Highlighting aglycone-dependent glycosylation aspects in Caryophyllaceae saponins by a simplex simulation approach

Background: Saponin metabolism shows high structural variability due to diversity of aglycones and glycosylations (Gly). Although they represent potential source of drug design, their metabolism suffers yet from a misunderstanding due to insufficient investments in analytical methods. Aim: Bibliographic structural data offer a wide field for extensive statistical analysis helping for highlighting mechanistic orders governing metabolic diversity. Methods: This work presents an original simulation method based on simplex rule for highlighting regulatory mechanisms of metabolism from categorical structural data. Simulation was applied on a set of 231 saponins of Caryophyllaceae plant family initially affiliated to four aglycone types: gypsogenin (Gyp), quiaillic acid (QA), gypsogenic acid (GA), 16-OH-gypsogenic acid (16-OH-GA). Molecules were initially characterized by relative glycosylation levels of different carbons. Simplex approach was applied by combining saponins of the four aglycone groups using a complete set of N gradual weightings between structural groups. In silico combinations were applied by randomly sampling representative saponins from the four groups conforming to their weights given by mixture design. Gly profiles of sampled saponins were averaged to calculate a barycentric molecular profile for each mixture. With N mixtures, N barycentric molecules were iteratively calculated by bootstrap leading to smoothed data from which Gly trends between carbons were highlighted. Results: Sequential, competing and cooperative Gly trends were highlighted according to the types of aglycones, attached saccharides and positions of substituted carbons. Conclusion: Such various and conditional Gly trends seemed to be linked to multiple factors including steric effects, regio-selectivity, enzymatic specificity and enzymatic promiscuity.

Synthesis of gypsogenin and gypsogenic acid derivatives with antitumor activity by damaging cell membranes

Forty-five gypsogenin and gypsogenic acid derivatives were synthesized and screened for their cytotoxic activities.

Triterpene saponins from the aerial parts of Dianthus caryophyllus var. remontant Hort.

Triterpene saponins from the aerial parts of carnation (<em>Dianthus caryophyllus</em> var. <em>remontant</em>) Hort. have been studied. Three gypsogenic acid glycosides including 3-O-glucopyranoside, 3,28-O-di-glucopyranoside and 3-O-glucopyranosy1,28-0-[glucopyranosyl(1→6)glucopyranoside] have been identified by means of LSI mass spectrometry and 1H and 13C NMR. Inhibitory activities of isolated compounds against growth of the fungus <em>Trichoderma viride</em> and the growth of the roots of <em>Lepidium sativum</em> and <em>D. caryophyllus</em> seedlings were measured. None of the isolated compounds showed pronounced activity in <em>T. viride</em> test. Seedling root growth was affected severely at the presence of gypsogenic acid 3-O-glucopyranoside. Bidesmosidic form showed marginal stimulatory activity. The obtained data are discussed in relation to the activity of medicagenic acid 3-O-glucopyranoside, the compound differing just with 2-OH substitution from gypsogenic acid glycosides.

New Triterpenoid Saponins from the Roots of Saponaria officinalis

Three new triterpenoid saponins (1–3), along with nine known saponins, were isolated from the roots of Saponaria officinalis L. Two of them: vaccaroside D (4) and dianchinenoside B (5) are known, but not previously reported for S. officinalis, and seven others: saponarioside C (6), D (7), F (8), G (9), I (10), K (11), and L (12) have been previously isolated from this plant. The structures of the new saponins were established as 3- O-β-D-xylopyranosyl-16α-hydroxygypsogenic acid-28- O-[β-D-glucopyranosyl-(1→6)]-β-D-glucopyranoside (1), 3- O-β-D-xylopyranosyl-16α-hydroxygypsogenic acid-28- O-[β-D-glucopyranosyl-(1→3)]-[α-D-galactopyranosyl-(1→6)-α-D-galactopyranosyl-(1→6)-β-D-glucopyranosyl-(1→6)]-β-D-glucopyranoside (2) and 3- O-β-D-xylopyranosyl-gypsogenic acid-28- O-[β-D-glucopyranosyl-(1→3)]-[6- O-(3-hydroxy-3-methylglutaryl)-β-D-glucopyranosyl-(1→6)]-β-D-glucopyranoside (3). Their structures were elucidated by extensive spectroscopic methods, including 1D- (1H, 13C) and 2D-NMR (D QF-COSY, TOCSY, ROESY, HSQC and HMBC) experiments, as well as high-resolution electrospray ionization mass spectrometry (HR-ESI-MS), ESI-MS/MS and acid hydrolysis.