Antiproliferative activity and apoptosis inducing effects of nitric oxide donating derivatives of evodiamine

The first series of nitric oxide donating derivatives of evodiamine were designed and prepared. NO releasing ability of all target derivatives was evaluated in BGC-823, Bel-7402 and L-02 cells. The cytotoxicity was evaluated against three human tumor cell lines (Bel-7402, A549 and BGC-823) and normal human liver cells L-02. The nitrate derivatives 11a and 11b only exhibited moderate activity and furoxan-based derivatives 13a–c, 14a and 14b showed promising activity. 13c showed good cytotoxic selectivity between tumor and normal liver cells and was further investigated for its apoptotic properties on human hepatocarcinoma Bel-7402 cells. The molecular mode of action revealed that 13c caused cell-cycle arrest at S phase and induced apoptosis in Bel-7402 cells through mitochondria-related caspase-dependent pathways.     

Sesquiterpenes from the roots of Illicium dunnianum

Six allo-cedrane sesquiterpenes, four seco-prezizaane-type sesquiterpenes, two monocyclofarnesane sesquiterpenes, together with four known sesquiterpenes, were isolated from the roots of Illicium dunnianum. The structures were elucidated by spectroscopic methods including 1D and 2D NMR. The absolute configuration of 10 was determined by a CD experiment. Compounds 11 and 13 showed potent activities against the release of β-glucuronidase in rat polymorphonuclear leukocytes induced by platelet-activating factor in vitro, with IC₅₀ values of 2.10 ± 0.40 and 1.93 ± 0.57 μM, respectively. All compounds were evaluated for cytotoxicities against five human cancer cell lines (A549, Bel-7402, BGC-823, HCT-8, and A2780) in the MTT assay, but none of them exhibited activity at concentrations tested (10⁻⁵–10⁻⁷ M).     

Multisubstituted indole–acrylonitrile hybrids as potential cytotoxic agents

A series of multisubstituted indole–acrylonitrile hybrids were designed, synthesized and evaluated for their potential cytotoxic activities. The bio-evaluation results indicated that some of the target compounds (such as 3a, 3f, 3k, 3n) exhibited good to moderate cytotoxic effect on HepG2, BCG-823, BEL-7402, and HL-7702 cell lines. Especially, the compounds 3a and 3k also exhibited high cytotoxic activities (3a, 19.38 ± 3.38 μM; 3k, 15.43 ± 3.54 μM) against the BEL-7402 cell line resistant to Taxol (>25 μM) and 5-FU (>500 μM), which might be developed as novel lead scaffold for potential anticancer agents.     

The synthesis and biological evaluation of some caffeic acid amide derivatives: E-2-Cyano-(3-substituted phenyl)acrylamides

A series of caffeic acid amide derivatives 2-cyano-(3-substituted phenyl)acrylamides were synthesized via Knoevenogal condensation of substituted benzaldehydes with cyanoacetamides. The structure of compound 1f was determined as E-isomer by X-ray diffractive analysis. The biological screening tests in vitro showed that compound 1b has obvious inhibitory activities against human gastric carcinoma cell line BGC-823, human nasopharyngeal carcinoma cell line KB and human hepatoma cell line BEL-7402 with IC₅₀ values of 5.6 μg/mL, 13.1 μg/mL and 12.5 μg/mL, respectively. Some preliminary structure–activity relationships (SAR) were also proposed which may provide a direction for further study.     

Cytotoxic cassaine diterpenoid–diterpenoid amide dimers and diterpenoid amides from the leaves of Erythrophleum fordii

Detailed phytochemical investigation from the leaves of Erythrophleum fordii resulted in the isolation of 13 compounds, including three cassaine diterpenoid–diterpenoid amide dimers (1, 3 and 5), and seven cassaine diterpenoid amides (6 and 8–13), together with three previously reported ones, erythrophlesins D (2), C (4) and 3β-hydroxynorerythrosuamide (7). Compounds 1, 3 and 5 are further additions to the small group of cassaine diterpenoid dimers represented by erythrophlesins A–D. Their structures were determined by analysis of extensive one- and two-dimensional NMR experiments and ESIMS methods. Cytotoxic activities of the isolated compounds were tested against HCT-8, Bel-7402, BGC-823, A549 and A2780 human cancer cell lines in the MTT test. Results showed that compounds 1 and 3–5 exhibited significantly selective cytotoxic activities (IC₅₀ < 10 μM) against these cells, respectively.     

Methanolysis of triterpenoid saponin from Ardisia gigantifolia stapf. and structure–activity relationship study against cancer cells

Thirteen 13,28-epoxy triterpenoid saponins were isolated from Ardisia gigantifolia stapf. and one potential anti-tumor saponin was methanolysised by H₂SO₄ to afford four new compounds. The seventeen compounds were evaluated for their anti-proliferative activity on A549, HCT-8 and Bel-7402 cells. The structure–activity relationship analysis indicated that the incorporation of O group at C-16, l-rhamnose at R⁵ and acetyl group at OH-6 of the d-glucose lead to a significant increase of the cytotoxic activity on A549 and HCT-8 but significant reduction of the cytotoxic activity on Bel-7402 cells. The synthesized saponins losing 13,28-epoxy and CHO at C-30, losed their cytotoxicities on A549 and HCT-8 cells, suggesting that the two moieties play an essential role for activity. 3β-O-α-l-rhamnopyranosyl-(1 → 3)-[β-d-xylopyranosyl-(1 → 2)]-β-d-glucopyranosyl-(1 → 4)-[β-d-glucopyranosyl-(1 → 2)]-α-l-arabinopyranoside-16α-hydroxy-13,28-epoxy-oleanane (2) showed better inhibitory activity to Bel-7402 (IC₅₀ 0.86 μM) than that of 5-FU (IC₅₀ 8.30 μM), which indicate that five saccharide and methyl moiety at C-30 are important for anti-proliferative activity. The activities of saponins 15 > 14, 17 > 16, suggested that the configuration of 28,30-epoxy is preferable to be 30(R) rather than 30(S) on Bel-7402 cells. Further molecular mechanism studies of saponins 1 and 2 were carried out on the cell cycle distribution of Bel-7402 cells.     

Two new glycosides and one new neolignan from the roots of Cynanchum stauntonii

Three new compounds including one C₂₁-steroidal glycoside, one methylglycoside, and one neolignan, named as Deoxyamplexicogenin A-3-O-yl-4-O-(4-O-α-l-cymaropyranosoyl-β-d-digitoxopyranosoyl)-β-d-canaropyranoside (1), Methyl-O-α-l-cymaropyranosoyl-(1 → 4)-β-D-digitoxopyranoside (2), and (+)-(7S, 8R, 7′E)-5-hydroxy-3, 5′-dimethoxy-4′, 7-epoxy-8, 3′-neolign-7′-ene-9, 9′-diol 9′-ethyl ether (3), respectively, were isolated from the roots of Cynanchum stauntonii. The structure elucidations were achieved by in-depth spectroscopic examination, mainly including the experiments and analyses of multiple 1D- and 2D-NMR and HRESIMS and CD analysis and qualitative chemical tests. Cytotoxicity activities of compounds 1–3 were evaluated against five tumor cell lines (HCT-8, Bel-7402, BGC-823, A549, and A2780) in cell based assays where they were found to be inactive.     

Synthesis and mechanistic studies of novel spin-labeled combretastatin derivatives as potential antineoplastic agents

Two series (14a–d and 21a–h) of novel spin-labeled combretastatin derivatives were synthesized and evaluated for cytotoxicity against four tumor cell lines (K562, SGC-7901, Hela and HepG-2). Simultaneously, a representative compound 21a was selected to investigate the antitumor mechanisms of these synthetic compounds. The results indicated that some of the compounds showed significant cytotoxicity against four tumor cell lines in vitro and were more active than etoposide, a clinically available anticancer drug. Among the newly synthesized compounds, 21a, 21b and 21c displayed the greatest cytotoxicity against three tested tumor cell lines (HEPG-2, BGC-832 and Hela), with IC₅₀ values ranging from 0.15 to 1.05 μM, compared with values of 0.014–0.403 μM for 3-amino-deoxycombretastatin A-4 (3). In addition, the mechanistic analysis revealed that compound 21a effectively interfered with tubulin dynamics to prevent mitosis in cancer cells, leading to cell cycle arrest and, eventually, dose dependent apoptosis.     

New bioactive derivatives of nonactic acid from the marine Streptomyces griseus derived from the plant Salicornia sp.

Three new compounds, butyl homononactate (5), butyl nonactate (6), 8-actyl homononactic acid (7), along with four known compounds homononactic acids (1), nonactic acid (2), homononactyl nonactate (3), homononactyl homononactate (4) were isolated from the marine Streptomyces griseus RSH0407, derived from the plant Salicornia sp., Chenopodiaceae. Their structures were elucidated by extensive spectroscopic techniques and by comparison with data reported in the literature. The absolute configuration of 3 was first reported by using X-ray copper radiation. Compound 5 exhibited cytotoxic activities against the HCT-8, A2780, BGC-823, BEL-7402, and A549 cell lines in vitro, with IC₅₀ values of 2.87 ± 0.20, 4.90 ± 0.30, 2.19 ± 0.32, 5.07 ± 0.23 and 1.78 ± 0.18 μM, respectively, and compounds 4–7 showed weak antibacterial activities against four bacterials respectively.     

DNA binding acridine–thiazolidinone agents affecting intracellular glutathione

Three new acridine–thiazolidinone derivatives (2a–2c) have been synthesized and their interactions with calf thymus DNA and a number of cell lines (leukemic cells HL-60 and L1210 and human epithelial ovarian cancer cell lines A2780) were studied. The compounds 2a–2c possessed high affinity to calf thymus DNA and their binding constants determined by spectrofluorimetry were in the range of 1.37 × 10⁶–5.89 × 10⁶ M^?1. All of the tested derivatives displayed strong cytotoxic activity in vitro, the highest activity in cytotoxic tests was found for 2c with IC₅₀ = 1.3 ± 0.2 μM (HL-60), 3.1 ± 0.4 μM (L1210), and 7.7 ± 0.5 μM (A2780) after 72 h incubation. The cancer cells accumulated acridine derivatives very fast and the changes of the glutathione level were confirmed. The compounds inhibited proliferation of the cells and induced an arrest of the cell cycle and cell death. Their influence upon cells was associated with their reactivity towards thiols and DNA binding activity.     

Cytotoxicity and DNA binding property of triphenylethylene–coumarin hybrids with two amino side chains

Novel triphenylethylene–coumarin hybrids containing two amino side chains were designed and synthesized. Some of these 3,4-diphenyl coumarins, 7b–c (the double chains at 4-position on 3-,4-phenyl, respectively), and 13b–f (the double chains at 4-position on 3-phenyl and 7-position, respectively), showed a broad-spectrum and good anti-proliferative activity against five tumor cells and low cytotoxicity in osteoblast. UV–vis, fluorescence, and circular dichroism (CD) spectroscopies and thermal denaturation exhibited that compounds 7b (R = piperidinyl), 7e (R = NEt₂), and 7f (R = 4-methylpiperazinyl) had significant interactions with Ct-DNA by the intercalative mode of binding. Structure activity relationships (SARs) analysis suggested that the location of the two amino alkyl chains would play an important role both in the compounds against tumor cells proliferation and their interactions with DNA.     

Two new quinic acid derivatives and one new lignan glycoside from Erycibe obtusifolia

Three new compounds, 4-{erythro-2-[3-(4-hydroxyl-3-methoxyphenyl)-3-O-β-d-glucopyranosyl-propan-1-ol]}-O-medioresinol (1), (7⿳E,9⿳E,1⿳R*,3⿳S*,5⿳R*,6⿳S*)-5-O-caffeoyl-3-O-dihydrophaseicoylquinic acid (2), and (7⿳E,9⿳E,1⿳R*,3⿳S*,5⿳R*,6⿳S*)-5-O-caffeoyl-4-O-dihydrophaseicoylquinic acid (3), were isolated from Chinese folk herb Erycibe obtusifolia together with six known compounds (4⿿9). Their structures were elucidated on the basis of comparisons of literatures and extensive spectroscopic analysis, including UV, IR, HRMS, and 1D and 2D NMR techniques. Further, the cytotoxicities of these compounds were evaluated against five cell lines (HCT-8, Bel-7402, BGC-823, A549, and A2780), but they were inactive against these tumor cell lines (IC₅₀ > 10 μmol/L).     

3-Substituted-4-hydroxycoumarin as a new scaffold with potent CDK inhibition and promising anticancer effect: Synthesis,molecular modeling and QSAR studies

A new series of 3-substituted-4-hydroxycoumarin derivatives was designed, synthesized, and evaluated for CDK inhibiting and anticancer activities. All the synthesized target compounds showed remarkably high affinity and selectivity towards CDK1B, compared to flavopiridol, with Ki values in the low nanomolar range (Ki = 0.35–0.88 nM). Most of them elicited considerable inhibiting effect against CDK9T1 (Ki = 3.26–23.45 nM). Moreover, all the target compounds were tested in vitro against eighteen types of human tumor cell lines. The hydrazone 3a, N-phenylpyrazoline derivative 6b and 2-aminopyridyl-3-carbonitrile derivative 8c were the most potent anticancer agents against MCF-7 breast cancer cell line (IC₅₀ = 0.21, 0.21 and 0.23 nM, respectively). The target compounds 3a, 6b and 8c were further evaluated in MCF-7 breast cancer mouse xenograft model and showed in vivo efficacy at 10 mg/kg dose. The docking study confirmed a unique binding mode in the active site of CDK1B with better score than flavopiridol. Quantitative structure activity relationship study was done and revealed a highly predictive power R² of 0.81.     

Synthesis and antiproliferative activity of some steroidal thiosemicarbazones,semicarbazones and hydrozones

Steroidal thiosemicarbazones, semicarbazones and hydrazones have received extensive attention of scientists recently because they exhibit some biological activities such as antibacterial, antiviral and anticancer. Using different steroids as starting materials, through different chemical methods, 24 steroidal compounds with thiosemicarbazone, semicarbazone or hydrazone groups in their structures, were synthesized, characterized by IR, NMR and MS. The antiproliferative activity of the compounds was evaluated against human gastric cancer (SGC-7901) and human liver cancer (Bel-7404) cells. The structure–activity relationship of these compounds was discussed. The results showed that compound 3 and 12a–12c exhibited significant inhibitory activity to Bel-7404 cells, and IC₅₀ values of them were 4.2, 11.0, 7.4 and 15.0 μM respectively (Cisplatin, IC₅₀: 11.6 μM).     

Synthesis,cytotoxicity and DNA-binding properties of Pd(II), Cu(II) and Zn(II) complexes with 4′-(4-(2-(piperidin-1-yl)ethoxy)phenyl)-2,2′:6′,2″-terpyridine

Pd(II), Cu(II) and Zn(II) complexes (1–3) based on 4′-(4-(2-(piperidin-1-yl)ethoxy)phenyl)-2,2′:6′,2″-terpyridine were synthesized and characterized by UV, IR, NMR, EPR, HRMS, elemental analyses, and molar conductivity measurements. The cytotoxicity of these complexes against HL-60, BGC-823, KB, Bel-7402, A549, Hela, K562 and MCF-7 cell lines in vitro was measured by MTT method. The DNA binding property of the complexes was evaluated by UV, fluorescence, CD spectroscopies and thermal denaturation. The cytotoxicity of complexes 1 and 3 against all the tested cell lines is better than that of cisplatin. Complexes 1 and 2 exhibit 7- and 4-folds higher cytotoxicity than cisplatin against Bel-7402 cell line. Complex 3 displays the highest cytotoxicity against all the cell lines tested, and shows 7-, 14-, 8-, 11- and 8-folds higher cytotoxicity than cisplatin against Bel-7402, A549, Hela, K562 and MCF-7 cell lines. The complexes bind to DNA via intercalation mode and complex 3 stabilizes the G-quadruplex. The results reveal that all the complexes display high cytotoxicity against all the tested cancer cell lines, and complex 3 is selective for G-quadruplex over duplex DNA.     

Synthesis and cytotoxicity evaluation of oleanolic acid derivatives

Twelve derivatives of oleanolic acid (1) have been synthesized and evaluated for their inhibitory activities against the growth of prostate PC3, breast MCF-7, lung A549, and gastric BGC-823 cancer cells by MTT assays. Within these series of derivatives, compound 17 exhibited the most potent cytotoxicity against PC3 cell line (IC₅₀ = 0.39 μM) and compound 28 displayed the best activity against A549 cell line (IC₅₀ = 0.22 μM). SAR analysis indicates that H-donor substitution at C-3 position of oleanolic acid may be advantageous for improvement of cytotoxicity against PC3, A549 and MCF-7 cell lines.     

Synthesis and cytotoxic activity of nitric oxide-releasing isosteviol derivatives

Fifteen novel hybrids containing diterpene skeleton and nitric oxide (NO) donor were prepared from isosteviol. All the compounds were tested on preliminary cytotoxicity, and the results showed that six target compounds (8c, 10b, 14a, 14c, 18c, and 18d) exhibited anti-proliferation activity on HepG2 cells, with 8c (IC₅₀ = 4.24 μM) and 18d (IC₅₀ = 2.75 μM) superior to the positive control CDDO-Me (2-cyano-3,12-dioxooleana-1,9(11)-dien-28-acid methyl ester, IC₅₀ = 4.99 μM); eleven target compounds (8a–c, 9a–c, 10a–b, 14a, 14c, 18d) exhibited anti-proliferation activities on B16F10 cells at different levels, among them, seven compounds were more potent than comptothecin (IC₅₀ = 2.78 μM) and CDDO-Me (IC₅₀ = 5.85 μM), particularly, 10b (IC₅₀ = 0.02 μM) presented the strongest effect, which was selected as a candidate for further study.     

Three cytotoxic Annonaceous acetogenins from the seeds of Annona squamosa

Three new Annonaceous acetogenins, squamocin-IV (1), squamocin-V (2) and squamoxinone-E (3), together with seven other known Annonaceous acetogenins (4–10) were isolated from the seeds of Annona squamosa. The structures of all of the isolates were established and characterized through spectral and chemical methods. The new Annonaceous acetogenins 1–3 were evaluated for their cytotoxicity against the Hep-G2, SMMC-7721, BEL-7402, BGC-803 and H460 human cancer cell lines. Compound 3 exhibited the best cytotoxic activity, with IC₅₀ values of 0.103, 0.687, 4.19, 0.43 and 6.56 μg/mL, respectively for the cell lines above; meanwhile, Compound 1 showed selective cytotoxic activity against H460, with an IC₅₀ value of 0.049 μg/mL. The first mono-ACG (2) composed of 38 carbons was discovered.     

Novel multipotent phenylthiazole–tacrine hybrids for the inhibition of cholinesterase activity, β-amyloid aggregation and Ca2+ overload

In this study, a series of multipotent phenylthiazole–tacrine hybrids (7a–7e, 8, and 9a–9m) were synthesized and biologically evaluated. Screening results showed that phenylthiazole–tacrine hybrids were potent cholinesterase inhibitors with pIC₅₀ (?log IC₅₀) value ranging from 5.78 ± 0.05 to 7.14 ± 0.01 for acetylcholinesterase (AChE), and from 5.75 ± 0.03 to 10.35 ± 0.15 for butyrylcholinesterase (BuChE). The second series of phenylthiazole–tacrine hybrids (9a–9m) could efficiently prevent Aβ_1–42 self-aggregation. The structure–activity relationship revealed that their inhibitory potency relied on the type of middle linker and substitutions at 4′-position of 4-phenyl-2-aminothiazole. In addition, 7a and 7c also displayed the Ca²⁺ overload blockade effect in the primary cultured cortical neurons. Consequently, these compounds emerged as promising molecules for the therapy of Alzheimer’s disease.     

Synthesis and evaluation of novel azetidine analogs as potent inhibitors of vesicular [3H]dopamine uptake

Lobelane analogs that incorporate a central piperidine or pyrrolidine moiety have previously been reported by our group as potent inhibitors of VMAT2 function. Further central ring size reduction of the piperidine moiety in lobelane to a four-membered heterocyclic ring has been carried out in the current study to afford novel cis-and trans-azetidine analogs. These azetidine analogs (15a–15c and 22a–22c) potently inhibited [³H]dopamine (DA) uptake into isolated synaptic vesicles (K_i ? 66 nM). The cis-4-methoxy analog 22b was the most potent inhibitor (K_i = 24 nM), and was twofold more potent that either lobelane (2a, K_i = 45 nM) or norlobelane (2b, K_i = 43 nM). The trans-methylenedioxy analog, 15c (K_i = 31 nM), was equipotent with the cis-analog, 22b, in this assay. Thus, cis- and trans-azetidine analogs 22b and 15c represent potential leads in the discovery of new clinical candidates for the treatment of methamphetamine abuse.