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: dalpatein glycoside hydrolysis, dalnigrein glycoside hydrolysis, dalpatein and dalnigrein biosynthesis
|Superclasses:||Biosynthesis → Secondary Metabolites Biosynthesis → Phenylpropanoid Derivatives Biosynthesis → Flavonoids Biosynthesis → Isoflavonoids Biosynthesis|
Some taxa known to possess this pathway include : Dalbergia nigrescens
Expected Taxonomic Range: Fabaceae
The isoflavonoid glycosides in legumes have conserved patterns of glycosylations, the more abundant monosaccharides are usually β-glucopyranosides and the fewer dissacharides are also of the β-glucopyranosides type. There are some uncommon sugars reported, among them β-apiofuranose which is found invariably linked to C-4' of the isoflavone aglycone and also appears as a terminal sugar on various disaccharides [Vietch07].
The biosynthesis of legume isoflavonoid glycosides is poorly understood. A few isoflavonoid-specific glucotransferases have been cloned providing some insight into the mechanism of isoflavonoid production in legumes. Most of the plant glucosidases belong to the glucosyl hydrolase family (GH1). The 3 dimensional structure of these enzymes reveal a common α-/β- barrel [Toonkool06].
In Dalbergia nigrescens, an isoflavonoid β-glucosidase has been isolated and cloned [Chuankhayan07]. This enzyme hydrolyzes the natural substrates dalpatein and dalnigrein [Chuankhayan05] by cleaving off only dissacharides, i.e. β-D-apiofuranosyl-(1->6)-D-glucose and not monosaccharides.
Chuankhayan05: Chuankhayan P, Hua Y, Svasti J, Sakdarat S, Sullivan PA, Ketudat Cairns JR (2005). "Purification of an isoflavonoid 7-O-beta-apiosyl-glucoside beta-glycosidase and its substrates from Dalbergia nigrescens Kurz." Phytochemistry 66(16);1880-9. PMID: 16098548
Chuankhayan07: Chuankhayan P, Rimlumduan T, Tantanuch W, Mothong N, Kongsaeree PT, Metheenukul P, Svasti J, Jensen ON, Cairns JR (2007). "Functional and structural differences between isoflavonoid beta-glycosidases from Dalbergia sp." Arch Biochem Biophys 468(2);205-16. PMID: 17998137
Toonkool06: Toonkool P, Metheenukul P, Sujiwattanarat P, Paiboon P, Tongtubtim N, Ketudat-Cairns M, Ketudat-Cairns J, Svasti J (2006). "Expression and purification of dalcochinase, a beta-glucosidase from Dalbergia cochinchinensis Pierre, in yeast and bacterial hosts." Protein Expr Purif 48(2);195-204. PMID: 16814564
Ahn04: Ahn YO, Mizutani M, Saino H, Sakata K (2004). "Furcatin hydrolase from Viburnum furcatum Blume is a novel disaccharide-specific acuminosidase in glycosyl hydrolase family 1." J Biol Chem 279(22);23405-14. PMID: 14976214
Chuankhayan07a: Chuankhayan P, Rimlumduan T, Svasti J, Cairns JR (2007). "Hydrolysis of soybean isoflavonoid glycosides by Dalbergia beta-glucosidases." J Agric Food Chem 55(6);2407-12. PMID: 17311399
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