Steroidal saponins with cytotoxic activity from the rhizomes of Paris polyphylla var. yunnanensis

Two previously unreported spirostanol saponins, dianchonglouosides A and B (1 and 2), along with 7 known steroidal saponins (3–9) were isolated from the rhizomes of Paris polyphylla var. yunnanensis. Their structures were elucidated by extensive spectroscopic analysis (MS, 1D, and 2D NMR), and chemical methods. The cytotoxic activities of the isolated compounds 1–9 were also evaluated against two human cancer cell lines (HEK293 and HepG2). The results showed that compound 7 had the strongest cytotoxic activity against the two cancer cell lines with the IC₅₀ values of 0.6 and 0.9 μM, respectively.     

Bioactive oleanane-type saponins from the rhizomes of Anemone taipaiensis

Investigation of the n-BuOH extract of the rhizomes of Anemone taipaiensis led to the isolation of five new oleanane-type triterpenoid saponins (1–5), together with seven known saponins (6–12). Their structures were determined by the extensive use of ¹D and ²D NMR experiments along with ESIMS analyses and acid hydrolysis. The aglycone of 1, 2 and 4 was determined as siaresinolic acid, which was reported in this genus for the first time. The cytotoxicities of the saponins 1–12, prosapogenins 4a, 5a, 10a–12a and sapogenins siaresinolic acid (SA), oleanolic acid (OA), hederagenin (HE) were evaluated against five human cancer cell lines, including HepG2, HL-60, A549, HeLa and U87MG. The monodesmosidic saponins 6–8, 5a, 10a–12a and sapogenins SA, OA, HE exhibited cytotoxic activity toward all cancer cell lines, with IC₅₀ values ranging from 2.25 to 57.28 μM. Remarkably, the bisdesmosidic saponins 1–4 and 9 showed selective cytotoxicity against the U87MG cells.     

Pro-apoptotic activity of acylated triterpenoid saponins from the stem bark of Albizia chevalieri harms

As a continuation of our interest in apoptosis-inducing triterpenoid saponins from Albizia genus, phytochemical investigation of the stem bark of Albizia chevalieri led to the isolation of three new oleanane-type saponins, named chevalierosides A–C (1–3). Their structures were established on the basis of extensive analysis of 1D and 2D NMR (¹H-, ¹³C NMR, DEPT, COSY, TOCSY, ROESY, HSQC and HMBC) experiments, HRESIMS studies, and by chemical evidence. The pro-apoptotic effect of the three saponins was evaluated on two human cell lines (pancreatic carcinoma AsPC-1 and hematopoietic monocytic THP-1). Cytometric analyses showed that saponins 1–3 induced apoptosis of both human cell lines (AsPC-1 and THP-1) in a dose-dependent manner.     

Haemolytic activity,cytotoxicity and membrane cell permeabilization of semi-synthetic and natural lupane- and oleanane-type saponins

The haemolysis of red blood cells inducing toxicity in most animals including humans is a major drawback for the clinical development of saponins as antitumour agents. In this study, the haemolytic and cytotoxic activities as well as the membrane cell permeabilization property of a library of 31 semi-synthetic and natural lupane- and oleanane-type saponins were evaluated and the structure–activity relationships were established. It was shown that lupane-type saponins do not exhibit any haemolytic activity and membrane cell permeabilization property at the maximum concentration tested (100 μM) independently of the nature of the sugar moieties. While oleanane-type saponins such as β-hederin (25) and hederacolchiside A₁ (27) cause the death of cancer cell lines by permeabilizing the cellular membranes, lupane-type saponins seem to proceed via another mechanism, which could be related to the induction of apoptosis. Altogether, the results indicate that the cytotoxic lupane-type glycosides 10 and 22 bearing an α-l-rhamnopyranose moiety at the C-3 position represent promising antitumour agents for further studies on tumour-bearing mice since they are devoid of toxicity associated with the haemolysis of red blood cells.     

Cytotoxic ent-Abietane-type diterpenoids from the roots of Euphorbia ebracteolata

Euphoroids A–C (1–3), three new ent-abietane-type diterpenoids, together with ten known analogues (4–13) were obtained from the roots of Euphorbia ebracteolata. The structures of these compounds were determined by extensive spectroscopic data analysis, including UV, HRESIMS, 1D-, and 2D-NMR data. The inhibitory effects of compounds 1–13 on human cancer cells were determined using the MTT assay. The results revealed that new compounds 2 and 3 showed moderate cytotoxic activities against human cancer cell lines. Especially, compound 3 displayed selective cytotoxic effect agains cancer cell lines.     

Mandshunosides C–E from the roots and rhizomes of Clematis mandshurica

Three new triterpene saponins, mandshunosides C–E (1–3) together with four known triterpene saponins (4–7) were isolated from the roots and rhizomes of Clematis mandshurica. Their structures were elucidated on the basis of spectroscopic evidence and hydrolysis products. Those compounds showed inhibitory activities against two human colorectal cancer cell lines HCT-116 and HT-29.     

Lysosomes-targeting imaging and anticancer properties of novel bis-naphthalimide derivatives

A series of novel N,N-bis(3-aminopropyl)methylamine bridged bis-naphthalimide derivatives NI1–NI8 containing saturated nitrogenous heterocycles were designed and synthesized, their cytotoxic activities against Hela, MCF-7, A549 and MGC-803 cells were investigated, Compounds NI1–NI4 modified with piperidine and piperazine exhibited good and selective cytotoxic activity, for instance, compounds NI1 and NI4 showed potent cytotoxic activity against Hela cells and MGC-803 cells with the IC₅₀ values of 2.89, 060, 2.73 and 1.60?μM, respectively, better than the control drug (Amonafide). However, compounds NI5–NI8 conjugated with pyrrole derivatives showed weak cytotoxic activities against the all tested cell lines. Furthermore, their DNA binding properties, fluorescence imaging and cell cycle were investigated. Interestingly, compounds NI1 and NI4 showed fluorescence enhancement because of the strong binding with Ct-DNA, and exhibited fluorescence imaging with Hela cells on the lysosomes.     

Cytotoxic activity of sesquiterpene lactones from Inula britannica on human cancer cell lines

Five new sesquiterpene lactones (1–5) were isolated from Inula britannica collected in the wild from Serbia along with five known compounds (6–10). Sesquiterpene lactones were isolated using centrifugal partition chromatography followed by combination of flash chromatography and semi-preparative HPLC. Isolated compounds were screened for cytotoxic activity on four different human cancer cell lines and their multi-drug resistant counterparts, as well as on normal human keratinocytes. Sesquiterpene lactones showed similar cytotoxic activity toward drug sensitive and drug resistant cancer cell lines.     

Cytotoxic steroidal saponins from Trillium kamtschaticum

Eight new steroidal saponins, trillikamtosides K–R (1–8), along with three known analogues, were isolated from the whole plants of Trillium kamtschaticum. Their structures were unambiguously established by interpretation of spectroscopic data (MS and NMR) and chemical methods. Compound 1 had a rare aglycone featuring a skeleton of 16-oxaandrost-5-en-3-ol-17-one, which was reported for the first time. The isolated saponins were tested for cytotoxicities against HCT116 cells, and trillikamtoside R (8) was found to show the most cytotoxic effect with an IC₅₀ value of 4.92 μM.     

Steroidal saponins with cytotoxic activities from the rhizomes of Anemarrhena asphodeloids Bge.

Two new steroidal saponins, named timosaponin R (1) and S (2), together with seven known compounds (3-9) were isolated from the rhizomes of Anemarrhena asphodeloides Bge. Their structures were elucidated on the basis of NMR spectroscopy and mass spectrometry. All the compounds were evaluated for cytotoxic activities against the four human cancer cell lines MCF7, SW480, HepG2 and SGC7901 in vitro. Compounds 7-9 showed moderate activities against all the cell lines.     

Tomensides A–D,new antiproliferative phenylpropanoid sucrose esters from Prunus tomentosa leaves

To search for novel cytotoxic constituents against cancer cells as lead structures for drug development, four new 3-phenylpropanoid-triacetyl sucrose esters, named tomensides A–D (1–4), and three known analogs (5–7) were isolated from the leaves of Prunus tomentosa. Their structures were elucidated by spectroscopic analyses (1D, 2D NMR, CD and HRESIMS). The cytotoxic activities of all isolates against four human cancer cell lines (MCF-7, A549, HeLa and HT-29) were assayed, and the results showed that these isolates displayed stronger inhibitory activities compared with positive control 5-fluorouracil. Tomenside A (1) was the most active compound with IC₅₀ values of 0.11–0.62 μM against the four tested cell lines. The structure–activity relationship (SAR) of the isolates was also discussed. The primary screening results indicated that these 3-phenylpropanoid-triacetyl sucrose esters might be valuable source for new potent anticancer drug candidates.     

Dammarane-type saponins from the flower buds of Panax ginseng and their effects on human leukemia cells

Six dammarane-type saponins, including three new compounds, floralginsenosides Ta–Tc (1–3), and three known, floralginsenoside Td (4), ginsenoside F₁ (5), and ginsenoside F₅ (6), were isolated from the flower buds of Panax ginseng. Floralginsenoside Td (4) was first isolated from natural plant sources. Their structures were elucidated on the basis of extensive chemical and spectroscopic methods. Compounds 1, 5, and 6 showed cytotoxic activities towards the HL-60 human leukemia cell line with respective IC₅₀ values of 36.3, 23.2, and 62.4 μM. In addition, after the HL-60 cells were treated with these compounds, several apoptosis events, including chromatin condensation and increase in the population of sub-G1 hypodiploid cells, were observed.     

Chemical constituents from Abrus cantoniensis and their cytotoxic effects on cancer cells

Two new compounds named 4-(4-hydroxybenzyl)-isofraxidin (1) and 1''-methoxyl-bavacoumestan B (2), along with five known compounds (3–7) were isolated from the EtOAc-soluble extract of Abrus cantoniensis. Their structures were elucidated with spectroscopic and physico-chemical analyses. All isolates were evaluated for their cytotoxic activities against four cancer cell lines including HepG2, SMMC-7721, A549 and MCF-7. Among them, compounds 1 and 5 exhibited significant cytotoxic activity on the above four cell lines. In particular, 1 showed the potent cytotoxic activity on HepG2 and SMMC-7721 cells with IC₅₀ values of 4.31 ± 0.5 and 3.24 ± 0.9 μM, respectively.     

C21 steroidal glycosides with cytotoxic activities from Cynanchum otophyllum

Eight new C21 steroidal glycosides, namely cynanotins A–H (1–8), together with fifteen known analogues, were isolated from the roots of Cynanchum otophyllum. Their structures were elucidated by spectroscopic analysis and chemical methods. In this study, all of isolates were tested for their vitro inhibitory activities against five human tumor cell lines (HL-60, SMMC-7721, A-549, MCF-7 and SW480). Compounds 3–15 showed moderate cytotoxic activities against HL-60 cell lines with IC₅₀ values ranging from 11.4 to 37.9?µM. Compounds 5, 9, and 10 showed marked or moderate cytotoxic activities against five human tumor cell lines with IC₅₀ values ranging from 11.4 to 36.7?µM. Compound 11 displayed moderate cytotoxic activities against HL-60, SMMC-7721, MCF-7 and SW480 cell lines with IC₅₀ values of 12.2–30.8?µM. Compared to the positive control (IC₅₀: 35.0?µM), compounds 5, 9–11 exhibited more potential inhibitory activity against MCF-7 cells (IC₅₀: 16.1–25.6?µM).     

Triterpenoid saponins from Albizia boromoensis Aubrév. & Pellegr

As part of our search of new bioactive saponins from Cameroonian medicinal plants, phytochemical investigation of the roots of Albizia boromoensis led to the isolation of four new oleanane-type saponins, named boromoenosides A–D (1–4). Their structures were established by direct interpretation of their spectral data, mainly HRESIMS, 1D NMR (¹H, ¹³C NMR, and DEPT) and 2D NMR (COSY, NOESY, HSQC and HMBC), and by comparison with the literature data. All isolated saponins were assayed for their cytotoxicity against U-87 MG human glioblastoma cell lines and TG1 glioblastoma stem-like cells with no positive activity detected.     

Three new triterpene saponins from Actinostemma lobatum MAXIM and their cytotoxicity in vitro

Three new triterpene saponins, lobatoside O (1), actinostemmoside I (2) and actinostemmoside J (3), were isolated from the herb of Actinostemma lobatum MAXIM. Their structures were elucidated by means of extensive chemical and spectroscopic methods. In addition, cytotoxic activities toward HCT-116, HT-29, MCF-7 and A549 cell lines were tested by the MTT method.     

Two new spirostanol saponins from the the roots and rhizomes of Tupistra chinensis

Two new spirostanol saponins (1) and (2), together with three known saponins (3–5), were isolated from the roots and rhizomes of Tupistra chinensis, and their structures were determined as (20S, 22R)-spirost-25(27)-en-1β, 3β, 4β, 5β-tetraol-5-O-β-d-glucopyranoside (1) and (20S, 22R)-spirost-25(27)-en-1β, 3β, 5β-triol-5-O-β-d-glucopyranoside (2), (20S, 22R)-spirost-25(27)-en-1β, 2β, 3β, 4β, 5β-pentaol-5-O-β-d-glucopyranoside (3), Δ²⁵⁽²⁷⁾-pentrogenin (4) and ranmogenin A (5) on the basis of physicochemical properties and spectral analysis. The isolated compounds were evaluated for their cytotoxic activities against A549 and H1299 tumor cell lines in vitro. Among them, compound 2 showed cytotoxicities against A549 cells (IC₅₀ 52.66 ± 3.12 μmol L⁻¹) and H1299 cells (IC₅₀ 57.29 ± 2.51 μmol L⁻¹), respectively.     

Five new degraded diterpenoids from Trigonostemon xyphophylloides

Five new degraded diterpenoids trigoxyphins J–N (1–5), among them trigoxyphins K and L have a novel carbon skeleton, together with four known analogues (6–9) have been obtained from the ethanol extract of the twigs of Trigonostemon xyphophylloides. Compounds 1?5 were evaluated for their cytotoxic activity in vitro against three human tumor cell lines by MTT assay. The results exhibited that Trigoxyphin N (5) showed moderate cytotoxicities against SPC-A-1 and SGC-7901 cancer cell lines.     

Cytotoxic quassinoids from Ailanthus altissima

Two new quassinoids, altissinol A (1) and B (7), together with 12 known quassinoids, were isolated from the 95% ethanol extract of the barks of Ailanthus altissima. The structures of the new compounds (1 and 7) were determined on the basis of the spectroscopic methods including UV, IR, HR-ESI-MS, 1D and 2D NMR. The cytotoxic potential of all isolates were evaluated in vitro against three human hepatoma cell lines. Quassinoids 1–7 displayed potent cytotoxic activities against human hepatoma Hep3B and HepG2 cell lines. Interestingly, compounds 2, 3, and 5 exhibited cytotoxic activity against multidrug resistance HepG2/ADM cell line with IC₅₀ value 4.3-fold more sensitive to Doxorubicin (DOX).