Design,synthesis and apoptosis-related antiproliferative activities of chelidonine derivatives

To get chelidonine derivatives with enhanced antiproliferative activity and selectivity, a series of nitric oxide donating derivatives (10a-f and 11a-j) were designed, synthesized and biologically evaluated. Compared with chelidonine, these compounds exhibited lower IC₅₀ values against human hepatoma cells HepG2, breast cancer cells MCF-7, colon cancer cells HCT-116, as well as leukemia cells K562. Compound 11j displayed the strongest antiproliferative activity with IC₅₀ values of 3.91, 6.90, 4.36 and 1.12 μM against the above four cells, respectively. Nevertheless, it showed an IC₅₀ value >40 μM against human peripheral blood mononuclear cells (PBMCs), which demonstrated high selectivity between normal and cancer blood cells. In further mechanism studies, 11j showed the capability to induce K562 cells apoptosis, S phase cell cycle arrest and mitochondrial membrane potential disorder. Besides, 11j was found to be effective in promoting the expression of proapoptotic protein Bad and suppressing the expression of anti-apoptotic proteins Bcl-xL, catalase, survivin, claspin and clusterin.     

Design and molecular modeling of novel P38α MAPK inhibitors targeting breast cancer,synthesized from oxygen heterocyclic natural compounds

Two new series of furochromone and benzofuran derivatives were designed, synthesized and evaluated for their in vitro anticancer activity against MCF-7 and MDA231 breast cancer cell lines. Compounds 5, 6, 7, 9, 15a, 16, 17a and 18 exhibited the best antiproliferative activities with IC₅₀ values ranging from 1.19 to 2.78?µM against MCF-7 superior to lapatinib as reference standard (IC₅₀; 4.69?µM). Compounds 15a and 18 revealed significant cytotoxic activity against MCF-7 and MDA231, therefore their inhibitory potencies against p38α MAP kinase were evaluated. Remarkably they exhibited significant IC₅₀ of 0.04?µM comparable to SB203580 (IC₅₀; 0.50?µM) as a reference standard. These promising results of cytotoxic activity and significant inhibition of p38α MAP kinase, were confirmed by exploring the effect of benzofuran derivative (18) on the apoptotic induction and cell cycle progression of MCF-7 cell line. Compound 18 induced preG1 apoptosis and cell growth arrest at G2/M phase preventing the mitotic cycle. Moreover it activated the caspase-7 which executes apoptosis. Molecular docking study was carried out using GOLD program to predict the mode of binding interaction of the synthesized compounds into the target p38α MAPK. Additionally, the physicochemical properties and ADME parameters of compound 18 were examined in silico to investigate its drug-likeness.     

Synthesis of ring-C modified oleanolic acid derivatives and their cytotoxic evaluation

Ring-C of oleanolic acid was chemically modified by treating with NBS under a variety of experimental conditions. The structures of the synthesized compounds were established by spectral analysis (¹H &¹³C NMR and Mass). All the compounds were evaluated against a panel of five human cancer cell lines by using MTT assay. Among the tested compounds, 2 and 7 showed significant activity against breast cancer cell line, MCF-7. Most significantly, compound 7 showed several folds enhanced activity against MCF-7 cancer cell lines (IC₅₀: 2.96 μM) than that of the parent (1) and the intermediate compound (6). Flow cytometric analysis revealed that these compounds arrested the cell cycle in G0/G1 phase and induced mitochondrial mediated apoptosis.     

Synthesis,anticancer effect and molecular modeling of new thiazolylpyrazolyl coumarin derivatives targeting VEGFR-2 kinase and inducing cell cycle arrest and apoptosis

New thiazolylpyrazolyl coumarin derivatives were synthesized and tested for their anticancer potential in vitro against five different human cell lines, including breast MCF-7, lung A549, prostate PC3, liver HepG2 and normal melanocyte HFB4. Breast carcinoma revealed higher sensitivity towards compounds 7a, 8c, 9b, 9c and 9d with IC₅₀ values ranging from 5.41 to 10.75 μM in comparison to the reference drug doxorubicin (IC₅₀ = 6.73 μM). In addition, no noticeable toxicity was exhibited towards normal cells HFB4. Moreover, in vitro studies of the VEGFR-2 inhibition in human breast cancer MCF-7 cell line for the promising cytotoxic compounds showed that compounds 7a, 8c, 9b, 9c and 9d were potent inhibitors at low micromolar concentrations (IC₅₀ = 0.034–0.582 μM) compared to the reference drug, sorafenib (IC₅₀ = 0.019 μM). Several theoretical and experimental studies were done to reveal the molecular mechanisms that control breast carcinoma metastasis. The mechanistic effectiveness in cell cycle progression, apoptotic induction and gene regulation were assessed for the promising compound 9d due to its remarkable cytotoxic activity against MCF-7 and significant VEGFR-2 inhibition. Flow cytometeric analysis showed that compound 9d induced cell growth cessation at G2/M phase and increased the percentage of cells at pre-G1 phase that stimulates the apoptotic death of MCF-7 cells. Furthermore, real time PCR assay illustrated that compound 9d up regulated p53 gene expression and elevated Bax/Bcl-2 ratio which confirmed the mechanistic pathway of compound 9d. Moreover, the apoptotic induction of breast cancer cells MCF-7 was enhanced effectively through activation of caspases-7 and 9 by compound 9d. On the other hand, a set of in silico methods such as molecular docking, molecular dynamics simulation, QSAR analysis as well as ADMET analysis was performed in order to study the protein-ligand interactions and the relationship between the physicochemical properties and the inhibitory activity of the promising compounds 7a, 8c and 9d. Based on the aforementioned findings, compound 9d could be considered as effective apoptosis modulator and promising lead for future development of new anti-breast cancer agents.     

Synthesis and anticancer activities of thieno[3,2-d]pyrimidines as novel HDAC inhibitors

A series of thieno[3,2-d]pyrimidines bearing a hydroxamic acid moiety as novel HDAC inhibitors were designed and synthesized. The structures of the new synthesized compounds were confirmed using IR, ¹H, ¹³C NMR spectrum. Compounds 11–13 showed potent inhibitory activities against HDACs with IC₅₀ values at 0.38, 0.49 and 0.61 μM. Most of target compounds displayed strong anti-proliferative activity by a MTT assay on three human cancer cell lines including HCT-116, MCF-7 and HeLa. Compound 11, having potent inhibitory activities against HDACs, induced apoptosis and G2/M cell cycle arrest in HCT-116 cell line.     

Design,synthesis and anticancer evaluation of 1H-pyrazolo[3,4-d]pyrimidine derivatives as potent EGFRWT and EGFRT790M inhibitors and apoptosis inducers

In our attempt to develop effective EGFR-TKIs, two series of 1H-pyrazolo[3,4-d]pyrimidine derivatives were designed and synthesized. All the newly synthesized compounds were evaluated in vitro for their inhibitory activities against EGFR^WT. Compounds 15_b, 15_j, and 18_d potently inhibited EGFR^WT at sub-micro molar IC₅₀ values comparable to that of erlotinib. Moreover, thirteen compounds that showed promising IC₅₀ values against EGFR^WT were tested in vitro for their inhibitory activities against mutant EGFR^T790M. Compounds 17_d and 17_f exhibited potent inhibitory activities towards EGFR^T790M comparable to osimertinib. Compounds that showed promising IC₅₀ values against EGFR^WT were further tested for their anti-proliferative activities against three cancer cell lines bearing EGFR^WT (MCF-7, HepG2, A549), and two cancer cell lines bearing EGFR^T790M (H1975 and HCC827). Compounds 15_g, 15_j, 15_n, 18_d and 18_e were the most potent anticancer agents against the EGFR^WT containing cells, while compounds 15_e, 17_d and 17_f showed promising anti-proliferative activities against EGFR^T790M containing cells. Furthermore, the most active compound 18_d was selected for further studies regarding to its effects on cell cycle progression and induction of apoptosis in the HepG2 cell line. The results indicated that this compound is good apoptotic agent and arrests G₀/G₁and G₂/M phases of cell cycle. Finally, molecular docking studies were performed to investigate binding pattern of the synthesized compounds with the prospective targets, EGFR^WT (PDB: 4HJO) and EGFR^T790M (PDB: 3W2O).     

In vitro cytotoxic potential of extracts from Aristolochia foetida Kunth against MCF-7 and bMECs cell lines

The aim of this study was to evaluate the cytotoxic potential of Aristolochia foetida Kunth. Stems and leaves of A. foetida Kunth (Aristolochiaceae) have never been investigated pharmacologically. Recent studies of species of the Aristolochiaceae family found significant cytotoxic activities. Hexane, dichloromethane, ethyl acetate and methanol extracts were analyzed by ¹H NMR and GC–MS to know the metabolites in each extract. In GC–MS analysis, the main compounds were methyl hexadecanoate (3); hexadecanoic acid (4); 2-butoxyethyl dodecanoate (9); ethyl hexadecanoate (20); methyl octadeca-9,12,15-trienoate (28) and (9Z,12Z,15Z)-octadeca-9,12,15-trienoic acid (40). The results showed a significant reduction in cell viability of the MCF-7 (breast cancer) cell line caused by organic extracts in a dose-dependent manner. The cytotoxicity activity of the dichloromethane extract from the stems (DSE) showed IC₅₀ values of 45.9 μg/mL and the dichloromethane extract of the leaves (DLE) showed IC₅₀ values of 47.3 μg/mL. DSE and DLE had the highest cytotoxic potential in an in vitro study against the MCF-7 cell line and non-tumor cells obtained from the bovine mammary epithelial (bMECs). DSE and DLE induced a loss in mitochondrial membrane potential (ΔΨm) and can cause cell death by apoptosis through the intrinsic pathway in the MCF-7 cell line. DSE and DLE are cytotoxic in cancer cells and cause late apoptosis. Higher concentrations of DSE and DLE are required to induce a cytotoxic effect in healthy mammary epithelial cells. This is the first report of the dichloromethane extract of A. foetida Kunth that induces late apoptosis in MCF-7 cancer cells and may be a candidate for pharmacological study against breast cancer.     

Synthesis and biological evaluation of 1-benzyl-N-(2-(phenylamino)pyridin-3-yl)-1H-1,2,3-triazole-4-carboxamides as antimitotic agents

A library of 1-benzyl-N-(2-(phenylamino)pyridin-3-yl)-1H-1,2,3-triazole-4-carboxamides (7a–al) have been designed, synthesized and screened for their anti-proliferative activity against some selected human cancer cell lines namely DU-145, A-549, MCF-7 and HeLa. Most of them have shown promising cytotoxicity against lung cancer cell line (A549), amongst them 7f was found to be the most potent anti-proliferative congener. Furthermore, 7f exhibited comparable tubulin polymerization inhibition (IC₅₀ value 2.04 µM) to the standard E7010 (IC₅₀ value 2.15 µM). Moreover, flow cytometric analysis revealed that this compound induced apoptosis via cell cycle arrest at G₂/M phase in A549 cells. Induction of apoptosis was further observed by examining the mitochondrial membrane potential and was also confirmed by Hoechst staining as well as Annexin V-FITC assays. Furthermore, molecular docking studies indicated that compound 7f binds to the colchicine binding site of the β-tubulin. Thus, 7f exhibits anti-proliferative properties by inhibiting the tubulin polymerization through the binding at the colchicine active site and by induction of apoptosis.     

Synthesis of 1,2,4-triazole-linked urea/thiourea conjugates as cytotoxic and apoptosis inducing agents

A new series of 1,2,4-triazole-linked urea and thiourea conjugates have been synthesized and evaluated for their in vitro cytotoxicity against selected human cancer cell lines namely, breast (MCF-7, MDA-MB-231), lung (A549) prostate (DU145) and one mouse melanoma (B16-F10) cell line and compared with reference drug. The compound 5t showed significant cytotoxicity on MCF-7 breast cancer cell line with a IC₅₀ value of 7.22?±?0.47?µM among all the tested compounds. Notably, induction of apoptosis by compound 5t on MCF-7 cells was evaluated using different staining techniques such as acridine orange/ethidium bromide (AO/EB), annexin V-FITC/PI, and DAPI. Further, clonogenic assay indicates the inhibition of colony formation on MCF-7 cells by compound 5t. Moreover, the flow-cytometric analysis also revealed that compound 5t caused the arrest of cells at G0/G1 phase of cell cycle. In addition, the compounds when tested on normal human cells (L-132) were found to be safer with low cytotoxicity profile.     

Design,synthesis, biological evaluation and molecular docking of new uracil analogs-1,2,4-oxadiazole hybrids as potential anticancer agents

A new series of uracil analogues-1,2,4-oxadiazole hybrid derivatives were synthesized by a new, simple, and efficient method using for the first time HAP-SO₃H as an heterogenous acid catalyst for the condensation and cyclization between amidoxime and aldehyde. The new derivatives were characterized by HRMS, FT-IR, ¹H NMR, and ¹³C NMR spectroscopy techniques. The synthesized 1,2,4-oxadiazole hybrids were evaluated for their cytotoxic activity in five human cancer cell lines: melanoma (A-375), fibrosarcoma (HT-1080), breast (MCF-7 and MDA-MB-231), and lung carcinoma (A-549). Data showed that compounds 22 and 23 were potent cytotoxic agents against HT-1080 and MFC-7 cells with IC₅₀ inferior to 1 µM. The possible mechanism of apoptosis induction by the derivatives was investigated using Annexin V staining, caspase-3/7 activity, mitochondrial membrane potential measurement, and analysis cell cycle progression. The compound 22 induced apoptosis through caspase-3/7 activation and S-phase arrest in HT-1080 and A549 cells. The molecular docking showed that compound 22 activated the caspase-3 by forming a stable protein-ligand complex.     

Benzo[b]furan derivatives induces apoptosis by targeting the PI3K/Akt/mTOR signaling pathway in human breast cancer cells

The PI3K/Akt/mTOR signaling pathway plays a key regulatory function in cell survival, proliferation, migration, metabolism and apoptosis. Aberrant activation of the PI3K/Akt/mTOR pathway is found in many types of cancer and thus plays a major role in breast cancer cell proliferation. In our previous studies, benzo[b]furan derivatives were evaluated for their anticancer activity and the lead compounds identified were 26 and 36. These observations prompted us to investigate the molecular mechanism and apoptotic pathway of these lead molecules against breast cancer cells. Benzo[b]furan derivatives (26 and 36) were evaluated for their antiproliferative activity against human breast cancer cell lines MCF-7 and MDA MB-231. These compounds (26 and 36) have shown potent efficiency against breast cancer cells (MCF-7) with IC₅₀ values 0.057 and 0.051 μM respectively. Cell cycle analysis revealed that these compounds induced cell cycle arrest at G2/M phase in MCF-7 cells. Western blot analysis revealed that these compounds inhibit the PI3K/Akt/mTOR signaling pathway and induced mitochondrial mediated apoptosis in human breast cancer cells (MCF-7).     

Discovery of novel quinoline-based analogues of combretastatin A-4 as tubulin polymerisation inhibitors with apoptosis inducing activity and potent anticancer effect

A new series of quinoline derivatives of combretastatin A-4 have been designed, synthesised and demonstrated as tubulin polymerisation inhibitors. These novel compounds showed significant antiproliferative activities, among them, 12c exhibited the most potent inhibitory activity against different cancer cell lines (MCF-7, HL-60, HCT-116 and HeLa) with IC₅₀ ranging from 0.010 to 0.042 µM, and with selectivity profile against MCF-10A non-cancer cells. Further mechanistic studies suggest that 12c can inhibit tubulin polymerisation and cell migration, leading to G₂/M phase arrest. Besides, 12c induces apoptosis via a mitochondrial-dependant apoptosis pathway and caused reactive oxygen stress generation in MCF-7 cells. These results provide guidance for further rational development of potent tubulin polymerisation inhibitors for the treatment of cancer.

Highlights

• A novel series of quinoline derivatives of combretastatin A-4 have been designed and synthesised.
• Compound 12c showed significant antiproliferative activities against different cancer cell lines.
• Compound 12c effectively inhibited tubulin polymerisation and competed with [³H] colchicine in binding to tubulin.
• Compound 12c arrested the cell cycle at G₂/M phase, effectively inducing apoptosis and inhibition of cell migration.

     

Artemisinin-indole and artemisinin-imidazole hybrids: Synthesis,cytotoxic evaluation and reversal effects on multidrug resistance in MCF-7/ADR cells

A series of artemisinin derivatives with MDR reversal activity were designed and synthesized. All hybrids were screened to anticancer activities against four human cancer cell lines (A549, MCF-7, HepG-2, MDA-MB-231) and normal human hepatic cell (L02) in vitro. Most of the new compounds showed higher anticancer activities than artemisinin, among which compounds 11a and 11c displayed superior potency with IC₅₀ 6.78?μM and 5.25?μM against MCF-7, respectively. The further research indicated that the most potent 11c induced cell cycle arrest at G2 phase in MCF-7. Additionally, compound 11c showed remarkable MDR reversal activity which reversed adriamycin against MCF-7/ADR cells with IC₅₀ 0.76?μM.     

Synthesis and bioevaluation of 6-chloropyridazin-3-yl hydrazones and 6-chloro-3-substituted-[1,2,4]triazolo[4,3-b]pyridazines as cytotoxic agents

An efficient synthesis of a series of 6-chloro-3-substituted-[1,2,4]triazolo[4,3-b]pyridazines is described via intramolecular oxidative cyclization of various 6-chloropyridazin-3-yl hydrazones with iodobenzene diacetate. The structures of the newly synthesized compounds were assigned on the basis of elemental analysis, IR, NMR (¹H and ¹³C) and mass spectral data. All the thirty three compounds 3a-q and 4b-q synthesized in the present study were evaluated for their in vitro cytotoxic activities against two Acute Lymphoblastic Leukemia (ALL) cell lines named, SB-ALL and NALM-6, and a human breast adenocarcinoma cell lines (MCF-7). The results revealed that triazoles 4 exhibit better cytotoxicity than their hydrazone precursors 3. Among triazoles, compounds 4f, 4j and 4q exhibited potent cytotoxic activity against SB-ALL and NALM-6 with IC₅₀ values in the range of ∼1.64–5.66 μM and ∼1.14–3.7 μM, respectively, compared with doxorubicin (IC₅₀ = 0.167 μM, SB-ALL). Compounds 4f, 4j and 4q were subjected to apoptosis assay after 48 h treatment and these compounds induced apoptosis of NALM-6 cells via caspase 3/7 activation. Results revealed that compound 4q represents potential promising lead.     

Design,synthesis and anticancer evaluation of thieno[2,3-d]pyrimidine derivatives as dual EGFR/HER2 inhibitors and apoptosis inducers

Deregulation of many kinases is directly linked to cancer development and the tyrosine kinase family is one of the most important targets in current cancer therapy regimens. In this study, we have designed and synthesized a series of thieno[2,3-d]pyrimidine derivatives as an EGFR and HER2 tyrosine kinase inhibitors. All the synthesized compounds were evaluated in vitro for their inhibitory activities against EGFR^WT; and the most active compounds that showed promising IC₅₀ values against EGFR^WT were tested in vitro for their inhibitory activities against mutant EGFR^T790M and HER2 kinases. Moreover, the antitumor activities of these compounds were tested against four cancer cell lines (HepG2, HCT-116, MCF-7 and A431). Compounds 13g, 13h and 13k exhibited the highest activities against the examined cell lines with IC₅₀ values ranging from 7.592 ± 0.32 to 16.006 ± 0.58 µM comparable to that of erlotinib (IC₅₀ ranging from 4.99 ± 0.09 to 13.914 ± 0.36 µM). Furthermore, the most potent antitumor agent (13k) was selected for further studies to determine its effect on the cell cycle progression and apoptosis in MCF-7 cell line. The results indicated that this compound arrests G₂/M phase of the cell cycle and it is a good apoptotic agent. Finally, molecular docking studies showed a good binding pattern of the synthesized compounds with the prospective target, EGFR^WT and EGFR^T790M.     

Synthesis of stable benzimidazole derivatives bearing pyrazole as anticancer and EGFR receptor inhibitors

A new series of benzimidazole linked pyrazole derivatives were synthesized by cyclocondensation reaction through one-pot multicomponent reaction in absolute ethanol. All the synthesized compounds were tested for their in vitro anticancer activities on five human cancer cell lines including MCF-7, HaCaT, MDA-MB231, A549 and HepG2. EGFR receptor inhibitory activities were carried out for all the compounds. Majority of the compounds showed potent antiproliferative activity against the tested cancer cell lines. Compound 5a showed the most effective activity against the lungs cancer cell lines (IC₅₀ = 2.2 µM) and EGFR binding (IC₅₀ = 0.97 µM) affinity as compared to other members of the series. Compound 5a inhibited growth of A549 cancer cells by inducing a strong G₂/M phase arrest. In addition, same compound inhibited growth of A549 cancer cells by inducing apoptosis. In molecular docking studies compound 5a was bound to the active pocket of the EGFR (PDB 1M17) with five key hydrogen bonds and two π-π interaction with binding energies ΔG = −34.581 Kcal/mol.     

Design,synthesis and biological evaluation of matrine derivatives as potential anticancer agents

Using matrine (1) as the lead compound, a series of new 14-(N-substituted-2-pyrrolemethylene) matrine and 14-(N-substituted-indolemethylene) matrine derivatives was designed and synthesized for their potential application as anticancer agents. The structure of these compounds was characterized by ¹H NMR, ¹³C NMR and ESI-MS spectral analyses. The target compounds were evaluated for their in vitro cytotoxicity against three human cancer cell lines (SMMC-7721, A549 and CNE2). The results revealed that compound A6 and B21 displayed the most significant anticancer activity against three cancer cell lines with IC₅₀ values in range of 3.42–8.05?μM, which showed better activity than the parent compound (Matrine) and positive control Cisplatin. Furthermore, the Annexin V-FITC/PI dual staining assay revealed that compound A6 and B21 could significantly induce the apoptosis of SMMC-7721 and CNE2 cells in a dose-dependent manner. The cell cycle analysis also revealed that compound A6 could cause cell cycle arrest of SMMC-7721 and CNE2 cells at G2/M phase.     

Synthesis and molecular docking study of new benzofuran and furo[3,2-g]chromone-based cytotoxic agents against breast cancer and p38α MAP kinase inhibitors

This study deals with synthesis of a new set of benzofuran and 5H-furo[3,2-g]chromone linked various heterocyclic functionalities using concise synthetic approaches aiming to gain new antiproliferative candidates against MCF-7 breast cancer cells of p38α MAP kinase inhibiting activity. The biological data proved the significant sensitivity of breast cancer cell lines MCF-7 towards most of the prepared compounds in comparison with doxorubicin. In addition, compounds IIa,b, Va,b, VIa,b, VIIa,b, VIIIa,b, XIc showed significant in vitro p38α MAPK inhibiting potency comparable to the reference standard SB203580. Cell cycle analysis and apoptosis detection data demonstrated that compound VIa induced G2/M phase arrest and apoptosis in MCF-7 cancer cells, in addition to its activation of the caspases-9 and -3. Gold molecular docking studies rationalized the highly acceptable correlation between the calculated docking scores of fitness and the biological data of p38α MAP kinase inhibition. The newly prepared benzofuran and 5H-furo[3,2-g]chromone derivatives might be considered as new promising nuclei in anti-breast cancer chemotherapeutics for further functionalization, optimization and in-depth biological studies.     

Synthesis of new chromeno-annulated cis-fused pyrano[4,3-c]isoxazole derivatives via intramolecular nitrone cycloaddition and their cytotoxicity evaluation

New cis-fused chromeno pyrano[4,3-c]isoxazole derivatives have been synthesized by intramolecular [1,3]-cycloaddition of the nitrones generated in situ from hydroxylamine derivatives and 7-O-prenyl derivatives of 8-formyl-2,3-disubstituted chromenones using PEG-400 as a reaction medium under catalyst-free conditions good to excellent yields. The structures were established by spectroscopic data and further confirmed by X-ray diffraction analysis. The results showed that compounds 4b, 4c, 4d, 4e and 4k exhibit very potent antiproliferative activity against MDA-MB-231 breast cancer cells. Compounds 4a, 4c, 4e, 4i and 4k displayed potent inhibitory activity against human MCF-7 breast cancer cell lines. Compounds 4h and 4i exhibited significant anti-proliferative activity against human cervical cancer cell line, HeLa. While 4b, 4d and 4j were active against human lung cancer cell line, A549. In addition, Compound 4j was found to be the most promising against A549 (Lung cancer) with IC₅₀ value of 0.194 μM.     

Synthesis and in vitro cytotoxic evaluation of new 1H-benzo[d]imidazole derivatives of dehydroabietic acid

A series of new 1H-benzo[d]imidazole derivatives of dehydroabietic acid were designed and synthesized as potent antitumor agents. Structures of the target molecules were characterized using MS, IR, ¹H NMR, ¹³C NMR and elemental analyses. In the in vitro cytotoxic assay, most compounds showed significant cytotoxic activities against two hepatocarcinoma cells (SMMC-7721 and HepG2) and reduced cytotoxicity against noncancerous human hepatocyte (LO2). Among them, compound 7b exhibited the best cytotoxicity against SMMC-7721 cells (IC₅₀: 0.36 ± 0.13 μM), while 7e was most potent to HepG2 cells (IC₅₀: 0.12 ± 0.03 μM). The cell cycle analysis indicated that compound 7b caused cell cycle arrest of SMMC-7721 cells at G2/M phase. Further, compound 7b also induced the apoptosis of SMMC-7721 cells in Annexin V-APC/7-AAD binding assay.