- New prodrugs of Adefovir and Cidofovir
-
New Adefovir (PMEA) prodrugs with a pro-moiety consisting of decyl or decyloxyethyl chain bearing hydroxyl function(s), hexaethyleneglycol or a (5-methyl-2-oxo-1,3-dioxolen-4-yl)methyl unit were prepared starting from the tetrabutylammonium salt of the phosphonate drug and an appropriate alkyl bromide or tosylate. Analogously, two esters of Cidofovir [(S)-HPMPC] bearing a hexaethyleneglycol moiety were prepared. The activity of the prodrugs was evaluated in vitro against different virus families. A loss in the antiviral activities of the hydroxylated decyl or decyloxyethyl esters and hexaethyleneglycol esters of PMEA against human immunodeficiency virus (HIV) and herpesviruses [including herpes simplex virus (HSV), varicella-zoster virus (VZV), and human cytomegalovirus (CMV)] occurred in comparison with the parent compound. On the other hand, the (5-methyl-2-oxo-1,3-dioxolen-4-yl)methyl ester of PMEA showed significant activities against HIV and herpesviruses. (S)-HPMPC prodrugs exhibited anti-cytomegalovirus activities in the same range as the parent drug, whereas the anti-HSV and anti-VZV activities were one- to seven-fold lower than that of Cidofovir.
- Tichy, Tomá?,Andrei, Graciela,Dra?ínsky, Martin,Holy, Antonín,Balzarini, Jan,Snoeck, Robert,Kre?merová, Marcela
-
-
Read Online
- Synthesis of epoxy-terminated dialkyl disulfides for polymerizable self- assembled monolayers
-
The synthesis of epoxy-terminated dialkyl disulfides for incorporation into polymerizable self-assembled monolayers is reported. The epoxide is installed by an indirect method in which the disulfide linkage is used as a built-in protecting group.
- Yeager, Laura J.,Amirsakis, Dafni G.,Newman, Elan,Garrell, Robin L.
-
-
Read Online
- Novel developing agents for (photo) thermographic systems
-
A thermographic element comprising in a non-aqueous binder medium a silver salt oxidising agent in reactive association with a compound comprising a plurality of redox colour releasing moieties such that oxidation of each redox colour releasing moiety causes release from said compound of a thermally diffusible dye. The compounds many of which are new incorporate two or more developer moieties into a single molecule to minimise the diffusibility of the compound. Following oxidation, either directly by the silver salt or by means of a cross-oxidising agent, each oxidised developer moiety releases a thermally diffusible dye. The compounds are of sufficient size and molecular weight to slow or prevent diffusion in imaging systems and yet possess several active developer moieties per molecule which is advantageous over known ballasted dye releasers which comprise bulky molecules with only a single developer moiety.
- -
-
-