Isolation, synthesis, and evaluation of a series of indencarbazates as hypotensive agents.

Two indencarbazates, 1 and 2, were isolated from the sponge Cliona caribboea. These compounds were found to possess mild hypotensive activity. A series of analogues of 1 was synthesized in order to study the structure-activity relationship of this unique class of compounds. A variety of structural changes did not result in a consistent pattern of biological activity.

Indeno[1,2-c]pyrazolone acetic acids as semirigid analogues of the nonsteroidal anti-inflammatory drugs.

A series of 3-substituted indeno[1,2-c]pyrazol-4(1H)-one-2-acetic acids (3a-e) and 3-substituted indeno[1,2-c]pyrazol-4(1H)-one-1-acetic acids (4a-e) were synthesized as semirigid analogues of tolmetin (1). These compounds were evaluated for their anti-inflammatory action by investigating their ability to block arachidonic acid metabolism in vitro as well as the ability to block carrageenan-induced rat foot edema in vivo. No consistent pattern of biological activity was noted.

beta-Adrenergic blocking agents. alpha- and gamma-methyl(aryloxy)propanolamines.

A series of gamma-methyl- (5) and alpha-methyl(aryloxy)propanolamines (6) were synthesized and evaluated for beta-adrenergic blocking action. The binding constant (KD) was determined for compounds 5a-j on cultured C6-2B astrocytoma cells. Compounds 5a-j and 6a-e were evaluated for beta 1-antagonist action on guinea pig atria and beta 2-antagonist action on guinea pig tracheal strips. Several gamma-methyl(aryloxy)propanolamines showed affinity for beta receptors and a possible preference for beta 2 receptors.

Phosphorus-nitrogen compounds. 22. Synthesis and antitumor activity of arylsulfonylhydrazone analogues.

A series of pyridine-2-carboxaldehyde N-oxide and pyridine-2-carboxaldehyde (thio)phosphoric hydrazones and two cupric chelates was synthesized. The hydrazones, chelates, and combinations of hydrazones and cupric chloride were tested against mice bearing P388 lymphocytic leukemia, Sarcoma 180, or Ehrlich carcinoma ascites cells. The effects of various structural modifications of the hydrazones on antineoplastic activity for this latter system were determined. In general, the pyridine-2-carboxaldehyde thiophosphoric monohydrazones containing P-phenyl or P-phenoxy substituents possessed the highest activity when concurrently administered with cupric ion, whereas the ligands themselves were inactive. Two of the compounds were prepared with P-hydroxyl groups to permit increased hydrophilicity. The ability of the hydrazones to chelate cupric, ferrous, and cobaltous salts was investigated, and discrepancies between determined and calculated log P values for three compounds are discussed.

Heterocyclic tricycles as potential CNS agents I: 4-aminoalkylindeno[1,2-c]pyrazoles.

Series of 4-(3-dimethylaminopropyl)-4-hydroxyindeno[1,2-c]pyrazoles and 4-(1-methyl-4-piperidyl)-4-hydroxyindeno[1,2-c-]pyrazoles were synthesized and identified. The compounds were evaluated as potential CNS agents using spontaneous and forced motor activity in mice as an initial test. 2-Ethyl-3-methyl-4-(1-methyl-4-piperidyl)-4-hydroxyindeno[1,2-c]pyrazole possessed significant biological activity.

Synthesis of 5,6-dihydro-8(7H)-quinolinone thiosemicarbazones as potential antitumor agents.

5,6-Dihydro-8(7H)-quinolinone was synthesized and converted into thiosemicarbazones which could be considered to be semirigid analogues of the 2-formylpyridine thiosemicarbazone class of antitumor agents. The Z and E isomers were separated and identified by 1H NMR and UV. Although the compounds showed essentially no inhibitory activity against the enzyme alkaline phosphatase, several of these agents had demonstrable anticancer activity in mice bearing the P388 leukemia. The E-configuration analogues in general were slightly more active than their corresponding Z isomers.

Effect of the solvent-dependent conformational system of hydroxyureas on predicted vs. observed log P.

Calculated and observed log P values are reported and compared with in vivo and in vitro biological action (L1210 leukemia ILS % and ribonucleotide reductase ID50) for hydroxyurea, the 1-N methyl and ethyl, and the 3-N ethyl, n-propyl, isopropyl, n-butyl, tert-butyl, phenyl, and p-chlorophenyl analogues. The log P values were calculated via the method of Hansch and Leo from literature f values and the observed log P values were obtained by direct determination after equilibration between octanol and water. Calculations of log P for hydroxyurea were found to be appreciably more hydrophilic than the values obtained experimentally. Differences in calculated and observed log P (delta log P) for the substituted analogues were lowest with the 1-N and the bulky 3-N substituents and greatest with the 3-N-substituted straight-chain analogues (delta log P = 0.70). Different structural species were observed by infrared spectroscopy in dry octanol vs. octanol after water equilibration and drying, and this is proposed as due to changes in conformational equilibrium in the hydroxyurea systems. Differences between calculated and observed log P are explained via the stabilization of internally hydrogen-bonded conformers in the case of 1-N or bulky 3-N analogues or destabilization of various conformers allowing maximal interactions with solvent or water which is the case with straight chain 3-N analogues.

Phosphorus-nitrogen compounds. 20. Thiophosphorus hydrazones.

Six pyridine-2-carboxaldehyde, one pyridine N-oxide 2-carboxaldehyde, and five diketone thiophosphoric hydrazones, three thiophosphoric hydrazides, and two cupric chelates were synthesized. The chelates and nine of the hydrazones were tested against Ehrlich ascites carcinoma. Seven of these latter agents were administered concurrently with either cupric and/or ferrous salts to mice bearing this tumor. The greatest activity was found with the chelate, cimethyl pyridine-2-carboxyaldehyde phosphorothioic hydrazone-copper (1:1). The hydrazone portion of this chelate also formed a ligand-copper (2:1) complex. Although all of the hydrazones but one were inactive when evaluated alone, the concurrent injection of cupric ion increased survival times by an avoli alkaline phosphatase was found to be inhibited by two thiosemicarbazones in a manner similar to that previously reported by these agents against alkaline phosphatase derived from Sarcoma 180-6-thiopurine resistant ascites cells. None of the 14 hydrazides or hydrazones tested against E. coli enzyme displayed significant inhibition.

Synthesis and biological actions of 2-substituted quinolizidines.

A series of 2-substituted quinolizidines was synthesized and tested for their effects on motor activity in mice. In the 2-aryl-2-hydroxyquinolizidines (5 and 6) a difference was noted in potency between the axial and equatorial aryl analogs. A significant difference in activity was also found between the epimeric 2-(4-fluorobenzoyl) quinolizidines (10c and 11c).

Analogs of the anorexic mazindol.

Mazindol, 5-(p-chlorophenyl)-2,5-dihydro-3H-imidazo[2,1-a]isoindol-5-ol, has been shown to be an effective anorexic. To explore the structure-activity relationships, several 1-ethyl-3-substituted-4-aryl-4-hydroxyindeno[1,2-c]pyrazoles were prepared and subjected to various animal screens. The 1-ethyl-3-tert-butyl-4-aryl-4-hydroxyindeno[1,2-c]pyrazoles are capable of significantly depressing forced and spontaneous motor activity in mice but have low LD50's. Two of these compounds were tested in an Ehrlich ascites tumor screen. The 1-ethyl-3-phenyl-4-aryl-4-hydroxyindeno[1,2-c]pyrazoles depressed forced and spontaneous motor activity at low doses and were relatively nontoxic.