title: Synthesis and in vitro activities of a new antiviral duplex drug linking Zidovudine (AZT) and Foscarnet (PFA) via an octadecylglycerol residue.
abstract: To prepare a new antiviral duplex drug linking Zidovudine (AZT) and Foscarnet (PFA) via a lipophilic octadecylglycerol residue we condensed 1-O-4-monomethoxytrityl-3-O-octadecyl-sn-glycerol-2-hydrogenphosphonate obtained from 3-O-octadecyl-sn-glycerol with AZT by the phosphonate method. The purified condensation product was de-tritylated resulting in 3'-azido-3'-deoxythymidylyl-(5'-->2-O)-3-O-octadecyl-sn-glycerol, followed by treatment with (ethoxycarbonyl)phosphoric dichloride. The resulting 3'-azido-3'-deoxy-thymidylyl-(5'-->2)-3-O-octadecyl-sn-glycerol-1-O-(ethoxycarbonyl)phosphonate was purified by preparative RP-18 column chromatography. The antiviral duplex drug 3'-azido-3'-deoxythymidylyl-(5'-->2-O)-3-O-octadecyl-sn-glycerol-1-O-phosphonoformate trisodium salt (AZT-lipid-PFA) was obtained after alkaline cleavage of the phosphonoformate ethylester residue. The overall yield of the five step synthesis performed at gram scale was about 30%. According to a supposed pathway AZT-lipid-PFA could be cleaved to yield a mixture of different antiviral compounds such as AZT, AZT-5'-monophosphate, octadecylglycerol-AZT, PFA and octadecylglycerol-PFA, possibly producing additive and/or synergistic antiviral effects. In vitro studies showed that the duplex drug exhibits antiviral activities against HIV and especially against drug-resistant strains and clinical isolates of HSV and HCMV. The E(50) values of AZT-lipid-PFA against HIV ranged between 170 and 200 nM. The half-maximal inhibitory doses (IC(50)) against highly acyclovir (ACV)-resistant HSV isolates determined by a plaque reduction assay ranged between 1.87 and 4.59 microM. Using ganciclovir (GCV)-sensitive, GCV resistant and drug cross-resistant HCMV strains the IC(50)-values of AZT-lipid-PFA were between 2.78 and 1.18 microM. With regard to PFA, the IC(50)-value of AZT-lipid-PFA determined on a multi-drug-resistant HCMV strain was about 90-fold lower than that of PFA, demonstrating the superior antiviral effect of the duplex-drug.
authors.affiliation: Institute for Organic Chemistry, University Tuebingen, Auf der Morgenstelle 18, D-72076 Tuebingen, Germany. herbert.schott@uni-tuebingen.de
authors.forename: Herbert
authors.initials: H
authors.lastname: Schott
authors.forename: Klaus
authors.initials: K
authors.lastname: Hamprecht
authors.forename: Sarah
authors.initials: S
authors.lastname: Schott
authors.forename: Timm C
authors.initials: TC
authors.lastname: Schott
authors.forename: Reto A
authors.initials: RA
authors.lastname: Schwendener
mesh_terms: D000998:Antiviral Agents / Q000138:chemical synthesis*; D003432:Cross-Linking Reagents; D003587:Cytomegalovirus / Q000187:drug effects; D004347:Drug Interactions; D017245:Foscarnet / Q000031:analogs & derivatives* / Q000737:chemistry / Q000494:pharmacology; D005995:Glyceryl Ethers; D006678:HIV / Q000187:drug effects; D006801:Humans; D020128:Inhibitory Concentration 50; D018139:Simplexvirus / Q000187:drug effects; D015215:Zidovudine / Q000031:analogs & derivatives* / Q000737:chemistry / Q000494:pharmacology
chemical_list: D000998:Antiviral Agents; D003432:Cross-Linking Reagents; D005995:Glyceryl Ethers; D017245:Foscarnet; D015215:Zidovudine