![cover image](https://wikiwandv2-19431.kxcdn.com/_next/image?url=https://upload.wikimedia.org/wikipedia/commons/thumb/4/40/Doxycycline_structure.svg/640px-Doxycycline_structure.svg.png&w=640&q=50)
Tetracyclic
Organic compound having 4 fused rings / From Wikipedia, the free encyclopedia
For flowers constructed of four whorls, see cyclic flower.
Tetracyclics are cyclic chemical compounds that contain four fused rings of atoms, for example, Tröger's base.
![Thumb image](http://upload.wikimedia.org/wikipedia/commons/thumb/4/40/Doxycycline_structure.svg/320px-Doxycycline_structure.svg.png)
![Thumb image](http://upload.wikimedia.org/wikipedia/commons/thumb/9/94/Mirtazapine.svg/320px-Mirtazapine.svg.png)
Some tricyclic compounds having three fused and one tethered ring (connected to main nucleus by a single bond) can also classified as tetracyclic, for example, ciclazindol.[1]
Tetracyclic compounds have various pharmaceutical uses, such as: