Studies of Nucleosides and Nucleotides. LII. Purine Cyclonucleosides.(17). Synthesis and Properties of Cyclonucleosides derived from Inosine and Thioinosine

• Published in: Chemical & pharmaceutical bulletin Vol. 20; no. 3; pp. 550 - 558
• Main Authors: IKEHARA, MORIO, MURAOKA, MASAKO
• Format: Journal Article
• Language: English
• Published: Tokyo The Pharmaceutical Society of Japan 1972; Japan Science and Technology Agency
• ISSN: 0009-2363; 1347-5223
• DOI: 10.1248/cpb.20.550

8, 2'-Anhydro-8-mercapto- 9-β-D-arabinofuranosyladenine (I), 8, 3'-anhydro-8-mercapto-9-β-D-xylofuranosyladenine (II) and 8, 5'-anhydro-8-mercapto-9-β-D-ribofuranosyladenine (III) were deaminated with barium nitrite in acetic acid to give the corresponding S-cycloinosines (IV-VI). These cyclonucleosides had characteristic properties in ultraviolet (UV), nuclear magnetic resonance (NMR), circular dichroism (CD) and mass spectra, which were as expected from those of adenosine cyclonucleosides. Compounds IV-VI were benzoylated on sugar OH groups and subjected to thiolation reaction using phosphorus pentasulfide in pyridine containing water. Deprotection either with sodium methoxide or ammonia in methanol gave 8, 2'-anhydro-6, 8-dimercapto-9-β-D-arabinofuranosylpurine (XVI), 8, 3'-anhydro-6, 8-dimercapto-9-β-D-xylofuranosylpurine (XVII) and 8, 5'-anhydro-6, 8-dimercapto-9-β-D-ribofuranosylpurine (XVIII), respectively. The structure of these cyclonucleosides was confirmed by their characteristic UV, CD, NMR and mass spectra. 6-Mercaptopurine cyclonucleosides were easily oxidized to form disulfides by air oxidation or iodine treatment.