- Phosphonomethyl Oligonucleotides as Backbone-Modified Artificial Genetic Polymers
-
Although several synthetic or xenobiotic nucleic acids (XNAs) have been shown to be viable genetic materials in vitro, major hurdles remain for their in vivo applications, particularly orthogonality. The availability of XNAs that do not interact with natu
- Liu, Chao,Cozens, Christopher,Jaziri, Faten,Rozenski, Jef,Maréchal, Amandine,Dumbre, Shrinivas,Pezo, Valérie,Marlière, Philippe,Pinheiro, Vitor B.,Groaz, Elisabetta,Herdewijn, Piet
-
-
Read Online
- Investigation on condensing agents for phosphinate ester formation with nucleoside 5′-hydroxyl functions
-
Condensation of a uridine 3′-deoxy-3′-C-methylenephosphinate with thymidine and guanosine derivatives to form methylenephosphinate esters was investigated. A number of different condensing agents were compared, and these include pivaloyl chloride, triisopropylbenzenesulfonyl chloride (TPSCl), phosphonium and uronium derivatives, numerous chlorophosphates and bis(2-oxo-3-oxazolidinyl)phosphinic chloride (OXP). The phosphonium derivatives gave slow condensations or oxidative side reactions (hydroxybenzotriazole derivatives) during preactivation of the methylenephosphinate. Pivaloyl chloride gave long coupling times, and competing 5′-O-pivaloylation was detected. TPS-Cl gave rapid condensation but also rapid oxidation of the product. Most chlorophosphates gave competing 5′-O-phosphorylation of the nucleoside component, as well as base phosphorylation. However, 2-chloro-5,5-dimethyl-2- oxo-1,3,2-dioxaphosphorinane (DMOCP) gave a rather efficient formation of dinucleoside methylenephosphinates at a decent rate. However, O 6-protection of guanines could become necessary with this reagent, since upon extended reaction time traces of O6-phosphorylation were detected even with a low concentration (60 mM) of DMOCP (2 equiv. to phosphinate). Bis(2-oxo-3-oxazolidinyl) phosphinic chloride (OXP) can, unlike DMOCP, be used in nearly equimolar amounts to phosphinate. Under such conditions OXP gives virtually quantitative condensation at a rate comparable to that of 2 equiv. of DMOCP and with no side reactions detected. We could also not detect any decomposition of OXP-preactivated phosphinate. Nucleophilic catalysts, more powerful than pyridine (N-methylimidazole, iodide and 4-methoxypyridine), accelerated the reactions with OXP, but preactivation in the absence of the 5′-OH component led to decomposition of the activated phosphinate. Wiley-VCH Verlag GmbH & Co. KGaA, 2008.
- Winqvist, Anna,Stroemberg, Roger
-
experimental part
p. 1705 - 1714
(2009/04/05)
-
- Synthesis of new nucleoside phosphoraziridines as potential site-directed antineoplastic agents
-
With the aim of increasing the selectivity of the 2,2-dimethylphosphoraziridine type antitumor agents towards the intracellular site of DNA synthesis, a series of new compounds was synthesized in which the reactive bis(2,2-dimethyl-1-aziridinyl)phosphinyl (2,2-DMAP) group was linked through a carbamate or amide linkage to thymidine or cytosine nucleoside moieties. The 3'- and 5'-(2,2-DMAP)carbamates of thymidine (1 and 2) were found to be highly unstable, therefore the corresponding O-acetyl derivatives 5 and 6 were prepared by reacting 5'- and 3'-acetylthymidine, respectively, with dichloroisocyanatophosphine oxide followed by the addition of 2,2-dimethylaziridine and triethylamine. The 3'- and 5'-(2,2-DMAP)amides of thymidine 14 and 15 were prepared by reacting the appropriate thymidinylamines with bis(2,2-dimethyl-1-aziridinyl)phosphinyl chloride (17). The N4-(2,2-DMAP)amides of cytidine, 2'-deoxycytidine, and cytosine arabinoside (18, 19, and 20, respectively) were prepared by reacting the hydrochlorides of the O-peracetylated cytosine nucleosides with triethylamine and POCl3 and, subsequently, with 2,2-dimethylaziridine and triethylamine, to give the corresponding N4-(2,2-DMAP)cytosine nucleoside peracetates 21, 22, and 23, respectively, which were then deacetylated by aminolysis. However, the peracetate intermediates were found to be more stable and, probably for the same reason, also more active against P388 leukemia in mice than the deacetylated products. Particularly, 22 and 23 showed sufficient activity in this in vivo assay system to warrant further evaluation. The relationships between the antitumor activities, the chemical alkylating activities, and the cholinesterase inhibitory activities of these agents are discussed.
- Breiner,Rose,Dunn,MacDiarmid,Bardos
-
p. 2596 - 2602
(2007/10/02)
-