from The American Heritage® Dictionary of the English Language, 4th Edition
- n. A single-ringed, crystalline organic base, C4H4N2, that forms uracil, cytosine, or thymine and is the parent compound of many drugs, including the barbiturates.
- n. Any of several organic compounds derived from or structurally related to pyrimidine, especially the nitrogen bases uracil, cytosine, and thymine.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. A diazine in which the two nitrogen atoms are in the meta- positions; it is the basis of three of the bases found in DNA and RNA, thymine, uracil and cytosine
from The Century Dictionary and Cyclopedia
- n. An organic compound, composed of carbon, hydrogen, and nitrogen, so arranged that the carbon and nitrogen atoms form a ring or chain, as shown in the formula .
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. any of several basic compounds derived from pyrimidine
- n. a heterocyclic organic compound with a penetrating odor
From these results Funk believed the vitamine to belong to a class of substances known as the pyrimidine bases.
To improve the fit, researchers led by chemical biologist Nathanael Gray, PhD, prepared a group of inhibitors with a different structural scaffold, known as a pyrimidine core, which, it was thought, would mesh more thoroughly.
Recommended name pyrimidine-deoxynucleoside 2'-dioxygenase Synonyms deoxyuridine
D. Sutherland, Synthesis of activated pyrimidine ribonucleotides in prebiotically plausible conditions, Nature 459, 239 (2009). doi: 10.1038/nature08013.
Furthermore, although Powner and colleagues 'synthetic sequence yields the pyrimidine ribonucleotides, it cannot explain how purine ribonucleotides (which incorporate guanine and adenine) might have formed.
Of the many difficulties encountered by those in the field, the most frustrating has been the failure to find any way of properly joining the pyrimidine nucleobases — cytosine and uracil — to ribose (Fig. 1a).
But Powner et al. 2 revive the prospects of the 'RNA first' model by exploring a pathway for pyrimidine ribonucleotide synthesis in which the sugar and nucleobase emerge from a common precursor (Fig. 1b).
Superpositions of dipole states of base pairs consisting of purine (A, G) and pyrimidine (C, T) ring structures play the role of qubits, and quantum communication (coherence, entanglement, non-locality) occur in the "pi stack" region of the DNA molecule.
The recent finding of a gene fusion encoding three pyrimidine biosynthetic enzymes, shared only by Dictyostelium, fungi andMetazoa, indicates that the amoebozoa are a true sister group of the fungi and Metazoa.
To Simon and Cyclefree who hold such credulous views about evolution, I wonder if they have considered the origin of pyrimidine nucleotides, especially cytosine - has it really come from outer space as the wildest contemporary theories suggest?!