Cytosine periodate oxidation

Because synthesis of l-(2-deoxy-2-fluoro-)S-D-arabinofuranosyl)cytosine (744, FAC), an elementary arabino type of nucleoside having a growth-inhibitory effect against L 1210 leukemia in mice, through direct introduction of a fluorine atom in the 2 - up (arabino) position was difficult, compound 744 was prepared by condensation of trimethylsilylated A -acetylcytosine with 3-0-acetyl-5-(7-benzoyl-2-deoxy-2-fluoro-D-arabin-ofuranosyl bromide (742), which had been prepared by periodate oxidation of 6-0-benzoyl-3-deoxy-3-fluoro-D-glucofuranose (741). Similar condensa-... 

The hydrazide derivative of AMCA can be used to modify aldehyde- or ketone-containing molecules, including cytosine residues using the bisulfite activation procedure described in Chapter 27, Section 2.1. AMCA-hydrazide reacts with these target groups to form hydrazone bonds (Figure 9.26). Carbohydrates and glycoconjugates can be labeled specifically at their polysaccharide portion if the required aldehydes are first formed by periodate oxidation or another such method (Chapter 1, Section 4.4). 

Until recently the lactol ring structure of 2-desoxy-D-ribose in nucleic acid had been proved conclusively only for the thymidine nucleoside component and in this case it was furanose in form.26 Subsequently Brown and Lythgoe,27 by application of the periodate oxidation procedure to the 2 -desoxy ribosides of guanine, hypoxanthine, cytosine and thymine, afforded proof of the presence of a furanose sugar in each compound. 

Alternatively, the starting compound could be L-arabinose, which upon isopropylidenation and then benzoylation gave 125. Glycosylations were effected by various procedures, which, except for the guanine and cytosine series, did not require prior protection of the heterocyclic bases to give 126. Removal of the isopropylidene and subsequent periodate oxidation, reduction, and then debenzoylation gave the acyclonucleosides 127 [92JCS(P1)1943],... 

Fig- 1- Chromatogram of nucleotide standards on a micro Bondapak C gcolumn before periodate oxidation-A- Adenine series B. Guanine series C- Cytosine series D Uracil plus thymine series. 

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