triterpène

Triterpenes are a large class of organic compounds derived from squalene. They are characterized by a skeleton of thirty carbon atoms, formed from six isoprene units. This structural basis leads to a diverse array of molecular architectures, with over 100 different skeletal frameworks identified. Triterpenes are found in a wide range of organisms, particularly in plants, fungi, and some bacteria.

In plants, triterpenes play various ecological roles, acting as defense mechanisms against herbivores and pathogens, and contributing to the structural integrity of cell walls. They are also responsible for some of the characteristic scents and flavors of certain plants. Many triterpenes possess significant biological activities, making them of interest in medicinal chemistry. Examples include saponins, which have detergent-like properties and are known for their expectorant and anti-inflammatory effects. Other notable triterpenes include betulinic acid, a compound investigated for its potential anti-cancer properties, and oleanolic acid, found in many medicinal herbs and used for its hepatoprotective and anti-inflammatory actions.

The biosynthesis of triterpenes begins with the cyclization of squalene, a process catalyzed by enzymes called squalene cyclases. This initial cyclization event is highly stereospecific and leads to the formation of a tricyclic intermediate, lanosterol or cycloartenol, which then undergoes further enzymatic modifications to produce the vast diversity of triterpene structures. Their presence in various natural products makes them a subject of ongoing research in fields such as natural product chemistry, pharmacology, and phytochemistry.