PLANT CHEMISTRY

Phytochemistry

Plant chemistry, also known as phytochemistry, from the ancient Greek for plant (phutón) is one of the richest areas of chemistry in terms of variety; with common chemical elements (carbon, hydrogen, oxygen and nitrogen) making up a seemingly infinite array of structures.

Some of the key compound classes (chemical 'families') are shown in the slides below.

Alkaloids

Alkaloids contain nitrogen atoms and generally oxygen atoms too. They are often bitter in taste. Alkaloid compounds are well known as recreational drugs (e.g. caffeine and nicotine) and they frequently have psychoactive properties. Alkaloids also figure prominently as pharmaceutical drugs, e.g. quinine and morphine.

Flavonoids

Flavonoids are based around phenolic ring structures. Flavonoids are found in most fruits and vegetables and some are responsible for the pigmentation (coloring) of plants. Although flavonoids often show antioxidant activity in vitro, there is little evidence of this activity in vivo.

Terpenes

Terpenoids are a diverse class of compounds which include essential oils or volatiles. Terpenes are composed from 5-carbon isoprene sub-units Terpenes are categorized according to the numbers of these 5-carbon isoprene units that they contain.