Phenylpropanoid glycosyltransferases from osage orange (Maclura pomifera) fruit

Abstract

Flavonoids and isoflavonoids are well known for their beneficial effects on human health and their anti-insect and antimicrobial activities in plants. Osage orange fruit is rich in prenylated isoflavones and dihydrokaempferol and its glucoside. Four glycosyltransferases were identified from a collection of osage orange fruit expressed sequence tags. Biochemical characterization suggested that the glycosyltransferase UGT75L4 might be responsible for glucosylation of dihydrokaempferol in vivo, although this enzyme exhibited broad substrate recognition toward isoflavonoids and flavonoids in vitro. UGT88A4 was active on coumarin substrates. Identification of highly active phenylpropanoid glycosyltransferases will facilitate the metabolic engineering of glycosylated natural products in plants.

Recombinant expression and functional characterisation of regiospecific flavonoid glucosyltransferases from Hieracium pilosella L.

“…The aYnity to umbelliferone, however, is rather common among UGTs, because out of 90 A. thaliana UGTs 48 were capable to glycosylate hydroxycoumarins (Lim et al 2003). Recent studies indicate that most plant UGTs are not absolutely substrate speciWc at least in vitro (Vogt and Jones 2000;Messner et al 2003;Kramer et al 2003;Lunkenbein et al 2006;Tian et al 2006;Suzuki et al 2007). The here described in vitro glucosylation pattern of H. pilosella UGTs could therefore not be attributed directly to in vivo functions.…”

“…H. pilosella UGT88A8 and UGT88A9 cluster with other GTs from this subfamily, which contains enzymes with regiospeciWcity for the 7-OH group of Xavonoids (analogue 4Ј-OH of chalcones) (Nagashima et al 2000;Ono et al 2006;Noguchi et al 2007) as well as a glucosyltransferase which catalyses two glucosylation steps at the 5-OH and 3-OH position of anthocyanidin (Ogata et al 2005) and UGT88A1 from A. thaliana glucosylating hydroxyls at four sites of quercetin ). It should be noted that UGT88A4 from M. pomifera did not exhibit any activity towards Xavonoids and isoXavonoids (Tian et al 2006), but produced glucosides from coumarin substrates. H. pilosella UGT72B11 also belongs to group E of the classiWcation scheme (Fig.…”

Characterization of a Glucosyltransferase Enzyme Involved in the Formation of Kaempferol and Quercetin Sophorosides in Crocus sativus

“…Among the functionally characterized UGTs, UGT707B1 shares the highest identity (40%) with UGT88A4 from Maclura pomifera, which did not exhibit any activity toward flavonoids and isoflavonoids but catalyzed the glucosylation of coumarin susbtrates, although the in vivo substrate is unknown (Tian et al, 2006). The same identity is shown with UGT88A8 and UGT88A9 from Hieracium pilosella, which showed activity with flavones, flavonols, caffeic acid, esculetin, catechol, resorcinol, and hydroquinone (Witte et al, 2009).…”

Prenylated flavonoids from maclura tinctoria fruits

“…However, several prenylated isoflavones have been reported to occur in M. pomifera [8][9][10][11][12] and other species of the Moraceae family. 21,25,26 The isolation of prenylated isoflavones from M. tinctoria may contribute to further chemotaxonomic studies on the genus Maclura and family Moraceae.…”

“…In M. pomifera, the most studied species of the genus, several flavonoids have been described, including isoflavones from the fruits, root, bark, and heartwood of the plant. [8][9][10][11][12][13] Five prenylated flavones and three prenylated isoflavones have been isolated from chloroform extracts of stems and leaves.…”