Selective and sensitive turn on fluorescence cyanide recognition in aqueous medium based on Zn(II)-hydrazone metal complex chemosensor.

Detection and quantification of the cyanide ion (CN ) has attracted considerable attention because of its extreme toxicity. A novel Zn(II)-complex, applicable as a fluorescent chemosensor for CN recognition, was synthesized in excellent yields from the reaction of zinc sulfate with the novel hydrazone: 3-(amino-9H-purin-yl)-N'-(hydroxybenzylidene) propanehydrazide. The structures of the hydrazone (L) and the zinc-hydrazone complex (L.

Novel triazine-based pyrimidines suppress glomerular mesangial cells proliferation and matrix protein accumulation through a ROS-dependent mechanism in the diabetic milieu.

Diabetic nephropathy (DN) is one of the most serious complications of diabetes worldwide. It is depicted as the leading cause of end-stage renal disease. Oxidative stress plays a key role in hyperglycemia-induced DN.

Spectroscopic Evaluation of Novel Adenine/Thymine-Conjugated Naphthalenediimides: Preference of Adenine-Adenine over Thymine-Thymine Intermolecular Hydrogen Bonding in Adenine- and Thymine-Functionalized Naphthalenediimides.

The synthesis and spectroscopic characterization of novel nucleobase (adenine/thymine)-conjugated naphthalenediimides (NDIs), namely, NDI-AA, NDI-TT, and NDI-AT have been successfully achieved. NDI-AA, NDI-TT and NDI-AT have similar absorption in the 300-400 nm region. The effect of solvent on the absorption spectrum indicates aggregation, either through intermolecular π-σ interaction among the main chromophore or through intermolecular hydrogen bonding between adenine and adenine group.

Synthesis and polymerization of 1-(2-diallylaminoethyl)pyrimidines.

We report the preparation and characterization of three pyrimidine-based monomers, specifically: 1-(2-diallylaminoethyl)uracil, 1-(2-diallylaminoethyl)thymine and 1-(2-diallylaminoethyl)cytosine. Monomer synthesis was initiated by reaction of the pyrimidine with ethylene carbonate to form the hydroxyethyl adduct which was subsequently chlorinated to afford the chloroethyl intermediate. Reaction of the chloroethyl derivatives with diallylamine resulted in the desired monomers.

Interactions of Some Divalent Metal Ions with Thymine and Uracil Thiosemicarbazide Derivatives.

The study of interactions between metal ions and nucleobases, nucleosides, nucleotides, or nucleic acids has become an active research area in chemical, biological, and therapeutic fields. In this respect, the coordination behavior of nucleobase derivatives to transition metals was studied in order to get a better understanding about DNA-metal interactions in in vitro and in vivo systems. Two nucleobase derivatives, 3-benzoyl-1-[3-(thymine-1-yl)propamido]thiourea and 3-benzoyl-1-[3-(uracil-1-yl)propamido]thiourea, were synthesized and their dissociation constants were determined at different temperatures and 0.

Novel carbocyclic nucleoside analogs suppress glomerular mesangial cells proliferation and matrix protein accumulation through ROS-dependent mechanism in the diabetic milieu. II. Acylhydrazone-functionalized pyrimidines.

We report herein the synthesis of a novel series of carbocyclic acylhydrazone derivatives of uracil, thymine and cytosine from the corresponding nucleic bases and their biological activity to treat diabetic nephropathy. Intriguingly, five derivatives significantly reduced high-glucose induced glomerular mesangial cells proliferation and matrix protein accumulation in vitro. The anti-oxidative effects displayed by these molecules suggest that their activity might involve a ROS-dependent mechanism.

Thiophene aldehyde-diamino uracil Schiff base: A novel fluorescent probe for detection and quantification of cupric, silver and ferric ions.

A new Schiff base from the condensation of 5,6-diamino-1,3-dimethyluracil with 5-methylthiophene-2-carboxaldehyde was synthesized. The compound was characterized by spectral data (UV-Vis, IR, (1)H NMR, fluorescence, MS). Ethanolic solutions of the Schiff base exhibit a strong fluorescence emission at 385 nm (λex=341 nm), and have been employed as a "turn-off" fluorescent probe for selective detection of Ag(+), Cu(2+) and Fe(3+) ions in presence of other cations such as Na(+), K(+), Ca(2+) and Mg(2+) ions abundant in natural water.

Poly (9-(2-diallylaminoethyl)adenine HCl-co-sulfur dioxide) deposited on silica nanoparticles constructs hierarchically ordered nanocapsules: curcumin conjugated nanocapsules as a novel strategy to amplify guanine selectivity among nucleobases.

Poly (9-(2-diallylaminoethyl)adenine HCl-co-sulfur dioxide) (Poly A) deposited on silica nanoparticles self-assembles to form hierarchically ordered nanocapsules. These nanocapsules can be conjugated with curcumin. The curcumin-conjugated nanocapsules are found to be spherical in size and their size ranges between 200 and 600 nm.

Novel carbocyclic nucleoside analogs suppress glomerular mesangial cells proliferation and matrix protein accumulation through ROS-dependent mechanism in the diabetic milieu.

The synthesis of a series of novel 3,4-cis- and 3,4-trans-substituted carbocyclic nucleoside analogs from protected uracil and thymine is described. The key reaction in the followed synthetic protocols utilized the Mitsunobu reaction to couple 3,4-substituted cyclopentanols to (3)N-benzoyl uracil or (3)N-benzoyl thymine. These molecules were evaluated with regard to their ability to treat diabetic nephropathy.

Synthesis, cyclopolymerization and cyclo-copolymerization of 9-(2-diallylaminoethyl)adenine and its hydrochloride salt.

We report herein the synthesis and characterization of 9-(2-diallylaminoethyl) adenine. We evaluated two different synthetic routes starting with adenine where the optimal route was achieved through coupling of 9-(2-chloroethyl)adenine with diallylamine. The cyclopolymerization and cyclo-copolymerization of 9-(2-diallylaminoethyl)adenine hydrochloride salt resulted in low molecular weight oligomers in low yields.

Facile preparation of the tosylhydrazone derivatives of a series of racemic trans-3,4-substituted cyclopentanones.

We report the synthesis and characterization of a variety of trans-3,4-substituted cyclopentanones and the corresponding tosylhydrazone derivatives starting with diethyl fumarate. Protection of the keto group followed by selective monohydrolysis of esters was achieved, resulting in cyclopentanones with different substituents at positions 3 and 4. The tosylhydrazone derivative of each cyclopentanone intermediate was prepared in moderate to good yields.

Photocrosslinked alginate hydrogels with tunable biodegradation rates and mechanical properties.

Photocrosslinked and biodegradable alginate hydrogels were engineered for biomedical applications. Photocrosslinkable alginate macromers were prepared by reacting sodium alginate and 2-aminoethyl methacrylate in the presence of 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide hydrochloride and N-hydroxysuccinimide. Methacrylated alginates were photocrosslinked using ultraviolet light with 0.

Controlled degradation of hydrogels using multi-functional cross-linking molecules.

Hydrogels, chemically cross-linked or physically entangled, have found a number of applications as novel delivery vehicles of drugs and cells. However, the narrow ranges of degradation rates and mechanical strength currently available from many hydrogels limits their applications. We have hypothesized that utilization of multi-functional cross-linking molecules to form hydrogels could provide a wider range and tighter control over the degradation rates and mechanical stiffness of gels than bi-functional cross-linking molecules.

Synthesis of purine- and pyrimidine-substituted heptadienes. The stereochemistry of cyclization and cyclopolymerization products.

A series of 1,6-heptadienes, substituted in the 4 position with nucleic acid bases 1-6, have been synthesized via Mitsunobu condensations. Guanine, adenine, thymine, and uracil derivatives can be prepared directly by coupling the protected base with 1,6-heptadien-4-ol (7). However, coupling protected cytosine and 7 gives an O-alkylated product.

Evaluation of chain stiffness of partially oxidized polyguluronate.

The chain stiffness of macromolecules is considered critical in their design and applications. This study utilizes polyguluronate derived from alginate, a typical polysaccharide widely utilized in many biomedical applications, as a model macromolecule to investigate how the chain stiffness can be tightly regulated by partial oxidation. Alginate has a backbone of inherently rigid alpha-L-guluronate (i.