title: Isosteric phosphonate analogs of ET-16-OMe. Synthesis and biological evaluation of the enantiomers of 2'-(trimethylammonio)ethyl 4-(hexadecyloxy)-3-methoxybutanephosphonate and 2'-(trimethylammonio)ethyl 4-(hexadecylthio)-3-methoxybutanephosphonate.
abstract: The enantiomers of two isosteric phosphonate analogs of the ether-linked antitumor agent 1-O-octadecyl-2-O-methyl-sn-glycero-3-phosphocholine (ET-18-OMe) were synthesized and evaluated for their cytotoxicity against various mouse leukemic cell lines in vitro and in vivo. The key step in the synthesis of the alkyloxy and alkylthio analogs (1 and 2, respectively) is the opening of an epoxide [hexadecyl 2-oxiranylmethyl ether (4) or hexadecyl 2-oxiranylmethyl thioether (8)] by LiCH2P(O)(OMe)2 using BF3.Et2O in tetrahydrofuran at low temperature. The cytotoxic activities of the hexadecyloxy and hexadecylthio phosphonate analogs of ET-18-OMe (1 and 2) against the murine leukemias WEHI-3B,L1210, and P388 were similar, indicating that substitution of a sulfur atom for oxygen in the long-chain ether does not result in a significant difference in cytotoxicity. The IC50 values of 1 and 2 were in the range of 1-5 microM. Alkyloxy phosphonate 1 was highly effective in inhibiting the growth of WEHI-3B and P388 tumors implanted in BALB/C mice. The alkyloxy and alkylthio phosphonates 1 and 2 prolonged the survival of CD1 mice bearing L1210 tumors. The antitumor activities of the phosphonate analogs of ET-18-OMe in these in vitro and in vivo studies were independent of chirality, consistent with previous studies with the enantiomers of 1-O-hexadecyl-2-O-methyl-sn-glycero-3-phosphocholine.
authors.affiliation: Department of Chemistry and Biochemistry, Queens College, City University of New York, Flushing 11367.
authors.forename: R
authors.initials: R
authors.lastname: Bittman
authors.forename: H S
authors.initials: HS
authors.lastname: Byun
authors.forename: B
authors.initials: B
authors.lastname: Mercier
authors.forename: H
authors.initials: H
authors.lastname: Salari
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000138:chemical synthesis* / Q000494:pharmacology / Q000627:therapeutic use; D002455:Cell Division / Q000187:drug effects; D007939:Leukemia L1210 / Q000188:drug therapy; D007941:Leukemia P388 / Q000188:drug therapy; D007942:Leukemia, Experimental / Q000188:drug therapy; D051379:Mice; D008807:Mice, Inbred BALB C; D015394:Molecular Structure; D009368:Neoplasm Transplantation; D063065:Organophosphonates; D010743:Phospholipids / Q000138:chemical synthesis* / Q000494:pharmacology / Q000627:therapeutic use; D013237:Stereoisomerism; D014407:Tumor Cells, Cultured
chemical_list: D000970:Antineoplastic Agents; D063065:Organophosphonates; D010743:Phospholipids; C079294:2'-(trimethylammonio)ethyl-4-(hexadecyloxy)-3-methoxybutane phosphonate; C085760:2'-(trimethylammonio)-ethyl-4-(hexadecylthio)-3-methoxybutane phosphonate