Structure and Nomenclature

Menthol has slightly anaesthetic or, rather, refreshing properties. It is used as an antipruritic in dermatology and as a very mild anaesthetic in otorhinolaryngology to treat pharyngitis. It also displays antiseptic properties.

Limonene can be dextrorotatory, levorotatory or racemic. Levorotatory limonene (-) is extracted from orange peel and is responsible for its smell.

Dextrorotatory limonene (+) is very abundant in Nature. It is an oily liquid easily extracted from lemon peel and responsible for its smell.

Camphor is a solid, crystalline and volatile substance with a burning taste and characteristic smell, found in the camphor tree and other plants of the laurel family. It is a mild topical anaesthetic (camphorated spirits).

Grandisol is a sex-attractant pheromone secreted by the male of an insect that is a pest of cotton plants.

Cholesterol was isolated from bile in 1769 but its structure was not established until 1932. Woodward performed its total synthesis in 1951. It is found in all animal fats. Cholesterol intercalates among the phospholipids forming the cell membranes in animals. It makes the membranes more rigid and less permeable. Without cholesterol, the animal cells would need a wall like that of bacteria.

The structural elucidation of cholic acid by Wieland was one of the most important achievements in classic organic chemistry. It is formed in the liver from cholesterol degradation and acts as an emulsifier in bile.

Cortisone is an adrenocortical hormone with a notable anti-inflammatory activity.

Testosterone is the main androgenic hormone, secreted by the interstitial tissue of the testicles. It controls sperm formation, the development of genitals and the secondary sexual characteristics.

Estradiol is a hormone that accounts for almost all the estrogen secreted by women during their reproductive years. A synthetic analogue is used in contraceptive pills.

Progesterone is a hormone secreted by the corpus luteum of the ovary. It prepares the uterine lining for the implantation, maintenance and development of the fertilized egg. It was isolated in 1934 and its structure was established in 1935.