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Four new spirostanol saponins, named pavitnosides A–D (1–4), with six known steroidal saponins 5–10 were isolated from the rhizomes of Paris vietnamensis. Their chemical structures were determined based on extensive spectroscopic studies and chemical methods. The aglycones of pavitnoside B and pavitnoside C were not reported in previous work. The cytotoxicity of all saponins was evaluated against human glioblastoma U87MG and U251 cell lines. The new spirostanol saponin 1 displayed weak anti-proliferative activity against U87MG cell line and the known saponins 8 and 9 exhibited significant cytotoxicity against the two tumor cell lines, with IC50 values of 2.16 to 3.14 µM, but did not affect the growth of primary cultures of human astrocytes. [ABSTRACT FROM AUTHOR]

Four new minor spirostanol glycosides ( 1–4 ) were isolated from the dried roots and rhizomes of Helleborus thibetanus. Structures of the compounds were established by means of a combination of 1D and 2D NMR experiments, together with HRESIMS and IR measurements as well as the results of acid hydrolysis. The spirostanol glycosides with both a double bond at C-25 and glycosidation at 1-OH have seldom been reported. [ABSTRACT FROM AUTHOR]

Abstract: The chromatographic behaviour of steroidal saponins found in Anemarrhena asphodeloides, Asparagus officinalis, Convallaria majalis, Digitalis purpurea and Ruscus aculeatus was studied by HPLC–MS using a C-18 reversed-phase column and aqueous acetonitrile or aqueous methanol mobile phase gradients, with or without the addition of 1% acetic acid. The behaviour was compared to that of triterpene saponins found in Aesculus hippocastanum, Centella asiatica, Panax notoginseng and Potentilla tormentilla. Inclusion of methanol in the mobile phase under acidic conditions was found to cause furostanol saponins hydroxylated at C-22 to chromatograph as broad peaks, whereas the peak shapes of the spirostanol saponins and triterpene saponins studied remained acceptable. In aqueous methanol mobile phases without the addition of acid, furostanol saponins chromatographed with good peak shape, but each C-22 hydroxylated furostanol saponin was accompanied by a second chromatographic peak identified as its C-22 methyl ether. Methanolic extracts analysed in non-acidified aqueous acetonitrile mobile phases also resolved pairs of C-22 hydroxy and C-22 methoxy furostanol saponins. The C-22 methyl ether of deglucoruscoside was found to convert to deglucoruscoside during chromatography in acidified aqueous acetonitrile, or by dissolving in water. Poor chromatography of furostanol saponins in acidified aqueous methanol is due to the interconversion of the C-22 hydroxy and C-22 methoxy forms. It is recommended that initial analysis of saponins by HPLC–MS using a C-18 stationary phase is performed using acidified aqueous acetonitrile mobile phase gradients. The existence of naturally-occurring furostanol saponins methoxylated at C-22 can be investigated with aqueous acetonitrile mobile phases and avoiding methanol in the extraction solvent. [Copyright &y& Elsevier]

Abstract: Four steroidal saponins were isolated from the leaves of Furcraea selloa var. marginata. These included one furostanol saponin, furcreafurostatin (1), and three known spirostanol saponins, furcreastatin (3), yuccaloeside C (4) and cantalasaponin-1 (5). The 22-O-methyl ether (2) of furcreafurostatin (1) was also characterized. The structures were determined by using a combination of spectroscopic techniques. [Copyright &y& Elsevier]

The phytochemical investigation of the aerial parts of Tribulus terrestris of Bulgarian origin has resulted in the isolation of the novel furostanol saponin 1, named tribol, together with the known spirostanol saponins 2 and 3 and sitosterol glucoside. The structure of tribol was determined as (25R)-furost-5(6)-ene-3β,16,26-triol-3-O-α-rhamnopyranosyl-(1→2)-[α-rhamnopyranosyl-(1→4)]-β-glucopyranoside (1) by spectral analysis, including extensive 1D and 2D-NMR experiments. [Copyright &y& Elsevier]