- The synthesis, antiviral, cytostatic and cytotoxic evaluation of a new series of acyclonucleotide analogues with a 1,2,3-triazole linker
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The efficient synthesis of a new series of acyclonucleotide analogues with a 1,2,3-triazole linker is described starting from diethyl azidomethyl-, 2-azidoethyl-, 3-azidopropyl-, 4-azidobutyl-, 2-azido-1-hydroxyethyl-, 3-azido-2-hydroxypropyl- and 3-azido-1-hydroxypropylphosphonates and selected alkynes under microwave irradiation. Several O,O-diethylphosphonate acyclonucleotides were transformed into the respective phosphonic acids. All compounds were evaluated in vitro for activity against a broad variety of DNA and RNA viruses and cytostatic activity against murine leukaemia L1210, human T-lymphocyte CEM and human cervix carcinoma HeLa cells. Acyclonucleotide 22e exhibited activity against both herpes simplex viruses (HSV-1, HSV-2) in HEL cell cultures (EC50 = 17 μM) and feline herpes virus (EC 50 = 24 μM) in CRFK cell cultures, while compounds 20k, 21k, 22k and 23k preferentially inhibited proliferation of human T-lymphocyte CEM cells at IC50 in the 2.8-12 μM range.
- G?owacka, Iwona E.,Balzarini, Jan,Wróblewski, Andrzej E.
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p. 703 - 722
(2013/12/04)
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- 3,1-Benzothiazin-4-ones and 3,1-benzoxazin-4-ones: Highly different activities in chymotrypsin inactivation
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3,1-Benzothiazin-4-ones are sulfur analogs of the potent serine protease inactivators of the 3,1-benzoxazin-4-one type, which acylate the serine residue within the active site of the enzymes. A series of 2-amino-3,1-benzothiazinones was synthesized, but these compounds showed only very little inhibitory activity toward chymotrypsin, a model serine protease. Detailed investigations revealed that benzothiazinones and benzoxazinones react with identical mechanisms, but benzothiazinones acylate chymotrypsin with much lower rate constants. Investigations of nonenzymatic hydrolysis showed the benzothiazinones to be intrinsically more stable than benzoxazinones. It was concluded from spectroscopic results, that benzoxazinones are highly activated due to the absence of ester-like resonance. 2-Benzoylamino-4H-3,1-benzoxazin-4-one was found to be a new, highly active chymotrypsin inactivator. In contrast, benzothiazinones were found to be resonance stabilized. The contribution of a resonance structure with an exocyclic oxanion to the overall structure of the benzothiazinones and its nonproductive binding to the active site explained their low reactivity toward chymotrypsin.
- Neumann,Guetschow
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