Synthesis, characterization and antibacterial studies of Schiff bases of acyclovir

There is a crucial medical need for the progress of new antibacterial agents with new and more efficient mechanisms. Schiff bases are stated to have a wide range of pharmacological activities, including antimicrobial, antibacterial, antifungal, antioxidant, and anticancer activities, which are largely due to the distinguishing C=N group. Furthermore, heterocyclic compounds containing acyclic hydroxylated side chains, for example, acyclovir (ACV), are an essential class of antiviral acyclonucleosides. Therefore, this work was to synthesize and evaluate a new series of acyclovir analogues bearing a Schiff base moiety. Some of Schiff's bases synthesis in an ethanolic solution of drug, aldehydes, and glacial acetic acid as a catalyst followed in the synthesis of substituted acyclovir drug compounds. In this work, two new series of acyclovir analogues bearing a Schiff base moiety were Synthesised, characterized, and confirmed by various spectral techniques like FTIR, CHN, and 1HNMR spectra, in addition to melting point and retardation factor (Rf.). The biological activity of synthesized Schiff base compounds measured against a panel of various bacteria. The results revealed that these compounds showed antibacterial activity against Gram-positive bacteria such as bacillus and Gram-negative bacteria such as proteus, E-coli, pseudomonas, and klebsiella. It concluded that synthesized Schiff base compounds showed higher antibacterial activity than acyclovir that they derived from it.

Parallel motif triplex formation via a new, bi-directional hydrogen bonding pattern incorporating a synthetic cyanuryl nucleoside into the sense chain

The triplex formation ability of a sense chain containing a cyanuryl nucleoside was evaluated and the tertiary structure of the triplex was calculated using the NOE in 1H NMR by incorporating a 15N into the base moiety.

Structure and photochromic properties of a novel diarylethene containing a 9-fluorenone hydrazone Schiff base moiety

A novel diarylethene containing a 9-fluorenone hydrazone Schiff base moiety is designed and synthesized. The structure is characterized by single-crystal diffraction analysis and it shows excellent photochromism in the single crystalline phase. Moreover, the diarylethene product shows relatively high fluorescence modulation efficiency and good fatigue resistance.

Synthesis of RNA Bearing C5-polyamine Modified Pyrimidine Nucleosides at the 3´-end by T4 RNA Ligase

The incorporation of the modified nucleoside into the 3´-overhang regions of short interfering RNAs (siRNAs) has been reported to enhance their nuclease resistance and improve RNA interference activity. In this study, DNA 2-mers containing C5-polyamine-modified pyrimidine nucleosides were synthesized and then ligated to the 3´-end of the RNA by T4 RNA ligase. The modification of the base moiety with tris(2-aminoethyl)amine affected the ligation efficiency, but the DNA 2-mer containing only one modified nucleoside was ligated with sufficient efficiency. We propose a novel synthetic route to modified siRNA bearing various modified groups in the 3´-overhang region.