3'-Amino-3'-deoxyadenosine

3'-aminoacylamino-3'-deoxyadenosines, analogues of the antibiotic puromycin, have been synthesized from adenosine. They key 3'-azido derivative 10 was obtained through a 3'-oxidation/reduction/substitution procedure. A modified purification protocol on a larger scale was developed for the oxidation step using the Garegg reagent. The coupling reaction between an Fmoc-l-amino acid and the fully protected form of 3'-amino-3'-deoxyadenosine 11 furnished the aminoacylated compounds 12 in high yields. The puromycin analogues were obtained in 10 steps and up to 23% (14c) overall yield.

Structural analysis of ribosomes in complex with aminoacyl- and/or peptidyl-transfer RNA (tRNA) often suffers from rapid hydrolysis of the ester bond of aminoacyl-tRNAs. To avoid this issue, several methods to introduce an unhydrolyzable amide bond instead of the canonical ester bond have been developed to date. However, the existing methodologies require rather complex steps of synthesis and are often inapplicable to a variety of amino acids including those with noncanonical structures. Here, we report a new method to synthesize 3'-aminoacyl-NH-tRNAs by means of flexizymes-ribozymes capable of charging amino acids onto tRNAs. We show that two types of flexizymes, dFx and eFx, are able to charge various amino acids, including nonproteinogenic ones, onto tRNA or microhelix RNA bearing the 3'-deoxy-3'-amino-adenosine. Due to the versatility of the flexizymes toward any pair of nonproteinogenic amino acids and full-length or fragment tRNAs, this method provides researchers an opportunity to use a wide array of hydrolytically stable 3'-aminoacyl-NH-tRNAs and analogs for various studies.

Several different nucleoside analogs have been demonstrated to inhibit retroviral RNA-dependent DNA polymerase activity in preference to cellular DNA-dependent DNA polymerases. 3'-Amino derivatives of 3-deoxyadenosine was analyzed for their antiviral activity toward HIV-1 and for their host cell toxicity. Puromycin aminonucleoside (PANS), PANS 5'-monophosphate, and 3'-amino-3'-deoxyadenosine triphosphate all inhibited HIV-1 replication in acutely infected cells. No significant antiviral effects of PANS were demonstrated in chronically infected cells. The effect of PANS was demonstrated at an early step in HIV-1 replication, most likely reverse transcription. 3'-Aminonucleoside analogs are a novel class of inhibitors of HIV-1 replication that require further analysis in cell culture and animal studies.