Triterpenoid saponins

Triterpenoid saponins are triterpenes which belong to the group of saponin compounds. Triterpenes belong to a large group of compounds arranged in a four or five ring configuration of 30 carbons with several oxygens attached. Triterpenes are assembled from a C5 isoprene unit through the cytosolic mevalonate pathway to make a C30 compound and are steroidal in nature. Cholesterol is one example of a triterpene. Phytosterols and phytoecdysteroids are also triterpenes. The triterpenes are subdivided into some 20 groups, depending on their particular structures. Though all terpenoid compounds have bioactivity in mammals, it is the triterpenes that are most important to the adaptogenic effect found in plants such as Panax ginseng or Eleutherococcus senticosus. Most triterpenoid compounds in adaptogenic plants are found as saponin glycosides which refers to the attachment of various sugar molecules to the triterpene unit. These sugars can be easily cleaved off in the gut by bacteria, allowing the aglycone (triterpene) to be absorbed. This allows them insert into cell membranes and modify the composition, influence membrane fluidity, and potentially affect signaling by many ligands and cofactors. Saponin glycosides reduce surface tension of water with foaming and will break down lipids. Usually triterpene saponins are designated as such by the suffix ending –side, such as ginsenoside, or astragaloside, named for the plant genera they were first discovered in. Some, such as the ginsenosides and eleutherosides are designated Rx where the suffix x = a, a1, b2, is indicative of the relative position of the saponin spots from top to bottom of a thin layer chromatogram.

Common Medicinally Active Triterpenoid Saponins from Adaptogenic Plants
Triterpenoids in Plants

Chemical compound:	  Common Name 	 (Latin Name)
 * 20-hydroxyecdysone:	maral root	(Rhaponticum carthamoides)
 * araloside:	      spikenard	(Aralia mandshurica)
 * astragaloside:	      huang qi	        (Astragalus membranaceus}
 * bacoside:	      brahmi	        (Bacopa monniera)
 * cucurbitacin:	      bryonia	        (Bryonia alba)
 * eleutheroside:	      Siberian ginseng	(Eleutherococcus senticosus)
 * ginsenoside:	      ginseng	        (Panax ginseng)
 * gypenoside:	      jiaogulan	(Gynostemma pentaphyllum)
 * tanshenoside:	      bellflower	(Codonopsis pilosula)
 * tinosporoside:	      guruchi	        (Tinospora cordifolia)
 * withanolide:	      ashwagandha	(Withania somnifera)