In chemistry, a glycoside is a molecule in which a sugar is bound to another functional group via a glycosidic bond. Glycosides play numerous important roles in living organisms. Many plants store chemicals in the form of inactive glycosides. These can be activated by enzyme hydrolysis, which causes the sugar part to be broken off, making the chemical available for use. Many such plant glycosides are used as medications. Several species of Heliconius butterfly are capable of incorporating these plant compounds as a form of chemical defense against predators. In animals and humans, poisons are often bound to sugar molecules as part of their elimination from the body.
The Panax (ginseng) genus belongs to the Araliaceae (ivy) family. Panax species are characterized by the presence of ginsenosides and gintonin. Panax is one of approximately 60 plant genera with a classical disjunct east Asian and east North American distribution. Furthermore, this disjunct distribution is asymmetric as only two of the ~18 species in genus are native to North America.
Squalene is an organic compound. It is a triterpene with the formula C30H50. It is a colourless oil, although impure samples appear yellow. It was originally obtained from shark liver oil (hence its name, as Squalus is a genus of sharks). An estimated 12% of bodily squalene in humans is found in sebum. Squalene has a role in topical skin lubrication and protection.
Neuroprotection refers to the relative preservation of neuronal structure and/or function. In the case of an ongoing insult the relative preservation of neuronal integrity implies a reduction in the rate of neuronal loss over time, which can be expressed as a differential equation.
Ambrein is a triterpene alcohol that is the chief constituent of ambergris, a secretion from the digestive system of the sperm whale. It has been suggested as the possible active component producing the supposed aphrodisiac effects of ambergris. Although ambrein itself is odorless, it serves as the biological precursor for aromatic derivatives such as ambroxan and is thought to possess fixative properties for other odorants.
Xylan is a type of hemicellulose, a polysaccharide consisting mainly of xylose residues. It is found in plants, in the secondary cell walls of dicots and all cell walls of grasses. Xylan is the third most abundant biopolymer on Earth, after cellulose and chitin.
Triterpenes are a class of terpenes composed of six isoprene units with the molecular formula C30H48; they may also be thought of as consisting of three terpene units. Animals, plants and fungi all produce triterpenes, including squalene, the precursor to all steroids.
Quisqualic acid is an agonist of the AMPA, kainate, and group I metabotropic glutamate receptors. It is one of the most potent AMPA receptor agonists known. It causes excitotoxicity and is used in neuroscience to selectively destroy neurons in the brain or spinal cord. Quisqualic acid occurs naturally in the seeds of Quisqualis species.
Squalene synthase (SQS) or farnesyl-diphosphate:farnesyl-diphosphate farnesyl transferase is an enzyme localized to the membrane of the endoplasmic reticulum. SQS participates in the isoprenoid biosynthetic pathway, catalyzing a two-step reaction in which two identical molecules of farnesyl pyrophosphate (FPP) are converted into squalene, with the consumption of NADPH. Catalysis by SQS is the first committed step in sterol synthesis, since the squalene produced is converted exclusively into various sterols, such as cholesterol, via a complex, multi-step pathway. SQS belongs to squalene/phytoene synthase family of proteins.
Lanosterol synthase (EC 5.4.99.7) is an oxidosqualene cyclase (OSC) enzyme that converts (S)-2,3-oxidosqualene to a protosterol cation and finally to lanosterol. Lanosterol is a key four-ringed intermediate in cholesterol biosynthesis. In humans, lanosterol synthase is encoded by the LSS gene.
Panax notoginseng is a species of the genus Panax, and it is commonly referred to in English as Chinese ginseng or notoginseng. In Chinese it is called tiánqī, tienchi ginseng, sānqī or sanchi, three-seven root, and mountain plant. P. notoginseng belongs to the same scientific genus as Panax ginseng. In Latin, the word panax means "cure-all", and the family of ginseng plants is one of the best-known herbs.
Ginsenosides or panaxosides are a class of natural product steroid glycosides and triterpene saponins. Compounds in this family are found almost exclusively in the plant genus Panax (ginseng), which has a long history of use in traditional medicine that has led to the study of pharmacological effects of ginseng compounds. As a class, ginsenosides exhibit a large variety of subtle and difficult-to-characterize biological effects when studied in isolation.
Oleanolic acid or oleanic acid is a naturally occurring pentacyclic triterpenoid related to betulinic acid. It is widely distributed in food and plants where it exists as a free acid or as an aglycone of triterpenoid saponins.
Salidroside (rhodioloside) is a glucoside of tyrosol found in the plant Rhodiola rosea. It has been studied, along with rosavin, as one of the potential compounds responsible for the putative antidepressant and anxiolytic actions of this plant. Salidroside may be more active than rosavin, even though many commercially marketed Rhodiola rosea extracts are standardized for rosavin content rather than salidroside.
Protopanaxadiol (PPD) is an organic compound that is an aglycone of ginsenosides, a group of steroid glycosides. It is a dammarane-type tetracyclic terpene sapogenin found in ginseng and in notoginseng.
American ginseng is a species of flowering plant in the ivy family Araliaceae. It is native to eastern North America and introduced in China. The specific epithet quinquefolius means "five-leaved", which refers to the typical number of leaflets per leaf. It is one of a group of taxa known as "ginseng".
The amyrins are three closely related natural chemical compounds of the triterpene class. They are designated α-amyrin (ursane skeleton), β-amyrin (oleanane skeleton) and δ-amyrin. Each is a pentacyclic triterpenol with the chemical formula C30H50O. They are widely distributed in nature and have been isolated from a variety of plant sources such as epicuticular wax. In plant biosynthesis, α-amyrin is the precursor of ursolic acid and β-amyrin is the precursor of oleanolic acid. All three amyrins occur in the surface wax of tomato fruit. α-Amyrin is found in dandelion coffee.
The squalene/phytoene synthase family represents proteins that catalyze the head-to-head condensation of C15 and C20 prenyl units (i.e. farnesyl diphosphate and genranylgeranyl diphosphate). This enzymatic step constitutes part of steroid and carotenoid biosynthesis pathway. Squalene synthase EC (SQS) and Phytoene synthase EC (PSY) are two well-known examples of this protein family and share a number of functional similarities. These similarities are also reflected in their primary structure. In particular three well conserved regions are shared by SQS and PSY; they could be involved in substrate binding and/or the catalytic mechanism. SQS catalyzes the conversion of two molecules of farnesyl diphosphate (FPP) into squalene. It is the first committed step in the cholesterol biosynthetic pathway. The reaction carried out by SQS is catalyzed in two separate steps: the first is a head-to-head condensation of the two molecules of FPP to form presqualene diphosphate; this intermediate is then rearranged in a NADP-dependent reduction, to form squalene:
Dammarenediol II synthase (EC 4.2.1.125, dammarenediol synthase, 2,3-oxidosqualene (20S)-dammarenediol cyclase, DDS, (S)-squalene-2,3-epoxide hydro-lyase (dammarenediol-II forming)) is an enzyme with systematic name (3S)-2,3-epoxy-2,3-dihydrosqualene hydro-lyase (dammarenediol-II forming). This enzyme catalyses the following chemical reaction
Pseudoginsenoside F11 is a chemical natural product found in American ginseng but not in Asian ginseng, although it has similar properties to the Asian ginseng compound ginsenoside Rf. The molecule is a triterpenoid saponin member of the dammarane family and contains a four-ring rigid skeleton. Compounds in the ginsenoside family are found almost exclusively in plants of the genus Panax. A wide variety of difficult-to-characterize in vitro effects have been reported for the compounds in isolation. Pseudoginsenoside F11 and its derivatives are sometimes referred to as having an ocotillol-type skeleton structure.
