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United States Patent |
6,225,337
|
Antonicek
,   et al.
|
May 1, 2001
|
Use of efomycins
Abstract
The present invention relates to the use of known efomycins and
elaiophylins for the treatment of autoimmune disorders, to new natural
substances efomycins M and T, and processes for their preparation; in
particular to their use as medicaments in psoriasis therapy.
Inventors:
|
Antonicek; Horst-Peter (Bergisch Gladbach, DE);
Bischoff; Erwin (Wuppertal, DE);
Gondol; Daniel (Bergisch Gladbach, DE);
Gutbrod; Oliver (Odenthal, DE);
Krahn; Thomas (Hagen, DE);
Rodriguez; Maria-Luisa (Erkrath, DE);
Schutz; Helmuth (Regensburg, DE)
|
Assignee:
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Bayer Aktiengesellschaft (Leverkusen, DE)
|
Appl. No.:
|
267322 |
Filed:
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March 12, 1999 |
Foreign Application Priority Data
| Dec 23, 1996[DE] | 196 54 073 |
Intern'l Class: |
A61K 031/365; C07D 321/00 |
Field of Search: |
549/267
514/450
|
References Cited
U.S. Patent Documents
4927810 | May., 1990 | Frobel et al. | 514/23.
|
5185326 | Feb., 1993 | Muller et al. | 514/23.
|
5233029 | Aug., 1993 | Hammann et al. | 536/7.
|
Foreign Patent Documents |
38 31 695 A1 | Mar., 1990 | DE.
| |
0 197 360 B1 | Oct., 1986 | EP.
| |
0 236 894 B1 | Sep., 1987 | EP.
| |
0 461 499 A2 | Dec., 1991 | EP.
| |
Other References
Journal of Antibiotics vol. XLIII, No. 11, S. 1431-1440, Nov./1990.
|
Primary Examiner: Trinh; Ba K.
Attorney, Agent or Firm: Norris McLaughlin & Marcus
Claims
What is claimed is:
1. A method of treating an autoimmune disorder in a patient comprising
administering to said patient an effective amount therefor of an efomycin
of the formula:
##STR10##
in which
R.sup.1, R.sup.2, R.sup.3 and R.sup.4 are identical and represent hydrogen
or the radical of the formula --CO--CH.sub.3,
or of a purified stereoisomer or stereoisomer mixture thereof.
2. A compound selected from the group consisting of:
a) Efomycin M of the formula (Ia):
##STR11##
and
b) Efomycin T of the formula (Ib):
##STR12##
3. A composition for treating an autoimmune disorder comprising an
effective amount therefor of a compound according to claim 2 and a
pharmaceutically acceptable carrier.
4. A method according to claim 1, wherein the autoimmune disorder is
psoriasis.
5. Method of treating an autoimmune disorder in a patient comprising
administering to said patient an effective amount therefor of a compound
according to claim 2.
6. A method according to claim 5, wherein the autoimmune disorder is
psoriasis.
7. Compound of claim 2, being Efomycin M of the formula
##STR13##
8. Compound of claim 1, being Efomycin T of the formula
##STR14##
9. Process for the preparation of efomycin M (Ia) and/or of efomycin T (Ib)
according to claim 2, characterized in that a mixture, comprising
efomycins A and G of the general formula (II)
##STR15##
in which
R.sup.5 represents methyl
and
R.sup.6 represents a radical of the formula
##STR16##
or
R.sup.5 represents methyl
and
R.sup.6 represents a radical of the formula
##STR17##
is first subjected to a base-catalysed deglycosylation with
.beta.-elimination of the deoxyfucose side chains and the efomycin M thus
obtained is optionally acetylated under mild conditions for the
preparation of efomycin T.
Description
The present invention relates to the use of known efomycins and
elaiophylins for the treatment of autoimmune disorders, to new natural
substances efomycins M and T, and processes for their preparation; in
particular to their use as medicaments in psoriasis therapy.
It is already known that efomycins and elaiophylins, in addition to their
growth-promoting properties, also have an antiviral, antibacterial and
anti-inflammatory action [cf. for this EP 461 499; DE 38 31 659 A1; The
Journal of Antibiotics Vol. XLIII, No. 11, pp. 1431-1440].
Surprisingly, it has now been found that efomycins of the general formula
##STR1##
in which
R.sup.1, R.sup.2, R.sup.3 and R.sup.4 are identical and represent hydrogen
or the radical of the formula --CO--CH.sub.3,
surprisingly have a strongly inhibiting action on the adhesion of
leukocytes, immunomodulatory effects with involvement of lymphocytes and
showed no cytotoxicity whatsoever and are thus suitable for the treatment
of autoimmune disorders, in particular for the treatment of psoriasis.
The compounds of the general formula (I) can exist in stereoisomeric forms,
which either behave as image and mirror image (enantiomers), or which do
not behave as image and mirror image (diastereomers). The invention
relates both to the enantiomers and diastereomers or to their respective
mixtures. Like the diastereomers, the racemic forms can also be separated
using known methods into the stereoisomerically uniform constituents.
The present invention moreover relates to the new substances of the general
formulae (Ia) and (Ib) having the configuration indicated here
##STR2##
##STR3##
The known compounds of the general formula (I) according to the invention
can be prepared by published methods.
The new compounds efomycins M (Ia) and T (Ib) can be prepared by first
subjecting the mixture isolated from a complex macrodiolide, comprising
efomycins A and G, of the general formula (II)
##STR4##
in which
R.sup.5 represents methyl and
R.sup.6 represents a radical of the formula
##STR5##
or
R.sup.5 represents methyl
and
R.sup.6 represents a radical of the formula
##STR6##
to a base-catalysed deglycosylation with .beta.-elimination of the
deoxyfucose side chains (efomycin M) and, in the case of the compound of
the formula (IIb/efomycin T), carrying out an acetylation under mild
conditions.
The process according to the invention can be illustrated by way of example
by the following reaction scheme:
##STR7##
Suitable solvents for the preparation of efomycin M are water and alcohols
such as methanol, ethanol, propanol, and/or ethyl acetate and mixtures
thereof. The system water/ethanol/ethyl acetate is preferred.
Suitable bases for this step in general are the customary inorganic or
organic bases. These preferably include alkali metal hydroxides such as,
sodium or potassium hydroxide, or alkali metal carbonates such as sodium
or potassium carbonate, or alkali metal hydrogencarbonates such as sodium
or potassium hydrogencarbonate, or alkali metal alkoxides such as, sodium
or potassium ethoxide.
The base is used in an amount from 1 mol to 5 mol, preferably from 1 mol to
2 mol, relative to 1 mol of the compounds of the general formula (II).
Potassium hydrogencarbonate is preferred.
The reaction can be carried out at normal, elevated or reduced pressure
(e.g. 0.5 to 5 bar). In general, it is carried out at normal pressure.
The reaction is carried out at the reflux temperature of the corresponding
alcohol.
The acetylation is carried out under protective gas atmosphere in pyridine
using acetic anhydride, if appropriate in the presence of
4-(N,N-dimethylamino)pyridine, at room temperature.
The compounds of the general formula (II), efomycins A and G, are known
[cf. EP 197 360; EP 236 894 and EP 461 499].
The compounds of the general formula (I) and the new substances of the
formulae (Ia)/(Ib) (efomycins M and T) show an unforeseeable spectrum of
pharmacological action.
Their action consists in the reduction or complete inhibition of the
adhesion of leukocytes and the immunomodulatory effects with involvement
of lymphocytes, in particular the T lymphocytes. Moreover, they have
excellent pharmacokinetics and, due to the absence of the sugar residue
typical of these structures, they show no cytotoxicity whatsoever on
endothelial cells in the MTT test
[MTT=(3-[4,5-di-methylthiazol-2-yl]-2,5-diphenyltetrazolium bromide; or
Thiazolyl Blue] at efficacious concentrations. The MTT test is well-known
in the art. It was carried out with a test kit which is commercially
available (e.g. "Cell growth determination kit MTT based", Stock No. CGD-1
from Sigma Chemical).
They are therefore suitable for the prophylaxis and treatment of autoimmune
disorders. These include psoriasis, acute and chronic disorders such as,
thyroiditis, inflammatory bowel disorders, inflammations of the
gastrointestinal tract, primary liver cirrhosis, or psoriasis, multiple
sclerosis, myasthenia, lupus erythematosus, Basedow's disease, Hashimoto's
disease, transplant rejection and autoimmune haemolytic anaemia. The
prophylaxis and treatment of psoriasis is preferred.
Inhibition of PMNL Adhesion to Hypoxia-Stimulated Pig Aortas
Freshly isolated pig aortas were brought into the laboratory from the local
slaughterhouse in oxygen-aerated, phosphate-buffered saline solution
(PBS). Freshly obtained pig or human blood was taken for the preparation
of polymorphonuclear neutrophilic granulocytes (PMNL). The aortas were
stimulated by placing them for 30 minutes in PBS which was aerated with
nitrogen (hypoxia stimulus). The aorta were then fixed between a Teflon
block (below) and a specially made steel plate (above) with drilled wells
(similar to a microtiter plate). PMNL and the potential adhesion
inhibitors were added to the luminal side, i.e. to the stimulated
endothelial cell layer, in cell media (M199, Gibco). After a 90-minute
coincubation at 37.degree. C. in an incubator, the wells were washed. The
remaining adherent PMNL were lysed. The activity of the PMNL-specific
myeloperoxidase (MPO) in the lysate was determined photometrically and
compared to the untreated control (only solvent). Table [A] shows the
inhibition of the action of the efomycins. The proportion of the adherent
PMNL in comparison with the control is indicated.
Table [A]:
Inhibition of the adhesion of pig PMNL or human PMNL to hypoxia-stimulated
pig aorta by efomycins
% adherent PMNL
Pig PMNL Human PMNL
Control 100 100
Ex. No. 1 (efomycin M) 33 .+-. 23 52 .+-. 2
Ex. No. 2 (efomycin T) 85 .+-. 11 90 .+-. 5
Surprisingly, efomycin M (Ia), which does not inhibit the adhesion of PMNL
to albumin-coated plastic surfaces, was active in the test model
described. The adhesion test to albumin-coated plastic surfaces is
described in detail, inter alia, in EP 0 461 499 A2 (Use Example 1). In an
MTT test, efomycin M (Ia) showed no cytotoxicity against cultured
endothelial cells.
The present invention also includes pharmaceutical preparations which, in
addition to inert, non-toxic, pharmaceutically suitable auxiliaries and
excipients, contain one or more compounds of the general formulae
(I)/(Ia)/(Ib), or which consist of one or more active compounds of the
formulae (I)/(Ia)/(Ib), and processes for the production of these
preparations.
The active compounds of the formulae (I)/(Ia)/(Ib) should be present in
these preparations in a concentration of 0.1 to 99.5% by weight,
preferably 0.5 to 95% by weight, of the total mixture.
In addition to the active compounds of the formulae (I)/(Ia)/(Ib), the
pharmaceutical preparations can also contain other pharmaceutical active
compounds.
The above-mentioned pharmaceutical preparations can be prepared in a
customary manner using known methods, for example using the auxiliary(ies)
or excipient(s).
In general, it has proved advantageous to administer the active compound(s)
of the formula(e) (I)/(Ia)/(Ib) in total amounts of approximately 0.01 to
approximately 100 mg/kg, preferably in total amounts of approximately 1
mg/kg to 50 mg/kg, of body weight every 24 hours, if appropriate in the
form of individual doses, to achieve the desired result.
However, if appropriate, it may be advantageous to depart from the amounts
mentioned, namely depending on the species and body weight of the subject
treated, on the individual behaviour towards the medicament, the nature
and severity of the disorder, the type of preparation and administration,
and the time or interval at which administration takes place.
.sup.1 H-NMR and .sup.13 C data are available for the two compounds
Examples 1 and 2.
EXAMPLE 1
##STR8##
1 g of the mixture of efomycins A and G is refluxed for 6 hours with 2.5 g
of potassium hydrogencarbonate in 15 ml of water, 5 ml of ethanol and 7 ml
of ethyl acetate. The organic phases are combined, washed once with water
and evaporated. The residue which remains is chromatographed on silica gel
using chloroform:methanol 8:1. The fractions are analysed by thin-layer
chromatography. The title compound is isolated from a mixture consisting
of two further components and characterized by FAB-MS and .sup.1 H-NMR
data.
.sup.3 J coupling constants
Efomycin M
H3-H4 11.0
H4-H5 14.5
H5-H6 9.7
H6-H7 10.5
H7-H8 1.2
H8-H9 6.5
H9-H10 3.5
H12-H13 16.0
H13-H14 9.5
H14-H15 7.0
EXAMPLE 2
##STR9##
The title compound is prepared by reaction of 2 mg of the compound from
Example 1 in 300 .mu.l of pyridine and acetic anhydride (1:1) and allowed
to stand overnight at room temperature. The solvent is then removed in
vacuo, and the residue which remains is analysed by .sup.1 H-NMR and
FAB-MS data.
.sup.3 J coupling constants
Efomycin T
H3-H4 11.1
H4-H5 15.1
H5-H6 9.6
H6-H7 10.3
H7-H8 1.9
H8-H9 9.1
H9-H10 3.8
H12-H13 15.2
H13-H14 11.0
H14-H15 4.8
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