STEROIDS
- They are a group of tetracyclic lipid derivatives which have a nucleus of cyclopentano-perhydrophenanthrene with phenanthrene part made of 3 hexane rings while the fourth ring is a pentane.
- The most common sterol is cholesterol.
- Ergasterol occurs in cell membranes of ergot fungi, yeast.
- Coprosterol is found in stool. It is formed by bacterial reduction of cholesterol.
- Sitosterol present in wheat germ oil.
- Steroids are of two types -
(i) Alcoholic steroids (Sterol) - Cholesterol, Coprosterol, 7-dehydroxycholesterol, Bile salts
(ii) Ketonic steroids (Sterone) - Ecdyson, Diosgenin, Adrenocorticoids, Sex hormone