Biosynthesis of Umbelliferose in Aegopodium podagraria

Abstract

The following reaction leading to the synthesis of the trisaccharide umbelliferose was demonstrated in an enzyme preparation from leaves of Aegopodium podagraria L.: sucrose + UDP-gal-'4C -e umbelliferose-'4C + UDP. Neither galactinol nor galactose 1-phosphate could replace UDP-gal. Among 10 different sugars tested only sucrose was a suitable galatosyl acceptor. The trisaccharide umbelliferose (O-a-D-galactopyranosyl-(l-2)-O-a-D-glucopyranosyl-(1 -2)-O-,8-D-fructofuranoside) wasfound and identified by Wickstrom and Svendsen (9). Although it is very widespread within the umbelliferes (1, 2, 7), its biosynthesis is hitherto unknown. Since raffinose, another much more widespread galactoside of sucrose, is formed by a transfer reaction in which galactinol is the galactosyl donor (4), we studied the occurrence of galactinol in umbellifers. Only traces of galactinol could be found in such leaves, which also contained very small amounts of raffinose in addition to umbelliferose. No correlation between the occurrence of umbelliferose and galactinol could be found, however (3). Also no other unusual galactoside which could serve as galactosyldonor was detected in labeling experiments similar to the studies of Senser and Kandler (6). It was, therefore, suggested that the galactosyldonor in the biosynthesis of umbelliferose may be a nucleotide-activated galactose or galactose 1-phosphate, both present in leaves of umbellifers. This paper describes an enzyme preparation from the leaves of Aegopodium podagraria which transfers galactose specifically from UDP-gal to position 2 of sucrose, yielding umbelliferose. MATERIALS AND METHODSThe enzyme was prepared as follows. Fifteen g of fully expanded leaves of Aegopodium podagraria L. grown in the open air were frozen in liquid nitrogen and ground in a mortar.After mixing with the same weight of polyvinylpyrrolidone (5), the powder was extracted in the cold with 100 ml of 0.1 M tris-HCl-buffer (pH 7.0) containing 10 mm dithioerythritol. Sucrose-'4C and UDP-gal-"4C were purchased from Amersham (England), labeled raffinose and umbelliferose were isolated from leaves of Lamium maculatum and Aegopodium podagraria, respectively, after the leaves were allowed to photosynthesize in "4CO2 for several hours (6). Paper electrophoresis was carried out in 0.05 M sodiumtetraborate, pH 9.8, and in 0.1 M ammonia formate, pH 3.7. The radioactive areas were located by autoradiography. The radioactivity was measured directly on paper with a methane flow counter Frieseke and Hoepfner 407 A. RESULTS AND DISCUSSION To demonstrate the synthesis of umbelliferose from sucrose and various galactosyldonors, as well as the exchange reaction between umbelliferose and sucrose, the combinations of labeled and unlabeled acceptors and donors listed in Table 1 were used. Only in assays No. 2 and 3 labeled umbelliferose could be found on the one-dimensional chromatogram (solvent III). Unlike the results of similar experiments on raffinose (5) and stachyose biosynthesis (8), no exchange reaction could b...

Umbelliferose Isolated from Cuminum cyminum L. Seeds Inhibits Antigen-Induced Degranulation in Rat Basophilic Leukemia RBL-2H3 Cells

“…W-2-4 and identified a trisaccharide in these fractions by electrospray ionization-mass spectrometry (ESI-MS), and various nuclear magnetic resonance (NMR) experiments led to the conclusion that its structure is α-d-galactopyranosyl-(1→2)-α-d-glucopyranosyl-(1↔2)-βd-fructofuranoside (umbelliferose) (Figure 2a). Umbelliferose has been identified to be present in the roots of Angelica archangelica L., a biennial plant of the Umbelliferae family, and is characteristically present in plants of this family [24][25][26][27]. Umbelliferose exhibited significant degranulation-suppressive activity, with a 57% inhibitory rate recorded at 15 mM (Figure 2b).…”

Isolation and Characterization of a Pentasaccharide from Stellaria media

“…Some of the characteristic signals can be assigned from 1D 13 C and 1 H NMR and selective TOCSY spectra, [22][23][24] but the majority of signals required 2D homonuclear and heteronuclear NMR techniques, which included COSY, 25 HSQC, [26][27][28] HSQC-TOC-SY, 29 HMBC, 30 and NOESY 31,32 experiments (Tables 1, 2). First, assignment and quantification of through-bond homonuclear couplings J H,H via 2D experiments such as COSY and TOCSY yielded the information required to assign each monosaccharide spin system to a characteristic configuration, including anomeric configuration and ring form.…”

“…This trisaccharide is typically accumulated in seeds of Festuca and Lolium, from which it was isolated and its chemical structure was elucidated. , A second type is umbelliferose [α- d -Gal-(1→2)α- d -Glc-(1→2)β- d -Fru], where a galactosyl residue is bound to sucrose at the glucosyl moiety by an α(1→2) linkage. Umbelliferose is restricted to the Apiaceae and the Araliaceae families, where it is found in both vegetative and reproductive plant parts. , The third isomer planteose [α- d -Glc-(1→2)β- d -Fru-(6→1)α- d -Gal] is formed by the transfer of a galactose to the fructosyl moiety of sucrose, forming an α(1→6) linkage . Planteose was first believed to be restricted to seeds, but recently it was reported to act as a short-term storage carbohydrate in Actinidia leaves .…”

“…Umbelliferose is restricted to the Apiaceae and the Araliaceae families, where it is found in both vegetative and reproductive plant parts. 13,14 The third isomer planteose [R-D-Glc-(1f2)β-D-Fru-(6f1)R-D-Gal] is formed by the transfer of a galactose to the fructosyl moiety of sucrose, forming an R(1f6) linkage. 15 Planteose was first believed to be restricted to seeds, but recently it was reported to act as a short-term storage carbohydrate in Actinidia leaves.…”

Sucrose analogs: an attractive (bio)source for glycodiversification

“…161 The biosynthesis of umbelliferose has also been demonstrated in an enzyme preparation from leaves of Aegopodium podagraria L. using sucrose as the acceptor and UDP-galactose as the donor. 162 An original trisaccharide derived from sucrose has been synthesized by transglycosylation using a recombinant b-glycosidase from Sulfolobus shibatae. This reaction involved lactose as the donor and sucrose as the acceptor to form a new product whose structure was determined to be the b-D-galactopyranosyl The biosyntheses of melezitose and erlose have also been performed by incubating, in an artificial phloem sap, isolated guts of Metropeurum fuscoviride and Macrosiphoniella tanacetaria, respectively.…”