This view shows enzymes only for those organisms listed below, in the list of taxa known to possess the pathway. If an enzyme name is shown in bold, there is experimental evidence for this enzymatic activity.
Synonyms: solanine/chaconine biosynthesis, α-solanine/α-chaconine biosynthesis, SGA biosynthesis
|Superclasses:||Biosynthesis → Secondary Metabolites Biosynthesis → Nitrogen-Containing Secondary Compounds Biosynthesis → Alkaloids Biosynthesis|
Some taxa known to possess this pathway include : Solanum tuberosum
Expected Taxonomic Range: Solanaceae
The potato steroidal glycoalkaloids (SGA) are toxic secondary metabolites found in potatoes Solanum tuberosum and other Solanaceous members like tomato and eggplant [McCue07]. They give a bitter taste and their total content should not exceed 20mg/100g fresh weight. The two major SGA's in cultivated potato are α-solanine and α-chaconine [Krits07].
Tuber phelloderm or the layers directly below the tuber skin is the main SGA-producing tissue in potato. Symptoms of SGA poisoning include gastrointestinal disorders, hallucinations, partial paralysis, convulsions, coma and death [Krits07]. At the cellular level they exhibit strong lytic properties and inhibit acetylcholine-esterase activty.
Cooking does not destroy the SGA's and varieties that contain low levels of SGA are bred. The biosynthetic pathway has not been completely worked out and possible positive roles these compounds may play in antifungal and wounding response are being studied. Wounding in potato activates the sterol and SGA synthesis [Krits07].
McCue06: McCue KF, Allen PV, Shepherd LV, Blake A, Whitworth J, Maccree MM, Rockhold DR, Stewart D, Davies HV, Belknap WR (2006). "The primary in vivo steroidal alkaloid glucosyltransferase from potato." Phytochemistry 67(15);1590-7. PMID: 16298403
McCue07: McCue KF, Allen PV, Shepherd LV, Blake A, Maccree MM, Rockhold DR, Novy RG, Stewart D, Davies HV, Belknap WR (2007). "Potato glycosterol rhamnosyltransferase, the terminal step in triose side-chain biosynthesis." Phytochemistry 68(3);327-34. PMID: 17157337
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