Microwave-Assisted Desulfation of the Hemolytic Saponins Extracted from Holothuria scabra Viscera

Saponins are plant and marine animal specific metabolites that are commonly considered as molecular vectors for chemical defenses against unicellular and pluricellular organisms. Their toxicity is attributed to their membranolytic properties. Modifying the molecular structures of saponins by quantitative and selective chemical reactions is increasingly considered to tune the biological properties of these molecules (i) to prepare congeners with specific activities for biomedical applications and (ii) to afford experimental data related to their structure–activity relationship. In the present study, we focused on the sulfated saponins contained in the viscera of Holothuria scabra, a sea cucumber present in the Indian Ocean and abundantly consumed on the Asian food market. Using mass spectrometry, we first qualitatively and quantitatively assessed the saponin content within the viscera of H. scabra. We detected 26 sulfated saponins presenting 5 different elemental compositions. Microwave activation under alkaline conditions in aqueous solutions was developed and optimized to quantitatively and specifically induce the desulfation of the natural saponins, by a specific loss of H₂SO₄. By comparing the hemolytic activities of the natural and desulfated extracts, we clearly identified the sulfate function as highly responsible for the saponin toxicity.     

Studies on the Chemical Constituents of Oxytropis Glabra DC (I)

Two new triterpenoid sapon.ins 1 and 2 were isolated from the crude saponin extract of Oxytropis glabra DC by Si gel chromato-grapny . Saponins 1 and 2 were determined to be 3-0-1 β-D-glucopyranosy 1 (1-2)- β -D-glucuronopyranosyl azukisapogenol methyl ester and 3-O-[β-D-glucopyranosyl(1 - 2 ) - β -D-glucuronopyranosyl] azukisapogenol amide, respectively by spectral analysis and chemical methods.     

Identification and structural characterisation of triterpene saponins from the root of Ardisia mamillata Hance by HPLC-ESI-QTOF-MS/MS

Triterpene saponins in medicinal plants attract scientific attentions for their structural diversity and significant bioactivities. In this work, a high-performance liquid chromatography coupled to electrospray ionisation and quadrupole time-of-flight mass spectrometry (HPLC-ESI-QTOF-MS/MS) method is used to rapidly separate and identify triterpene saponins from the extract of Ardisia mamillata Hance (AMH). In the full scan mass spectrum, the accurate determination of molecular formula is obtained by the predominant ion [M + HCOO]^? in negative ion mode. As a result, 30 triterpene saponins are identified or tentatively identified in the plant extract. Of these, 17 triterpene saponins are new compounds. In conclusion, the HPLC-ESI-QTOF-MS/MS is an efficient technique to separate and identify triterpene saponins in complex matrices of medicinal plant.     

Triterpenoid saponins from the buds of Lonicera similis

Four new lupane triterpenoid saponins, along with one known lupane and eight hederagenin saponins, were isolated from the EtOH extract of the buds of Lonicera similis Hemsl. The structures of the new compounds were established as 3-O-β-D-glucopyranosyl-(1→2)-β-D-glucopyranosyl 23-hydroxybetulinic acid 28-O-β-D-glucopyranosyl ester (lonisimilioside A, 1), 3-O-β-D-glucopyranosyl-(1→2)-β-D-glucopyranosyl 23-hydroxybetulinic acid 28-O-β-D-glucopyranosyl-(1→6)-β-D-glucopyranosyl ester (lonisimilioside B, 2), 3-O-β-D-glucopyranosyl-(1→2)-β-D-glucopyranosyl betulinic acid 28-O-β-D-glucopyranosyl-(1→6)-β-D-glucopyranosyl ester (lonisimilioside C, 3) and 3-O-β-D-glucopyranosyl-(1→2)-β-D-glucopyranosyl-(1→6)-β-D-glucopyranosyl betulinic acid 28-O-β-D-glucopyranosyl ester (lonisimilioside D, 4), respectively. The cytotoxic activities of the isolates against human cancer cell lines HepG2, MCF-7 and A-549 were evaluated. Only the monodesmosidic saponin with a free carboxyl group at C-28 (12) exhibited significant cytotoxicities against HepG2, MCF-7 and A-549 cell lines with the IC₅₀ values of 8.98 ± 0.19, 12.48 ± 0.45 and 11.62 ± 0.54 μM, respectively. Furthermore, Hoechst fluorescence 33342 staining was used to demonstrate that 12 could induce HepG2 and A-549 cells apoptosis significantly.     

Triterpenoid Saponins from Luculia pincia Hook

Two new triterpenoid saponins, cincholic acid-3-O-β-D-xylopyranoside, 28-O-β-D-glucopyranosyl ester (I), quinovic acid28-O-β-D-glucopyranosyl ester (4), and a new phenolic glucoside, 4-[4‘‘-O-( 2‘‘, 3‘‘, 5‘‘, 6‘‘-tetrahydroxy phenyl)-β-D-glucoside]-l-butene (2), along with five known triterpenoid saponins and one phenolic glucoside were isolated from the n-butanol fraction of the stems of Luculia pinciana Hook. Their structures were established by means of spectroscopic methods.     

Four new dimeric triterpene glucosides from Sanguisorba officinalis

In search for bioactive compounds from the roots of Sanguisorba officinalis L. (Rosaceae), four new dimeric triterpene glucosides, namely sanguidioside A, B, C, and D (1-4) were isolated. Alkaline hydrolysis of 1-2 afforded the corresponding dimeric aglycones (1a and 2a). Meanwhile, a ready intra-molecular transesterification was observed, providing dimeric triterpenes 1b and 2b. Alkaline hydrolysis of the crude dimmeric saponin also provided a new dimeric triterpene, sanguidiogenin (9). The structures of all these compounds are elucidated via spectroscopic and chemical methods, and are further confirmed by the X-ray diffraction analysis of the dimeric aglycone 2a. Compound 3 represents the first dimeric saponin of an oleanolic acid and an ursonic acid derivative, while compound 4 is the first dimeric saponin of oleanolic acid derivatives.     

Simultaneous determination of 12 active components in the roots of Pulsatilla chinensis using tissue‐smashing extraction with liquid chromatography and mass spectrometry

Ultra high performance liquid chromatography coupled with mass spectrometry and combining a tissue‐smashing extraction technique was developed for the simultaneous quantitative analysis of 12 compounds in the roots of Pulsatilla chinensis . Among them, compound 6 was characterized and accurately quantified in this herb for the first time. The parameters of extraction condition were simultaneously optimized with a Box–Behnken design and Derringer's function. The optimized conditions were as follows: sample quantity of 0.5 g, ethanol concentration of 70%, and extraction time of 200 s. Multiple‐reaction monitoring scanning was employed for the quantification between positive and negative mode in a single run of 6 min. Full validation of the method was carried out, and the results indicated that the method was rapid, specific, and reliable. The developed method was successfully applied to quantify the 12 compounds in 33 batches of P. chinensis from different provinces. Moreover, the principal component analysis was performed to compare the P. chinensis collected from different provinces of China based on quantitative data and the results indicated that the content of compounds could be used to differentiate the origins of P. chinensis . These results demonstrated that this method is feasible and reliable for the quality control of P. chinensis .     

Two new triterpenoid saponins from Polygala crotalarioides

<正>Two new oleanane-type saponins,crotalarioside A(1) and crotalarioside B(2),were isolated from the roots of Polygala crotalarioides.Their structures were elucidated on the basis of spectroscopic and chemical evidence.     

A New Triterpenoid Oligoglycoside Escin IVe from the Seeds ofAesculus Chinensis

Inthecourseofourstudiesonnewbiologicallyactivesaponinsofnaturalmedicines,wehaveisolatedescinsla.fo.IVa.IVb,IVc,andIVdtyolnseedsof.4e'v"11/llSchinensisBee.(Hippocastanaceae),andsinglecrystalX-raydiffractionanalysiswasundertakenonescinla'.whichconfirmstheabsoluteconfigurationandsugarsequence.ThepresentpaperdescribesthestructuredeterminationofanewtriterpenoidsaponinnamedescinIVefromthesameplant.EscinIVe,whitepowder.Positive-modeTOF-MScm/zI111[M Na] ,coupledwitllNMRdata.correspondstoane…     

Spirostanol Saponins from the Fibrous Roots of Ophiopogon japonicus (Thunb.) Ker‐Gawl

Three new steroidal saponins, (25R)‐ruscogenin‐3‐yl α‐L ‐rhamnopyranosyl‐(1→2)‐[β‐D ‐xylopyranosyl‐(1→4)]‐β‐D ‐glucopyranoside ( 1 ), diosgenin‐3‐yl 2‐O‐acetyl‐α‐L ‐rhamnopyranosyl‐(1→2)‐[β‐D ‐xylopyranosyl‐(1→4)]‐β‐D ‐glucopyranoside ( 2 ), and pennogenin‐3‐yl 2‐O‐acetyl‐α‐L ‐rhamnopyranosyl‐(1→2)‐[β‐D ‐xylopyranosyl‐(1→4)]‐β‐D ‐glucopyranoside ( 3 ) were isolated from the fibrous roots of Ophiopogon japonicus (Thunb .) Ker‐Gawl . Their structures were determined by spectroscopic methods including IR, HR‐ESI‐MS, and 1D‐ and 2D‐NMR. All of these three steroidal saponins exhibited weak cytotoxicities against Hela and Hep2 cell lines.