Triterpenoid saponins from Pteleopsis suberosa stem bark

Leo, Marinella De; Tommasi, Nunziatina De; Sanogo, Rokia; D’Angelo, Valeria; Germanò, Maria Paola; Bisignano, Carlo; Braca, Alessandra

doi:10.1016/j.phytochem.2006.07.017

Cited by 48 publications

(18 citation statements)

References 22 publications

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“…A major challenge is thus to understand the processes of saponin biosynthesis, which structural variants of saponins play a role in defense against biotic antagonists, and how saponin biosynthesis evolved in different plant taxa. This knowledge is also of interest for biotechnological production and the use of saponins as protection agents against agricultural pests as well as for pharmacological and industrial uses as bactericides (De Leo et al, 2006), anticancerogens (Musende et al, 2009), and adjuvants (Sun et al, 2009).…”

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confidence: 99%

UDP-Glycosyltransferases from the UGT73C Subfamily in Barbarea vulgaris Catalyze Sapogenin 3-O-Glucosylation in Saponin-Mediated Insect Resistance

et al. 2012

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Triterpenoid saponins are bioactive metabolites that have evolved recurrently in plants, presumably for defense. Their biosynthesis is poorly understood, as is the relationship between bioactivity and structure. Barbarea vulgaris is the only crucifer known to produce saponins. Hederagenin and oleanolic acid cellobioside make some B. vulgaris plants resistant to important insect pests, while other, susceptible plants produce different saponins. Resistance could be caused by glucosylation of the sapogenins. We identified four family 1 glycosyltransferases (UGTs) that catalyze 3-O-glucosylation of the sapogenins oleanolic acid and hederagenin. Among these, UGT73C10 and UGT73C11 show highest activity, substrate specificity and regiospecificity, and are under positive selection, while UGT73C12 and UGT73C13 show lower substrate specificity and regiospecificity and are under purifying selection. The expression of UGT73C10 and UGT73C11 in different B. vulgaris organs correlates with saponin abundance. Monoglucosylated hederagenin and oleanolic acid were produced in vitro and tested for effects on P. nemorum. 3-Ob-D-Glc hederagenin strongly deterred feeding, while 3-O-b-D-Glc oleanolic acid only had a minor effect, showing that hydroxylation of C23 is important for resistance to this herbivore. The closest homolog in Arabidopsis thaliana, UGT73C5, only showed weak activity toward sapogenins. This indicates that UGT73C10 and UGT73C11 have neofunctionalized to specifically glucosylate sapogenins at the C3 position and demonstrates that C3 monoglucosylation activates resistance. As the UGTs from both the resistant and susceptible types of B. vulgaris glucosylate sapogenins and are not located in the known quantitative trait loci for resistance, the difference between the susceptible and resistant plant types is determined at an earlier stage in saponin biosynthesis.

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mentioning

confidence: 99%

UDP-Glycosyltransferases from the UGT73C Subfamily in Barbarea vulgaris Catalyze Sapogenin 3-O-Glucosylation in Saponin-Mediated Insect Resistance

et al. 2012

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“…3 concluded that the OH groups at positions C-2 and C-3 must be equatorial, since the coupling constants of H-2 (J 2ax,1ax ϭ12.5, J 2ax,3ax ϭ10 Hz) and H-3 (J 3ax,2ax ϭ10 Hz) were consistent with axial configurations for both protons. The 2a,3b relative configuration was further confirmed by comparison of the 1 H-NMR coupling constants with those reported for related compounds [21,22]. The hydrolysis of 2 with K 2 CO 3 in MeOH at room temperature afforded 2a -hydoxyerythrodiol [23].…”

Section: Structure Elucidationmentioning

confidence: 86%

Antimalarial Compounds from the Root Bark of Garcinia polyantha Olv.

et al. 2008

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Eight compounds were isolated from the roots of Garcinia polyantha, and identified. Two of them, the xanthone garciniaxanthone I (1), and the triterpene, named garcinane (2), are reported as new natural products. The structures of the new compounds were elucidated on the basis of 1D and 2D NMR spectroscopic studies. The structure of compound 1 was confirmed by Xray crystallography. Among the remaining six known compounds, three were known xanthones [smeathxanthone A (3), smeathxanthone B (4), and chefouxanthone (5)], one benzophenone [isoxanthochymol (6)], one triterpene [magnificol], and one sterol [b -sitosterol]. The in vitro antimalarial activity of isoxanthochymol (6) against Plasmodium falciparum shows strong chemosuppression of parasitic growth.Keywords Garcinia polyantha, garciniaxanthone I, Xray crystallography, xanthones; antimalarial activity IntroductionThe genus Garcinia of the Guttiferae family is well known to be a rich source of bioactive prenylated xanthones [1ϳ3], triterpenes [4], and benzophenones [5,6]. In continuation of our search for bioactive substances from African medicinal plants, we investigated the methanol extract of the root bark of Garcinia polyantha, a tree distributed in the lowland tropical rainforest of West, East and Central Africa [7,8]. In the current investigation we focused on minor constituents from G. polyantha, and one new xanthone (1), one new triterpene (2), and six known compounds (3ϳ6, magnificol, and b -sitosterol), were isolated (Fig. 1). We report herein the structure elucidation of the eight natural products and their antimalarial activity. Materials and Methods General Experimental ProceduresMelting points were determined on a Büchi SMP-20 melting point apparatus and are uncorrected. UV spectra were measured with a UV-210 PC UV. IR spectra were recorded on a SHIMADZU FTIR-8400S spectrometer in KBr disks. EI-MS (ionization voltage 70 eV) and HR-EI-MS mass spectra were recorded on Finnigan MAT double focusing spectrometer Model 8230. 1 H-and 13 C-NMR spectra were recorded with a Bruker Avance 500 MHz NMR spectrometer in CDCl 3 or CDCl 3 /CD 3 OD. Chemical shifts are recorded relative to TMS (dϭ0) internal standard and coupling constants J are reported in Hz. Optical rotation were recorded with a Perkin-Elmer 241

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“…Les autres détails de nos différents protocoles sont mentionnés dans les publications respectives [6][7][8][9].…”

Section: Evaluation De L'activité Antimicrobienneunclassified

Triterpenoid saponins from Pteleopsis suberosa stem bark

Cited by 48 publications

References 22 publications

UDP-Glycosyltransferases from the UGT73C Subfamily in Barbarea vulgaris Catalyze Sapogenin 3-O-Glucosylation in Saponin-Mediated Insect Resistance

UDP-Glycosyltransferases from the UGT73C Subfamily in Barbarea vulgaris Catalyze Sapogenin 3-O-Glucosylation in Saponin-Mediated Insect Resistance

Antimalarial Compounds from the Root Bark of Garcinia polyantha Olv.

Pteolopsis suberosa Engl. et Diels (Combretaceae) : une plante à activité antiulcère et anti Helicobacter pylori

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