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.

Enantioselectivity of microsomal epoxide hydrolase toward arene oxide substrates

The enantioselectivity of native and purified hepatic microsomal epoxide hydrolase toward one symmetrical arene oxide, phenanthrene 9,10-oxide, and the resolved enantiomers of the three chiral arene oxide substrates, benzo[a]pyrene 4,5- and 7,8-oxide and benzo[a]anthracene 5,6-oxide was examined. A model lipid system of nonionic detergent micelles was used to solubilize both substrates and products. The enantioselectivity of purified epoxide hydrolase in micellar solution was essentially the same as the microsomal enzyme in the absence of detergent. Regioselectivity of the enzyme was determined by a gas chromatographic-mass spectrometric procedure in which bis-trifluoroacetates of the dihydrodiols were pyrolyzed to trifluoroacetylphenols to locate the position of the enzyme-catalyzed incorporation of 18O from H218O into the dihydrodiol. Correlation of the enantio- and regioselectivity data with the known absolute configurations of the dihydrodiols permitted the assignment of the (4S,5R) and (5S,6R) absolute configurations to (+)-benzo[a]pyrene 4,5- and (+)-benzo[a]anthracene 5,6-oxide, respectively. A kinetic analysis of the hydration of arene oxide substrates in micellar solution is presented. The kinetic discrimination of the enzyme toward substrate enantiomers and the product enantioselectivity of the enzyme are discussed in terms of possible molecular deformations occurring in the transition state and the ability of the enzyme to bind and stabilize these transition states.

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.

Fluorescent probes for asymmetric lipid bilayers: synthesis and properties in phosphatidyl choline liposomes and erythrocyte membranes

We have synthesized three sets of fluorescent probes which we believe will be useful in studies of asymmetric membranes and have studied their interactions with model lipid bilayers and erythrocyte membranes. The probes were designed to partition preferentially into one face of a lipid bilayer with asymmetrically disposed phospholipids and to report lipid transitions in that monolayer. We synthesized more than twenty probes containing anthroyl-, dansyl-, or pyrene rings with acidic, basic, and neutral functional groups and alkyl "spacers" of various lengths. The interactions of these probes with liposomes of phosphatidyl choline and with erythrocyte membranes were characterized to determine whether probe insertion was asymmetric, how deeply the probe penetrated the bilayer, and whether the probe reflected thermotropic phase transitions in model membranes. The set of variously charged anthroyl esters, analogs of local anaesthetics, appears to be promising for studies of asymmetric membranes. Fluorescent probes have been used extensively to provide information on the lipid regions of biological membranes. Membrane fluidity, a composite of molecular packing and motion of acyl chains in lipid bilayers, has been assessed with a variety of fluorescent probes, the fluorescence of which undergoes some measurable change at the temperature of the membrane's thermotropic phase transition. A large number of fluorescent probes have been used for this purpose. Bashford, Morgan and Radda (Bashford, C.L., Morgan, C.G., Radda, G.K. 1976; Biochim. Biophys. Acta 426:157) and Thulborn and Sawyer (Thulborn, K.R., Sawyer, W. H. 1978; Biochim. Biophys. Acta 511:125) synthesized several fatty acid derivatives in which an anthracene group is attached (in ester linkage) along the acyl chain at various positions, and have shown that this set of probes may be useful in probing membrane fluidity at different depths within the bilayer. This report describes the synthesis and properties of several sets of amphipathic fluorescent probes, which may partition unequally into the two faces of an asymmetric lipid bilayer, and may therefore provide information about membranes complementary to that obtainable with existing probes.

Properties and the locations of a set of fluorescent probes sensitive to the fluidity gradient of the lipid bilayer

The synthesis and properties of a set of four fluorescent probes (n-(9-anthroyloxy) fatty acids, n = 2, 6, 9, 12) sensitive to the fluidity gradient of the lipid bilayer are described. Fluorescent quenching experiments show that the probes locate at a graded series of depths in the bilayer. A fifth probe, methyl-9-anthroate, locates near the bilayer centre. As an example of their application, the probes are used to study the phase transitions of dipalmitoyl phosphatidyl-choline. Changes in the rotational relaxation times of the probes across the transitions are more pronounced at the centre of the bilayer than at the surface.

Antimalarial amino alcohols II: anthraceneaminoethanols and anthraceneaminopropanols (1- and 9-substituted)

The syntheses of seven anthracene amino alcohols with one, two, or three additional substituents are described. These compounds include three 1-aminoethanols, two 9-aminoethanols, and two 9-aminopropanols, prepared from substituted anthraquinones or from 10-chloro-9-anthraldehydes. The antimalarial activity of these compounds, as well as tentative structure-activity relationships, is discussed in the light of previously published work.