Novel oligonucleotide analogues, containing a 3'-amino-2',4'-BNA unit, were successfully synthesized, and they showed superior duplex and triplex forming ability as well as BNA itself, along with remarkable enzymatic stability.

The effect of the size of phosphatidylcholine (PC) vesicles on the induction of chirality and chiral discrimination was examined. Three kinds of vesicles formed with l-dimyristoyl, l-dipalmitoyl, or egg yolk PCs induced circular dichroisms (CDs) with the sign and intensity of the Cotton effect different from those of monomeric PCs. The CD intensity of the vesicles increased with a decrease in the vesicle size. Furthermore, the helicity of heterohelicene derivatives in a rapid equilibrium between right-handed (P) and left-handed (M) enantiomers was biased toward the M enantiomer side in l-PC vesicles, implying chiral discrimination by the vesicles. The extent of the bias toward the M enantiomer increased with an increase in vesicle size. Both the chirality induction and chiral discrimination were enhanced in a low-fluidity gel phase in comparison with those in a high-fluidity liquid-crystalline phase for every kind of vesicle of every size examined.

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Nucleic acidsNucleic acids U 0700 Synthesis of a Novel Bridged Nucleoside Bearing a Fused-Azetidine Ring, 3'-Amino-3',4'-BNA Monomer. -The aziridine ring of the title compound (I) is formed under Staudinger conditions. -(OBIKA, S.; ANDOH, J.-I.; ONODA, M.; NAKAGAWA, O.; HIROTO, A.; SUGIMOTO, T.; IMANISHI*, T.; Tetrahedron Lett. 44 (2003) 28, 5267-5270; Grad. Sch. Pharm. Sci., Osaka Univ., Suita, Osaka 565, Japan; Eng.) -M. Paetzel 42-214