1. Field of the Invention
The invention relates to novel [4S-(4,12a.alpha.)]-4-(dimethylamino)-7-(substituted)-9-(substituted amino)-1,4,4a,5,5a,6,11,12a-octahydro-3,10,12,12a-tetrahydroxy-1,11-dioxo- 2-naphthacenecarboxamides hereinafter called 7-(substituted)-9-(substituted amino)-6-demethyl-6-deoxytetracyclines, which exhibit antibiotic activity against a wide spectrum of organisms including organisms which are resistant to tetracyclines and are useful as antibiotic agents. The invention also relates to novel 7-(substituted)-9-(substituted amino)-6-demethyl-6-deoxytetracycline intermediates useful for making the novel compounds of the present invention and to novel methods for producing the novel compounds and intermediate compounds.
2. Description of the Prior Art
A variety of tetracycline antibiotics have been synthesized and described for the treatment of infectious diseases in man and animals since 1947. Tetracyclines inhibit protein synthesis by binding to the 30S subunit of the bacterial ribosome preventing binding of aminoacyl RNA (Chopra, Handbook of Experimental Pharmacology, Vol. 78, 317-392, Springer-Verlag, 1985). Resistance to tetracyclines has emerged among many clinically important microorganisms which limit the utility of these antibiotics. There are two major mechanisms of bacterial resistance to tetracyclines: a) energy-dependent efflux of the antibiotic mediated by proteins located in the cytoplasmic membrane which prevents intracellular accumulation of tetracycline (S. B. Levy, et al., Antimicrob. Agents Chemotherapy 33, 1373-1374 (1989); and b) ribosomal protection mediated by a cytoplasmic protein which interacts with the ribosome such that tetracycline no longer binds or inhibits protein synthesis (A. A. Salyers, B. S. Speers and N. B. Shoemaker, Mol. Microbiol, 4:151-156, 1990). The efflux mechanism of resistance is encoded by resistance determinants designated tetA-tetL. They are common in many Gram-negative bacteria (resistance genes Class A-E), such as Enterobacteriaceae, Pseudomonas, Haemophilus and Aeromonas, and in Gram-positive bacteria (resistance genes Class K and L), such as Staphylococcus, Bacillus and Streptococcus. The ribosomal protection mechanism of resistance is encoded by resistance determinants designated TetM, N and O, and is common in Staphylococcus, Streptococcus, Campylobacter, Gardnerella, Haemophilus and Mycoplasma (A. A. Salyers, B. S. Speers and N. B. Shoemaker, Mol. Microbiol, 4:151-156 1990).
A particularly useful tetracycline compound is 7-(dimethylamino)-6-demethyl-6-deoxytetracycline, known as minocycline (see U.S. Pat. Nos. 3,148,212, Re. 26,253 and 3,226,436 discussed below). However, strains harboring the tetB (efflux in gram-negative bacteria) mechanism, but not tetK (efflux in Staphylococcus) are resistant to minocycline. Also, strains carrying tetM (ribosomal protection) are resistant to minocycline. This invention describes the synthesis of novel tetracycline compounds which demonstrate significant in vitro and in vivo activity vs. tetracycline and minocycline susceptible strains and some tetracycline and minocycline resistant strains, that is, those harboring the tetM (ribosomal protection) resistance determinants.
Duggar, U.S. Pat. No. 2,482,055, discloses the preparation of Aureomycin.RTM. (I) by fermentation which have antibacterial activity. Growich et al., U.S. Pat. No. 3,007,965, disclose improvements to the fermentation preparation of I. Neither of these patents teaches or suggests the 6-demethyl-6-deoxytetracyclines. ##STR1##
Beereboom et al., U.S. Pat. No. 3,043,875 discloses tetracycline derivatives of the formulae (II) and (III) where R is H or CH.sub.3 ; R.sub.1 is H and when R is CH.sub.3, OH; R.sub.2 is H and N(CH.sub.3).sub.2 ; X and Y are halogen; Z is H and halogen and B is bromo, chloro and iodo, which have antibacterial activity. This patent does not teach or suggest the inclusion of both di(lower alkyl)amino or mono(lower alkyl)amino substituents (at Y or Z) and an amino function (at B). ##STR2##
Boothe et al. , U.S. Pat. No. 3,148,212, reissued as U.S. Pat. No. Re. 26,253, and Petisi et al., U.S. Pat. No. 3,226,436, discloses tetracycline derivatives of the formula (IV) wherein R is hydrogen or methyl and R.sub.1 and R.sub.2 is hydrogen, mono(lower alkyl)amino or di(lower alkyl)amino with the proviso that R.sub.1 and R.sub.2 cannot both be hydrogen, which are useful for treating bacterial infections. This patent does not teach or suggest the inclusion of a 9-amino functionality (at R.sub.2). ##STR3##
Blackwood et al., U.S. Pat. No. 3,200,149 discloses tetracycline derivatives of the formulae (V) and (VI) and reduction products thereof wherein Y may be hydrogen or hydroxyl, X may be hydrogen, chloro, iodo, or bromo, X.sub.1 may be hydrogen, amino, and lower alkanoylamino, X.sub.2 may be hydrogen or nitro and Z is chloro or fluoro which possess microbiological activity. This patent does not teach or suggest the inclusion of both a di(lower alkyl)amino group (at X) and another nitrogen functionality (at X.sub.1) on the 6-demethyl-6-deoxytetracycline nucleus. ##STR4##
Petisi et al., U.S. Pat. No. 3,338,963 discloses tetracycline compounds of the formula (VII) wherein R.sub.1 and R.sub.2 are hydrogen, nitro, amino, formylamino, acetylamino, p-(dihydroxyboryl)benzoylamino, p-(aminobenzenesulfonyl)amino, chlorine, bromine or diazonium with the proviso that R.sub.1 and R.sub.2 may not both be hydrogen and with the further proviso that when R.sub.1 is chlorine or bromine, R.sub.2 may not be hydrogen and vice versa, R.sub.3 is hydrogen or methyl and R.sub.4 is hydrogen or hydroxy, which have broad-spectrum antibacterial activity. This patent does not teach or suggest the inclusion of both di(lower alkyl)amino or mono(lower alkyl)amino substituents (at R.sub.1) and amino substituents (at R.sub.2). ##STR5##
Bitha et al., U.S. Pat. No. 3,341,585 discloses tetracycline compounds of the formula (VIII) wherein R.sub.5 is hydrogen, .alpha.-hydroxy or .beta.-hydroxy, R.sub.6 is .alpha.-methyl or .beta.-methyl, and R.sub.7 and R.sub.9 are each hydrogen, mono(lower alkyl)amino or di(lower alkyl)amino with the proviso that R.sub.7 and R.sub.9 cannot both be hydrogen and with the further proviso that when R.sub.5 is hydrogen then R.sub.6 is .alpha.-methyl. A preferred embodiment of the general formula (VIII) is when R.sub.5 is .alpha.-hydroxy or .beta.-hydroxy, R.sub.6 is .alpha.-methyl or .beta.-methyl, R.sub.7 is di(lower alkyl)amino and R.sub.9 is hydrogen, which have broad-spectrum antibacterial activity. This patent does not teach or suggest the inclusion of both di(lower alkyl)amino or mono(lower alkyl)amino substituents (at R.sub.7) and amino substituents (at R.sub.9). ##STR6##
Shu, U.S. Pat. No. 3,360,557 discloses 9-hydroxytetracyclines of the formula (IX) wherein R.sub.1 is hydrogen or hydroxy, R.sub.2 is hydrogen or hydroxy, R.sub.3 is hydrogen or methyl, R.sub.2 and R.sub.3 taken together is methylene, and R.sub.4 is hydrogen, halogen, nitro, amino, mono(lower alkyl)amino or di(lower alkyl)amino, which have been found to possess antibacterial activity. This patent is restricted to 9-hydroxytetracyclines and does not teach or suggest the presently claimed compounds. ##STR7##
Zambrano, U.S. Pat. No. 3,360,561 discloses a process for preparing 9-nitrotetracyclines of the formula (X) wherein R.sub.5 is hydrogen or hydroxy, R.sub.1 is hydrogen or hydroxy, R.sub.6 is hydrogen or methyl, R.sub.1 and R.sub.6 taken together is methylene, R.sub.7 is hydrogen, chloro or nitro and R.sub.9 is hydrogen or nitro with the proviso that R.sub.7 and R.sub.9 cannot both be hydrogen. This patent does not teach or suggest the inclusion of both a di(lower alkyl)amino or mono(lower alkyl)amino substituent (at R.sub.7) and an amino functionality (at R.sub.9). ##STR8##
Martell et al., U.S. Pat. No. 3,518,306 discloses 7-and/or 9-(N-nitrosoalkylamino)-6-demethyl-6-deoxytetracyclines of the formula (XI) which possess in vivo antibacterial activity. This patent does not teach or suggest the inclusion of both a di(lower alkyl)amino or mono(lower alkyl)amino substituent (at C-7) and an amino functionality (at C-9). ##STR9##
In U.S. Pat. No. 5,021,407, a method of overcoming the resistance of tetracycline resistant bacteria is disclosed. The method involves utilizing a blocking agent compound in conjunction with a tetracycline type antibiotic. This patent does not disclose novel tetracycline compounds which themselves have activity against resistant organisms.
In summary, none of the above patents teach or suggest the novel compounds of this application. In addition, none of the above patents teach or suggest novel tetracycline compounds having activity against tetracycline and minocycline resistant strains as well as strains which are normally susceptible to tetracyclines.