Nucleic acids : their chemical properties and physiological conduct / by Walter Jones.

  • Jones, Walter, 1865-1935
Date:
1920
Catalogue details

Licence: In copyright

Credit: Nucleic acids : their chemical properties and physiological conduct / by Walter Jones. Source: Wellcome Collection.

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    eight substances constitute the fundamental groups of nucleic acids. Kossel introduced four of them into chemistry (adenine, cytosine, thymine, uracil). It is necessary to make a close examination of them all. The Purine Derivatives of Nucleic Acids. In view of the communications of Inouye [1906], Inouye and Kotake [1905], Mochizuki and Kotake [1904-5], and of Steudel [1904]: [1904-5]: [1905], it must be insisted that guanine and adenine are the only purine bases ever obtained as primary hydrolytic products of nucleic acid. Nevertheless, physiology is concerned with three others that are formed from these by metabolic processes: so that five purine derivatives are to be considered, guanine, adenine, hypoxan- thine, xanthine and uric acid. Four of these compounds have long been known (Strecker [1861], Wulff [1893]) and have furnished material for some of the most important investigations of organic chemistry (Fischer [1907]), but the fifth (adenine) was more recently discovered by Kossel [1886] among the hydrolytic products of pancreas nucleic acid. All five are chemical derivatives of one mother substance, purine (Fischer [1898]), whose constitution is expressed by the formula:— N=CH (6) (2) HC^ \ C NH\ 11 uCH (8) C N A or (N N N Representing the purine ring with its three replaceable hydrogen /H (2) atoms by the abbreviated expression P—H (6), the relation of the five \H (8) purine compounds to one another is seen in the following diagram :— /NH„ P—01L \H Guanine (2-amino-6-oxy-purine) AH p-nh2 \H Adenine (6-amino-purine) v v /OH /OH /H P—OH < P—OH < P—OH \OH \ H \H Uric Acid Xanthine Hypoxanlhine (2-6-8-trioxy-purine) (2-6-dioxy-purine) (6-oxy-purine) The exhaustive proof of these five structures would be entirely out of question here, and any such attempt is made superfluous by the