GB2118932A

GB2118932A - A daunorubicin derivative

Info

Publication number: GB2118932A
Application number: GB08302842A
Authority: GB
Inventors: Sergio Penco; Federico Arcamone; Anna Maria Casazza
Original assignee: Farmitalia Carlo Erba SRL
Current assignee: Pfizer Italia SRL
Priority date: 1982-04-22
Filing date: 1983-02-02
Publication date: 1983-11-09
Also published as: GB2118932B; GB8302842D0

Abstract

4-Demethoxy-13-dihydrodaunorubicin having antitumour activity may be prepared by reducing 4- demethoxydaunorubicin with NaBH4 in aqueous solution. It can be incorporated into pharmaceutical compositions.

Description

SPECIFICATION A daunorubicin derivative The invention relates to an antitumour antibiotic of the anthracyline glycoside series, to a process for its preparation and to pharmaceutical compositions containing it.

The invention provides 4-demethoxy-1 3-dihydrodaunorubicin, which has the formula

and further provides its pharmaceutically acceptable acid addition salts.

The compound according to the invention may be prepared by reduction of the side-chain ketone function of 4-demethoxydaunorubicin, a compound described and claimed in United States Patent Specification No. 4,046,878. The treatment of 4-demethoxydaunorubicin with an excess of sodium borohydride gives 4-demethoxy-1 3-dihydrodaunorubicin in high yield. The sodium borohydride may be added to an aqueous solution of 4-demethoxydaunorubicin at room temperature at pH 1 0. The reduction is very fast. After removal of the excess reducing agent, the crude product, obtained by extraction with organic solvents from the aqueous phase, may be purified by chromatography and isolated, preferably as one of its salts, for example the hydrochloride. This process is within the scope of the invention.

The invention further provides a pharmaceutical composition comprising 4-demethoxy-1 3- dihydrodaunorubicin or a pharmaceutically acceptable salt thereof in admixture with a diluent or carrier.

The invention is illustrated by the following Example.

Example Preparation of 4-demethoxy-1 3-dihydrodaunorubicin A solution of 0.875 g of 4-demethoxydaunorubicin in 250 ml of water was adjusted to pH 10 with a 0.1 N aqueous solution of sodium hydroxide and treated with 0.09 g of sodium borohydride.

After 8 to 10 minutes the solution was poured under stirring into 250 ml of 0.2 N aqueous hydrochloric acid. Then the solution, adjusted to pH 8.5, was repeatedly extracted with ethyl acetate. The combined extracts were evaporated to dryness under vacuum. The residue, dissolved in methylene chloride, was purified by chromatography on a column of silica gel using, as eluent, a mixture of methylene dichloride:methanol:water (100:20:2 by volume). The fractions, containing the title compound were collected and evaporated to a small volume. Upon addition of the stoichiometric amount of 0.1 N methanolic hydrogen chloride and excess diethyl ether to the solution a precipitate was obtained.The product was collected, washed with ether and dried under vacuum. 0.5 g of the title compound was obtained: m.p. 1 59-1 600 (dec.), FD-MS: m/z 499 (M+ ); TLC on Kieselgel plates (Merck F254) solvent system chloroform:methanol:acetic acid:water (8:2:0.7:0.3 by volume): Rf 0.26. "E. Merck" is a Trade Mark.

Biological activity Activity in vitro Cytotoxicity. Colony inhibition test on HeLa cells. The test was carried out on HeLa cells according to the method described in J. Med. Chem., 1975, 18, 703. Exponentially growing cells (2 days after inoculation) were treated with several concentrations of daunorubicin, 4- demethoxydaunorubicin, and 4-demethoxy-1 3-dihydrodaunorubicin. After 24 hours exposure to the drugs, they were washed, tripsinized and plated (200 cells/plate). On day 6 the colonies containing more than 50 cells were counted. The dose causing 50% inhibition was calculated on the basis of dose-responsive curves. The data are reported in Table 1.

Table 1 Colony inhibition on HeLa cellsa Dose D/so Compound (ng/mI) % coloniesb (ng/mlJ Daunorubicin 25 3 12.5 32 11 6.2 92 4-demethoxy 25 0 daunorubicin 12.5 10 6.2 37 5.5 3.1 73 1.5 126 4-demethoxy-1 3- 12.5 0 dihydrodaunoru- 6.2 9 3 bicin 3.1 45 1.56 100 a 24 hours exposure b % respect with control Antitumour activity in vivo Activity against ascitic leukemia P 388 The experiments were performed in mice CDF-1 innoculated i.p. with 10S leukemic cells/mouse.

Table 2 Activity against leukemia P388: treatment i.p. on day 1 dose Compound (mg/Kg) T/C% toxic deaths daunorubicin 4.4 1 80 0/10 6.6 168 2/10 4-demethoxydauno- 0.33 1 50 0/10 rubicin 0.5 170 0/10 0.75 155 3/10 4-demethoxy-13-di- 0.14 130 0/10 hydrodaunorubicin 0.22 1 60 0/10 0.33 170 0/10 0.5 170 3/10 Activity against gross leukemia The experiments were performed in mice C3H inoculated i.v. with 2x 106 leukemic cells/mouse Table 3 Activity against gross leukemia i.v. treatment on day 1 dose Compound (mg/Kg) TIC% toxic deaths daunorubicin 10 150 0/10 15 183 0/10 22.5 233 0/10 4-demethoxy- 1.9 233 0/10 daunorubicin 2.5 233 0/10 3.3 266 0/10 4-demethoxy-13-di- 0.84 200 0/10 hydrodaunorubicin 1.26 250 0/10 1.9 258 0/10 Activity against advanced mammary Carcinoma.

The experiments were performed on C3H female mice innoculated with 2x 106 tumoral cells/mouse. The mice were treated 4 times a week, starting when the tumour was palpable. The results are shown in Table 4.

Table 4 dose growth % * inhibition % Compounds (mg/kgJ on day 48 on day 48 Controls - 3476 4-demethoxy- 0.8 4322 0 daunorubicin 1.2 2029 42 4-demethoxy-13- 0.6 5124 0 didehydro- 0.8 3374 3 daunorubicin 1.2 1201 65 * tumour weight at the end of treatment x100-100 tumour weight at the beginning of treatment

Claims

Claims 1. 4-Demethoxy-1 3-didehydrodaunorubicin or a pharmaceutically acceptable acid addition salt thereof.
2. A process for the preparation of 4-demethoxy-1 3-didehydrodaunorubicin, the process comprising reducing 4-demethoxydaunorubicin in aqueous solution with an excess of sodium borohydride.
3. A process for the preparation of 4-demethoxy-1 3-didehydrodaunorubicin, the process being substantially as described herein with reference to the Example.
4. A pharmaceutical composition comprising 4-demethoxy-1 3-dihydrodaunorubicin or pharmaceutically acceptable acid addition salt thereof in admixture with a pharmaceutically acceptable diluent or carrier.

4. A pharmaceutical composition comprising 4demethoxy-1 3-didehydrodaunorubicin or a pharmaceutically acceptable acid addition salt thereof in admixture with a pharmaceutically acceptable diluent or carrier.

Superseded ciaims 1 New or amended claims 1.4-demethoxy-l 3-dihydrodadaunorubicin or a pharmaceutically acceptable acid addition salt thereof.

2. A process for the preparation of 4-demethoxy-1 3-dihydrodaunorubicin, the process comprising reducing 4-demethoxydaunorubicin in aqueous solution with an excess of sodium borohydride.

3. A process for the preparation of 4-demethoxy-1 3-dihydrodaunorubicin, the process being substantially as described herein with reference to the Example.