New saponins from the seeds of Agrostemma githago var. githago

A new acetylated triterpene saponin from Agrostemma githago L. modulates gene delivery efficiently and shows a high cellular tolerance

Transfection is the process to deliver nucleic acid into eukaryotic cells. Different transfection techniques already exist. However, they can be expensive and toxic toward subjected cells. Previous research shed light on natural occurring molecules called triterpene saponins that have great potential for the non-viral gene delivery. Using a combination of different chromatographic techniques and in vitro transfection bioassays, a new triterpenoid saponin (agrostemmoside E) from the plant Agrostemma githago L. was isolated. Agrostemmoside E was characterized by mass spectrometry, intense NMR spectroscopy and was identified as 3-{O-ß-D-Galactopyranosyl-(1→2)]-[ß-D-xylopyranosyl-(1→3)]-ß-D-glucuronopyranosyl} quillaic acid 28-O-{[ß-D-4,6-di-(O-acetyl)-glucopyranosyl-(1→3)]-[ß-D-xylopyranosyl-(1→4)]-α-L-rhamnopyranosyl-(1→2)}-[3,4-di-(O-acetyl)-ß-D-quinovopyranosyl-(1→4)]-ß-D-fucopyranoside ester. Agrostemmoside E has a great potential for delivery of gene loaded nanoplexes and increased the transfection efficiency by 70% compared to 2% without agrostemmoside E. By comparative toxicity studies, we show that agrostemmoside E can be applied at high concentrations without toxicity, justifying its use as a new tool for gene transfections.

An unusual type I ribosome-inactivating protein from Agrostemma githago L

Agrostemma githago L. (corn cockle) is an herbaceous plant mainly growing in Europe. The seeds of the corn cockle are toxic and poisonings were widespread in the past by consuming contaminated flour. The toxic principle of Agrostemma seeds was attributed to triterpenoid secondary metabolites. Indeed, this is in part true. However Agrostemma githago L. is also a producer of ribosome-inactivating proteins (RIPs). RIPs are N-glycosylases that inactivate the ribosomal RNA, a process leading to an irreversible inhibition of protein synthesis and subsequent cell death. A widely known RIP is ricin from Ricinus communis L., which was used as a bioweapon in the past. In this study we isolated agrostin, a 27 kDa RIP from the seeds of Agrostemma githago L., and determined its full sequence. The toxicity of native agrostin was investigated by impedance-based live cell imaging. By RNAseq we identified 7 additional RIPs (agrostins) in the transcriptome of the corn cockle. Agrostin was recombinantly expressed in E. coli and characterized by MALDI-TOF–MS and adenine releasing assay. This study provides for the first time a comprehensive analysis of ribosome-inactivating proteins in the corn cockle and complements the current knowledge about the toxic principles of the plant.

Triterpenoid saponins from the roots of Gypsophila trichotoma Wender

Eleven triterpenoid saponins were isolated from the roots of Gypsophila trichotoma Wender. (G. trichotoma Wender. var. trichotoma) (Caryophyllaceae), together with one known compound. The structures were established on the basis of extensive NMR analysis ((1)H, (13)C NMR, COSY, TOCSY, ROESY, HSQC, and HMBC), completed by analysis of HR-ESI-MS and ESI-MS(n). The saponins have the commonly found gypsogenin as the aglycone substituted at C-3 with trisaccharide and at C-28 with oligosaccharide through a fucose residue, as saponins isolated from Gypsophila perfoliata L. originated from China. The oligosaccharide attached to C-28 is substituted with acetyl and (or) sulfate groups. Тhe cytotoxicity of the saponin extract from G. trichotoma was evaluated against a rat alveolar macrophage-like cell line NR8383 and human leukemia cell lines U937 and BV-173. The synergistic effect of the aminoacyl saponins, previously isolated from G. trichotoma, was tested for its ability to enhance the cytotoxicity of the targeted toxin in HER14 cells.

Triterpene glycosides from Agrostemma gracilis

Four triterpene saponins, agrostemmosides A-D were isolated from the methanol extract of Agrostemma gracilis. The structures of the compounds were determined as 3-O-beta-D-xylopyranosyloleanolic acid 28-O-beta-D-glucopyranosyl-(1-->2)-[beta-D-xylopyranosyl-(1-->6)]-beta-D-glucopyranosyl-(1-->6)-beta-D-glucopyranosyl ester, 3-O-alpha-L-rhamnopyranosyl-(1-->2)-beta-D-xylopyranosyloleanolic acid 28-O-beta-D-glucopyranosyl-(1-->2)-[beta-D-xylopyranosyl-(1-->6)]-beta-D-glucopyranosyl-(1-->6)-beta-D-glucopyranosyl ester, 3-O-beta-D-xylopyranosylechinocystic acid 28-O-beta-D-glucopyranosyl-(1-->2)-beta-D-glucopyranosyl-(1-->6)-beta-D-glucopyranosyl ester, 3-O-beta-D-xylopyranosylechinocystic acid 28-O-beta-D-glucopyranosyl-(1-->2)-[beta-D-xylopyranosyl-(1-->6)]-beta-D-glucopyranosyl-(1-->6)-beta-D-glucopyranosyl ester by a combination of one- and two-dimensional NMR techniques, and mass spectrometry. To the best of our knowledge this is the first phytochemical report on A. gracilis, and echinocystic acid saponins were encountered for the first time in Caryophyllaceae family.

Antihypercholesterolaemic and antioxidant activity assessment of some plants used as remedy in Turkish folk medicine

Ethanolic and aqueous extracts from five plant species used in Turkish traditional medicine were evaluated for in vivo hypercholesterolaemic and antioxidant activities: Agrostemma githago L., Potentilla reptans L., Thymbra spicata var. spicata L., Urtica dioica L. and Viscum album var. album L. We assayed the effects of the administration of plant extracts on serum total cholesterol, triglyceride, HDL-C, LDL-C, glucose, AST and ALT concentrations in mice fed with cholesterol-rich diet. In addition, plasma TAA, MDA and NO(x) levels in the same animals were assayed. All the aqueous plant extracts did not affect the serum cholesterol concentration. However, the ethanolic extracts of Agrostemma githago, Thymbra spicata and Viscum album decreased the serum cholesterol concentration in the mice fed with high-cholesterol diet without inducing any gastric damage. The ethanolic extracts of Thymbra spicata, Viscum album, Potentilla reptans and Urtica dioica and the aqueous extract of Agrostemma githago increased the serum HDL concentration, whereas the ethanolic extracts of Agrostemma githago, Thymbra spicata, Viscum album and Urtica dioica decreased the serum LDL-C concentration. Thymbra spicata and Viscum album were observed to decrease the serum triglyceride concentration. Among the plant extracts studied, the ethanolic extracts of Thymbra spicata significantly decreased the MDA level in mice. The ethanolic extract of Potentilla reptans increased in NO(x). None of these plants showed statistically prominent activity on plasma TAA. Results of the present study indicated that the ethanolic extracts of Agrostemma githago, Thymbra spicata and Viscum album showed potent hypocholesterolaemic activity in the mice fed with a diet containing high-cholesterol.

Junceosides A-C, new triterpene saponins from Arenaria juncea

Three novel triterpenoid saponins, junceosides A (1), B (2), and C (3), together with two known saponins have been isolated from the roots of Arenaria juncea. Their structures were elucidated using a combination of homo- and heteronuclear 2D NMR techniques (COSY, TOCSY, NOESY, HSQC, and HMBC) and by FABMS. The new compounds were characterized as 3-O-alpha-L-arabinopyranosyl-(1-->2)-[beta-D-galactopyranosyl-(1-->3)]-beta-D-glucuronopyranosylgypsogenin-28-O-beta-D-glucopyranosyl(1-->3)-[beta-D-xylopyranosyl-(1-->4)]-alpha-L-rhamnopyranosyl-(1-->2)-beta-D-fucopyranoside (1), 3-O-alpha-L-arabinopyranosyl-(1-->2)-[beta-D-galactopyranosyl-(1-->3)]-beta-D-glucuronopyranosylgypsogenin-28-O-beta-D-xylopyranosyl-(1-->3)-beta-D-xylopyranosyl-(1-->4)-alpha-L-rhamnopyranosyl-(1-->2)-beta-D-fucopyranoside (2), and 3-O-beta-D-xylopyranosyl-(1-->3)-[beta-D-galactopyranosyl-(1-->2)]-beta-D-glucuronopyranosylgypsogenin-28-O-beta-D-xylopyranosyl-(1-->4)-alpha-L-rhamnopyranosyl-(1-->2)-beta-D-fucopyranoside (3).

Three new acylated triterpene saponins from Acanthophyllum squarrosum

Three new triterpenoid saponins, 1-3, were isolated from the roots of Acanthophyllum squarrosum. Their structures were established mainly by 2D NMR techniques as 3-O-beta-D-galactopyranosyl-(1-->2)-[beta-D-xylopyranosyl-(1-->3)]-beta-D-glucuronopyranosyl-gypsogenin-28-O-beta-D-xylopyranosyl-(1-->3)-beta-D-xylopyranosyl-(1-->4)-beta-D-xylopyranosyl-(1-->4)-3-O-acetyl-alpha-L-rhamnopyranosyl-(1-->2)-3,4-di-O-acetyl-beta-D-fucopyranoside (1), 3-O-beta-D-galactopyranosyl-(1-->2)-[beta-D-xylopyranosyl-(1-->3)]-beta-D-glucuronopyranosyl-gypsogenin-28-O-beta-D-xylopyranosyl-(1-->4)-alpha-L-rhamnopyranosyl-(1-->2)-[5-O-acetyl-alpha-L-arabinofuranosyl-(1-->3)]-4-O-acetyl-beta-D-fucopyranoside (2), and 3-O-beta-D-glucopyranosyl-quillaic acid-28-O-alpha-L-rhamnopyranosyl-(1-->2)-alpha-L-arabinopyranosyl-(1-->2)-[beta-D-glucopyranosyl-(1-->6)]-beta-D-glucopyranoside (3).

Two new biologically active triterpene saponins from Acanthophyllum squarrosum

Two novel triterpenoid saponins (1 and 2) have been isolated from the roots of Acanthophyllum squarrosum. The structures were established mainly by a combination of 2D NMR techniques as 3-O-beta-D-galactopyranosyl-(1-->2)-[beta-D-xylopyranosyl-(1-->3)]-be ta-D-glucuronopyranosylgypsogenin-28-O-beta-D-xylopyranosyl-(1-->3 )-b eta-D-xylopyranosyl-(1-->4)-alpha-L-rhamnopyranosyl-(1-->4)-[alpha-L- rhamnopyranosyl-(1-->3)]-beta-D-fucopyranoside (1) and 3-O-beta-D-glucopyranosylgypsogenin-28-O-alpha-L-rhamnopyranosyl-( 1-- >2)-alpha-L-arabinopyranosyl-(1-->2)-[beta-D-glucopyranosyl-(1-->6 )]- beta-D-glucopyranoside (2). Compound 1 showed a moderate concentration-dependent immunomodulatory effect in an in vitro lymphocyte proliferation assay.

Silenosides A-C, triterpenoid saponins from Silene vulgaris

Three new triterpenoid saponins named silenosides A-C (1-3) were obtained from the roots of Silene vulgaris. Their structures were elucidated by spectral and chemical methods as beta-D-galactopyranosyl(1-->2)-beta-D-glucuronopyranosyl-3beta- hydrox y-23-oxoolean-12-en-28-oic acid 28-O-beta-D-xylopyranosyl(1-->3)-beta-D-xylopyranosyl(1-->4)-alpha-L- rhamnopyranosyl(1-->2)-beta-D-fucopyranoside; 3-O-beta-D-galactopyranosyl(1-->2)-beta-D-glucuronopyranosyl-3beta , 16alpha-dihydroxy-23-oxoolean-12-en-28-oic acid 28-O-beta-D-xylopyranosyl(1-->4)-[beta-D-glucopyranosyl(1-->2)]-alpha -L-rhamnopyranosyl(1-->2)-beta-D-fucopyranoside; and 3-O-alpha-L-arabinopyranosyl(1-->3)-[beta-D-galactopyranosyl(1-->2 )]- beta-D-glucuronopyranosyl-3beta, 16alpha-dihydroxy-23-oxoolean-12-en-28-oic acid 28-O-beta-D-xylopyranosyl(1-->4)-[beta-D-glucopyranosyl(1-->2)]-alpha -L-rhamnopyranosyl(1-->2)-beta-D-fucopyranoside, respectively.