NUCLEOSIDES AND NUCLEOTIDES .147. SYNTHESIS OF DNA DODECAMERS CONTAINING OXETANOCIN-A AND 4-ANHYDRO-2,3-DIDEOXY-3-C-HYDROXYMETHYL-D-ARABITOL

Oxetanocin A (I) and -yl)-1,4-anhydro-2,3-dideoxy-3-C-hydroxy-methyl-D - arabitol (2). a ring-expanded oxetanocin analogue, were incorporated into DNA dodecamers, 5'-d(CGCG1ATTCGCG)-3' (II), 5'-d(CGCGA1TTCGCG)-3 ' (III), 5'-d(CGCG2ATTCGCG)-3' (IV), and 5'-d(CGCGA2TTCGCG)-3' (V). Th ermally induced transitions of II, III, IV, and V together with a pare nt dodecamer, 5'-d(CGCGAATTCGCG)-3' (I) were monitored at 260 nm in a buffer containing 0.01 M sodium phosphate (pH 7.0), 0.02 M NaCl. and 6 mu M of each dodecamer. The order of Tms was 40 degrees C (I) > 37 de grees C (IV) > 36 degrees C (V) > 34 degrees C (II) > 32 degrees C (II I). The oligonucleotide containing 2 was more resistant to snake venom phosphodiesterase than unmodified DNA dodecamer (I).