Yushin Nakamura

HIGHLY REGIO- AND STEREOSELECTIVE PHOTOCYCLOADDITION BETWEEN COUMARIN AND THYMINE BY MOLECULAR RECOGNITION

The photoreaction of Kemps imide-linked coumarin 1 and thymine 3 gave two crossadducts, cis-syn 4 cis-anti 5. The yield and ratio of 45 in benzene solution remarkably increased by factors of 4.2 and 10 than those in acetonitrile solution, respectively. On the other hand, the reaction of acetoxycoumarin 2 and 3 gave only the cis-anti crossadduct in each solution.

Synthesis and characterization of naphthalimide-containing peptide nucleic acid

Naphthalimide-containing PNA monomer unit 6 was synthesized for the preparation of PNAs containing a naphthalimide chromophore (NPNA). PNA oligomers were purified by reversed-phase HPLC and characterized by MALDI-TOF MS and UV spectra. Thermodynamic analyses revealed that the PNA oligomer containing a naphthalimide moiety at the amino terminal stabilizes PNA–DNA hybrids.

Nuclease activity of a hydroxamic acid derivative in the presence of various metal ions

Phenanthridine-linked hydroxamic acid 1 effectively cleaves ColE1 DNA in the presence of transition (ferrous, ferric and vanadyl) or lanthanide(III)(lutetium, thulium and europium) metal ions; in the presence of the former, the cleavage is inhibited by free radical scavengers, but in the latter case it is not.