(of an organic compound) having four fused rings of atoms in its molecule.
- ‘Practitioners prescribing the tetracyclic antibiotics should be aware of the syndrome of increased intracranial pressure, and pay particular attention to the ocular fundus for papilloedema.’
- ‘Maprotiline is the only tetracyclic antidepressant available in the US.’
- ‘Cucurbitacins are oxygenated tetracyclic triterpenes that have been shown to have emetic, antineoplastic, and cytotoxic effects on herbivores, resulting in feeding and oviposition deterrence and reduced growth of consumers.’
- ‘A 1998 study showed that pentacyclic alkaloids weakly activated human B- and T-lymphocytes, and that tetracyclic oxindole alkaloids reduced the activity of pentacyclic oxindoles.’
- ‘Mirtazapine is a tetracyclic antidepressant unrelated to tricyclic antidepressants and SSRIs.’
Early 20th century: from tetra- four + Greek kuklos circle + -ic.
We take a look at several popular, though confusing, punctuation marks.