Antitumor agents. 1. 1,4-Bis[(aminoalkyl)amino]-9,10-anthracenediones.

The condensation of alkylenediamines with quinizarin or with 2,3-dihydro-1,4,5,8-tetrahydroxy-9,10-anthracenedione, followed by oxidation, gave 1,4-bis[aminoalkyl)amino]-9,10-anthracenediones. Some of these compounds and their 2,3-dihydro derivatives were markedly active against both leukemias and solid tumors in mice. Activity was maximal with 5,8-dihydroxylation and 1,4-bis[(2-aminoethyl)amino] substitution, in which the terminal nitrogen atoms were either unsubstituted (compound 50) or carried 2-hydroxyethyl groups (compound 40), indicating the importance of hydrophilicity. Against B-16 melanoma, 50 gave greater than 433% increase in median life span (ILS) with 7/10 80-day survivors. Against P-388 leukemia, 40 gave greater than 500% ILS with 4/5.60-day survivors; its efficacy and therapeutic index equaled or surpassed those of adriamycin, cyclophosphamide, daunorubicin, methotrexate, or 5-fluorouracil. Against L-1210 leukemia, B-16 melanoma, and colon tumor 26, 40 was generally as effective or more effective than adriamycin and is now undergoing preclinical toxicological evaluation.

Water-soluble third generation antitumor platinum complexes, [2,2-bis (aminomethyl)-1,3-propanediol-N,N']-[1,1-cyclobutanedicarboxylato (2-)-O,O']platinum(II) and [1,1-cyclobutanedicarboxylato(2-)-O,O'] [tetrahydro-4H-pyran-4,4-dimethanamine-N,N']platinum(II).

The synthesis, stability, and antitumor activity of a series of water-soluble third generation platinum(II) complexes have been described. Among these complexes, [2,2-bis(aminomethyl)-1,3- propanediol-N,N'] [1,1-cyclobutanedicarboxylato(2-)-O,O']platinum(II) and [1,1-cyclobutanedicarboxylate(2-)-O,O'](tetrahydro-4H-pyran-4,4- dimethanamine-N,N'-)platinum(II) have shown the greatest promise for further investigation and are currently under clinical evaluation.

Antitumor agents. 2. Bisguanylhydrazones of anthracene-9,10-dicarboxaldehydes.

9,10-Anthracenedicarboxaldehyde bis[(4,5-dihydro-1H-imidazol-2-yl)hydrazone] (bisantrene, VI-1) showed anticancer activity in mice vs. both leukemias and solid tumors. Increases in life span vs. the following neoplasms were: P-388 leukemia, 137%; B-16 melanoma, 122%; Lieberman plasma cell tumor, greater than 85%; colon tumor 26, 150%; Ridgway osteogenic sarcoma, 85%. There were significant numbers of long-term survivors. Both DNA and RNA synthesis were strongly inhibited. The drug was resistant to biodegradation and was bound strongly to tissues; in monkeys the half-life for disappearance from serum was 6 days. Related hydrazones were synthesized, and structure-activity relationships are discussed. Two routes to ring-substituted anthracene-9,10-dicarboxaldehyde intermediates were developed.

Fenbufen, a new anti-inflammatory analgesic: synthesis and structure-activity relationships of analogs.

One hundred analogs of fenbufen were prepared and tested using the carrageenan, polyarthritis, and UV erythema anti-inflammatory tests and the 2-phenyl-1,4-benzoquinone writhing and inflamed paw pressure analgesic tests. Only three retained the same full spectrum of activity as fenbufen: dl-4-(4-biphenylyl)-4-hydroxybutyric acid, dl-4-(4-biphenylyl)-1,4-butanediol, and 4-biphenylacetic acid. Fenbufen had the same spectrum of activity as aspirin, phenylbutazone, and indomethacin in the five tests. In addition, dose-response derived potencies show fenbufen more potent than aspirin and at least as potent as phenylbutazone in all five tests. Two related compounds were generally similar.

A new non-steroidal anti-inflammatory analgesic: gamma-oxo (1,1'-biphenyl)-4-butanoic acid (fenbufen). Chemistry and activity of analogs.

100 analogs of gamma-oxo(1,1'-biphenyl)-4-butanoic acid (fenbufen) were prepared and tested using the carrageenin, polyarthritis, and UV erythema anti-inflammatory tests and the 2-phenyl-1,4-benzoquinone writhing and inflamed paw pressure analgesic tests. Only three retained the same full spectrum of activity as fenbufen: dl-4-(4-biphenyly)-4-hydroxybutyric acid, dl-4-(4-biphenylyl)-1,4-butanediol, and 4-biphenylacetic acid. Fenbufen had the same spectrum of activity as acetylsalicylic acid (ASA), phenylbutazone, and indometacin in the five tests. In addition, dose-response derived potencies show fenbufen more potent than ASA and at least as potent as phenylbutazone in all five tests.

Fast atom bombardment mass spectrometry of cisplatin analogs.

Cisplatin analogs of the type PtLACl2 and PtLALB are thermally unstable, non-volatile and highly insoluble. For these platinum coordination complexes, LA is a bidentate amine ligand and LB is a bidentate carboxylate ligand. Mass spectral data for structural elucidation of these compounds are absent in the literature because they are difficult to ionize. Nevertheless, a routine fast atom bombardment mass spectroscopic method has been developed utilizing the mixed solvent system of dimethyl sulfoxide:thioglycerol in a ratio of about 1:3 v/v. Using both positive and negative ionization modes, structurally significant ions were observed from representative molecules of the two named classes of compounds. [M-H]- ions were observed in both structural classes while [M + H]+ ions were observed only in the PtLALB class of compounds. Additional ions observed are rationalized in terms of the condensed-phase solution chemistry of the cisplatin analogs and the mixed solvent system when exposed to the fast atom beam. The two mechanisms causing ionization of the cisplatin analogs in the condensed phase appear to be: displacement of the ligands with dimethyl-sulfoxide and addition of chloride and the ionized solvents [dimentyl sulfoxide + H]+ and [thioglycerol - H]- to the cisplatin analogs. It is hypothesized that the addition reactions of the ionized solvents occur because of the differences in the basicity of the solvents and their reactivity in forming platinum(II)-sulfur bonds.