Phenylethanoid and flavone glycosides from Ruellia tuberosa L.

A new phenylethanoid glycoside, isocassifolioside (8), and two new flavone glycosides, hispidulin 7-O-α-l-rhamnopyranosyl-(1′″ → 2″)-O-β-d-glucuronopyranoside (11) and pectolinaringenin 7-O-α-l-rhamnopyranosyl-(1′″ → 2″)-O-β-d-glucuronopyranoside (12) were isolated from the aerial portions of Ruellia tuberosa L., together with verbascoside (1), isoverbascoside (2), nuomioside (3), isonuomioside (4), forsythoside B (5), paucifloside (6), cassifolioside (7), hispidulin 7-O-β-d-glucuronopyranoside (9) and comanthoside B (10). The structure elucidations were based on analyses of chemical and spectroscopic data including 1D- and 2D-NMR. The isolated compounds 1–12 exhibited radical scavenging activity using ORAC assay.     

Flavonoids from Astragalus membranaceus and their inhibitory effects on LPS-stimulated pro-inflammatory cytokine production in bone marrow-derived dendritic cells

Radix Astragali (Astragalus membranaceus) is an important traditional Chinese medicine that is widely used as a tonic to enhance the body’s natural defense mechanisms. In this phytochemical study, 12 flavonoids, isoliquiritigenin (1), liquiritigenin (2), calycosin (3), calycosin 7-O-β-d-glucoside (4), formononetin (5), formononetin 7-O-β-d-glucoside (6), daidzein (7), daidzein 7-O-β-d-glucoside (8), methylnissolin (9), methylnissolin 3-O-β-d-glucoside (10), isomucronulatol (11), and isomucronulatol 7-O-β-d-glucoside (12), were isolated from the roots of A. membranaceus. Their structures were elucidated by comparing spectroscopic data with reported values. The effects of the isolated compounds on lipopolysaccharide (LPS)-stimulated bone marrow-derived dendritic cells were investigated. Compounds 1 and 2 exhibited significant inhibitory effects on LPS-induced IL-6 and IL-12 p40 production, with IC₅₀ values ranging from 2.7 to 6.1 μM. Compound 1 also showed a moderate inhibitory effect on LPS-stimulated production of TNF-α with an IC₅₀ value of 20.1 μM. Further studies of the potential anti-inflammatory effects and benefits of flavonoids from A. membranaceus are warranted.     

Collagenase inhibitors from Viola yedoensis

Fractionation of acetone and methanol extracts of Viola yedoensis, under the guidance of inhibition against Clostridium histolyticum collagenase (ChC), resulted in the isolation of esculetin (1) (IC₅₀ 12 μM) and scopoletin (2) (IC₅₀ 1.8 μM) as the active constituents, together with trans-p-coumaric acid (3), cis-p-coumaric acid (4), 3-O-β-d-glucosyl-7-O-α-L-rhamnosylkaempferol (5), rutin (6), isovitexin (7), isoorientin (8), vicenin-2 (9), isoscoparin (10), vanillic acid (11) and adenosine (12). Modification of phenolic hydroxy groups of 1 showed that small O-alkyl groups largely increased the activity, whereas larger O-alkyl groups decreased the activity, and 6,7-dimethoxycoumarin (scoparone 13) potently inhibited ChC (IC₅₀ 24 nM).     

A novel saponin from Manilkara hexandra seeds and anti-inflammatory activity

Chromatographic separation of acetone precipitate of the seeds of Manilkara hexandra has resulted in a novel saponin, 3-O-(β-d-apiofuranosyl-(1 → 3)-β-d-glucopyranosyl)-28-O-(α-l-rhamnopyranosyl(1 → 3)-β-d-xylopyranosyl(1 → 4)-α-l-rhamnopyranosyl(1 → 2)-α-l-arabinopyranosyl)-16-α-hydroxyprotobassic acid (Saponin 3), together with two known saponins isolated for the first time from the family Sapotaceae, viz, 3-O-β-d-glucopyranosyl(1 → 6)[(β-d-apiofuranosyl-(1 → 3)]-β-d-glucopyranosyl)-28-O-(α-l-rhamnopyranosyl(1 → 3)-β-d-xylopyranosyl(1 → 4)-α-l-rhamnopyranosyl(1 → 2)-α-l-arabinopyranosyl)-16α-hydroxyprotobassic acid (Saponin 1), 3-O-(β-d-glucopyranosyl)-28-O-(α-l-rhamnopyranosyl(1 → 3)-β-d-xylopyranosyl(1 → 4)-α-l-rhamnopyranosyl(1 → 2)-α-l-arabinopyranosyl)-protobassic acid, and 3-O-(β-d-glucopyranosyl)-28-O-(α-l-rhamnopyranosyl(1 → 3)-β-d-xylopyranosyl(1 → 4)-α-l-rhamnopyranosyl(1 → 2)-α-l-arabinopyranosyl)-protobassic acid (Saponin 2). Also, three known phenolic compounds were isolated for the first time from the species hexandra, viz, gallic acid, myrecetin, and quercetin. The chemical structures of the isolated saponin compounds were established by spectral techniques (UV, ¹H, ¹³C NMR, and MS). The acetone fraction containing the crude saponin mixture possessed a significant inhibitory effect on LPS-induced nitric oxide to the extent of 60 % compared to the LPS-stimulated cells and to the extent of 20 % compared to the control level showing significant anti-inflammatory activity. Acetone and MeOH seed extracts as well as the crude saponin fraction of M. hexandra showed no antioxidant activity as measured by DPPH assay (SC₅₀ = 217.65, 496.68, and 562.38 μg/ml, respectively) compared to that of ascorbic acid (SC₅₀ = 12.9). The MeOH seed extract showed no cytotoxic activity against three different human cancer cell lines, viz, colon carcinoma (HCT-116), hepatocellular carcinoma (Hep-G2), and breast adenocarcinoma (MCF-7), estimated by MTT assay (IC₅₀ = 95.20, 73.39, and 79.15 μg/ml, respectively).     

Evaluation of antioxidant activity of new constituents from the fruits of Lycium chinense

Two new compounds as labd-7,11-dien-3β, 13α-diol-3α-l-arabinopyranosyl-(2a → 1b)-α-l-arabinopyranosyl-(2b → 1c)-α-l-arabinopyranosyl-(2c → 1d)-α-l-arabinopyranosyl-(2d → 1e)-α-l-arabinopyranosyl-(2e → 1f)-α-l-arabinopyranosyl-(2f → 1g)-α-l-arabinopyranoside (1), and 5 (6), 11 (12), 15 (15′), 5′ (6′), 11′ (12′)-decadehydro-β-carotenyl-4β,4′β-diol-4-α-l-arabinopyranosyl-(2a → 1b)-α-l-arabinopyranosyl-(2b → 1c)-α-l-arabinopyranosyl-(2c → 1d)-β-l-arabinopyranosido-4′-α-l-arabinopyranosyl-(2e → 1f)-α-l-arabinopyranosyl-(2f → 1g)-α-l-arabinopyranosyl-(2g → 1h)-α-l-arabinopyranosyl-(2h → 1i)-β-l-arabinopyranoside (2) along with known compound have been isolated from the methanol extract of fruits of Lycium chinense. Their chemical structures were established with the help of physical, chemical, and spectroscopic methods. The compounds 1 and 2 were investigated for scavenging of the diphenylpicrylhydrazyl (DPPH) radical scavenging activity, reducing power, and the phosphomolybdenum activity, and the results demonstrate that the compound (1) has potential as a natural antioxidant whereas the compound (2) exhibited moderate antioxidant activity.     

New cycloartane glycosides from the aerial part of Thalictrum fortunei

Four new cycloartane glycosides, 3-O-β-d-xylopyranosyl-(1 → 6)-β-d-glucopyranosyl-(1 → 4)-β-d-fucopyranosyl (22S,24Z)-cycloart-24-en-3β,22,26-triol 26-O-(6-O-acetyl)-β-d-glucopyranoside (1), 3-O-α-l-arabinopyranosyl-(1 → 6)-β-d-glucopyranosyl-(1 → 4)-β-d-fucopyranosyl (22S,24Z)-cycloart-24-en-3β,22,26-triol 26-O-(6-O-acetyl)-β-d-glucopyranoside (2), 3-O-β-d-glucopyranosyl (24S)-cycloartane-3β,16β,24,25,30-pentaol 25-O-β-d-glucopyranosyl-(1 → 6)-β-d-glucopyranoside (3) and 3-O-β-d-glucopyranosyl (24S)-cycloartane-3β,16β,24,25,30-pentaol 25-O-β-d-glucopyranosyl-(1 → 4)-β-d-glucopyranoside (4), were isolated from the aerial parts of Thalictrum fortunei. Their structures were established on the basis of extensive NMR and HR-ESI-MS analyses, along with acid hydrolysis.     

Novel quercetin glucosides from Helminthostachys zeylanica root and acceleratory activity of melanin biosynthesis

Two novel quercetin glucosides, namely 4′-O-β-d-glucopyranosyl-quercetin-3-O-β-d-glucopyranosyl-(1→4)-β-d-glucopyranoside (compound 1) and 4′-O-β-d-glucopyranosyl-(1→2)-β-d-glucopyranosyl-quercetin-3-O-β-d-glucopyranosyl-(1→4)-β-d-glucopyranoside (compound 2), were isolated from Helminthostachys zeylanica root 50 % EtOH extract. Structural analysis of isolated compounds was achieved mainly by 600 MHz and 800 MHz NMR, UPLC–TOFMS and GC–MS. Of the two quercetin glucosides, compound 1 showed a high melanogenic acceleratory effect, 2.7 times higher than control, at 10 μM concentration in murine B16 melanoma cells, with no cytotoxic effect.     

(−)-Catechin glycosides from Ulmus davidiana

Extensive chromatographic separation of the n-BuOH soluble fraction obtained from the stem and root barks of U. davidiana resulted in five hitherto unknown compounds together with a known one (?)-catechin 1. Structures of the five compounds were elucidated by chemical and spectroscopic analyses, to be (?)-catechin-7-O-gallate-5-O-(5″″-trans-caffeoyl)-β-d-apiofuranoside-3-O-β-d-apiofuranosyl-(1 → 2)-β-d-glucopyranoside 2, (?)-catechin-7-O-gallate-5-O-(5″″-trans-caffeoyl)-β-d-apiofuranoside-3-O-β-d-glucopyranoside 3, (?)-catechin-7-O-gallate-5-O-β-d-apiofuranoside-3-O-(2″-O-galloyl)-β-d-glucopyranoside 4, (?)-catechin-7-O-gallate-5-O-(5″″-trans-caffeoyl)-β-d-apiofuranoside 5, and (?)-catechin-7-O-gallate-5-O-(5″″-trans-feruloyl)-β-d-apiofuranoside 6.     

A new anti-inflammatory triterpene saponin isolated from Anabasis setifera

A bio-guided fractionation of Anabasis setifera Moq. (Chenopodiaceae) for anti-inflammatory activity was carried out using carrageenin rat paw edema model in rats. On the basis of percent edema inhibition after 3 h of carrageenin injection, n-butanol fraction showed promising activity through a significant (p < 0.05) decrease in paw volume by 85.6 % from control using indomethacin as reference standard. Moreover, the n-butanol fraction significantly (p < 0.05) decreased PGE₂ and TNF-α in the exudates of rat paw edema. Chemical investigation of n-butanol fraction afforded α-amyrin 3-O-glucopyranoside (1), patuletin 7-O-glucopyranoside (2), myricitrin (3) and a new oleanane triterpene saponin derivative (4), sophradiol 3-O-α-l-¹C₄-rhamnopyranosyl-(1′′′→4′′)-O-β-d-⁴C₁-galactopyranosyl (1′′→6′)-O-β-d-⁴C₁-glucopyranoside. The structure of the new compound was determined by comprehensive analyses of their 1D and 2D NMR, mass spectral data and comparison with previously known analogs. Only compound 4 revealed a significant (p < 0.05) inhibition of cyclooxygenase 1 and 2 (COX) activities.     

Steroidal saponins from the leaves of Yucca de-smetiana and their in vitro antitumor activity: structure activity relationships through a molecular modeling approach

Four steroidal saponins were isolated from the leaves of Yucca de-smetiana Baker. Their structures were established using one- and two- dimensional NMR spectroscopy and mass spectrometry. The structure of the new steroidal saponin was identified as: (25R)-3β-hydroxy-5α-spirostan-3-O-β-d-xylopyranosyl-(1 → 2)-β-d-galactopyranosyl-(1 → 2)-O-[β-d-glucopyranosyl-(1 → 3)]-β-d-glucopyranosyl-(1 → 4)-β-d-galactopyranoside (desmettianoside C) along with three known spirostanol and furostanol saponins. The isolated saponins were evaluated for their antitumor activity against HCT116, MCF7, HepG2, and A549 cell lines. Saponins 3 and 4 showed potent activity against HCT116, MCF7, and HepG2 cell lines in comparison with the positive control doxorubicin. A molecular modeling approach was performed to establish conformational criteria that could affect the biological activity of the isolated saponins.     

Antihepatotoxic, nephroprotective, and antioxidant activities of phenolic compounds from Satureja macrostema leaves against carbon tetrachloride-induced hepatic damage in mice

Satureja macrostema (SM) is used with culinary and medicinal purposes. Methanol extract from SM was investigated for its phenolic content, antioxidant, hepatoprotective, and kidney protective activities. Liver and kidney damage were induced in rats with CCl₄. Hepatoprotective efficacy was measured by the activity of aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, total bilirubin, cholesterol, high density lipoprotein and total protein, and lipid peroxidation. Kidney function was evaluated by measuring plasma urea and creatinine. Antioxidant activity was evaluated by measuring blood glutathione content, superoxide dismutase and catalase activities, and malondialdehyde equivalent; their activity was comparable to that of silymarin, a well-known hepatoprotective agent. Methanol extracts of S. macrostema showed potent antioxidant, kidney protective, and hepatoprotective activities; in-depth chromatographic investigation resulted in the identification of six new flavonoid glycosides: 5-hydroxy-3,6,4′-trimethoxyflavonol-7-C-α-l-rhamnopyranosyl-(1 → 3)-β-d-glucopyranoside (2), 4′-methoxy-5,7,3′,5′-tetra-hydroxyflavanone-3-O-β-d-rhamnopyranosyl-(1 → 2)-β-d-rhamnopyranoside (3), 5,4′-dimethoxy-7,3′,5′-trihydroxyflavanone-3-O-β-d-rhamnopyranoside (4), 5,3′,4′,5′-tetrahydroxyflavanone-7-O-β-d-rhamnopyranoside (5), 5,3′,4′,5′-tetramethoxyflavanone-7-O-β-d-rhamnopyranoside (6), and 5,4′-dimethoxy-3′-hydroxyflavone-7-β-d-rhamnopyranoside (8) along with three known compounds: 5-hydroxy-7,4′-dimethoxyflavone (1), prunin (7), and diosmin (9) that were isolated. Structural elucidation of the new compounds was established based on the spectral data. The present study revealed that S. macrostema leaves have a significant radical scavenging and hepatoprotective activity.     

Inhibition of DNA topoisomerases I and II of compounds from Reynoutria japonica

Three anthraquinones (1, 2 and 4), three stilbenes (5, 6 and 7) and 3,5-dihydroxybenzyl alcohol (3) were isolated from Reynoutria japonica. Their structures were identified as emodin (1), emodin-8-O-??-d-glucoside (2), 3,5-dihydroxybenzyl alcohol (3), citreorosein (4), cis-resveratrol (5), trans-resveratrol (6) and trans-resveratrol-5-O-??-d-glucopyranoside (7) by comparing their physicochemical and spectral data with published data. Compound 3 was isolated for the first time from the Polygonaceae family. Among the purified compounds, 3 showed more potent inhibitory activity against topoisomerase I (IC₅₀: 4 ??M) than camptothecin, as the positive control (IC₅₀: 18 ??M). Compounds 3, 4, 5, 6 and 7 showed stronger inhibitory activities toward DNA topoisomerase II (IC₅₀: 0.54, 14, 15, 0.77 and 3 ??M, respectively) than the positive control, etoposide (IC₅₀: 44 ??M). Compounds 1 and 4 displayed weak cytotoxicities against human lung cancer (A549), ovarian cancer (SK-OV-3), human liver hepatoblastoma (HepG2) and colon adenocarcinoma (HT-29) cell lines.     

Induced-fit docking and binding free energy calculation on furostanol saponins from Tupistra chinensis as epidermal growth factor receptor inhibitors

Three furostanol saponins isolated from Tupistra chinensis were studied to investigate the reasons for their different inhibitory activities toward non-small-cell lung cancer (NSCLC) A549 cell using induced-fit docking (IFD) between them and epidermal growth factor receptor (EGFR). Their binding free energies were also calculated by molecular mechanics–generalized Born surface area (MM–GBSA) method. The calculation results were all in excellent agreement with experimental activities (IC₅₀ values of compound 1–3 against NSCLC A549 cell: 6.6, 6.7, and 29.1 μM). With EGFR (PDB code: 1M17 and 2ITY), the docking IFD score, binding free energy, and binding free energy neglecting the effect of entropy contributions of compound 1 ((25R)-26-O-β-d-glucopyranosyl-furost-1β,3β,22α,26-tetrahydroxy-3-O-β-d-glucopyranoside) were ?553.9223, ?59.6101, and ?70.8088 kcal/mol in 1M17 (?536.2678, ?62.2158, and ?68.4053 kcal/mol in 2ITY), respectively. The binding sites of compound 1 are similar to erlotinib in 1M17 and gefitinib in 2ITY. There are two hydrogen bonds between compound 1 and the key amino acid residue Met769 in 1M17 or Met793 in 2ITY. The only structure difference between compound 3 and compound 1 is 5-hydroxyl polar group in compound 3, which hinders the hydrophobic interactions with EGFR and increases polar solvation free energy term that opposes binding. This indicates that compound 1 could be a potent EGFR inhibitor for NSCLC treatment.     

Acylated phenylethanoid glycosides,echinacoside and acteoside from Cistanche tubulosa,improve glucose tolerance in mice

Acylated phenylethanoid glycosides, echinacoside (1) and acteoside (2), principal constituents in stems of Cistanche tubulosa (Orobanchaceae), inhibited the increase in postprandial blood glucose levels in starch-loaded mice at doses of 250–500 mg/kg p.o. These compounds (1 and 2) also significantly improved glucose tolerance in starch-loaded mice after 2 weeks of continuous administration at doses of 125 and/or 250 mg/kg/day p.o. without producing significant changes in body weight or food intake. In addition, several constituents from C. tubulosa, including 1 (IC₅₀ = 3.1 μM), 2 (1.2 μM), isoacteoside (3, 4.6 μM), 2′-acetylacteoside (4, 0.071 μM), tubulosides A (5, 8.8 μM) and B (9, 4.0 μM), syringalide A 3-O-α-l-rhamnopyranoside (10, 1.1 μM), campneoside I (13, 0.53 μM), and kankanoside J₁ (14, 9.3 μM), demonstrated potent rat lens aldose reductase inhibitory activity. In particular, the potency of compound 4 was similar to that of epalrestat (0.072 μM), a clinical aldose reductase inhibitor.     

Cytotoxic and anti-inflammatory constituents from the seeds of Descurainia sophia

A new sinapoyl glycoside, 1,3-di-O-sinapoyl-β-d-glucopyranose (1) along with 13 known compounds, including, sinapoyl glycosides (2 and 3), cardenolide glycoside (4), flavonoids (5–10), lignan (11), phenolic acids (12 and 13), and phytosterol (14), were isolated from the seeds of Descurainia sophia by chromatographic separation methods. The structures of 1–14 were determined by the interpretation of spectroscopic data as well as by comparison of that data with previously reported values. Compounds 2, 3, 5, 6, and 11 were identified in and isolated from this plant for the first time in this study. All isolates were evaluated for in vitro cytotoxic activities against seven human cancer cell lines and for in vitro anti-inflammatory potential using LPS-stimulated RAW264.7 murine macrophages. Compound 4 showed potent cytotoxicity (IC₅₀ values ranging from 0.034 to 0.596 μM) against all human cancer cell lines tested and was identified as the main active cytotoxic constituent of this plant. Compound 8 (ED₅₀ = 5.45 μM) and 11 (ED₅₀ = 10.02 μM) exerted dose-dependent inhibitory effects on NO production in LPS-stimulated RAW264.7 cells.     

Phytochemical constituents of Mongolian traditional medicinal plants, Chamaerhodos erecta and C. altaica, and its constituents prevents the extracellular matrix degradation factors

Activity-guided isolation of the n-butanol fraction of Chamaerhodos erecta and water soluble fraction of C. altaica resulted in the isolation of 39 compounds, including new compounds identified as 4,5-dihydroxybenzaldehyde-3-O-β-d-glucopyranoside (1) from C. erecta and quercetin-3-O-β-d-glucuronopyranosyl-4′-O-β-d-glucopyranoside (2) from C. altaica. A total of 37 other compounds were identified based on physico-chemical properties and spectroscopic data. Antioxidative activity was evaluated using a DPPH radical-scavenging method, hyaluronidase inhibitory activity, and advanced glycation end products production inhibitory activity of isolated compounds. Some flavonols (4, 6, 9–11, 14, 15), catechins (18, 19), an amino acid (20), a lignan glucoside (23), and tannins (29–39) exhibited potential a free radical scavenging activity while the new compound (1) showed weak activity. A catechin (18) and some of the tannins (32, 33, 35, 36, 38) had moderate hyaluronidase inhibitory activity. Some of flavonoids and tannins prevented advanced glycation end products production, and the IC₅₀ of compounds 3, 9, 14–16, 33, 34, 36, 38, and 39 were determined.     

Protective effect of Centaurea pallescens Del. against CCl4-induced injury on a human hepatoma cell line (Huh7)

Through a hepatoprotective bioassay-guided fractionation of the methanol extract from Centaurea pallescens Del. (Asteraceae), a new acylated flavonoid triglycoside, 4′-methoxy kaempferol 3-O-[α-l-rhamnopyranosyl-(1→3)-(2-O-E-p-coumaroyl)] β-d-glucopyranoside-7-O-(4-O-E-p-coumaroyl) α-l-rhamnopyranoside (1) was isolated from the highly active aqueous fraction. In addition, six known compounds were isolated from both aqueous (2–3) and ethyl acetate soluble fractions (4–7). The structure of (1) was determined by comprehensive analysis of 1D and 2D NMR and mass spectral data. The protective effects of the methanol extract of C. pallescens and its fractions on the human hepatoma cell line were evaluated using Silymarin as a positive control. Hepatoprotection was assessed through determination of aspartate aminotransferase (AST), alanine transaminase (ALT), and superoxide dismutase (SOD) activities in addition to glutathione (GSH) levels before and after incubating the cells with carbon tetrachloride. Compound 1, the major constituent of the aqueous fraction, showed a significant cytoprotection at 100 μg/mL as evidenced by decreasing ALT activity to 18.6 ± 0.12, and enhancing SOD activity to 264.6 ± 4.3 U/mL. Meanwhile, compound 2 at 10 μg/mL decreased AST activity to 5.8 ± 2.4 U/mL. Moreover, Compounds 2 and 3 at 1,000 μg/mL significantly enhanced GSH levels. In conclusion, the protective effects of C. pallescens extract, its fractions and compounds 1–3 are concluded to be partly mediated by its antioxidant activity.     

New minor glycoside components from saffron

Phytochemical investigation of the stigmas of Crocus sativus resulted in the isolation of eight glycosides (1–8) including a new safranal glycoside (2) and a new carotenoid pigment (6). The structures of the new compounds were identified as (4R)-4-hydroxy-2,6,6-trimethylcyclohex-1-enecarbaldehyde 4-O-[β-d-glucopyranosyl(1 → 3)-β-d-glucopyranoside] (2) and trans-crocetin-1-al 1-O-β-gentiobiosyl ester (6) on the basis of extensive chemical and spectroscopic evidence.     

Triterpenoid saponins from the root of Anemone tomentosa

Three new triterpenoid saponins, tomentoside A (1), B (2) and C (3), along with four known saponins (4?C7) were isolated from the root of Anemone tomentosa. The structures of the new compounds were elucidated as 3-O-??-d-ribopyranosyl-(1??3)-??-l-rhamnopyranosyl-(1??2)-[??-d-glucopyranosyl-(1??4)]-??-l-arabinopyranosyl hederagenin 28-O-??-l-rhamnopyranosyl-(1??4)-??-d-glucopyranosyl-(1??6)-??-d-glucopyranoside (1), 3-O-??-d-ribopyranosyl-(1??3)-??-l-rhamnopyranosyl-(1??2)-[??-d-glucopyranosyl-(1??4)]-??-d-xylopyranosyl hederagenin 28-O-??-l-rhamnopyranosyl-(1??4)-??-d-glucopyranosyl-(1??6)-??-d-glucopyranoside (2) and 3-O-??-d-galactopyranosyl-(1??3)-??-l-rhamnopyranosyl-(1??2)-??-d-xylopyranosyl oleanolic acid 28-O-??-l-rhamnopyranosyl-(1??4)-??-d-glucopyranosyl-(1??6)-??-d-glucopyranoside (3) on the basis of chemical and spectral evidence. In the oligosaccharide chains of compound 3, the characteristic d-galactose residue is a rare structural feature and secondly encountered among triterpenoid saponins from Anemone.     

Synthesis and antiproliferative activity evaluation of imidazole-based indeno[1,2-b]quinoline-9,11-dione derivatives

A series of new imidazole substituted indeno[1,2-b]quinoline-9,11-dione derivatives were synthesized and evaluated for their antiproliferative effects on HeLa, LS180, MCF-7 and Jurkat human cancer cell lines. Antiproliferative effects were evaluated using MTT assay. Prepared compounds exhibited weak to good antiproliferative activity in evaluated cell lines. Prepared compounds were more potent in Jurkat cell line when compared to LS180, HeLa and MCF-7 cell lines. Compounds 29 (IC₁₆ = 0.7 μM) and 31 (IC₁₆ = 1.7 μM) and 33 (IC₁₆ = 1.7 μM) were found to be the most potent molecules on Jurkat cell lines. Moreover; it was found that some of the tested compounds bearing imidazole-2-yl moiety on the C₁₁-position of dihydropyridine ring exhibited superior antiproliferative activity in comparison to cis-platin especially in Jurkat cell line (compounds 29, 31, and 33). It seemed that the introduction of electron-withdrawing groups on the imidazole ring enhanced the antiproliferative potential of these compounds (compounds 27, 29 and 31). The results of this study proposed that some of the imidazole substituted indeno[1,2-b]quinoline-9,11-dione compounds may act as efficient anticancer agents in vitro, emphasizing their potential role as a source for rational design of potent antiproliferative agents.