Spirostanol and sesquiterpenoid glycosides from the rhizomes of Trillium tschonoskii

Three new spirostanol glycosides, trilliumosides K-M (1-3), one new sesquiterpenoid glycoside, tritschsesuquiside A (4), along with three known analogues (5-7) were obtained from the rhizomes of Trillium tschonoskii. The structures of new glycosides were elucidated by spectroscopic analyses (HRMS and NMR) and chemical methods. Glycosides 5-7 displayed cytotoxicities against five human cancer cell lines with IC₅₀ values ranging from 10.5 ± 1.0 to 1.0 ± 0.2 μM, with 7 being the most cytotoxic compound with IC₅₀ values of 1.0 ± 0.2, 2.2 ± 1.2, and 3.4 ± 0.4 μM against Huh7, CCRF-CEM, and HeLa cell lines, respectively. The flow cytometric results revealed that both 5 and 6 could induce apoptosis of HCT116 and Huh7 cells.

Spirostanol glycosides with hemostatic and antimicrobial activities from Trillium kamtschaticum

Ten spirostanol glycosides, trillikamtosides A-J, together with eleven known analogues, were isolated from the hemostatic fraction of the 75% aqueous EtOH extract of the whole herbs of Trillium kamtschaticum. Their structures were established by extensive spectroscopic data analysis and chemical methods. The aglycones of three of these compounds had unique 3β,17α-dihydroxy-spirostanes featuring a double bond between C-4 and C-5, while two others represent a rare class of spirostanol glycosides which possess a 5(6 → 7) abeo-steroidal aglycone. All the compounds were evaluated for their hemostatic and antimicrobial activities. Three of the spirostanol glycosides exhibited induced-platelet aggregation at a concentration of 300 μg/mL with maximal induced-platelet aggregation rates of 72%, 71%, and 62% in rabbits, respectively, and their EC₅₀ values were 492.7, 203.3, and 109.8 μM. Five of the spirostanol glycosides showed an anti-Candida albicans effect with MIC values of 21.1, 10.6, 8.8, 21.6, and 11.0 μM, respectively.

Saponins of Agave: Chemistry and bioactivity

The genus Agave comprises more than 400 species with geographical presence in the tropical and sub-tropical regions of the world. These plants have a rich history of folkloric use and are known for a wide spectrum of applications. Secondary metabolites of diverse chemical classes have been reported from Agave species. Owing to their pharmacological significance, the steroidal saponins of Agave have caught the attention of phytochemists, biologists and drug discovery scientists. The present review describes 141 steroidal saponins and sapogenins and covers the literature published from 1970 to 2015. It is a comprehensive and coherent presentation of the structures, methods of chemical profiling, structure elucidation and biological activities of the saponins and sapogenins reported from Agave. The article provides a perspective of the research on steroidal compounds of Agave.

Spirostanol glucosides from the leaves of Cestrum laevigatum L

Two new steroidal saponins, (25R)-spirost-5-ene-3β,26β-diol 3-O-α-L-rhamnopyranosyl-(1 → 4)-α-L-rhamnopyranosyl-(1 → 4)-[(1 → 2)-α-L-rhamnopyranosyl]-β-D-glucopyranoside (1) and (25R)-spirost-6-ene-3β,5β-diol 3-O-α-L-rhamnopyranosyl-(1 → 4)-α-L-rhamnopyranosyl-(1 → 4)-[(1 → 2)-α-L-rhamnopyranosyl]-β-D-glucopyranoside (2), along with the known diosgenin 3-O-α-L-rhamnopyranosyl-(1 → 4)-α-L-rhamnopyranosyl-(1 → 4)-β-D-glucopyranoside (3), chonglouoside SL-5 (4) and Paris saponin Pb (5) were isolated from the leaves of Cestrum laevigatum. The structures of the compounds were determined using spectroscopic analyses including HRESI-MS, 1D and 2D NMR data, followed by comparison with data from the literature. Among them, two are particularly unique, compound 1 is the first (6)Δ-spirostanol saponin and compound 2 has an unusual C-26 hydroxyl in the (5)Δ-spirostanol skeleton. Antifungal testing showed a potent activity to formosanin C against Candida albicans and Candida parapsilosis. Evaluation of the cytotoxic activity indicated that compound 1 has a moderate activity against HL-60 and SF-295 cell lines, while compound 2 were active only against HL-60.

Steroidal glycosides from the underground parts of Dracaena thalioides and their cytotoxic activity

Six spirostanol glycosides (1-6) and 12 known compounds (7-18) were isolated from the underground parts of Dracaena thalioides (Agavaceae). Their structures were determined by spectroscopic analysis, including 2D NMR spectroscopic data, and chemical transformations. The isolated compounds were evaluated for cytotoxic activity against HL-60 human leukemia cells. Compounds 1, 3-6, and 8-18 showed cytotoxicity against HL-60 cells, of which 10, a bisdesmosidic spirostanol derivative, showed potent cytotoxicity against HL-60 cells with an IC50 value of 0.38μM and induced apoptosis in HL-60 cells.

Steroidal glycosides from the underground parts of Yucca glauca and their cytotoxic activities

Six steroidal glycosides and 14 known compounds were isolated from the underground parts of Yucca glauca (Agavaceae). Their structures were determined from extensive spectroscopic analysis, including analysis of two-dimensional NMR data, and from chemical transformations. The compounds were also evaluated for cytotoxic activities against HL-60 human leukemia cells and A549 human lung adenocarcinoma cells. Four spirostanol glycosides and three furostanol glycosides exhibited cytotoxic activities against both HL-60 and A549 cells. Two of the compounds induced apoptosis in HL-60 cells.