purine analogue

analogue [an´ah-log]

1. a part or organ having the same function as another, but of different evolutionary origin.

2. a chemical compound having a structure similar to that of another but differing from it in respect to a certain component; it may have similar or opposite action metabolically. Also spelled analog.

nucleoside analogue a structural analogue of a nucleoside, a category that includes both purine analogues and pyrimidine analogues.

purine analogue a structural analogue of one of the purine bases(purine, adenine, or guanine); mercaptopurine and thioguanine are used as antineoplastics and azathioprine is an immunosuppressive. The antiviral agent vidarabine is an analogue of the adenine nucleoside adenosine.

pyrimidine analogue a structural analogue of one of the pyrimidine bases(cytosine, thymine, or uracil); fluorouracil and cytarabine are important antineoplastic agents.

---

purine analogue

Pharmacology A therapeutic that mimics the chemical structure of purine; in pathologic conditions, where there is ↑ production of DNA, PAs compete with normal purines–guanine and adenine and are incorporated in the DNA of mitotically active 'rogue' cells, eventually destroying them. See 6-MP, Nucleoside analogues.