Structure-activity of novel rhodacyanine dyes as antitumor agents.
Kawakami M. Koya K. Ukai T. Tatsuta N. Ikegawa A. Ogawa K. Shishido T. Chen LB.
Ashigara Research Laboratories, Fuji Photo Film Company, Ltd., Kanagawa, Japan.
We have previously reported that rhodacyanine dyes, such as 1 and 2, exhibited a potent inhibitory effect on the growth of several tumor cells and that 4-oxothiazolidine (rhodanine) was an essential moiety for antitumor activity. On the basis of our foregoing work, two types of rhodacyanine dyes, which categorized into class I and II depending on the methine length, were synthesized and evaluated as a novel antitumor agent. Attention was particularly focused on the structure-activity study of two heteroaromatic rings. In class I, where the A rings were conjugated to rhodanine via two methine groups, compounds 1, 20, 23, and 24 were found to be efficacious in tumor-bearing nude mice model study, but they did not have the chemical properties (stability, solubility) suitable for clinical use. In contrast, in class II, where the A rings were directly conjugated to rhodanine, compounds 13 and 25, which possessed a benzothiazole moiety for the A ring, exhibited the favorable biological and chemical properties. Therefore, we decided to have a benzothiazole moiety as the A ring and introduce various heterocyclic groups for the B ring. As a result, the pyridinium ring was selected as the optimal moiety for the B ring (compound 13). Further, the variation of counteranion had a profound effect on solubility in water without influence on antitumor activity. Chloride anion was selected as the favorable anion with respect to synthetic method as well as solubility in water. Our study finally led us to the identification of compound 3 (MKT 077, 1-ethyl-2-[[3-ethyl-5-(methylbenzothiazolin-2-ylidene)-4-oxothi azolidin-2 -ylidene]methyl]pyridinium chloride) as the candidate for clinical trials and is currently subjected to further investigation as a potent antitumor agent in phase I clinical trial for the treatment of solid tumors.
1,4-Cyclohexanecarboxylates: potent and selective inhibitors of phosophodiesterase 4 for the treatment of asthma.
Christensen SB. Guider A. Forster CJ. Gleason JG. Bender PE. Karpinski JM. DeWolf WE Jr. Barnette MS. Underwood DC. Griswold DE. Cieslinski LB. Burman M. Bochnowicz S. Osborn RR. Manning CD. Grous M. Hillegas LM. Bartus JO. Ryan MD. Eggleston DS. Haltiwan
SmithKline Beecham Pharmaceuticals, King of Prussia, Pennsylvania 19406-0939, USA.
Evaluation of a variety of PDE4 inhibitors in a series of cellular and in vivo assays suggested a strategy to improve the therapeutic index of PDE4 inhibitors by increasing their selectivity for the ability to inhibit PDE4 catalytic activity versus the ability to compete for high affinity [3H]rolipram-binding sites in the central nervous system. Use of this strategy led ultimately to the identification of cis-4-cyano-4-[3-(cyclopentyloxy)-4-methoxyphenyl]cyclohexane-1-carboxyl ic acid (1, SB 207499, Ariflo), a potent second-generation inhibitor of PDE4 with a decreased potential for side effects versus the archetypic first generation inhibitor, (R)-rolipram.
Newly synthesized L-enantiomers of 3-fluoro-modified beta-2-deoxyribonucleoside 5-triphosphates inhibit hepatitis B DNA polymerases but not the five cellular DNA polymerases alpha, beta, gamma, delta, and epsilon nor HIV-1 reverse transcriptase.
von Janta-Lipinski M. Costisella B. Ochs H. Hubscher U. Hafkemeyer P. Matthes E.
Max-Delbruck-Centrum fur Molekulare Medizin, Robert-Rossle-Strasse 10, D-13125 Berlin-Buch, Germany.
Novel beta-L-2',3'-dideoxy-3'-fluoro nucleosides were synthesized and further converted to their 5'-triphosphates. Their inhibitory activities against hepatitis B virus (HBV) and duck hepatitis B virus (DHBV) DNA polymerases, human immunodeficiency virus (HIV) reverse transcriptase (RT), and the cellular DNA polymerases alpha, beta, gamma, delta, and epsilon were investigated and compared with those of the corresponding 3'-fluoro-modified beta-d-analogues. The 5'-triphosphates of 3'-deoxy-3'-fluoro-beta-L-thymidine (beta-L-FTTP), 2',3'-dideoxy-3'-fluoro-beta-L-cytidine (beta-L-FdCTP), and 2',3'-dideoxy-3'-fluoro-beta-l-5-methylcytidine (beta-L-FMetdCTP) emerged as effective inhibitors of HBV/DHBV DNA polymerases (IC50 = 0.25-10.4 microM). They were either equally (FTTP) or less (FMetdCTP, FdCTP) effective than their beta-d-counterparts. Also the 5'-triphosphate of beta-L-thymidine (beta-L-TTP) was shown to be a strong inhibitor of these two viral enzymes (IC50 = 0.46/1.0 microM). However, all beta-L-FdNTPs (also beta-L-TTP) were inactive against HIV-RT, a result which contrasts sharply with the high efficiency of the beta-D- FdNTPs against this polymerase. Between the cellular DNA polymerases only the beta and gamma enzymes displayed a critical susceptibility to beta-D-FdNTPs which is largely abolished by the beta-L-enantiomers. These results recommend beta-L-FTdR, beta-L-FCdR, and beta-L-FMetCdR for further evaluation as selective inhibitors of HBV replication at the cellular level.