In-Vitro Cytotoxicity, Antimicrobial activities and DNA binding studies, of Novel Copper (II) complex with Heterocyclic base

A novel ternary copper (II) complex have been synthesized by the addition of N, N-heterocyclic ligand with L-amino acid. The copper (II) complex, [Cu(1,10-phen) (L-Thr) Br] (where phen=1,10-phenanthroline and Threo=Threonine) characterized by various spectroscopic method. The intense UV band around 271nm was due to π-π* transition. The DNA binding study of these copper (II) complex are examined by UV–Visible, Emission spectroscopic, cyclic voltammetric and viscosity method. The results revealed that complex shown to be a intercalation mode of binding into DNA. The anticancer activity of Cu (II) complexes has capability to the kill HepG2 liver cancer cell as assessed by the MTT method, The Ic50value was found 21.50µg/ml The biological activity of the complex tested against certain pathogenic bacteria and fungi results revealed it was found to be potent antibacterial agent.

De Novo Nucleic Acids: A Review of Synthetic Alternatives to DNA and RNA That Could Act as Bio-Information Storage Molecules

Modern terran life uses several essential biopolymers like nucleic acids, proteins and polysaccharides. The nucleic acids, DNA and RNA are arguably life’s most important, acting as the stores and translators of genetic information contained in their base sequences, which ultimately manifest themselves in the amino acid sequences of proteins. But just what is it about their structures; an aromatic heterocyclic base appended to a (five-atom ring) sugar-phosphate backbone that enables them to carry out these functions with such high fidelity? In the past three decades, leading chemists have created in their laboratories synthetic analogues of nucleic acids which differ from their natural counterparts in three key areas as follows: (a) replacement of the phosphate moiety with an uncharged analogue, (b) replacement of the pentose sugars ribose and deoxyribose with alternative acyclic, pentose and hexose derivatives and, finally, (c) replacement of the two heterocyclic base pairs adenine/thymine and guanine/cytosine with non-standard analogues that obey the Watson–Crick pairing rules. This manuscript will examine in detail the physical and chemical properties of these synthetic nucleic acid analogues, in particular on their abilities to serve as conveyors of genetic information. If life exists elsewhere in the universe, will it also use DNA and RNA?

Anion exchange resins in phosphate form as versatile carriers for the reactions catalyzed by nucleoside phosphorylases

In the present work, we suggested anion exchange resins in the phosphate form as a source of phosphate, one of the substrates of the phosphorolysis of uridine, thymidine, and 1-(β-ᴅ-arabinofuranosyl)uracil (Ara-U) catalyzed by recombinant E. coli uridine (UP) and thymidine (TP) phosphorylases. α-ᴅ-Pentofuranose-1-phosphates (PF-1Pis) obtained by phosphorolysis were used in the enzymatic synthesis of nucleosides. It was found that phosphorolysis of uridine, thymidine, and Ara-U in the presence of Dowex® 1X8 (phosphate; Dowex-nPi) proceeded smoothly in the presence of magnesium cations in water at 20–50 °C for 54–96 h giving rise to quantitative formation of the corresponding pyrimidine bases and PF-1Pis. The resulting PF-1Pis can be used in three routes: (1) preparation of barium salts of PF-1Pis, (2) synthesis of nucleosides by reacting the crude PF-1Pi with an heterocyclic base, and (3) synthesis of nucleosides by reacting the ionically bound PF-1Pi to the resin with an heterocyclic base. These three approaches were tested in the synthesis of nelarabine, kinetin riboside, and cladribine with good to excellent yields (52–93%).

Synthesis and Antiviral Evaluation of 3′-Fluoro-5′-norcarbocyclic Nucleoside Phosphonates Bearing Uracil and Cytosine as Potential Antiviral Agents

Carbocyclic nucleoside analogues are an essential class of antiviral agents and are commonly used in the treatment of viral diseases (hepatitis B, AIDS). Recently, we reported the racemic synthesis and the anti-human immunodeficiency virus activities (HIV) of 3′-fluoro-5′-norcarbocyclic nucleoside phosphonates bearing purines as heterocyclic base. Based on these results, the corresponding racemic norcarbocyclic nucleoside phosphonates bearing pyrimidine bases were synthesized. The prepared compounds were evaluated against HIV, but none of them showed marked antiviral activity compared to their purine counterparts.

Organocatalytic Trapping of Elusive Carbon Dioxide based Heterocycles through a Kinetically Controlled Cascade Process

<div>A conceptually novel approach is described for the</div><div>synthesis of larger-ring cyclic carbonates derived from carbon dioxide. The approach utilizes homoallylic precursors that are converted into five-membered cyclic carbonates having a beta-positioned alcohol group in one of the ring substituents. The activation of the pendent alcohol group through an N-heterocyclic base allows for equilibration towards a thermodynamically disfavored six-membered carbonate analogue that can be conveniently trapped by an acylation agent. Various control experiments and computational analysis of this manifold are in line with a process that is primarily dictated by a kinetically controlled acylation step. This cascade process delivers an ample diversity of novel six-membered cyclic carbonates in excellent yields and chemoselectivities under remarkably mild reaction conditions. This newly developed protocol helps to expand the repertoire of CO2-based heterocycles that are otherwise difficult to generate by conventional approaches.</div>

Organocatalytic Trapping of Elusive Carbon Dioxide based Heterocycles through a Kinetically Controlled Cascade Process

<div>A conceptually novel approach is described for the</div><div>synthesis of larger-ring cyclic carbonates derived from carbon dioxide. The approach utilizes homoallylic precursors that are converted into five-membered cyclic carbonates having a beta-positioned alcohol group in one of the ring substituents. The activation of the pendent alcohol group through an N-heterocyclic base allows for equilibration towards a thermodynamically disfavored six-membered carbonate analogue that can be conveniently trapped by an acylation agent. Various control experiments and computational analysis of this manifold are in line with a process that is primarily dictated by a kinetically controlled acylation step. This cascade process delivers an ample diversity of novel six-membered cyclic carbonates in excellent yields and chemoselectivities under remarkably mild reaction conditions. This newly developed protocol helps to expand the repertoire of CO2-based heterocycles that are otherwise difficult to generate by conventional approaches.</div>

Ribavirin and its analogs: Сan you teach an old dog new tricks?

The review article focuses on the current state of synthetic and biological studies of ribavirin analogs. Ribavirin is a broad-spectrum nucleoside antiviral drug with a 50-year long history of research and application, but its mechanism of action still remains unclear. This article examines contemporary views on the antiviral and antitumor effects of ribavirin and its analogs and describes the contradictions and gaps that exist in our knowledge. In recent years, new nucleoside analogs of ribavirin have been synthesized. These ribavirin derivatives modified at the heterocyclic base, have the potential to become the antiviral and antitumor agents of the new generation. Thus, this paper presents a systematic review of antiviral activities, antitumor activities and structure–activity relationship (SAR) correlations of 39 ribavirin analogs created in the past 15 years. Biological targets and possible mechanisms of action of these new compounds are also discussed, as well as the prospects and possible directions for further research.