Spirostanol saponins from the rhizomes of Tacca chantrieri and their cytotoxic activity

The rhizomes of Tacca chantrieri have been analysed for steroidal saponin constituents, resulting in the isolation of four new spirostanol saponins (1-4), along with one known saponin (5); their structures were elucidated on the basis of extensive spectroscopic analysis, including 2D NMR, and the results of hydrolytic cleavage. The isolated compounds were evaluated for their cytotoxic activity against HL-60 human promyelocytic leukemia cells.     

New triterpene saponins from the roots of Acacia macrostachya (Mimosaceae)

Four new oleanane-type saponins, macrostachyaosides A, B, C, and D (1–4) were isolated from the roots of Acacia macrostachya. Their structures were elucidated on the basis of extensive 1D- and 2D-NMR data and HR-ESI-MS analyses. At concentrations of 100 μM of each compounds, none of the tested compounds caused a significant growth reduction against HL60 cells.     

Steroidal saponins from the whole plants of Agave utahensis and their cytotoxic activity

Phytochemical investigation of the whole plants of Agave utahensis Engelm. (Agavaceae) has resulted in the isolation of 15 steroidal saponins (1-15), including five spirostanol saponins (1-5) and three furostanol saponins (11-13). Structures of compounds 1-5 and 11-13 were determined by spectroscopic analysis and the results of hydrolytic cleavage. The isolated compounds were evaluated for their cytotoxic activity against HL-60 human promyelocytic leukemia cells.     

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.     

Four new triterpenoidal saponins from Ilex cornuta and their cytotoxic activities

Four new triterpenoidal saponins (1–4), oleanolic acid 3β-O-α-l-arabinopyranosyl-(1 → 2)-β-d-glucuronopyranoside-6-O-butyl ester (1), oleanolic acid 3β-O-[α-l-arabinopyranosyl-(1 → 2)-β-d-glucuronopyranoside-6-O-butyl ester]-28-O-β-d-glucopyranoside (2), 19α-hydroxy oleanolic acid 3β-O-β-d-glucuronopyranoside-6-O-methyl ester (3), and 19α-hydroxy urs-12-en-28-oic acid 3β-O-α-l-arabinopyranosyl-(1 → 2)-β-d-glucuronopyranoside-6-O-methyl ester (4) were isolated from the roots of Ilex cornuta. Their structures were determined by means of extensive spectroscopic analyses (IR, ESIMS, HRESIMS, 1D and 2D NMR). Compounds 1–9 were tested for their cytotoxic activities by MTT assay, and 1, 3, 5 and 6 showed moderate cytotoxic activities against HeLa, SMMC-7721, and HL-60 human tumor cell lines.     

Five new triterpenoid saponins from the Roots of Camellia oleifera C. Abel with cytotoxic activities

Five new triterpenoid saponins, oleiferosides P–T (1–5) were isolated from the EtOH extract of the roots of Camellia oleifera C. Abel. The structures of saponins 1–5 were elucidated on the basis of integrated spectroscopic techniques. All the compounds were characterized to be oleanane-type saponins with sugar moieties linked to the C-3 of the aglycone. By using the MTT assay, an in vitro analysis of the cytotoxic activities of these saponins on the human tumor cell lines (lung adenocarcinoma A549 cells, hepatic carcinoma SMMC-7721 cells and breast cancer MCF-7 cells). Among them, compound 4 showed a certain cytotoxic activity against all the tested cell lines.     

New phenanthrene glycosides from Dendrobium denneanum and their cytotoxic activity

Five new phenanthrene glycosides, denneanosides A–E (1–5), and one new 9,10-dihydrophenanthrene glycoside, denneanoside F (6) were isolated from the stem of Dendrobium denneanum. The chemical structures of the new compounds were established on the basis of extensive spectroscopic data. The isolated compounds were evaluated for their in vitro cytotoxic activity against SNU387 hepatocellular carcinoma cell line. Compounds 1–3 showed moderate cytotoxic activities while compounds 4–6 showed weak activities.     

Triterpenoid saponins and C-glycosyl flavones from stem bark of Erythrina abyssinica Lam and their cytotoxic effects.

Six new compounds including two oleanane-type triterpenoid saponins (1, 2) and four C-glycosyl flavones (3–6), along with a known saponin (7), three di-C-glycosyl flavones (8–10) and a glycosyl auronol (11), were isolated from the stem bark of Erythrina abyssinica Lam. The structures of the new compounds, identified as 3-O-[α-l-rhamnopyranosyl-(1 → 2)-β-d-galactopyranosyl-(1 → 2)-β-d-glucuronopyranosyl]-22-O-β-d-glucopyranosyl sophoradiol (1), 3-O-[α-l-rhamnopyranosyl-(1 → 2)-β-d-glucopyranosyl-(1 → 2)-β-d-glucuronopyranosyl]-22-O-β-d-glucopyranosyl sophoradiol (2), 6-C-β-glucopyranosyl-8-C-β-quinovopyranosyl apigenin (3), 6-C-β-quinovopyranosyl-8-C-β-glucopyranosyl apigenin (4), 8-C-[6″-O-α-l-rhamnopyranosyl-(1‴ → 6″)]-β-glucopyranosyl 7,4′-dihydroxyflavone (5) and 8-C-[6″-O-β-d-xylopyranosyl-(1‴ → 6″)]-β-glucopyranosyl 7,4′-dihydroxyflavone (6), were determined by comprehensive spectroscopic analysis, including 1D and 2D NMR techniques, mass spectrometry and acid hydrolysis. These new compounds together with the known saponins 7 were evaluated for their cytotoxic activity against MCF-7 (estrogen dependent) and MDA-MB-231 (estrogen independent) cell lines. The new saponin 2 exhibited the highest cytotoxic activity among tested compounds, exerting a selective inhibitory effect against the proliferation of MCF-7 cells, with lower IC₅₀ value (12.90 μM) than that of the positive control, resveratrol (13.91 μM). Structure–activity relationship of these compounds is also discussed.     

New biphenyl derivatives from the leaves of Nicotiana tabacum and their cytotoxic activity

With the aim of searching for new bioactive metabolites from medicinal plants, three new biphenyls, tababiphenyls G–I (1–3), together with four known ones (4–7) were isolated from the leaves of Nicotiana tabacum. Their structures were elucidated by extensive NMR and MS spectroscopic analyses. All the isolated compounds were evaluated for their cytotoxicity against NB4, A549, SHSY5Y, PC3, and MCF7 human cancer cell lines, and some of them showed moderate inhibitory activities against several human tumor cell lines with IC₅₀ values ranging from 2.8 to 9.4 μM.     

New glycosides from Tetracentron sinense and their cytotoxic activity

One novel neolignan (tetracentronsine; 1), one new indole alkaloid (=3-(2-hydroxyethyl)-1H-indole-5-O-beta-D-glucopyranoside; 2), and two new phenol derivatives, 3-{2-[(beta-glucopyranosyl)oxy]-4,5-(methylenedioxy)phenyl}propanoic acid (3) and methyl 3-{2-[(beta-glucopyranosyl)oxy]-4,5-(methylenedioxy)phenyl}propanoate (4), together with six known compounds were isolated from the stem bark of Tetracentron sinense. Their structures were determined by spectral analysis, including 1D- and 2D-NMR, and MS analyses. These compounds were tested for their cytotoxic activity against human leukaemia cells in vitro. Among them, compound 2, (E)-3-(4-hydroxyphenyl)-N-[2-(4-hydroxyphenyl)ethyl]prop-2-enamide (5), and maslinic acid (6) showed significant inhibitory activities against human leukaemia cells CCRF-CEM and its multidrug-resistant sub-line, CEM/ADR5000, with IC50 values in a range of 7.1 to 29.7 microM.     

New triterpene saponins from Phryna ortegioides

Four new and three known oleanane-type saponins have been isolated from the methanolic extract of Phryna ortegioides, a monotypic and endemic taxon of Caryophyllaceae.The structures of the new compounds were determined as gypsogenic acid 28-O-β-d-glucopyranosyl-(1→2)-O-β-d-glucopyranosyl-(1→6)-O-β-d-glucopyranosyl ester (1), 3-O-α-l-arabinofuranosyl-gypsogenic acid 28-O-β-d-glucopyranosyl-(1→3)-O-[β-d-glucopyranosyl-(1→6)]-O-β-d-glucopyranosyl ester (2), 3-O-α-l-arabinofuranosyl-gypsogenic acid 28-O-β-d-glucopyranosyl-(1→3)-O-[β-d-glucopyranosyl-(1→2)-O-β-d-glucopyranosyl-(1→6)-O-]-β-d-glucopyranosyl ester (3), 3-O-α-l-arabinofuranosyl-16α-hydroxyolean-12-en-23,28-dioic acid-28-O-β-d-glucopyranosyl-(1→3)-O-[β-d-glucopyranosyl-(1→2)-O-β-d-glucopyranosyl-(1→6)]-O-β-d-glucopyranosyl ester (4). Their structures were established by a combination of one- and two-dimensional NMR techniques, and mass spectrometry. Noteworthy, none of isolated compounds possesses as aglycone moiety gypsogenin, considered a marker of Caryophyllaceae family.The cytotoxic activity of the isolated compounds was evaluated against three cancer cell lines including A549 (human lung adenocarcinoma), A375 (human melanoma) and DeFew (human B lymphoma) cells. Only compound 6 showed a weak activity against A375 and DeFew cell lines with IC₅₀ values of 77 and 52 μM, respectively. None of the other tested compounds, in a range of concentrations between 12.5 and 100 μM, caused a significant reduction of the cell number.     

Pregnane alkaloids from Sarcococca ruscifolia and their cytotoxic activity

Six pregnane alkaloids were isolated from the root of Sarcococca ruscifolia. The structures of three new alkaloids, namely, sarcorucinine E–G (1–3), were elucidated using spectroscopic methods, while three known alkaloids, namely, epipachysamine D, pachysamine M, and sarcovagine D, were identified by comparing their spectral data with those of the compounds reported earlier. All compounds were evaluated for their inhibitory activities against multiple types of cancer cells.     

Steroidal saponins from the leaves of Cordyline fruticosa (L.) A. Chev. and their cytotoxic and antimicrobial activity

Three new steroidal saponins, spirosta-5,25(27)-diene-1β,3β-diol-1-O-α-l-rhamnopyranosyl-(1→2)-β-d-fucopyranoside (fruticoside H) 1, 5α-spirost-25(27)-ene-1β,3β-diol-1-O-α-l-rhamnopyranosyl-(1→2)-(4-O-sulfo)-β-d-fucopyranoside (fruticoside I) 2, and (22S)-cholest-5-ene-1β,3β,16β,22-tetrol 1-O-β-galactopyranosyl-16-O-α-l-rhamnopyranoside (fruticoside J) 3, together with the known quercetin 3-O-β-d-glucopyranoside, quercetin 3-O-[6-trans-p-coumaroyl]-β-d-glucopyranoside, quercetin 3-rutinoside, apigenin 8-C-β-d-glucopyranoside and farrerol, were isolated from the leaves of Cordyline fruticosa. Their structures were elucidated by spectroscopic techniques (¹H NMR, ¹³C NMR, HSQC, ¹H–¹H COSY, HMBC, TOCSY, NOESY), mass spectrometry (HRESIMS, Tandem MS–MS), chemical methods and by comparison with published data. Compounds 1 and 2 showed moderate cytotoxic activity against MDA-MB 231 human breast adenocarcinoma cell line, HCT 116 human colon carcinoma cell line, and A375 human malignant melanoma cell line, while compound 3 was not active. Compound 2 also showed a moderate antibacterial activity against the Gram-positive Enterococcus faecalis.     

Biological activities and chemistry of saponins from Chenopodium quinoa Willd.

Chenopodium quinoa Willd. is a valuable food source which has gained importance in many countries of the world. The plant contains various bitter-tasting saponins which present an important antinutritional factor. Various triterpene saponins have been reported in C. quinoa including both monodesmosidic and bidesmosidic triterpene saponins of oleanolic acid, hederagenin, phytolaccagenic acid, and serjanic acid as the major aglycones and other aglycones as 3β-hydroxy-23-oxo-olean-12-en-28-oic acid, 3β-hydroxy-27-oxo-olean-12-en-28-oic acid, and 3β, 23α, 30β-trihydroxy-olean-12-en-28-oic acid. A tridesmosidic saponin of hederagenin has also been reported. Here we review the occurrence, analysis, chemical structures, and biological activity of triterpene saponins of C. quinoa. In particular, the mode of action of the mono- and bidesmosidic triterpene saponins and aglycones are discussed.     

Two tirucallane derivatives from Paramignya scandens and their cytotoxic activity

Various chromatographic separations of the methanolic extract of Paramignya scandens stem and leaves resulted in the isolation of two new tirucallane derivatives, paramignyols A and B (1 and 2). Their structures were established by HR-ESI-MS, 1D and 2D NMR experiments, as well as, comparison with literature data. Compounds 1 and 2 showed significant cytotoxic activity (IC₅₀s ∼ 3.55–10.50 μM) on four tested human cancer cell lines: KB (epidermoid carcinoma), SK-Mel-2 (melanoma), LU-1 (lung adenocarcinoma), and MCF7 (breast cancer). This is the first report on chemical constituents and biological activities of P. scandens.     

Albizosides D and E, two new cytotoxic triterpene saponins from Albizia chinensis

Two oleanane-type triterpene saponins, named albizosides D and E (1 and 2), together with a known compound, Julibroside J₈ (3), were isolated from the stem bark of Albizia chinensis. The structures of compounds 1 and 2 were established by 1D, 2D NMR experiments, and chemical methods, and they showed moderate cytotoxic activity against a small panel of human tumor cell lines.     

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.     

Triterpene saponins of Genista ulicina Spach

From the n-BuOH extract of the aerial parts of Genista ulicina, six triterpene saponins, 3-O-β-d-glucopyranosyl-olean-12-ene-3β,27,28,30-tetraol, 3-O-β-d-glucopyranosyl-olean-12-ene-3β,27,28,29-tetraol, 3,29-di-O-β-d-glucopyranosyl-olean-12-ene-3β,27,28,29-tetraol, 3-O-β-d-glucopyranosyl-olean-12-ene-3β,28,29-triol-27-oic acid, 3-O-β-d-glucopyranosyl-olean-12-ene-3β,27,28-triol-29-oic acid, and 3-O-β-d-glucopyranosyl-14-H-27-nor-olean-12-ene-3β,28,29-triol, were isolated together with eight known triterpene saponins and six flavonoids. Their structures were established mainly by means of spectroscopic methods (1D and 2D-NMR as well as HR-ESI-MS). The n-BuOH extract, investigated for its antitumor growth inhibition of human colon cancer HT-29 cells, presented no significant activity (IC₅₀ > 100 μg).     

New cytotoxic steroidal saponins from Cestrum parqui

Two new steroidal saponins, 25(R)-3β [(O-β-d-glucopyranosyl-(1 → 3)-β-d-glucopyranosyl-(1 → 2)-O-[β-d-xylopyranosyl-(1 → 3)-O-β-d-glucopyranosyl-(1 → 4)-β-d-galactopyranosyl)oxy]-5α, 15β, 22R, 25R-spirostan-3,15-diol (1, named parquispiroside) and 25R-26-[(β-d-glucopyranosyl)Oxy]-(3β [(O-β-d-glucopyranosyl-(1 → 3)-β-d-glucopyranosyl-(1 → 2)-O-[β-d-xylopyranosyl-(1 → 3)-O-β-d-glucopyranosyl-(1 → 4)-β-d-galactopyranosyl)oxy], 5α, 15β, 22R, 25R)-furostane-3,15,22-triol (2, named parquifuroside), along with the known saponins, capsicoside D (3) and 22-OMe-capsicoside D (4) and the known glycoside, benzyl primeveroside (5), were isolated from the leaves of Cestrum parqui. The structures of these compounds were elucidated by careful analysis of 1D and 2D NMR spectra and ESIMS data. Parquispiroside (1) exhibited moderate inhibition of Hela, HepG2, U87, and MCF7 cell lines with IC₅₀ values in the range of 3.3–14.1 μM.     

Triterpenoid saponins from the fruits and galls of Sapindus mukorossi

Six saponins, sapinmusaponin K (1) [hederagenin-3-O-(3-O-acetyl-alpha-L-arabinopyranosyl)-(1-->3)-alpha-L-rhamnopyranosyl-(1-->2)-alpha-L-arabinopyranoside], sapinmusaponin L (2) [hederagenin-3-O-(4-O-acetyl-alpha-L-arabinopyranosyl)-(1-->3)-alpha-L-rhamnopyranosyl-(1-->2)-alpha-L-arabino-pyranoside], sapinmusaponin M (3) [hederagenin-3-O-(2,3-O-diacetyl-beta-D-xylopyranosyl)-(1-->3)-alpha-L-rhamnopyranosyl-(1-->2)-alpha-L-arabinopyranoside], sapinmusaponin N (4) [hederagenin-3-O-(2,4-O-diacetyl-beta-D-xylopyranosyl)-(1-->3)-alpha-L-rhamnopyranosyl-(1-->2)-alpha-L-arabinopyranoside], sapinmusaponin O (5) [3,7,20(S)-trihydroxydammar-24-ene-3-O-alpha-L-rhamnopyranosyl-(1-->2)-beta-D-glucopyranoside], and sapinmusaponin P (6) [3,7,20(R)-trihydroxydammar-24-ene-3-O-alpha-L-rhamnopyranosyl-(1-->2)-beta-d-glucopyranoside], along with seven known saponins (7-13), were isolated from fruits and the galls of Sapindus mukorossi. Their structures were elucidated by 1D and 2D NMR spectroscopic techniques and acid hydrolysis. Biological evaluation indicated that saponins 1-4 and 7-13 showed moderate cytotoxicity against several human tumor cell lines.