alkaloid
Meaning of alkaloid: An alkaloid is a nitrogen containing compound found in many plants, including well known examples such as caffeine, nicotine, and morphine.
Definition of alkaloid
An alkaloid is a member of a large group of naturally occurring compounds that contain nitrogen and are typically found in plants, though some occur in fungi and animals as well. Alkaloids can also be synthesized or modified in a laboratory setting.
Alkaloids include a very wide range of substances with very different effects on the body. Caffeine and nicotine are stimulant alkaloids, morphine and codeine are pain relieving alkaloids derived from the opium poppy, atropine affects the nervous system and is used in certain medical situations, and vincristine, derived from a periwinkle plant, is used as a chemotherapy drug.
Because alkaloids as a group are defined by a shared chemical feature rather than a shared effect, knowing that a substance is an alkaloid says little on its own about how it acts in the body, and each alkaloid's specific properties must be considered individually.
Used in a sentence
Laboratory analysis identified several plant alkaloids in the ingested material.
Good to know
Calling a substance an alkaloid describes its chemical structure, not its effect on the body, so alkaloids range from stimulants and pain relievers to substances with no established medical use.
Word origin
Where “alkaloid” comes from
Formed from alkali, from Arabic al-qaly, meaning the ashes of a plant used to produce a soda like substance, combined with the Greek suffix -oid, meaning resembling, since alkaloids share chemical properties with alkalis.