heterocyclic
Ring with intruders
Heterocyclic describes a ring-shaped molecular structure containing atoms of more than one element—typically carbon plus nitrogen, oxygen, or sulfur.
The term belongs to organic chemistry, where heterocyclic compounds form the backbone of many drugs, vitamins, and DNA bases: Most antibiotics contain heterocyclic rings.
Basic six-membered nitrogen heterocycle
- furanAromatic oxygen-containing ring
- indoleFused benzene-pyrrole heterocycle
- purineTwo-fused-ring nitrogenous base
- pyrimidineHeterocyclic aromatic nitrogen compound
Pleasantly strong-smelling
- fusedJoined by melting together
- saturatedThoroughly soaked through
- unsaturatedNot fully saturated
- sulfur-containingBearing element S
Nitrogen-based organic compounds
- nucleotidesDNA and RNA subunits
- vitaminsEssential organic nutrients
- antibioticsBacteria-destroying medicines
- antidepressantsMedications treating clinical despair
antimalarials · antivirals · benzodiazepines · barbiturates · sulfonamides · caffeine · nicotine · morphine
Cyclic pi-electron stabilization
- conjugationVerb form variation system
- resonanceAmplified oscillation at natural frequency
- tautomerismInterconvertible structural isomer equilibrium
- basicityDegree of alkaline character
Purine nucleobase in DNA
- guaninePurine nucleobase in DNA
- cytosinePyrimidine nucleobase in genetics
- thymineDNA nitrogen base
- uracilRNA pyrimidine nucleobase
histidine · tryptophan · proline · heme · chlorophyll · biotin · thiamine · riboflavin
pyridine
Basic six-membered nitrogen heterocycle
- furanAromatic oxygen-containing ring
- indoleFused benzene-pyrrole heterocycle
- purineTwo-fused-ring nitrogenous base
pyrimidine · lactone · dioxin · coumarin
aromatic
Pleasantly strong-smelling
- fusedJoined by melting together
- saturatedThoroughly soaked through
- unsaturatedNot fully saturated
alkaloids
Nitrogen-based organic compounds
- nucleotidesDNA and RNA subunits
- vitaminsEssential organic nutrients
- antibioticsBacteria-destroying medicines
antidepressants · antimalarials · antivirals · benzodiazepines · barbiturates · sulfonamides · caffeine · nicotine · morphine · quinine
aromaticity
Cyclic pi-electron stabilization
- conjugationVerb form variation system
- resonanceAmplified oscillation at natural frequency
- tautomerismInterconvertible structural isomer equilibrium
cyclization
Closing into rings
- condensationVapor turning to liquid
- catalystAgent enabling change
adenine
Purine nucleobase in DNA
uracil · histidine · tryptophan · proline · heme · chlorophyll · biotin · thiamine · riboflavin · FAD