Cytotoxic oleanane triterpene saponins from Albizia chinensis

Ingadosides A-C, acacic acid-type saponins from Inga sapindoides with potent inhibitory activity against downy mildew

As part of a project aiming at the discovery of environmentally friendly alternatives to copper in organic agriculture, a 96% ethanolic extract from the leaves of Inga sapindoides showed potent inhibitory activity against grapevine downy mildew (Plasmopara viticola) in vitro (MIC₁₀₀ 25 μg/mL). Separation of the n-BuOH soluble fraction by silica gel column chromatography followed by a combination of RP₁₈ and HILIC HPLC resulted in the isolation of a series of bidesmosidic saponins characterized by the presence of a monoterpenoid unit attached to a triterpenoid aglycone, a p-methoxycinnamoyl residue, and rare sugar residues such as N-acetyl-d-glucosamine, d-quinovose, and d-fucose. The isolated compounds inhibited the formation or activity of P. viticola zoospores with MIC₁₀₀ values of 3 or 6 μg/mL, respectively. I. sapindoides, a tree which is often cultivated for shading coffee plantations in Central America, may represent a sustainable source of fungicidal products to be used in the replacement of copper.

Oleanane-type saponins and prosapogenins from Albizia julibrissin and their cytotoxic activities

Two undescribed oleanane-type saponins, julibrosides K-L, along with three undescribed oleanane-type prosapogenins, julibrosides M-O, were isolated from the stem bark of Albizia julibrissin Durazz. and the mild alkaline hydrolysate of the total saponin, respectively. Their structures were established by extensive analysis of 1D and 2D NMR experiments (COSY, TOCSY, HSQC, HMBC, and HSQC-TOCSY) and mass spectrometry. Furthermore, the cytotoxic activities of the isolated compounds against BGC-823, A549, HCT-116, and HepG2 cell lines were evaluated, and julibroside L showed significant cytotoxic activities against the four cancer cell lines with IC₅₀ values of 5.77, 4.80, 4.26, and 4.93 μM, respectively.

The ethnopharmacology, phytochemistry, pharmacology and toxicology of genus Albizia: A review

ETHNOPHARMACOLOGICAL RELEVANCE

The genus Albizia (Leguminosae) comprises about 150 species and some species have been used for the treatment of rheumatism, stomachache, cough, diarrhea, and wounds in traditional and local medicine. The aim of the review: This review article documents and critically assesses the current status of the traditional uses, phytochemistry, pharmacology, and toxicology of the Albizia species.

MATERIALS AND METHODS

All provided literatures on the Albizia species were searched using the electronic databases (e.g. Web of Science, Elsevier, Springer, PubMed, ACS, CNKI, Google Scholar, and Baidu Scholar), books, and theses with keywords of 'Albizia' and 'Albizzia'.

RESULTS

Albizia species have been used for melancholia, insomnia, wounds, fever, abscesses, diabetes, headache, stomachache, diarrhea, cough, rheumatism, snake bite, malaria, and parasitic infection in traditional and local medicine. These plants mainly contain triterpenoid saponins, flavonoids, lignanoids, alkaloids, phenolic glycosides, etc. Albizia species have been demonstrated to possess various pharmacological activities. Among them, the antidiabetic, anti-inflammatory, antifertility, antianxiety, antidepressant, and anti-fever properties are consistent with the traditional and local applications of the Albizia species.

CONCLUSIONS

The traditional and local uses of Albizia species have been partially demonstrated by the pharmacological investigation. However, some traditional applications have not been assessed scientifically due to incomplete methodologies and ambiguous findings. Moreover, no clinical evidences support the health benefits of these plants. The systematic and comprehensive preclinical studies and clinical trials are still required to verify the pharmacological activities, clinical efficacy, and safety of Albizia species.

Structural characterization of a complex triterpenoid saponin from Albizia lebbeck and investigation of its permeability property and supramolecular interactions with membrane constituents

As part of the ongoing efforts in discovering potentially bioactive natural products from medicinal plants, the present study was conducted to isolate a new complex triterpenoid saponin from the barks of Albizia lebbeck. It was isolated by using chromatographic methods and its structural elucidation was performed using detailed analyses of ¹H and ¹³C NMR spectra including 2D-NMR (COSY, TOCSY, HSQC and HMBC) spectroscopic techniques, high-resolution electrospray ionization mass spectrometry (HRESIMS) analysis and chemical conversions. Its structure was established as 21-[[(2E,6S)-6-[6-deoxy-4-O-[(2E,6S)-6-hydroxy-2-(hydroxymethyl)-6-methyl-1-oxo-2,7-octadienyl]-[(β-d-glucopyranosyl)oxy]-2-(hydroxymethyl)-6-methyl-1-oxo-2,7-octadienyl]-[(β-d-glucopyranosyl)oxy]-2,6-dimethyl-1-oxo-2,7-octadienyl]oxy]-16-hydroxy-3-[[O-β-d-xylopyranosyl-(1 → 2)-O-α-l-arabinopyranosyl-(1 → 6)-2-(acetylamino)-2-deoxy-β-d-glucopyranosyl]oxy]-(3β,16α,21β)-olean-12-en-28-oic acid O-α-l-arabinofuranosyl-(1 → 4)-O-[β-d-glucopyranosyl-(1 → 3)]-O-6-deoxy-α-l-mannopyranosyl-(1 → 2)-β-d-glucopyranosyl ester (1). Additionally, this study aimed to investigate the permeability property of 1, its activity on membrane integrity and supramolecular interactions with cellular constituents using in vitro experimental models.

Melanogenesis-Inhibitory and Cytotoxic Activities of Triterpene Glycoside Constituents from the Bark of Albizia procera

Five oleanane-type triterpene glycosides including three new ones, proceraosides E-G (1-3), were isolated from a MeOH-soluble extract of Albizia procera bark. The structures of 1-3 were determined by use of NMR spectra, HRESIMS, and chemical methods. Compounds 1-5 exhibited inhibitory activities against the proliferation of the A549, SKBR3, AZ521, and HL60 human cancer cell lines (IC₅₀ 0.28-1.8 μM). Additionally, the apoptosis-inducing activity of compound 2 was evaluated by Hoechst 33342 staining and flow cytometry, while the effects of 2 on the activation of caspases-9, -8, and -3 in HL60 cells were revealed by Western blot analysis.

Immunomodulatory, hemolytic and cytotoxic activity potentials of triterpenoid saponins from eight Cephalaria species

BACKGROUND

Saponins isolated from a number of plants possess a broad spectrum of biological and pharmacological activities by using in vitro and in vivo bioassays. The recent investigations and findings in biological activity studies of saponins have mostly focused on immunomodulatory, hemolytic and cytotoxic properties.

HYPOTHESIS/PURPOSE

Considering the great potential of saponins as bioactive agents, we investigated the cytotoxic, hemolytic and immunomodulatory activities of nineteen triterpenoid saponins from the aerial parts of eight Cephalaria species from Turkey.

STUDY DESIGN

The isolated oleanane type saponins from Cephalaria species were tested for their hemolytic, cytotoxic and immunomodulatory activities through anin vitro cell based assay systems.

METHODS

HeLa, A549, and a normal cell line HEK293 were used for testing cytotoxicity using MTT method. Immunomodulatory activity was performed in stimulated whole blood cells by PMA plus ionomycin. Hemolytic activity was assessed on human erythrocytes.

RESULTS

Aristatoside C (3) and davisianoside B (16) displayed significant inhibitory effects on cancerous A549 and HeLa cells, and non-cancerous HEK293 cells with IC₅₀ values of 3.52 ± 0.11, 35.69 ± 0.50, 8.96 ± 0.62 µM and 4.08 ± 0.06, 11.74 ± 0.82, 20.43 ± 3.21 µM, respectively. Thirteen saponins out of the nineteen tested increased IL-1β concentrations considerably, while six compounds changed IL-2 or IFN-γ levels slightly. Almost all of the saponins showed noticeable hemolysis in human erythrocyte cells based on the sugar units.

CONCLUSION

In this study, almost all saponins with oleanolic acid as aglycones exhibited significant hemolysis, monodesmosidic saponins with hederagenin as aglycone were the most active compounds against lung cancer cells with greater activity than standard commercial chemotherapy drug doxorubicin and some of the hederagenin type saponins induced remarkable IL-1β secretion.

Novel microspheres based on triterpene saponins from the roots of Physospermum verticillatum (Waldst & Kit) (Apiaceae) for the improvement of gemcitabine release

Objectives

This study concerns the preparation and characterization of microspheres based on a mixture of triterpene saponins, from Physospermum verticillatum (Waldst & Kit), as a carrier for the specific release of gemcitabine.

Methods

Triterpene saponins were derivatized with acrylic acid. The obtained polymerizable product was characterized by Fourier transform infrared to confirm the ester linkage. Then, spherical microparticles were prepared by suspension radical copolymerization and impregnated with gemcitabine.

Key findings

Microspheres exhibited a mean diameter of 2.7 μ. The swelling studies showed that particles swell most at pH 6.2, typical of the tumour pathology, than at pH 7.4, miming physiological conditions. The microspheres were loaded with gemcitabine (LE 72.2%). Their release profile showed an initial dot of around 24% and a further release for 24 h.

Conclusions

This carrier could be potentially release the drug in the lung, as a function of different pHs between tumour cells and healthy, reducing the systemic drug toxicity, allowing the reduction of the doses number, increasing the drug half-life and eliminating the problems related to the fast clearance of gemcitabine administration.

Evaluation of Phenolic Content Variability along with Antioxidant, Antimicrobial, and Cytotoxic Potential of Selected Traditional Medicinal Plants from India

Plants have been used since ancient times as an important source of biologically active substances. The aim of the present study was to investigate the phytochemical constituents (flavonoids and phenolics), antioxidant potential, cytotoxicity against HepG2 (human hepato carcinoma) cancer cell lines, and the antimicrobial activity of the methanol extract of selected traditional medicinal plants collected from Mizoram, India. A number of phenolic compounds were detected using HPLC-DAD-ESI-TOF-MS, mainly Luteolin, Kaempferol, Myricetin, Gallic Acid, Quercetin and Rutin, some of which have been described for the first time in the selected plants. The total phenolic and flavonoid contents showed high variation ranging from 4.44 to 181.91 μg of Gallic Acid equivalent per milligram DW (GAE/mg DW) and 3.17 to 102.2 μg of Quercetin/mg, respectively. The antioxidant capacity was determined by DPPH (IC50 values ranges from 34.22 to 131.4 μg/mL), ABTS (IC50 values ranges from 24.08 to 513.4 μg/mL), and reducing power assays. Antimicrobial activity was assayed against gram positive (Staphylococcus aureus), gram negative (Escherichia coli, Pseudomonas aeruginosa), and yeast (Candida albicans) demonstrating that the methanol extracts of some plants were efficacious antimicrobial agents. Additionally, cytotoxicity was assessed on human hepato carcinoma (HepG2) cancer cell lines and found that the extracts of Albizia lebbeck, Dillenia indica, and Bombax ceiba significantly decreased the cell viability at low concentrations with IC50 values of 24.03, 25.09, and 29.66 μg/mL, respectively. This is the first report of detection of phenolic compounds along with antimicrobial, antioxidant and cytotoxic potential of selected medicinal plants from India, which indicates that these plants might be valuable source for human and animal health.

Potent anti-proliferative effects against oral and cervical cancers of Thai medicinal plants selected from the Thai/Lanna medicinal plant recipe database "MANOSROI III"

CONTEXT

Thai/Lanna medicinal plant recipes have been used for the treatment of several diseases including oral and cervical cancers.

OBJECTIVE

To investigate anti-proliferative activity on human cervical (HeLa) and oral (KB) cancer cell lines of medicinal plants selected from Thai/Lanna medicinal plant recipe database "MANOSROI III".

MATERIALS AND METHODS

Twenty-three methanolic plant crude extracts were tested for phytochemicals and anti-proliferative activity on HeLa and KB cell lines for 24 h by the sulforhodamine B (SRB) assay at the doses of 1 × 10(1)-1 × 10(-6 )mg/ml. The nine extracts with the concentrations giving 50% growth inhibition (GI50) lower than 100 µg/ml were further semi-purified by liquid/liquid partition in order to evaluate and enhance the anti-proliferative potency.

RESULTS

All extracts contained steroids/triterpenoids, but not xanthones. The methanolic extracts of Gloriosa superba L. (Colchinaceae) root and Albizia chinensis (Osbeck) Merr. (Leguminosae-Mimosoideae) wood gave the highest anti-proliferative activity on HeLa and KB cell lines with the GI50 values of 0.91 (6.0- and 0.31-fold of cisplatin and doxorubicin) and 0.16 µg/ml (28.78- and 82.29-fold of cisplatin and doxorubicin), respectively. Hexane and methanol-water fractions of G. superba exhibited the highest anti-proliferative activity on HeLa and KB cell lines with the GI50 values of 0.15 (37- and 1.9-fold of cisplatin and doxorubicin) and 0.058 µg/ml (77.45- and 221.46-fold of cisplatin and doxorubicin), respectively.

DISCUSSION AND CONCLUSION

This study has demonstrated the potential of plants selected from MANOSROI III database especially G. superba and A. chinensis for further development as anti-oral and cervical cancer agents.

Potent Antiproliferative Effect on Liver Cancer of Medicinal Plants Selected from the Thai/Lanna Medicinal Plant Recipe Database "MANOSROI III"

Thai/Lanna medicinal plant recipes have been used for the treatment of several diseases including liver cancer. In this study, methanolic extracts (MEs) of 23 plants were tested for antiproliferative activity on human hepatoma cell line (Hep G2) by the sulforhodamine B (SRB) assay. Nine MEs with potent antiproliferative activity (IC50 < 100 µg/mL) were obtained and further semipurified by liquid/liquid partition extraction. The semipurified fractions were tested for the antiproliferative and antioxidative activities. ME of Stemona collinsae and the semipurified extract and methanol-water fraction (MF) of Gloriosa superba gave the highest antiproliferative activity on HepG2 which were 4.79- and 50.07-fold cisplatin, respectively. The semipurified fractions showed an increased antiproliferative activity. MF of Caesalpinia sappan and HF of Senna alata showed the highest free radical scavenging and metal chelating activities, respectively. The compound in n-hexane fraction (HF) of Ventilago denticulata which showed an increase in antiproliferative activity comparing to its ME was isolated and identified as emodin. This study has demonstrated the potential of the ME from S. collinsae, MF from G. superba, and emodin isolated from V. denticulata, for further development as an antiliver cancer agent.

Analysis of carbohydrates and glycoconjugates by matrix-assisted laser desorption/ionization mass spectrometry: an update for 2009-2010

This review is the sixth update of the original article published in 1999 on the application of MALDI mass spectrometry to the analysis of carbohydrates and glycoconjugates and brings coverage of the literature to the end of 2010. General aspects such as theory of the MALDI process, matrices, derivatization, MALDI imaging, arrays and fragmentation are covered in the first part of the review and applications to various structural typed constitutes the remainder. The main groups of compound that are discussed in this section are oligo and polysaccharides, glycoproteins, glycolipids, glycosides and biopharmaceuticals. Many of these applications are presented in tabular form. Also discussed are medical and industrial applications of the technique, studies of enzyme reactions and applications to chemical synthesis.

Triterpenoid saponins from Albizia lebbeck (L.) Benth and their inhibitory effect on the survival of high grade human brain tumor cells

As part of our search of new bioactive triterpenoid saponins from Cameroonian Mimosaceae plants, phytochemical investigation of the roots of Albizia lebbeck led to the isolation of two new oleanane-type saponins, named lebbeckosides A-B (1-2). Their structures were established on the basis of extensive 1D and 2D NMR ((1)H, (13)C NMR, DEPT, COSY, TOCSY, ROESY, HSQC, and HMBC) and HRESIMS studies, and by chemical evidence. Compounds 1-2 were evaluated for their inhibitory effect on the metabolism of high grade human brain tumor cells, the human glioblastoma U-87 MG cell lines and the glioblastoma stem-like TG1 cells isolated from a patient tumor, and known to be particularly resistant to standard therapies. The isolated saponins showed significant cytotoxic activity against U-87 MG and TG1 cancer cells with IC50 values of 3.46 μM and 1.36 μM for 1, and 2.10 μM and 2.24 μM for 2, respectively.

Potent anti-cervical cancer activity: synergistic effects of Thai medicinal plants in recipe N040 selected from the MANOSROI III database

ETHNOPHARMACOLOGICAL RELEVANCES

One of the prestigious Thai/Lanna folklore wisdoms is the medicinal plant recipes. Thai/Lanna medicinal plant recipe database MANOSROI III has been developed by Prof. Dr. Jiradej Manosroi. It consists of over 200,000 recipes covering all diseases including cancer.

AIM OF THIS STUDY

To investigate the in vitro and in vivo anti-cervical cancer activity and the active constituents of the Thai medicinal plant recipe N040 selected from the MANOSROI III database.

MATERIALS AND METHODS

The extracts of recipe N040 and single medicinal plants in the recipe were prepared by hot water and methanol extraction, respectively. The n-hexane, ethyl acetate (EtOAc), n-butanol (n-BuOH) and water fractions of Caesalpinia sappan, the plant which showed the highest anti-proliferative activity were prepared by liquid-liquid partition extraction. The fraction which showed the highest anti-proliferative activity was further isolated for active constituents. Anti-proliferative activity of recipe N040, methanolic extracts, fractions of Caesalpinia sappan and brazilin, an active constituent on HeLa cell were investigated using sulforhodamine B (SRB) assay. Anti-oxidative activities including free radical scavenging and metal ion-chelating activities, as well as the phenolic and flavonoid contents of these fractions were also determined. The in vivo anti-cancer activity of recipe N040 on HeLa cell xenograft and the subchronic toxicity were performed in nude mice and rats, respectively.

RESULTS AND CONCLUSIONS

N040 showed the potent in vitro anti-proliferative activity on HeLa cell with the IC50 value of 0.11 µg/ml. Phytochemicals detected in the plants were steroids/triterpenoids, tannins, flavonoids, saponins and alkaloids. For the single plant, methanolic extract of Caesalpinia sappan gave the highest anti-proliferative activity with the IC50 of 33.46 µg/ml. EtOAc fraction of Caesalpinia sappan showed the highest anti-proliferative and free radical scavenging activities with the IC50 and SC50 of 17.81 and 21.95 µg/ml which were 1.88 and 0.83 folds of its methanolic extract and ascorbic acid, respectively. Poor metal chelating activity (MC50>500 µg/ml) was observed in methanolic extract and all fractions. The highest phenolic and flavonoid contents were observed in the methanolic extract. Brazilin, the known compound isolated from the EtOAc fraction exhibited potent anti-proliferative activity with the IC50 of 0.28 µg/ml which was higher than its methanolic extract and EtOAc fraction of 119.50 and 63.61 folds, respectively, but only 0.39 fold of the recipe extract N040. The tumor size of the HeLa cell xenograft nude mice treated with the recipe N040 at the dose of 44.50mg/kg body weight per day was significantly smaller (p<0.05) than that of the control with the relative tumor weight inhibition of 57.23% which was 0.65 fold of cisplatin. In the subchronic toxicity study, N040 given orally at the dose of 1000 mg/kg body weight per day for 90 days showed no alteration in body weight gain, hematology [except the increase mean corpuscular hemoglobin (MCH) in the treated male rats] and clinical blood chemistry (except the increase blood glucose in the treated male rats) both in female and male rats. Only minor lesions of the organs including lung, liver, kidney and small intestine were observed in both sexes. This study has demonstrated the synergistic effect of the plants composed in the recipe which resulted in the potent anti-cancer activity and confirmed the traditionally use of the recipe N040. In addition, this study has also suggested the compound brazilin isolated from Caesalpinia sappan for its high potential to be further investigated as a novel anti-cervical cancer drug.

Chemical Fingerprint Analysis of Phenolics of Albizia chinensis Based on Ultra-Performance LC-Electrospray Ionization-Quadrupole Time-of-Flight Mass Spectrometry and Antioxidant Activity

Albizia species have been shown to have anti-inflammatory and antiallergic properties. However, efficient analytical methods for identification of their active constituents are still lacking. Ultra-performance liquid chromatography coupled with electrospray ionization-quadrupole time-of-flight mass spectrometry (UPLC-ESI-QTOF-MS) was used to study the phenolic composition of the ethanolic extracts of different parts (flowers, leaves, pods and bark) of A. chinensis. In addition, the antioxidant activity of the ethanolic extracts was evaluated by the 1,1-diphenyl-2-picryl hydrazyl (DPPH) free-radical and 2,2′-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid (ABTS) radical cation scavenging methods. Four compounds were isolated from the ethanolic extract of the flowers and characterized by 1H and 13C NMR spectroscopy as quercetin-3- O-rhamnoside, quercetin, quercetin-3- O-arabinofuranoside, and myricetin-3- O-rhamnoside. Separation and quantification of the phenolics was accomplished using a reversed-phase BEH C18 column with the mobile phase of methanol–water (0.05% formic acid), and detection wavelengths of 360 and 254 nm.

Triterpenoids

This review covers the isolation and structure determination of triterpenoids, including squalene derivatives, protostanes, lanostanes, holostanes, cycloartanes, dammaranes, euphanes, tirucallanes, tetranortriterpenoids, quassinoids, lupanes, oleananes, friedelanes, ursanes, hopanes, serratanes and saponins; 278 references are cited.

Structure elucidation of new acacic acid-type saponins from Albizia coriaria

Three new acacic acid derivatives, named coriariosides C, D, and E (1-3) were isolated from the roots of Albizia coriaria. Their structures were elucidated on the basis of extensive 1D- and 2D-NMR studies and mass spectrometry as 3-O-[β-D-xylopyranosyl-(1 → 2)-β-D-fucopyranosyl-(1 → 6)-2-(acetamido)-2-deoxy-β-D-glucopyranosyl]-21-O-{(2E,6S)-6-O-{4-O-[(2E,6S)-2,6-dimethyl- 6-O-(β-D-quinovopyranosyl)octa-2,7-dienoyl]-4-O-[(2E,6S)-2,6-dimethyl-6-O-(β-D-quinovopyranosyl)octa-2,7-dienoyl]-β-D-quinovopyranosyl}-2,6-dimethylocta-2,7-dienoyl}acacic acid 28-O-β-D-xylopyranosyl-(1 → 4)-α-L-rhamnopyranosyl-(1 → 2)-β-D-glucopyranosyl ester (1), 3-O-{β-D-fucopyranosyl-(1 → 6)-[β-D-glucopyranosyl-(1 → 2)]-β-D-glucopyranosyl}-21-O-{(2E,6S)-6-O-{4-O-[(2E,6S)-2,6-dimethyl-6-O-(β-D-quinovopyranosyl)octa-2,7-dienoyl]-4-O-[(2E,6S)-2,6-dimethyl-6-O-(β-D-quinovopyranosyl)octa-2,7-dienoyl]-β-D-quinovopyranosyl}-2,6-dimethylocta-2,7-dienoyl}acacic acid 28-O-α-L-rhamno pyranosyl-(1 → 2)-β-D-glucopyranosyl ester (2), and 3-O-[β-D-fucopyranosyl-(1 → 6)-β-D-glucopyranosyl]-21-O-{(2E,6S)-6-O-{4-O-[(2E,6S)-2,6-dimethyl-6-O-(β-D-quinovopyranosyl)octa-2,7-dienoyl)-β-D-quinovopyranosyl]octa-2,7-dienoyl}acacic acid 28-O-β-D-glucopyranosyl ester (3).

Saponins as cytotoxic agents: a review

Saponins are natural glycosides which possess a wide range of pharmacological properties including cytotoxic activity. In this review, the recent studies (2005-2009) concerning the cytotoxic activity of saponins have been summarized. The correlations between the structure and the cytotoxicity of both steroid and triterpenoid saponins have been described as well as the most common mechanisms of action.

Echinocystic acid 3,16-O-bisglycosides from Albizia procera

Three triterpene glycosides and two known ones were isolated from the bark of Albizia procera by using chromatographic techniques. The structures of the compounds were determined to be 3-O-beta-D-xylopyranosyl-(1-->2)-beta-D-galactopyranosyl-(1-->6)-2-acetamido-2-deoxy-beta-D-glucopyranosyl echinocystic acid 16-O-beta-D-glucopyranoside, 3-O-beta-D-xylopyranosyl-(1-->2)-alpha-L-arabinopyranosyl-(1-->6)-2-acetamido-2-deoxy-beta-D-glucopyranosyl echinocystic acid 16-O-beta-D-glucopyranoside and 3-O-alpha-L-arabinopyranosyl-(1-->2)-alpha-L-arabinopyranosyl-(1-->6)-2-acetamido-2-deoxy-beta-D-glucopyranosyl echinocystic acid 16-O-beta-D-glucopyranoside. Their structures were determined by NMR techniques including HOHAHA, (1)H-(1)H COSY, ROE, HMQC and HMBC experiments together with FABMS as well as acid hydrolysis. To the best of our knowledge, the new compounds are considered the first examples of echinocystic acid 3,16-O-bisglycosides. In contrast to other cytotoxic echinocystic acid glycosides with N-acetyl glucosamine unit, the new glycosides were found inactive when assayed by MTT method for their cytotoxicities against the human tumor cell lines HEPG2, A549, HT29 and MCF7. The results showed the importance of the free hydroxyl group at the aglycone C-16 for exhibiting cytotoxic properties.

Cytotoxic activity and inhibitory effect on nitric oxide production of triterpene saponins from the roots of Physospermum verticillatum (Waldst & Kit) (Apiaceae)

Three triterpene saponins isolated from the roots of Physospermum verticillatum and identified as saikosaponin a (1), buddlejasaponin IV (2), and songarosaponin D (3) were investigated in vitro for their cytotoxic activity against a panel of seven different cancer cell lines including ACHN, C32, Caco-2, COR-L23, A375, A549, and Huh-7D12 cell lines. The hydrolysis of sugar unit was performed on saikosaponin a (1) to obtain saikosapogenin a (4). All isolated saponins exhibited strong cytotoxic activity against COR-L23 cell line with IC(50) values ranged from 0.4 to 0.6 microM. A similar activity was recorded for saikogenin a (4). None of the tested compounds affected the proliferation of skin fibroblasts 142BR suggesting a selective action against cancer cells. Moreover, buddlejasaponin IV (2) and songarosaponin D (3) exerted significant inhibition of NO production in LPS induced RAW 264.7 macrophages with IC(50) of 4.2 and 10.4 microM, respectively.