Cynaropicrin and inhibition of NF-κB activation: A structure activity relationship study.

Cynaropicrin is a guaianolide sesquiterpene lactone with a 5-7-5 tricyclic skeleton, four exo-olefins, and two hydroxyl groups. This natural product has various biological activities including anti-inflammatory properties and antitrypanosomal activity. It was also found to suppress photoaging of the skin by inhibiting the transcription activity of nuclear factor-kappa B (NF-κB).

Synthesis and Electron Paramagnetic Resonance Studies of Oligodeoxynucleotides Containing 2-N-tert-Butylaminoxyl-2'-deoxyadenosines.

Oligodeoxynucleotides (ODNs) containing 2-N-tert-butylaminoxyl-2'-deoxyadenosine (A*) residues were synthesized to allow accurate monitoring of adenine motion by EPR spectroscopy through the agency of direct linkage of the acyclic aminoxyl group to the nucleobase, and EPR studies of the ODNs in single- and double-stranded forms were performed. Upon duplex formation, peak broadening and decreases in peak height were observed in EPR spectra, and the synthesized ODNs were shown to be excellent monitors of hybridization. Comparison of peak height and the h /h signal ratio provided information on the relative mobility of A* in duplexes with different stability.

Dynamics of 2-N-tert-butylaminoxyladenosine incorporated into oligodeoxynucleotides.

We synthesized oligodeoxynucleotide (ODN, 3) containing 2-N-tert-butylaminoxyladenosine (1) and studied EPR spectra of 1 and its duplexes with varied sequences. Duplex formation resulted in a broadening of spectrum and a significant decrease in peak-to-peak height and peak height ratio values. The h(+)/ho values in EPR spectra well correlated with stability of duplex which indicated ODN containing 1 has the potential to monitor DNA structure.

Studies on DNA dynamics using 2-N-tert-butylaminoxylpurines.

2-N-tert-Butylaminoxylpurines (1) and (2) were synthesized from 2'-deoxy-6-chloropurine derivative by lithiation strategy. Effects of motion of 1 and 2 on EPR spectra were studied by EPR measurement in sucrose solution at various temperatures. The single stranded and duplexed 15-mers containing 1 showed the clear difference in the EPR spectra to indicate 1 has the potential to accurately study the dynamics of purine residues.