Separation of aglucones, glucosides and prenylated isoflavones by high-performance liquid chromatography

Gagnon, Hubert; Tahara, Satoshi; Bleichert, Ernst; Ibrahim, Ragai K.

doi:10.1016/0021-9673(92)87033-5

Cited by 11 publications

(7 citation statements)

References 23 publications

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“…The low specific activities of both aglucones and glucosides reflect their large cellular pool size, except for genistein [1], which represents the entry point aglucone in the formation of other isoflavone derivatives. In contrast, the prenylated compounds exhibited relatively high specific activities, especially wighteone [3], isowighteone [5], and alpinumisoflavone [8] Of the total isoflavonoids recovered from the culture medium, both mono-and diprenylated compounds represented 90% and contained more than 80% of the total radioactivity incorporated into this fraction. It is interesting to note that most prenylated compounds [4,8,9] have relatively high specific activities (Table I).…”

Section: Resultsmentioning

confidence: 95%

Biosynthesis of White Lupin Isoflavonoids from [U-¹⁴C]l-Phenylalanine and Their Release into the Culture Medium

Gagnon

Séguin²,

Bleichert³

et al. 1992

Plant Physiol.

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Pulse-labeling experiments of white lupin (Lupinus albus L.) cell cultures with [U-14C1L-phenylalanine for 72 h resulted in the incorporation of the radioactivity into the isoflavone aglucones, glucosides, and prenylated derivatives. Both the aglucones genistein and 2'-hydroxygenistein and their 7-0-glucosides accounted for 85% of the total isoflavonoids identified in the cultured cells and contained 35% of the radioactivity, whereas the prenylated derivatives comprised 15 and 65%, respectively. Almost 20% of the labeled isoflavones of the cellular pool was recovered from the culture medium, 90% of which were monoprenylated and diprenylated derivatives containing 80% of the radioactivity. These results clearly demonstrate the release into the culture medium of a substantial amount of the endogenously synthesized isoflavonoids, especially the prenylated derivatives.With few exceptions, most plant cell cultures fail to produce the secondary metabolites/natural products characteristic of the intact plants from which they were derived (13,17). Furthermore, of the limited variety of natural products that have been produced by cultured cells, flavonoid compounds are the least represented (4, 9). Among the few examples that have been reported in the literature are isoflavonoids formed in response to biotic or abiotic elicitors (1,3,11) or those produced by cell suspension and hairy root cultures transformed with Agrobacterium tumefaciens and A. rhizogenes, respectively (2).Cell cultures of white lupin (Lupinus albus L.) accumulate a complex pattern of isoflavones ( Fig. 1) [3-5, 3a-5a], and 6,3'-diprenyl [6, 6a] The isoflavonoid pattern is quite similar to that of the intact lupin roots (8,10,18,19). However, it was observed that lupin cell cultures release a portion of their metabolites into the culture medium, the latter eventually turning reddishbrown in color. Microscopic examination revealed that this phenomenon was not due to lysis of the cultured cells because the latter remained viable until the end of the culture period. It was considered important, therefore, to investigate the biosynthesis of lupin isoflavones, using "4C-labeled L-phenylalanine as a precursor, and their release into the culture medium. MATERIALS AND METHODS Cell CultureA cell-suspension culture derived from the radicles of white lupin (Lupinus albus L. cv Kievskij Mutant) was maintained on B5 nutrient medium (6) containing 2% sucrose and supplemented with 2,4-D (1 ppm) and kinetin (0.1 ppm). Preparation of Cell and Medium ExtractsAt the end of the metabolic period, the cultured cells were separated from the media by centrifugation at 2000g and washed twice with distilled water. The cells were extracted twice by homogenization with 80% aqueous MeOH4 (5:1, w/ v) at room temperature. The combined extracts were evaporated to an aqueous residue in a rotary evaporator at 300C, and the latter extracted twice with ethyl acetate. The organic layer was dried over anhydrous sodium sulfate before evaporation, and the residue dissolved in 8...

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Section: Resultsmentioning

confidence: 95%

Biosynthesis of White Lupin Isoflavonoids from [U-¹⁴C]l-Phenylalanine and Their Release into the Culture Medium

Gagnon

Séguin²,

Bleichert³

et al. 1992

Plant Physiol.

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“…This may explain luteone (a tetrahydroxyisoflavone) which was detected in immature seeds of L. luteus (Fukui et al, 1973). Additionally, genistein, 2 0 -hydroxygenistein and its glycosylated and prenylated derivatives (complex isoflavones) were detected in sprouts (Gagnon and Ibrahim, 1997;Gagnon et al, 1992), leaves (Tahara et al, 1984) and pods (Katagiri et al, 2000) of L. albus. In spite of the fact that several studies indicate that mature lupin seeds of albus, angustifolius and luteus species contain isoflavones in trace amounts (Katagiri et al, 2000;Sirtori et al, 2004), data obtained in the present study indicate that mature lupin seeds from mutabilis species show interesting quantities of total isoflavones (expressed as genistein) ( Table 2).…”

Section: Isoflavonesmentioning

confidence: 93%

Isoflavones and antioxidant capacity of Peruvian and Brazilian lupin cultivars

Ranilla

Genovese

Lajolo

2009

Journal of Food Composition and Analysis

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“…The generic chemical structure of isoflavonoids, a subgroup of flavonoids, is based on two aromatic and one pyrone ring. Due to various carbohydrate substitutions many isoflavonoids occur in plants as glucosides (Gagnon et al, 1992b;Shibuya et al, 1991). Both abiotic elicitors such as CuCl 2 and biotic elicitors such as yeast have been shown to induce isoflavonoid production in Lupinus albus L. (Bednarek et al, 2001;Gagnon and Ibrahim, 1997;Wojtaszek and Stobiecki, 1997).…”

Section: Introductionmentioning

confidence: 99%

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et al. 2003

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The mechanisms enabling plants to tolerate high concentrations of available Cu in their rhizosphere are still poorly understood. To better understand the mechanisms involved, Lupinus albus L. (white lupin) was grown over 40 days in a hydroponic system compelling roots to develop under sterile conditions in the presence of a nutrient solution containing 0.5, 20 or 62 µM Cu. The following parameters were investigated in detail: low molecular weight phenols in nutrient solution (colorimetric assay), high molecular weight phenols in roots and in solution (HPLC-MS, HPLC-UV), pH, redox potential in solution (electrochemistry) and Cu distribution in the plant (AAS) as well as in apical root sections (EDX microanalysis). Finally, in vitro adsorption studies using voltammetry were conducted to evaluate the Cu adsorption behaviour of different phenolic compounds. When exposed to 62 µM Cu, biomass production of white lupin was strongly reduced. Plants grown in the presence of 20 µM Cu had a similar dry matter production compared to the control plants grown in a 0.5 µM Cu solution. However, an increased release of soluble and high molecular weight phenols into the solution was observed. The concentration of polyphenolic compounds in the roots (particularly isoflavonoids like genistein and genistein-(malonyl)-glucoside) was significantly higher for lupins grown in a 20 µM Cu solution compared to the control plants. As shown by an in vitro adsorption study, these phenolic compounds can bind Cu ions. In addition, plants exposed to 20 and 62 µM Cu cumulated high Cu amounts in root cell walls whereas only low amounts reached the symplasm. Therefore, it is proposed that the complexation of Cu 2+ ions in the rhizosphere and in the roots apoplasm by phenolic compounds could alleviate Cu-mediated toxicity. Abbreviations: Control-plants grown in nutrient solution containing 0.5 µM Cu 2+ ; 20Cu-plants grown in nutrient solution containing 20 µM Cu 2+ ; 62Cu-plants grown in nutrient solution containing 62 µM Cu 2+ ; HMWP-high molecular weight phenols; AAS-atomic absorption spectrometry; EDX-energy dispersive X-ray diffraction; DM-dry matter; ∅-diameter; MS-mass spectrometry

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Separation of aglucones, glucosides and prenylated isoflavones by high-performance liquid chromatography

Cited by 11 publications

References 23 publications

Biosynthesis of White Lupin Isoflavonoids from [U-¹⁴C]l-Phenylalanine and Their Release into the Culture Medium

Biosynthesis of White Lupin Isoflavonoids from [U-¹⁴C]l-Phenylalanine and Their Release into the Culture Medium

Isoflavones and antioxidant capacity of Peruvian and Brazilian lupin cultivars

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Separation of aglucones, glucosides and prenylated isoflavones by high-performance liquid chromatography

Cited by 11 publications

References 23 publications

Biosynthesis of White Lupin Isoflavonoids from [U-14C]l-Phenylalanine and Their Release into the Culture Medium

Biosynthesis of White Lupin Isoflavonoids from [U-14C]l-Phenylalanine and Their Release into the Culture Medium

Isoflavones and antioxidant capacity of Peruvian and Brazilian lupin cultivars

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Biosynthesis of White Lupin Isoflavonoids from [U-¹⁴C]l-Phenylalanine and Their Release into the Culture Medium

Biosynthesis of White Lupin Isoflavonoids from [U-¹⁴C]l-Phenylalanine and Their Release into the Culture Medium