3--azido-2--3--dideoxyuridine and Leukemia-L1210

A series of the anti-HIV nucleoside conjugates of either (1-O-alkyl) and thioether (1-S-alkyl) lipids linked by a pyrophosphate diester bond has been synthesized as micelle-forming prodrugs of the nucleosides to improve their therapeutic efficiency. These include AZT 5'-diphosphate-rac-1-S-octadecyl-2-O-palmitoyl-1-thioglycerol (1), 3'-azido-2',3'-dideoxyuridine 5'-diphosphate-rac-1-S-octadecyl-2-O-palmitoyl-1-thioglycerol (2) 2',3'-dideoxycytidine 5'-diphosphate-rac-1-S-octadecyl-2-O-palmitoyl-1-thioglycerol (3), and AZT 5'-diphosphate-rac-1-O-tetradecyl-2-O-palmitoylglycerol (4). The conjugates form micelles by sonication (mean diameters ranging 6.8-55.5 nm). Conjugate 1 protected 80% of HIV-infected CEM cells as low as 0.58 microM and lost the protection at 180 microM due to prevailing cytotoxicity, while the conjugate started to show the cytotoxicity at 100 microM. Pharmacokinetics studies showed a significant increase of half-life values (t1/2) of AZT and AZddU2 (respective t1/2 = 5.69 and 6.5 h) after administration of conjugates 1 and 2, while those after administration of AZT and AZddU were 0.28 and 0.89 h, respectively. The fractions of the prodrugs 1 and 2 converted to the parent compounds AZT and AZddU were 36% and 55%, respectively. The results indicate that AZT and AZddU thioether lipid conjugates 1 and 2 warrant further investigation.

Topics: Animals; Antiviral Agents; Cell Line; Ethers; Female; HIV-1; Humans; In Vitro Techniques; Leukemia L1210; Magnetic Resonance Spectroscopy; Mice; Mice, Inbred DBA; Phospholipids; Tumor Cells, Cultured

Various new 5-substituted 3'-azido- and 3'-amino derivatives of 2'-deoxyuridine and 2'-deoxycytidine have been synthesized and biologically evaluated. Among these compounds, 3'-amino-2',3'-dideoxy-5-fluorouridine (3), 3'-amino-2',3'-dideoxycytidine (7a), and 3'-amino-2',3'-dideoxy-5-fluorocytidine (7c) were found to be the most active against murine L1210 and sarcoma 180 neoplastic cells in vitro, with an ED50 of 15 and 1 microM, 0.7 and 4 microM, and 10 and 1 microM, respectively. The 3'-azido derivatives, 2 and 6c, were less active in comparison with their 3'-amino counterparts. In addition, the 5-fluoro-3'-amino nucleosides, 3 and 7c, were tested against L1210 leukemia bearing CDF1 mice. Our preliminary findings indicate that compound 7c (6 X 200 mg/kg) was as active as the positive control, 5-fluorouracil (6 X 20 mg/kg), yielding a T/C X 100 of 146 and 129, respectively. However, 3 was found to be inactive in this experiment.

Topics: Animals; Antineoplastic Agents; Deoxycytidine; Deoxycytidine Kinase; Deoxyuridine; Leukemia L1210; Mice; Sarcoma 180; Thymidine Kinase

Several new 3'-azido and 3'-amino nucleosides (8, 9, 12, and 13) have been synthesized and their biological activities evaluated. Among them, 3'-amino-2',3'-dideoxycytidine (13) was found to exhibit potent cytotoxic activity against both L1210 and S-180 cells in vitro with an ID50 of 0.7 and 4.0 microM, respectively. Furthermore, 13 has also shown antitumor activity against L1210 tumor bearing mice with a T/C X 100 value of 283.

Topics: Animals; Antineoplastic Agents; Body Weight; DNA Replication; Leukemia L1210; Mice; Pyrimidine Nucleosides