatase activity in accordance with the definition already provided, and their N-alkyl, N-cycloalkyl, N-alkenyl and N-aryl derivatives. These compounds are of Formula I hereinbefore given.

Preferably the polycyclic group will contain, inclusive of all substituents, a maximum of about 40 carbon atoms, more usually no more than about Preferred polycycles are those containing a steroidal ring structure, that is to say a cyclopentanophenanthrene skeleton. Preferably, the sulphamyl or substituted sulphamyl group is attached to that skeleton in the 3-position, that is to say are compounds of the Formula II: 8 FORMULA (11) D I R 1B 0 where R 1 and R 2 are as above defined and the ring system ABCD represents :a substituted or unsubstituted, saturated or unsaturated steroid nucleus, preferably oestrone or dehydroepiandrosterone.

Other suitable steroid ring systems are: substituted oestrones, viz: 2-OH-oestrone 2-methoxy-oestrone 4-OH-oestrone 6 -OH-oestrone 7 -OH-oestrone 16 -OH-oestronel6 -OH-oestrone oestradiols and substituted oestradiols, viz: 2-OH-17 -oestradiol 2-methoxy-17 -oestradiol 4-OH-17 -oestradiol 6 -OH-17 -oestradiol 7 -OH-17 -oestradiol 16 -OH-1 7 -oestradiol 20 16 -OH-17 -oestradiol 16 -OH-17 -oestradiol 17 -oestradiol 1 17 -oestradiol 17 -ethinyl-1 7 -oestradiol oestriols and substituted oestriols, viz: oestriol 2-OH-oestriol 2-methoxy-oestriol 4-OH-oestriol6 -OH-oestriol 7 -OH-oestriol substituted dehydroepiandrosterones, viz: 6 -OH-dehydroepiandrosterone 7 -OH-dehydroepiandrosterone 16 -OH-dehydroepiandrosterone 16 -OH-dehydroepiandrosterone In general terms the steroid ring system ABOD may contain a variety of non-interfering substituents. In particular, the ring system ABCD may contain one or more hydroxy, alkyl especially lower (01-06) alkyl, e.g. methyl, ethyl, npropyl, isopropyl, n-butyl, sec-butyl, tert-butyl, n-pentyl and other pentyl isomers, and n-hexyl and other hexyl isomers, alkoxy especially lower (C 1 -Cg) alkoxy, e.g. methoxy, ethoxy, propoxy etc., alkinyl, e.g. ethinyl, or halogen, e.g.

fluoro substituents.

Suitable non-steroidal ring systems include: diethylstilboestrol, stilboestrol and other ring systems providing sulfates having Km values of less than 50pmoles with steroid sulphatase EC3.1.6.2.

When substituted, the N-substituted compounds of this invention may contain one or two N-alkyl, N-alkenyl, N-cycloalkyl or N-aryl substituents, preferably containing or each containing a maximum of 10 carbon atoms.

When R 1 and/or R 2 is alkyl, the preferred values are those where R 1 and R 2 are each independently selected from lower alkyl groups containing from 1 to carbon atoms, that is to say methyl, ethyl, propyl etc. Preferably R 1 and R 2 are both methyl. When R 1 and/or R 2 is aryl, typical values are phenyl and tolyl (-PhCH 3 m- or Where R 1 and R 2 represent cycloalkyl, typical values are cyclopropyl, cyclopentyl, cyclohexyl etc. When joined together Rl.and R 2 typically represent an alkylene group providing a chain of 4 to 6 carbon atoms, optionally interrupted by one or more hetero atoms or groups, e.g. or -NH- to provide a 6- or 7- membered heterocycle, e.g. morpholino, pyrrolidino or piperidino.

S 20 Within the values alkyl, cycloalkyl, alkenyl and aryl we include substituted groups containing as substituents therein one or more groups which do not interfere with the sulphatase inhibitory activity of the compound in question. Exemplary non-interfering substituents include hydroxy, amino, halo, alkoxy, alkyl and aryl.

Most preferred are compounds of the Formula III and IV: FORMULA (111) 0 N-S -0 0 FORMULA (IV) S 0 S..R2, whr 1adRSr rC-5akyie etoe3slhm n deyreinrseoe3slhmt ndter.(lC)akldrvtvs espcill 0h iehldrvtieR 2=C ula y whereoriade R1 areN02 H e ore 0105 actlioe. cemtoe3suaae an 11 REACTION SCHEME I 0

RR

2

NSO

2 CI R, I N S -0 NaH R2 I HO 2 Oestrone Conditions for carrying out reaction scheme I are as follows: Sodium hydride and a sulphamoyl chloride are added to a stirred solution of oestrone in anhydrous dimethyl formamide at 0 C. Subsequently, the reaction is allowed to warm to room temperature whereupon stirring is continued for a further 24 hours. The reaction mixture is poured onto a cold saturated solution of sodium bicarbonate and the resulting aqueous phase is extracted with dichloromethane. The combined organic extracts are dried over anhydrous MgSO 4 Filtration followed by solvent evaporation in vacuo and coevaporation with toluene affords a crude residue which is further purified by flash chromatography.

Where necessary, functional groups in the polycyclic alcohol (sterol) may be protected in known manner and the protecting group or groups removed at the end of the reaction.

For pharmaceutical administration, the steroid sulphatase inhibitors of this invention can be formulated in any suitable manner utilising conventional pharmaceutical formulating techniques and pharmaceutical carriers, exipients, diluents etc. and usually for parenteral administration. Approximate effective dose rates are in the range 100 to 800 mg/day depending on the individual activities of the compounds in question and for a patient of average bodyweight. More usual dosage rates for the preferred and more active compounds will be in the range 200 to 800 mg/day, more preferably, 200 to 500 mg/day, most preferably from 200 to 250 mg/day. They may be given in single dose regimes, split dose regimes and/or in multiple dose regimes lasting over 12 several days. For oral administration they may be formulated in tablets, capsules, solution or suspension containing from 100 to 500 mg of compound per unit dose. Alternatively and preferably the compounds will be formulated for parenteral administration in a suitable parenterally administrable carrier and providing single daily dosage rates in the range 200 to 800 mg, preferably 200 to 500, more preferably 200 to 250 mg. Such effective daily doses will, however, vary depending on inherent activity of the active ingredient and on the bodyweight of the patient, such variations being within the skill and judgement of the physician.

For particular applications, it is envisaged that the steroid sulphatase inhibitors of this invention may be used in combination therapies, either with another sulphatase inhibitor, or, for example, in combination with an aromatase inhibitor, such as for example, 4-hydroxyandrostenedione (4-OHA).

The invention is illustrated by the following preparative Examples and test data: 9 Example 1 Preparation of oestrone-3-sulphamate Sodium hydride (60% dispersion; 2 eq) and sulphamoyl chloride (2 eq) were added to a stirred solution of oestrone (1 eq) in anhydrous dimethyl formamide at 0 C. Subsequently, the reaction was allowed to warm to room 9 temperature whereupon stirring was continued for a further 24 hours.

The reaction mixture was poured onto a cold saturated solution of sodium bicarbonate and the resulting aqueous phase was extracted with dichloromethane. The combined organic extracts were dried over anhydrous MgSO 4 Filtration followed solvent evaporation in vacuo and co-evaporation with toluene afforded a crude residue which is further purified by flash chromatography.

Analysis showed the following data: H. (270MHz; CD 3 OD): 0.91 3H, C 1 8 1.40-2.55 (series of m, 13H), 2.90-2.92 (in, 2H), 7.04 (br d, 2H, J=1 0.44Hz), 7.33 (br d, 1 H, J=8.42Hz).

130 (67.8MHz; CD 3 OD): 14.53 C 18 22.80 27.24 27.73 30.68 33.05 37.01 39.76 45.73 018), 51.86 120.76 123.54 127.89 139.83 150.27 223.87 0=0).

mlz 349 270 (100), 213 185 172 159 146 91 69 57 43 29 (24).

:Microanalysis: so0C H N

S

sesExpected: 61 .87% 6.63% 4.01% Found: 61 .90% 6.58% 3.95% 1 Example 2 Preparation of oestrone-3-N-methylsulphamate The procedure of Example 1 was repeated save that suiphamoyl chloride was replaced by the same quantity of N-methylsulphamoyl chloride.

Analysis showed the following data: 1 H (270MHz; CDCI 3 0.91 3H, C 18 1.28-1.68 (mn, 6H), 1.93-2.60 (series of m, 7H), 2.90-2.95 (in, 2H), 2.94 3H, J=5.13 Hz, MeN-), 4.68-4.71 (br in, exchangeable, 1 H, 7.02-7.07 (in, 2H), 7.26-7.32 (mn, 1 H).

m/z (%:364 Example 3 Preparation of oestrone-3-N.N-dimethylsulphamate The procedure of Example 1 was repeated save that sulphamoyl chloride was replaced by the same quantity of N,N-dimethylsulphamoyl chloride.

Analysis showed the following data: 1 H (270MHz; CDCI 3 0.92 3H, C 1 8 1.39-1.75 5H), 1.95-2.60 10 (series of m, 6H), 2.82 3H, MeN-), 2.96-3.00 4H), 2.98 3H, MeN-), 7.04 (br d, 2H, J=7.69Hz), 7.29 (br d, 1H, J=7.88Hz).

m/z 377 15 Microanalysis: C H N Expected: 63.63% 7.21% 3.71%

S

Found: 63.50% 7.23% 3.60% o 20 Example 4 Inhibition of Steroid Sulphatase Activity in MCF-7 cells by oestrone-3sulphamate Steroid sulphatase is defined as: Steryl Sulphatase EC 3.1.6.2.

Steroid sulphatase activity was measured in vitro using intact MCF-7 human breast cancer cells. This hormone dependent cell line is widely used to study the control of human breast cancer cell growth. It possesses significant steroid sulphatase activity (Maclndoe et al. Endocrinology, 123, 1281-1287 (1988); Purohit Reed, Int. J. Cancer, 50, 901-905 (1992)) and is available in the U.S.A. from the American Type Culture Collection (ATCC) and in the U.K.

from The Imperial Cancer Research Fund). Cells were maintained in Minimal Essential Medium (MEM) (Flow Laboratories, Irvine, Scotland) containing 20 mM HEPES, 5% foetal bovine serum, 2 mM glutamine, nonessential amino acids and 0.075% sodium bicarbonate. Up to 30 replicate cm 2 tissue culture flasks were seeded with approximately 1 x 105 cells/flask using the above medium. Cells were grown to 80% confluency and medium was changed every third day.

Intact monolayers of MCF-7 cells in triplicate 25 cm 2 tissue culture flasks were washed with Earle's Balanced Salt Solution (EBSS from ICN Flow, High Wycombe, and incubated for 3-4 hours at 37 C with 5 pmol (7 x 105 dpm) [6,7- 3 H]oestrone-3-sulphate (specific activity 60 Ci/mmol from New England Nuclear, Boston, Mass., in serum-free MEM (2.5 ml) together with 10 oestrone-3-sulphamate (11 concentrations: 0; 1fM; 0.01pM; 0.1pM; 1pM; 0.01nM; 0.1nM; 1nM; 0.01pM; 0.1pM; 1pM). After incubation each flask was cooled and the medium (1 ml) was pipetted into separate tubes containing [1 4 C]oestrone (7 x 103 dpm) (specific activity 97 Ci/mmol from Amersham International Radiochemical Centre, Amersham, The mixture was 15 shaken thoroughly for 30 seconds with toluene (5 ml). Experiments showed that >90% 1 4 C]oestrone and 3 H]oestrone-3-sulphate was removed from the aqueous phase by this treatment. A portion (2 ml) of the organic phase was removed, evaporated and the 3 H and 14C content of the residue determined by scintillation spectrometry. The mass of oestrone-3-sulphate hydrolysed was calculated from the 3 H counts obtained (corrected for the volumes of the medium and organic phase used, and for recovery of [1 4 C]oestrone added) and the specific activity of the substrate. Each batch of experiments included incubations of microsomes prepared from a sulphatasepositive human placenta (positive control) and flasks without cells (to assess apparent non-enzymatic hydrolysis of the substrate). The number of cell nuclei per flask was determined using a Coulter Counter after treating the cell monolayers with Zaponin. One flask in each batch was used to assess cell membrane status and viability using the Trypan Blue exclusion method (Phillips, H.J. (1973) In: Tissue culture and applications, [eds: Kruse, D.F. Patterson, pp. 406-408; Academic Press, New York).

a 16 Data for oestrone-3-sulphamate are shown in Table I and Figures 2 and 4. Results for steroid sulphatase activity are expressed as the mean 1 S.D. of the total product (oestrone oestradiol) formed during the incubation period hours) calculated for 106 cells and, for values showing statistical significance, as a percentage reduction (inhibition) over incubations containing no oestrone- 3-sulphamate. Unpaired Student's t-test was used to test the statistical significance of results.

TABLE I Steroid Sulphatase Activity in MCF-7 cells in the presence of Oestrone-3-sulphamate Oestrone-3- Steroid Sulphatase reduction over sumphamate Activity (fmol/20 hr/106 control inhibition) concentration cells) 0 (control) 319.7 18.5 ifM 353.3 39.0 0.01 pM 362.3 21.2 0.1pM 330.7 17.8 1pM 321.8 6.2 0.01 nM 265.1 11.0* 17.2% 0.1nM 124.8 60.9% 1nM 16.49 95.0% 0.01 PM 3.92 98.8% 0.1 pM 2.53 99.2% 1 pM 1.68 99.5% mean 1 S.D. n=3 *p 0.05 p 0.001 Example Inhibition of Steroid Sulphatase Activity in MCF-7 cells by oestrone-3-N,Ndimethylsulphamate An identical experimental protocol to that described in Example 4 was used to generate results for oestrone-3-N,N-dimethylsulphamate except that incubations contained oestrone-3-N,N-dimethylsulphamate (5 concentrations: 0; 0.001p M; 0.01 pM; 0.1pM; 1pM) in place of oestrone-3-sulphamate.

Results for oestrone-3-N,N-dimethylsulphamate are shown in Table II and Figure 3 and are expressed in an identical manner to Table I and Figure 2 respectively. Additionally the log dose-response curve is compared with oestrone-3-sulphamate in Figure 4.

S. 10 TABLE II Steroid Sulphatase Activity in MCF-7 cells in the presence of oestrone-3- N,N-dimethylsulphamate 'S

S

Oestrone-3-N,N- Steroid Sulphatase reduction over dimethylsulphamate Activity (fmol/20 hr/106 control inhibition) concentration cells) 0 (control) 82.63 3.6 0.001 pM 68.33 17.3% 0.01 pM 46.0 44.3% 0.1 M 17.43 78.9% 1pM 11.89 85.6% mean 1 S.D. n=3 p 0.01 p 0.001 Example 6 Inhibition of Steroid Sulphatase Activity in MCF-7 cells by ore-treatment with oestrone-3-NN-dimethylsulphamate and oestrone-3-N,N-dimethylsulphamate A similar experimental protocol to that described in Example 4 was used to determine the effect of pre-treating MCF-7 cells with oestrone-3-sulphamate and oestrone-3-N,N-dimethylsulphamate respectively.

Intact monolayers were initially incubated for 2 hours at 37 C with 0.1 pM oestrone-3-sulphamate, oestrone-3-N,N-dimethylsulphamate or medium alone 18 (control). The medium bathing the cells was then removed by aspiration and cells were washed 3 times successively with 5 ml of medium on each occasion.

The resultant 'washed' cells were then re-suspended and incubated for 3-4 hours at 37 C in medium containing 5 pmol (7 x 105 dpm) [6,7- 3 H]oestrone-3sulphate. All other aspects were identical to those described in Examples 3 and 4.

Results for oestrone-3-sulphamate and oestrone-3-N,N-dimethylsulphamate are shown in Table III and are expressed in a similar manner to Table I.

TABLE III Steroid Sulphatase Activityin MCF-7 cells pre-incubated with oestrone-3- 'pc" sulphamates

S

Pre-treatment Steroid Sulphatase reduction over Activity (fmol/20 control hr/106 cells) inhibition) Control 65.4 6.4 Oestrone-3-sulphamate 1.7 97.4% Oestrone-3-N,N- 53.1 3.4* 18.8% dimethylsulphamate mean 1 S.D. n=3 p 0.05 p 0.001 Example 7 Inhibition of Steroid Sulphatase Activity in Placental Microsomes by Oestrone- 3-sulphamate Sulphatase-positive human placenta from normal term pregnancies (Obstetric Ward, St. Mary's Hospital, London) were thoroughly minced with scissors and washed once with cold phosphate buffer (pH 7.4, 50 mM) then resuspended in cold phosphate buffer (5 ml/g tissue). Homogenisation was accomplished with an Ultra-Turrax homogeniser, using three 10 second bursts 19 separated by 2 minute cooling periods in ice. Nuclei and cell debris were removed by centrifuging (4 C) at 2000g for 30 minutes and portions (2 ml) of the supernatant were stored at -20 C. The protein concentration of the supernatants was determined by the method of Bradford (Anal. Biochem., 72, 248-254 (1976)).

Incubations (1 ml) were carried out using a protein concentration of 100 pg/ml, substrate concentration of 20 pM [6,7- 3 H]oestrone-3-sulphate (specific activity 60 Ci/mmol from New England Nuclear, Boston, Mass., and an incubation time of 20 minutes at 37 C. Eight concentrations of oestrone-3- S'.i 10 sulphamate were employed: 0 control); 0.05pM; 0.1pM; 0.2pM; 0.4pM; 0.6pM; 0.8pM; 1.0pM. After incubation each sample was cooled and the medium (1 ml) was pipetted into separate tubes containing 14 C]oestrone (7 x 103 dpm) (specific activity 97 Ci/mmol from Amersham International Radiochemical Centre, Amersham, The mixture was shaken thoroughly 15 for 30 seconds with toluene (5 ml). Experiments showed that [1 4 C]oestrone and 3 H]oestrone-3-sulphate was removed from the aqueous phase by this treatment. A portion (2 ml) of the organic phase was removed, evaporated and the 3 H and 14C content of the residue determined by scintillation spectrometry. The mass of oestrone-3-sulphate hydrolysed was 20 calculated from the 3 H counts obtained (corrected for the volumes of the medium and organic phase used, and for recovery of [1 4 C]oestrone added) and the specific activity of the substrate.

Results for oestrone-3-sulphamate are shown in Table IV and Figure Results for steroid sulphatase activity are expressed in Table IV as total product (oestrone oestradiol) formed during the incubation period (time) and as a percentage reduction (inhibition) over incubations containing no oestrone-3sulphamate which acted as control. Results for steroid sulphatase activity are expressed in Figure 4 as percentage reduction (inhibition) over control against concentration of oestrone-3-sulphamate and include the calculated IC 5 0 value the concentration of oestrone-3-sulphamate which produces 50% inhibition in relation to control) of 0.07pM.

TABLE IV Steroid Sulphatase Activity in placental microsomes in the presence of Oestrone-3-sulphamate Oestrone-3- Steroid Sulphatase Activity reduction over sulphamate (pmol/hr/0.1 mg protein) control inhibition) concentration 0 (control) 768.6 0.05pM 430.4 44.0% 0.1pM 305.9 60.2% 0.2pM 140.0 81.8% 0.4pM 83.3 89.2% 0.6pM 61.8 92.0% 0.8pM 49.2 93.6% 1.OpM 51.6 93.3% mean of 2 estimates Example 8 Inhibition of Steroid Sulphatase Activity in Liver Microsome Preparations from Rats treated with subcutaneous Oestrone-3-sulphamate Four groups of 3 female Wistar rats (weight range 80-110g) were given 100 pl subcutaneous injections (once daily for 7 days, vehicle: propylene glycol) of either: Propylene glycol (vehicle control) Oestrone-3-sulphamate (10 mg/kg/day) Oestrone-3-sulphate (10 mg/kg/day) (substrate control) Oestrone-3-sulphate (10 mg/kg/day) Oestrone-3-sulphamate mg/kg/day) On the eighth day all rats were sacrificed and livers were removed by dissection. Liver microsomal preparations were prepared by an identical protocol to that described in Example 6 except that the tissue source was rat

I

liver and that duplicate experiments to determine steroid sulphatase activity were performed using [6,7- 3 H]oestrone-3-sulphate and 3 H]dehydroepiandrosterone-3-sulphate as separate substrates.

Results for steroid sulphatase activity are shown in Table V and are expressed as total product formed during the incubation period in the form of mean t 1 S.D. Results for incubations of tissue obtained from groups of rats treated with oestrone-3-sulphamate are also expressed as a percentage reduction (inhibition) in steroid sulphatase activity compared to their respective controls.

TABLE V Steroid Suiphatase Activity in Liver Microsome Preparations fromRats treated with subcutaneous Oestrone-3-sulphamate r Treatment Group Assay Steroid Sulphatase Substrate Activity (nmol/30 min/200 pg protein) control (vehicle) E 1 -S 20.95 0.2

E

1

-SO

3

NH

2 Ej-S 0.34 0.1 control (E 1

E

1 -S 20.6 t 0.4

E

1

E

1 -S0 3

NH

2

E

1 -S 0.21 0.03" control (vehicle) DHA-S 1.73 0.4

E

1 -S0 3

NH

2 DHA-S 0.1 0.01m control (E 1 DHA-S 1.71 0.1 E -S E 1

-SO

3

NH

2 DHA-S 0.09 0.01reduction over control 98.4% 99.0% 94.2% 94.7%

L

mean S.D. n=3 p 0 00 1 E,-S oestrone-3-sulphamate DHA-S dehydroepiandrosterone-3-sulphate E,-SO,NH, oestrone-3-N,N-dimethylsulphamate Disclaimer The compounds claimed in Australian patent 668882 are specifically excluded from the laims herein.

.2,

Claims

1. A purified compound subject to the foregoing disclaimer comprising a ring system and a sulphamate group of the formula R 1 O N-0 R/ II 2 O wherein each of R, and R, is independently selected from H, alkyl, alkenyl, cycloalkyl and aryl; wherein at least one of R, and R, is H; and wherein the ring system comprises at least three rings, at least two of which are fused; wherein the compound is an inhibitor of an enzyme having steroid sulphatase activity wherein if the sulphamate group of said compound is replaced with a sulphate group to form a sulphate compound it would be a substrate for a steroid sulphatase enzyme

2. A purified compound subject to the foregoing disclaimer comprising a steroidal ring structure and a sulphamate group of the formula 9 R 0 N-8-O 2 R wherein each of R, and R 2 is independently selected from H, alkyl, alkenyl, cycloalkyl and aryl; wherein at least one of R, and R, is H; and wherein the compound is an inhibitor of an enzyme having steroid sulphatase activity 23 wherein if the sulphamate group of said compound is replaced with a sulphate group to form a sulphate compound it would be a substrate for a steroid sulphatase enzyme

3. A purified compound according to any one of claims 1 to 2, wherein R, and R, are independently selected from H, or a C,-Co alkyl; but wherein at least one of R, and R 2 is H.

4. A purified compound according to any one of claims 1 to 3 wherein R i and R, are independently selected from H, or alkyl; but wherein at least one of R, and R, is H. A purified compound according to any one of claims 1 to 4 wherein R, and R2 are independently selected from H or methyl; but wherein at least one of R, and R, is H. S: 6. A purified compound according to any one of claims 1 to 5 wherein R, is H and R, is H. *0

7. A purified compound according to any one of claims 1 to 6 wherein the sulphamate group is attached to the ring system or the steroidal ring structure.

8. A purified compound according to claim 1 wherein the compound is a compound of the formula R N R/ 1 R2

9. A purified compound according to any one of claims 1 to 8 wherein if the sulphamate group of said compound is replaced with a sulphate group to form a sulphate compound and incubated with a steroid sulphatase enzyme at a pH 7.4 and 37 0 C it would provide a value of less than 50 iM. A4u 0De 4 )-e