Redirected from Heterocyclic
That is, unlike the carbon-only ring like in benzene and napthalene, there are other elements in the backbone, such as in pyrimidine and purine.
... empire in Mexico; sent out expeditions to Baja California D Jacques-Yves Cousteau, (died 1997), French marine biologist and explorer Alexandra David-Néel, (1868-1969), ...