Separation and Bioactive Assay of 25R/S-Spirostanol Saponin Diastereomers from Yucca schidigera Roezl (Mojave) Stems.

In order to find a simple, generic, efficient separation method for 25R/S-spirostanol saponin diastereomers, the liquid chromatographic retention behaviors of C12 carbonylation and C12 unsubstituted 25R/S-spirostanol saponin diastereomers on different stationary phases (C8, C18, C30 columns) and different mobile phases (MeOH-1% CH3COOH and CH3CN-1% CH3COOH) were investigated. A C30 column was firstly found to offer the highest efficiency for the separation of this kind of diastereomers than C8 and C18 columns. Meanwhile, the analysis results indicated that both CH3CN-1% CH3COOH and MeOH-1% CH3COOH eluate systems were selective for C12 unsubstituted 25R/S-spirostanol saponin diastereomers, while MeOH-1% CH3COOH possessed better selectivity for C12 carbonylation ones. Using the abovementioned analysis method, six pairs of 25R/S-spirostanol saponin diastereomers 1a⁻6a and 1b⁻6b from Yucca schidigera Roezl (Mojave) were isolated successfully by using HPLC on C30 column for the first time. Among them, three pairs were new ones, named as (25R)-Yucca spirostanoside E1 (1a), (25S)-Yucca spirostanoside E1 (1b), (25R)-Yucca spirostanoside E2 (2a), (25S)-Yucca spirostanoside E2 (2b), (25R)-Yucca spirostanoside E3 (3a), (25S)-Yucca spirostanoside E3 (3b), respectively. Moreover, 3a, 5a, 6a, 3b⁻6b showed strong inhibitory activities on the growth of SW620 cell lines with the IC50 values of 12.02⁻69.17 µM.

Steroidal Saponins from the Rhizomes of Anemarrhena asphodeloides.

Four new steroid saponins 1-4 were isolated from the rhizomes of Anemarrhena asphodeloides (Asparagaceae), as well as four known saponins: anemarsaponin B (5) timosaponin D (6), timosaponin E1 (7) anemarsaponin B II (8). Their structures were established through UV and NMR as well as MS data. All the compounds were evaluated for cytotoxicity against HepG2 and SGC7901 human cancer lines. Compounds 3 and 7 displayed medium antiproliferative activities on HepG2 and SGC7901 cells, with IC50 values of 43.90 and 57.90 µM, respectively.

Analytical and semipreparative separation of 25 (R/S)-spirostanol saponin diastereomers using supercritical fluid chromatography.

Spirostanol saponins are a class of steroidal saponins with many pharmacological activities. The structural complexity of the spirostanol saponins presents a daunting challenge in separating their 25 R/S diastereomers. Using two CHIRALPAK IC columns coupled in series, six 25 (R/S)-spirostanol saponin diastereomers from the Trigonella foenum-graecum L. seed were successfully separated using supercritical fluid chromatography (SFC) for the first time. In addition, three 25 (R/S)-spirostanol saponin diastereomers were isolated into their respective individual isomers. The structures of the isolated isomers were unambiguously confirmed by NMR analysis. The SFC method development strategy and its associated underlying principles presented in this paper are generally applicable. SFC is a viable addition to the natural product research toolbox, especially for stereoselective analysis and purification.

Terrestrosin D, a spirostanol saponin from Tribulus terrestris L. with potential hepatorenal toxicity.

ETHNOPHARMACOLOGICAL RELEVANCE: Fructus Tribuli (FT) has been commonly used as a traditional medicine for thousands of years. With the diverse uses of FT, more attention has been paid to its hepatorenal toxicity. However, the compounds causing the hepatorenal toxicity of FT remain undetermined. Terrestrosin D (TED), a major spirostanol saponin isolated from FT, may exert hepatorenal toxicity. AIM OF THE STUDY: This study aimed to evaluate the potential hepatorenal toxicity of TED, and preliminarily explore the possible mechanism of TED-induced hepatorenal toxicity. MATERIALS AND METHODS: Cytotoxicity assays, a repeated-dose 28-day in-vivo study, a toxicokinetic study, and a tissue distribution study were used to evaluate the potential hepatorenal toxicity of TED. Furthermore, network pharmacology was applied to preliminarily explore the possible mechanism of TED-induced hepatorenal toxicity. RESULTS: Both the in vitro and in vivo studies showed that the spirostanol saponin TED had potential hepatorenal toxicity. Nonetheless, hepatorenal toxicity induced by oral treatment with TED at a dosage range of 5 - 15 mg/kg daily for 28 consecutive days to Sprague-Dawley (SD) rats was reversible after 14 days of TED withdrawal. The toxicokinetic study demonstrated that the systematic exposure of SD rats to TED had an accumulation phenomenon and a dose-dependent trend after a 28-day repeated-dose oral administration. The tissue distribution study revealed that TED had a targeted distribution in the liver and kidneys accompanied by a phenomenon of accumulation in SD rats. Network pharmacology combined with molecular docking methods was used to screen for the key targets (HSP90AA1, CNR1, and DRD2) and the key pathways of TED-induced hepatorenal toxicity. CONCLUSIONS: The spirostanol saponin TED, a major spirostanol saponin isolated from FT, had potential hepatorenal toxicity.

Apoptosis and pro-death autophagy induced by a spirostanol saponin isolated from Rohdea chinensis (Baker) N. Tanaka (synonym Tupistra chinensis Baker) on HL-60 cells.

BACKGROUND: Our previous study has revealed that the spirostanol saponins isolated from the rhizomes of Rohdea chinensis (Baker) N. Tanaka (synonym Tupistra chinensis Baker) (Convallariaceae) (a reputed folk medicine) exhibited potent antiproliferative activity. However, the underlying mechanism of purified saponins remains unclear. More studies are necessary to assess the apoptosis and autophagy activities of the saponins from R. chinensis and clarify their antiproliferative mechanisms. PURPOSE: The present study certificated the potential antiproliferative activity and mechanism of 5ß-spirost-25(27)-en-1ß,3ß-diol-1-O-α-L-rhamnopyranosyl-(1→2)- ß-D-xylopyranosyl-3-O-α-L-rhamnopyranoside (SPD), a spirostanol saponin from R. chinensis, against human acute promyelocytic leukemia cells (HL-60). METHODS: The antiproliferative activity of SPD in vitro was evaluated by MTT assay compared with cis-dichlorodiammineplatinum (II). The autophagic activity was assessed using MDC staining and western blot, cell apoptosis inspection was detected by Annexin V-FITC/PI double staining and the mitochondrial membrane potential was detected by JC-1 fluorescence dye combined with flow cytometry. The potential mechanisms for protein levels of apoptosis and autophagy were evaluated by western blot. RESULTS: Treatment of HL-60 cells with SPD resulted in growth inhibition (IC50 value of 2.0 ± 0.2 µM, after 48 h treatment) and induction of apoptosis and autophagy. Results from Annexin V-FITC/PI double-staining assay and mitochondrial membrane potential detection showed that apoptosis was happened after SPD treatment. The regulation of caspase-3, Bax, Bcl-2, PARP following SPD treatment contributed to the induction of mitochondria-dependent apoptosis. Meanwhile, SPD induced autophagy related with Akt/mTOR/p70S6K signaling and activated of AMPK signaling pathway. Furthermore, blocking autophagy with bafilomycin A1 reduced the cytotoxicity of SPD in HL-60 cells. CONCLUSION: The antiproliferative, apoptosis and pro-death autophagy activities of SPD suggested that spirostanol saponins from R. chinensis would be a potential cytotoxic candidate against acute promyelocytic leukemia.

New steroidal saponins from the rhizomes of Paris delavayi and their cytotoxicity.

Four new furostanol saponins, named padelaosides C-F (1-4), together with four known spirostanol saponins 5-8 were isolated from the rhizomes of Paris delavayi Franchet. Their structures were elucidated on the basis of extensive spectroscopic analysis and chemical evidences. The discovery of the new compounds 1-4 extended the diversity and complexity of this furostanol saponin family. The cytotoxicity of all the saponins was evaluated for their cytotoxicity against human glioblastoma U87MG and human hepatocellular carcinoma Hep-G2 cell lines. The known spirostanol saponins 7 and 8 exhibited notable cytotoxicity against the two tumor cell lines with IC50 values of 1.13 and 3.42µM, respectively, while the new furostanol saponins 3 and 4 showed moderate cytotoxicity with IC50 values of 15.28 to 16.98µM.