1,3,5-triazine ,2,4,6-triamine and formaldehyde
A bioisosterism is a relationship between bioisosteres, substituents or groups with similar physical or chemical properties that impart similar biological properties to a chemical compound.
Tungsten carbide is known as the hardest metal on the planet, it's second to diamond and rings made of tungsten meaning the unchanged. The best known for tungsten rings are wedding band. But now tungsten rings are as well as Cluster rings, Engagement rings, Eternity rings.
Of course now it is very common to do it, for example stackable rings can be mixed of different metals and gems rings. These rings are very popular now. You can find everywhere in internet silver and gold rings together . I actually love it.
31 electrons, 4 rings/shells.
By the fused imidazole and pyrimidine rings.
A pyrimidine ring and an imidazole ring.
Nitrogen rings in the base
there are double rings in the purine bases and there is only a single ring in the pyrimidine base.
Monochloro-s-triazine is a chemical compound that belongs to the triazine group. It is commonly used as an intermediate in the production of herbicides and as a chemical building block in various industrial processes. It is a chlorinated derivative of s-triazine, which is a six-membered heterocyclic compound containing three nitrogen atoms.
They include the F, Cl, NH2, and OH group.
melamine(2,4,6-Triamino-1,3,5-triazine) & formaldehyde
Cytosine and thymine are the pyrimidine bases in DNA.
1,3,5-triazine ,2,4,6-triamine and formaldehyde
when a purine base only pairs with a pyrimidine
in this a purine base is substitued in place or pyrimidine and a pyrimidine is substitued in place of purine
Adenine(purine)=========thymine(pyrimidine)Guanine(purine)----------------cytosine(pyrimidine)