From ribosenucleic acid

As regards the next four details of structure, let us first consider the purine nucleosides from ribosenucleic acid. 

The purine nucleosides from ribosenucleic acid are adenosine and guanosine. Historically, guanosine was the first ribose nucleoside to be discovered, having been isolated from plant extracts by Schulze in 1885 and named vernine. In 1909 it was prepared from ribosenucleic acid by Levene and Jacobs, who also isolated adenosine from the same source. These two nucleosides are readily hydrolyzed by dilute mineral acid to give the respective bases and the same sugar. 

Inosinic and Adenylic Adds, Similarly, Levene and Harris found that the adenylic acid from ribosenucleic acid can be deaminated to an inosinic acid which undergoes hydrolysis at its own pH to give hypo-xanthine and 3-phosphoribose. On the other hand, Thannhauser had shown that ammoniacal hydrolysis of the adenylic acid gives adenosine and phosphoric acid. 

Synthetic 3-phospho-adenosine, identical with that from ribosenucleic acid, has been prepared by direct phosphorylation of adenosine with phosphorus oxychloride in the presence of barium hydroxide, but this method of synthesis affords no confirmation of the above formulation. 

Gulland and Jackson confirmed that phosphomonoesterase liberates 7%, or less, of the phosphoric acid from ribosenucleic acid. They therefore concurred with Takahashi that this kind of ribosenucleic acid contains no phosphomonoester group and that each phosphorus atom is present as a disubstituted phosphoryl group, but they pointed out that this is not necessarily a di-ester group. The liberation of 7%, or less, of the total phosphorus is in accord with the idea of a polymerized tetranucleotide 25% of the phosphorus in the simple tetranucleotide (VII) should be hydrolyzable by phosphatase. 

They also found that phosphodtesterase does not liberate phosphoric acid from ribosenucleic acid. 

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