Synthesis of non-nucleoside triphosphate analogues, a new type of substrates for terminal deoxynucleotidyl transferase

A series of non-nucleoside triphosphate analogues were synthesized. In place of the nucleoside fragment, substituents bearing aromatic groups were introduced; the triphosphate component was replaced at alpha, beta, or gamma-positions by phosphonates. Alpha-[2-N-(9-Fluorenylmethoxycarbonyl)aminoethylphosphonyl]-beta,gamma-difluoromethylenediphosphonate (IIc) revealed the best substrate properties toward terminal deoxynucleotidyl transferase.     

New Phosphonoformic Acid Derivatives of 3′-Azido-3′-Deoxythymidine

New 5-alkyl ethoxy- and aminocarbonylphosphonates of 3-azido-3-deoxythymidine (AZT) were synthesized, and their antiviral properties in HIV-1-infected cell cultures and stability to chemical hydrolysis were studied. The AZT 5-aminocarbonylphosphonates were shown to be significantly more stable in phosphate buffer (pH 7.2) than the corresponding ethoxycarbonylphosphonates. The therapeutic (selectivity) index of some of the compounds exceeded that of the parent AZT due to their higher antiviral activity.     

Fertilization rates in superovulated and spontaneously ovulating mares

Embryo recovery per ovulation has been shown to be lower in superovulated mares than in untreated controls. The objectives of this study were to 1) determine whether follicles stimulated with superovulatory treatment ovulate or luteinize without ovulation, 2) determine fertilization rates of oocytes in oviducts of superovulated and control mares, and 3) evaluate viability of early stage embryos from superovulated and control mares when cultured in equine oviductal cell-conditioned medium. Cyclic mares were randomly assigned to 1 of 2 groups (n=14 per group) on the day of ovulation (Day 0): Group 1 received 40 mg of equine pituitary extract (EPE; i.m.) daily beginning on Day 5 after ovulation; mares assigned to Group 2 served as untreated controls. All mares were given 10 mg PGF(2alpha) on Day 5 and Day 6, and 3,300 IU of human chorionic gonadotropin (hCG) were administered intravenously once mares developed 2 follicles >/=35 mm in diameter (Group 1) or 1 follicle >/=35 mm in diameter (Group 2). Mares in estrus were inseminated daily with 1 x 10(9) progressively motile spermatozoa once a >/=35 mm follicle was obtained. Two days after the last ovulation the ovaries and oviducts were removed. Ovaries were examined for ovulatory tracts to confirm ovulation, while the oviducts were trimmed and flushed with Dulbeccos PBS + 10% FCS to recover fertilized oocytes. All fertilized oocytes (embryos) recovered were cultured in vitro for 5 d using TCM-199 conditioned with equine oviductal cells. Ninety-two percent of the CL's from EPE mares resulted from ovulations compared with 94% for mares in the control group (P>0.05). The percentages of ovulations resulting in embryos were 57.1 and 62.5% for EPE-treated and control mares, respectively (P>0.05). Eighty-eight (Group 1) and 91% (Group 2) of the freshly ovulated oocytes recovered were fertilized (P>0.05). After 5 d of culture, 46.4 and 40.0% of the embryos from EPE-treated and control mares developed to the morula or early blastocyst stage (P>0.05). In summary, the CL's formed in superovulated mares were from ovulations not luteinizations. Although embryo recovery was less than expected, fertilization rates and embryo development were similar (P>0.05) between superovulated and control mares.     

New Dinucleoside Phosphonate Derivatives as Prodrugs of 3′-Azido-3′-Deoxythymidine and β-L-2′,3′-Dideoxy-3′-Thiacytidine: Synthesis and Anti-HIV Properties

New phosphonate homodimers of 3′-azido-3′-deoxythymidine (AZT) and a phosphonate heterodimer of β-L-2′,3′-dideoxy-3′-thiacytidine (3TC) and AZT were synthesized. The compounds demonstrated moderate anti-HIV activity. Stability of the compounds in human blood serum was studied. A correlation between anti-HIV activity and stability was defined.     

2′-Deoxynucleoside 5′-Triphosphates with Reporter Groups Modified at α-, β,γ- or γ-Phosphates as Substrates for DNA Polymerases

Abstract

The presence of reporter or ligand groups in 2′-deoxynucleoside 5′-triphosphates (dNTP) makes it possible to monitor the diffusion of these compounds into cell and to observe their incorporation into DNA. Here we present the synthesis of new dNTPs modified at α-, β,γ- or γ-phosphates of types I-IV, and containing reporter or ligand groups at the C5 position of dUTP.     

3'-(N-hydroxyimino)-2',3-dideoxynucleosides and their derivatives: synthesis, broad spectrum antiviral properties and synthetical application for the preparation of other nucleoside analogues.

A series of 3'-(N-hydroxyimino)-2',3'-dideoxynucleosides bearing different nucleic bases has been prepared. In vitro antiviral activity studies showed that among these compounds the thymine derivative possesses significant activity against HIV, HSV, EBV and HBV. Conveniently 5'-protected 3'-(N-hydroxyimino)-2',3'-dideoxythymidine was further used as a synthon for the preparation of other nucleoside analogues.     

Aryl-Containing Esters Of Triphosphoric Acid As Substrates Of Terminal Deoxynucleotidyl Transferase

A new group of terminal deoxynucleotidyltransferase (TDT) substrates, namely, non-nucleoside triphosphates (NNTP) bearing 5-substituted 2,4-dinitrophenyl fragments instead of nucleoside residues was synthesized.     

Synthesis of novel alkyl triphosphates and their substrate properties toward terminal deoxynucleotidyltransferase

Novel triphosphate derivatives bearing bulky or small groups at alpha-position attached to the triphosphate residue through linkers of different structures and lengths were synthesized and studied as substrates toward terminal deoxynucleotidyltransferase. The substrate efficacy depends on the structure of substituents, linker length, and nature of metal activator. The replacement of hydrophobic groups by small substituents decreased the substrate efficacy by about 20 times in respect to hydrophobic residues. The dependence on metal activator is the following: Co(2+) > Mn(2+) > Mg(2+). The model of interaction of alkyl triphosphates with linkers of different lengths bearing TdT active site is presented.     

Aryl-containing esters of triphosphoric acid as substrates of terminal deoxynucleotidyl transferase

A new group of terminal deoxynucleotidyltransferase (TDT) substrates, namely, non-nucleoside triphosphates (NNTP) bearing 5-substituted 2,4-dinitrophenyl fragments instead of nucleoside residues was synthesized.