Search Results (7)

‘Globemaster’ is an ornamental hybrid cultivar whose parent plants are Allium cristophii and A. macleanii. The chemical constituents of ‘Globemaster’ bulbs have not yet been examined; thus, a systematic phytochemical investigation was undertaken herein. A series of chromatographic separations of the MeOH extract of ‘Globemaster’ bulbs afforded 27 steroidal glycosides (1–27), which are classified into 23 spirostanol glycosides (1–8 and 11–25), two furostanol glycosides (9 and 26), a pregnane glycoside (10), and a cholestane glycoside (27). The structures of the hitherto undescribed compounds (1–10) were determined from the two-dimensional NMR spectroscopic data and hydrolysis. The cytotoxicity of the isolated compounds (1–27) toward HL-60 human promyelocytic leukemia cells, A549 human adenocarcinoma lung cancer cells, and SBC-3 human small-cell lung cancer cells was evaluated. Compounds 8, 22, 23, 24, and 26 exhibited cytotoxicity toward all cell lines in a dose-dependent manner, with IC₅₀ values in the 1.3–49 µM range. Full article

Saponins, a diverse group of natural compounds, offer an interesting pool of derivatives with biomedical application. In this study, three structurally related spirostanol saponins were isolated and identified from the leek flowers of Allium porrum L. (garden leek). Two of them were identical with the already known leek plant constituents: aginoside (1) and 6-deoxyaginoside (2). The third one was identified as new component of A. porrum; however, it was found identical with yayoisaponin A (3) obtained earlier from a mutant of elephant garlic Allium ampeloprasun L. It is a derivative of the aginoside (1) with additional glucose in its glycosidic chain, identified by MS and NMR analysis as (2α, 3β, 6β, 25R)-2,6-dihydroxyspirostan-3-yl β-D-glucopyranosyl-(1 → 3)-β-D-glucopranosyl-(1 → 2)-[β-D-xylopyranosyl-(1 → 3)]-β-D-glucopyranosyl]-(1 → 4)-β-D-galactopyranoside, previously reported also under the name alliporin. The leek native saponins were tested together with other known and structurally related saponins (tomatonin and digitonin) and with their related aglycones (agigenin and diosgenin) for in vitro cytotoxicity and for effects on NO production in mouse peritoneal cells. The highest inhibitory effects were exhibited by 6-deoxyaginoside. The obtained toxicity data, however, closely correlated with the suppression of NO production. Therefore, an unambiguous linking of obtained bioactivities of saponins with their expected immunobiological properties remained uncertain. Full article

Two new spirostanol sapogenins (5β-spirost-25(27)-en-1β,2β,3β,5β-tetrol 3 and its 25,27-dihydro derivative, (25S)-spirostan-1β,2β,3β,5β-tetrol 4) and four new saponins were isolated from the roots and rhizomes of Convallaria majalis L. together with known sapogenins (isolated from Liliaceae): 5β-spirost-25(27)-en-1β,3β-diol 1, (25S)-spirostan-1β,3β-diol 2, 5β-spirost-25(27)-en-1β,3β,4β,5β-tetrol 5, (25S)-spirostan-1β,3β,4β,5β-tetrol 6, 5β-spirost-25(27)-en-1β,2β,3β,4β,5β-pentol 7 and (25S)-spirostan-1β,2β,3β,4β,5β-pentol 8. New steroidal saponins were found to be pentahydroxy 5-O-glycosides; 5β-spirost-25(27)-en-1β,2β,3β,4β,5β-pentol 5-O-β-galactopyranoside 9, 5β-spirost-25(27)-en-1β,2β,3β,4β,5β-pentol 5-O-β-arabinonoside 11, 5β-(25S)-spirostan-1β,2β,3β,4β,5β-pentol 5-O-galactoside 10 and 5β-(25S)-spirostan-1β,2β,3β,4β,5β-pentol 5-O-arabinoside 12 were isolated for the first time. The structures of those compounds were determined by NMR spectroscopy, including 2D COSY, HMBC, HSQC, NOESY, ROESY experiments, theoretical calculations of shielding constants by GIAO DFT, and mass spectrometry (FAB/LSI HR MS). An attempt was made to test biological activity, particularly as potential chemotherapeutic agents, using in silico methods. A set of 12 compounds was docked to the PDB structures of HER2 receptor and tubulin. The results indicated that diols have a higher affinity to the analyzed targets than tetrols and pentols. Two compounds (25S)-spirosten-1β,3β-diol 1 and 5β-spirost-25(27)-en-1β,2β,3β,4β,5β-pentol 5-O-galactoside 9 were selected for further evaluation of biological activity. Full article

Previously, various steroidal glycosides were reported from plants of Cestrum species. However, phytochemical investigation has not been conducted on Cestrum newellii. A systematic phytochemical investigation of the leaves of C. newellii resulted in the isolation of eight novel steroidal glycosides (1–8), which were classified into three spirostanol glycosides (1–3), two furostanol glycosides (4 and 5), two pseudofurostanol glycosides (6 and 7), and one cholestane glycoside (8). In addition, three known cholestane glycosides (9–11) were isolated and identified. The structures of the new compounds were determined based on spectroscopic data and chemical transformations. Compounds 1 and 2 are spirostanol glycosides having hydroxy groups at C-2, C-3, C-12, and C-24 of the aglycone moiety. Although C. newellii is known to be a poisonous plant, the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide assay exhibited that none of the isolated compounds were cytotoxic to HL-60 human promyelocytic leukemia cells. Full article

Phytochemical examination of Convallaria majalis (Liliaceae) whole plants yielded 15 steroidal glycosides (1–15), including nine new compounds (4–6, 10–15) with a lycotetrose unit. The structures of the new compounds were determined using two-dimensional Nuclear magnetic resonance (NMR) analyses and chemical methods. The isolated compounds were evaluated for cytotoxicity against HL-60 human promyelocytic leukemia cells, A549 human lung adenocarcinoma cells, and HSC-4 and HSC-2 human oral squamous cell carcinoma cell lines. Of these, (25S)-spirost-5-en-3β-yl O-β-d-glucopyranosyl-(1→2)-O-[β-d-xylopyranosyl-(1→3)]-O-β-d-glucopyranosyl-(1→4)-β-d-galactopyranoside (1) exhibited cytotoxic activity against HL-60, A549, HSC-4, and HSC-2 cells with IC₅₀ values ranging from 0.96 to 3.15 μM. The corresponding furostanol glycoside of 1, (25S)-26-[(β-d-glucopyranosyl)oxy]-22α-hydroxyfurost-5-en-3β-yl O-β-d-glucopyranosyl-(1→2)-O-[β-d-xylopyranosyl-(1→3)]-O-β-d-glucopyranosyl-(1→4)-β-d-galactopyranoside (8), was cytotoxic to the adherent cell lines of A549, HSC-4, and HSC-2 cells with IC₅₀ values of 2.97, 11.04, and 8.25 μM, respectively. The spirostanol lycotetroside (1) caused necrotic cell death in A549 cells in a dose-dependent manner. Alternatively, the furostanol lycotetroside (8) induced apoptotic cell death in A549 cells in a time-dependent manner, as was evident by morphological observations and flow cytometry analyses. Full article

Two new furostanol saponins 1–2 and three new sulphated glycosides 3a,b and 4 were isolated from the underground parts of Ruscus aculeatus L., along with four known furostanol and one spirostanol saponins 5–9 and three free sterols. All of the structures have been elucidated on the basis of spectroscopic data 1D and 2D NMR experiments, MS spectra and GC analyses. Full article

Seven steroidal saponins were isolated for the first time from the green berries of Solanum unguiculatum. Their structures were determined by spectroscopic analysis as well as hydrolysis of the glycosides into the corresponding sapogenins, diosgenin, chlorogenin, diosgenin-3-O-β-D-galactopyranoside, diosgenin-3-O-β-D-glucopyranosyl-(1 → 4)-β-D-galactopyranoside, 3β-hydroxyl-(25R) 5 α-spirostan-6-one (laxogenin) 3-O-α-L-rhamnopyranosyl-(1 → 2)-β-D-glucopyranoside, isonarthogenin-3-O-α-L-rhamnopyranosyl-(1 → 2)-O-[α-L-rhamnopyranosyl-(1 → 4)-β-D-glucopyranoside and 25(S) spirost-5-en-3 β, 17 α, 27 triol-3-O-[α-L-rhamnopyranosyl-(1 → 2)] [α-L-rhamnopyranosyl (1 → 4)]-β-D-glucopyranoside. Full article