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.
|Superclasses:||Activation/Inactivation/Interconversion → Interconversions|
|Biosynthesis → Secondary Metabolites Biosynthesis → Phenylpropanoid Derivatives Biosynthesis → Flavonoids Biosynthesis → Isoflavonoids Biosynthesis|
|Biosynthesis → Secondary Metabolites Biosynthesis → Phytoalexins Biosynthesis → Isoflavonoid Phytoalexins Biosynthesis|
Expected Taxonomic Range: Fabaceae
Malonyl glucosides have been frequently overlooked due to their lability and inadequate isolation procedures. Numerous N-and O-malonyl conjugates have been reported in different plant species, including isoflavones, isoflavanones and isoflavonoids but also xenobiotics, D-amino acids and the ethylene precursor 1-aminocyclopropane-1-carboxylic acid.
The latter are considered to be detoxification products [Koester84], whereas the former may serve as pools for the release of free aglycons. Released isoflavones can be either incorporated into the biosynthetic pathway of phytoalexins or act as phytoanticipins [Hsieh01].
The finding that isoflavone conjugates are sometimes constitutively present in considerable amounts in legumes [Graham91], support such a possible role as preformed toxins (phytoanticipins).
Glucosides and malonyl glucosides of isoflavones, such as biochanin A and formononetin and further metabolic derivatives (e.g. cicerin, medicarpin) are exclusively located in the vacuole [Mackenbrock92] and it has been speculated, that acylation of these compounds could precede and facilitate their transport through the tonoplast [Matern83].
Superpathways: superpathway of formononetin derivative biosynthesis
Hsieh01: Hsieh MC, Graham TL (2001). "Partial purification and characterization of a soybean β-glucosidase with high specific activity towards isoflavone conjugates." Phytochemistry 58(7);995-1005. PMID: 11730862
Koester84: Koester J, Bussmann R, Barz W (1984). "Malonyl-coenzyme A:isoflavone 7-O-glucoside-6"-O-malonyltransferase from roots of chick pea (Cicer arietinum L.)." Arch Biochem Biophys 234(2);513-21. PMID: 6497385
Mackenbrock92: Mackenbrock U, Vogelsang R, Barz W, (1992) "Isoflavone and pterocarpan malonylglucosides and β-1,3-glucan- and chitin hydrolases are vacuolar constituents in chick pea (Cicer arietinum L.)." Z. Naturforsch (1992) 47c, 815-822.
Matern83: Matern U, Feser C, Hammer D (1983). "Further characterization and regulation of malonyl-coenzyme A: flavonoid glucoside malonyltransferases from parsley cell suspension cultures." Arch Biochem Biophys 226(1);206-17. PMID: 6639051
Hinderer86: Hinderer W, Koster J, Barz W (1986). "Purfication and properties of a specific isoflavone 7-O-glucoside-6''-malonate malonyestrase from roots of chickpea (Cicer arietinum L.)." Arch Biochem Biophys 248(2);570-8. PMID: 3740841
Rubio06: Rubio S, Larson TR, Gonzalez-Guzman M, Alejandro S, Graham IA, Serrano R, Rodriguez PL (2006). "An Arabidopsis mutant impaired in coenzyme A biosynthesis is sugar dependent for seedling establishment." Plant Physiol 140(3);830-43. PMID: 16415216
©2016 SRI International, 333 Ravenswood Avenue, Menlo Park, CA 94025-3493