Design,synthesis, molecular docking,and anticancer activity of benzoxazole derivatives as VEGFR‐2 inhibitors

Novel series of benzoxazole s 4 _a‐f ‐16 were designed, synthesized, and evaluated for anticancer activity against HepG2, HCT‐116, and MCF‐7 cells. HCT‐116 was the most sensitive cell line to the influence of the new derivatives. In particular, compound 5 _e was found to be the most potent against HepG2, HCT‐116, and MCF‐7 with IC₅₀ = 4.13 ± 0.2, 6.93 ± 0.3, and 8.67 ± 0.5 µM, respectively. Compounds 5 _c , 5 _f , 6 _b , 5 _d , and 6 _c showed the highest anticancer activities against HepG2 cells with IC₅₀ of 5.93 ± 0.2, 6.58 ± 0.4, 8.10 ± 0.7, 8.75 ± 0.7, and 9.95 ± 0.9 µM, respectively; HCT‐116 cells with IC₅₀ of 7.14 ± 0.4, 9.10 ± 0.8, 7.91 ± 0.6, 9.52 ± 0.5, and 12.48 ± 1.1 µM, respectively; and MCF‐7 cells with IC₅₀ of 8.93 ± 0.6, 10.11 ± 0.9, 12.31 ± 1.0, 9.95 ± 0.8, and 15.70 ± 1.4 µM, respectively, compared with sorafenib as a reference drug with IC₅₀ of 9.18 ± 0.6, 5.47 ± 0.3, and 7.26 ± 0.3 µM, respectively. The most active compounds 5 _c‐f and 6 _b,c were further evaluated for their vascular endothelial growth factor receptor‐2 (VEGFR‐2) inhibition. Compounds 5 _e and 5 _c potently inhibited VEGFR‐2 at lower IC₅₀ values of 0.07 ± 0.01 and 0.08 ± 0.01 µM, respectively, compared with sorafenib (IC₅₀ = 0.1 ± 0.02 µM). Compound 5 _f potently inhibited VEGFR‐2 at low IC₅₀ value (0.10 ± 0.02 µM) equipotent to sorafenib. Our design was based on the essential pharmacophoric features of the VEGFR‐2 inhibitor sorafenib. Molecular docking was performed for all compounds to assess their binding pattern and affinity toward the VEGFR‐2 active site.     

5-(4-Methoxybenzylidene)thiazolidine-2,4-dione-derived VEGFR-2 inhibitors: Design,synthesis, molecular docking,and anticancer evaluations

A novel series of 5-(4-methoxybenzylidene)thiazolidine-2,4-dione derivatives, 5a–g and 7a–f , was designed, synthesized, and evaluated for their anticancer activity against HepG2, HCT116, and MCF-7 cells. HepG2 and HCT116 were the most sensitive cell lines to the influence of the new derivatives. In particular, compounds 7f , 7e , 7d , and 7c were found to be the most potent derivatives of all the tested compounds against the HepG2, HCT116, and MCF-7 cancer cell lines. Compound 7f (IC₅₀ = 6.19 ± 0.5, 5.47 ± 0.3, and 7.26 ± 0.3 µM, respectively) exhibited a higher activity than sorafenib (IC₅₀ = 9.18 ± 0.6, 8.37 ± 0.7, and 5.10 ± 0.4 µM, respectively) against HepG2 and MCF-7, cells but a lower activity against HCT116 cancer cells, respectively. Also, this compound displayed a higher activity than doxorubicin (IC₅₀ = 7.94 ± 0.6, 8.07 ± 0.8, and 6.75 ± 0.4 µM, respectively) against HepG2 and MCF-7 cells, but nearly the same activity against HCT116 cells, respectively. All derivatives, 5a–g and 7a–f , were evaluated for their inhibitory activities against vascular endothelial growth factor receptor-2 (VEGFR-2). Among them, compound 7f was found to be the most potent derivative that inhibited VEGFR-2 at an IC₅₀ value of 0.12 ± 0.02 µM, which is nearly the same as that of sorafenib (IC₅₀ = 0.10 ± 0.02 µM). Compounds 7e , 7d , 7c , and 7b exhibited the highest activity, with IC₅₀ values of 0.13 ± 0.02, 0.14 ± 0.02, 0.14 ± 0.02, and 0.18 ± 0.03 µM, respectively, which are more than the half of that of sorafenib. Furthermore, molecular docking was performed to investigate their binding mode and affinities toward the VEGFR-2 receptor. The data obtained from the docking studies highly correlated with those obtained from the biological screening.     

Design,synthesis, molecular docking,and anticancer evaluations of 1-benzylquinazoline-2,4(1H,3H)-dione bearing different moieties as VEGFR-2 inhibitors

A novel series of 1-benzylquinazoline-2,4(1H,3H)-dione derivatives, 6a , b to 11a – e , was designed, synthesized, and evaluated for their anticancer activity against HepG2, HCT-116, and MCF-7 cells. Compounds 11b , 11e , and 11c were found to be the most potent derivatives of all tested compounds against the HepG2, HCT-116, and MCF-7 cancer cell lines, with GI₅₀ = 9.16 ± 0.8, 5.69 ± 0.4, 5.27 ± 0.2 µM, 9.32 ± 0.9, 6.37 ± 0.7, 5.67 ± 0.5 µM, and 9.39 ± 0.5, 6.87 ± 0.7, 5.80 ± 0.4 µM, respectively. These compounds exhibited nearly the same activity as sorafenib against HepG2 and HCT-116 cells and a higher activity against MCF-7 cells (GI₅₀ = 9.18 ± 0.6, 5.47 ± 0.3, and 7.26 ± 0.3 µM, respectively). Also, these compounds displayed a lower activity than doxorubicin against HepG2 cells and a higher activity against HCT-116 and MCF-7 cells (GI₅₀ = 7.94 ± 0.6, 8.07 ± 0.8, and 6.75 ± 0.4 µM, respectively). The most active antiproliferative derivatives, 6a , b , 8 , 9 , and 11a – e , were selected to evaluate their enzymatic inhibitory activity against VEGFR-2. Compounds 11b , 11e , and 11c potently inhibited VEGFR-2 at IC₅₀ values of 0.12 ± 0.02, 0.12 ± 0.02, and 0.13 ± 0.02 µM, respectively, which are nearly equipotent as sorafenib IC₅₀ value (0.10 ± 0.02 µM). Furthermore, molecular docking studies were performed for all synthesized compounds to assess their binding pattern and affinity toward the VEGFR-2 active site.     

Design,synthesis, and antitumor evaluation of quinoline‐imidazole derivatives

A series of compounds bearing quinoline‐imidazole ( 8a–e , 9a–e , 10a–e , 11a–e , and 12a–e ) not reported previously were designed and synthesized. The target compounds were evaluated for antitumor activity against A549, PC‐3, HepG2, and MCF‐7 cells by the MTT method, with NVP‐BEZ235 being the positive control. Most compounds showed moderate activity and compound 12a showed the best activity against HepG2, A549, and PC‐3 cells, with half‐maximal inhibitory concentration (IC₅₀) values of 2.42 ± 1.02 µM, 6.29 ± 0.99 µM, and 5.11 ± 1.00 µM, respectively, which was equal to NVP‐BEZ235 (0.54 ± 0.13 µM, 0.36 ± 0.06 µM, 0.20 ± 0.01 µM). Besides, the IC₅₀ value of 12a against the cell line WI‐38 (human fetal lung fibroblasts) was 32.8 ± 1.23 µM, indicating that the target compounds were selective for cancer cells. So, 11a and 12a were evaluated against PI3Kα and mTOR to find out if the compounds acted through the PI3K‐Akt‐mTOR signal transduction pathway. The inhibition ratios to PI3Kα and mTOR were slightly lower than that of NVP‐BEZ235, suggesting there may be some other mechanisms of action. The structure–activity relationships and docking study of 11a and 12a revealed that the latter was superior. Moreover, the target compounds showed better in vitro anticancer activity when the C‐6 of the quinoline ring was replaced by a bromine atom.

     

Design,synthesis, docking,and anticancer evaluations of phthalazines as VEGFR-2 inhibitors

Twenty new N-substituted-4-phenylphthalazin-1-amine derivatives were designed, synthesized, and evaluated for their anticancer activities against HepG2, HCT-116, and MCF-7 cells as VEGFR-2 inhibitors. HCT-116 was the most sensitive cell line to the influence of the new derivatives. In particular, compound 7f was found to be the most potent derivative among all the tested compounds against the three cancer cell lines, with 50% inhibition concentration, IC₅₀ = 3.97, 4.83, and 4.58 µM, respectively, which is more potent than both sorafenib (IC₅₀ = 9.18, 5.47, and 7.26 µM, respectively) and doxorubicin (IC₅₀ = 7.94, 8.07, and 6.75 µM, respectively). Fifteen of the synthesized derivatives were selected to evaluate their inhibitory activities against VEGFR-2. Compound 7f was found to be the most potent derivative that inhibited VEGFR-2 at an IC₅₀ value of 0.08 µM, which is more potent than sorafenib (IC₅₀ = 0.10 µM). Compound 8c inhibited VEGFR-2 at an IC₅₀ value of 0.10 µM, which is equipotent to sorafenib. Moreover, compound 7a showed very good activity with IC₅₀ values of 0.11 µM, which is nearly equipotent to sorafenib. In addition, compounds 7d , 7c , and 7g possessed very good VEGFR-2-inhibitory activity, with IC₅₀ values of 0.14, 0.17, and 0.23 µM, respectively.     

Design,synthesis and cytotoxic evaluation of nitric oxide‐releasing derivatives of isosteviol

Twenty‐six novel isosteviol derivatives coupled with two types of nitric oxide (NO) donors (furoxans and NONOates) were synthesized and screened for cytotoxic activities against four human cancer cell lines with sunitinib as the positive control. The results showed that seven furoxan‐based derivatives ( 8a , 8b , 8c , 8d , 8e , 9e , and 9f ) exhibited desirable cytotoxic activities, while NONOate‐based derivatives displayed poor potency because of unstability. Compared with sunitinib, compounds 8a and 8e were more active on all tested cell lines, especially in HCT116 ( 8a , IC₅₀ = 0.48 ± 0.02 μm ; 8e , IC₅₀ = 0.94 ± 0.01 μm ); compounds 8b and 8d were more potent on HCT116 (IC₅₀ = 3.39 ± 0.06 and 3.29 ± 0.03 μm ), HepG2 (IC₅₀ = 1.05 ± 0.03 and 5.37 ± 0.08 μm ), and SW620 (IC₅₀ = 1.33 ± 0.02 and 4.11 ± 0.05 μm ) cell lines, and 8c exhibited higher activities on HepG2 cells with an IC₅₀ = 4.76 ± 0.14 μm . NO‐releasing experiment of compounds 8a – e , 17a , 18a , 19a , and 21a reminded us that NO‐releasing amount of this series of isosteviol derivatives positively correlates with their cytotoxic activities.     

Novel Pyrazole and Indazole Derivatives: Synthesis and Evaluation of Their Anti‐Proliferative and Anti‐Angiogenic Activities

The synthesis of several new pyrazole and indazole derivatives from acetophenone and tetralone substrates is reported. The bioactivities of the new compounds were evaluated through in vitro assays for endothelial cell proliferation and tube formation. Results herein indicate that the easily prepared compounds containing the indazole structural framework exhibit potent cytostatic properties against all cell lines tested, with compounds 13 and 14 being the most active displaying IC₅₀ values of 1.5 ± 0.4 µM and 5.6 ± 2.5 µM, respectively, against MCF‐7 cells. In addition, the indazole derivative 16 was assessed as a competent inhibitor of endothelial tube formation at 30 µM.     

Discovery of novel pyrrolopyrimidine/pyrazolopyrimidine derivatives bearing 1,2,3‐triazole moiety as c‐Met kinase inhibitors

Six series of pyrrolo[2,3‐d]pyrimidine and pyrazolo[3,4‐d]pyrimidine derivatives bearing 1,2,3‐triazole moiety were designed and synthesized, and some bio‐evaluation was also carried out. As a result, four points can be summarized: Firstly, some of compounds exhibited excellent cytotoxicity activity and selectivity with the IC₅₀ values in single‐digit μm level. In particular, the most promising compound 16d showed equal activity to lead compound foretinib against A549, HepG2, and MCF‐7 cell lines, with the IC₅₀ values of 4.79 ± 0.82, 2.03 ± 0.39, and 2.90 ± 0.43 μm , respectively. Secondly, the SARs and docking studies indicated that the in vitro antitumor activity of pyrrolo[2,3‐d]pyrimidine derivatives bearing 1,2,3‐triazole moiety was superior to the pyrazolo[3,4‐d]pyrimidine derivatives bearing 1,2,3‐triazole moiety. Thirdly, three selected compounds ( 16d , 18d , and 20d ) were further evaluated for inhibitory activity against the c‐Met kinase, and the 16d could inhibit the c‐Met kinase selectively by experiments of enzyme‐based selectivity. What is more, 16d could induce apoptosis of HepG2 cells and inhibitor the cell cycle of HepG2 on G2/M phase by acridine orange staining and cell cycle experiments, respectively.     

Synthesis and antitumor activity of isolongifoleno[7,8‐d]thiazolo[3,2‐a]pyrimidine derivatives via enhancing ROS level

A series of novel isolongifoleno[7,8‐d]thiazolo[3,2‐a]pyrimidine derivatives ( 4a – 4x ) were synthesized from isolongifolanone according fragment‐based design strategy, and their anticancer activity against human aortic smooth muscle cells (HASMC), human breast cancer (MCF‐7) cells, human cervical cancer (HeLa) cells, and human liver cancer (HepG2) cells were investigated. Results of the anticancer activity illustrated that most of the compounds showed potent antitumor activity and compound 4i proved to be the most active derivative with IC₅₀ values of 0.33 ± 0.24 (for MCF‐7 cells), 0.52 ± 0.13 (for HeLa cells), and 3.09 ± 0.11 μM (for HepG2 cells), respectively. Moreover, we assessed the effects of 4i on cell apoptosis, cell cycle distribution, mitochondrial membrane potential, and reactive oxygen species (ROS) generation. The results indicated that compound 4i altered mitochondrial membrane potential and produced ROS leading to cell apoptosis of MCF‐7 cells in a dose‐dependent manner, however, without affecting cell cycle progression. These findings suggested that 4i was an effective compound and provided a promising candidate for anticancer drugs.     

New 2,4‐disubstituted‐2‐thiopyrimidines as VEGFR‐2 inhibitors: Design,synthesis, and biological evaluation

A new series of 2,4‐disubstituted‐2‐thiopyrimidines 6a–t, 9a , and 9b was efficiently designed and synthesized as antiangiogenic and cytotoxic agents. Compounds 6j, 6l , and 6d showed IC₅₀ values of 1.23, 3.78, and 3.84 μM, respectively, against the vascular endothelial growth factor receptor‐2 (VEGFR‐2). Most of the synthesized 2‐thiouracils showed antiproliferative activity against the HepG2 cell line (hepatocellular carcinoma) in the micromolar range, for instance, 9b, 6l, 6m, 6n , and 6j displayed IC₅₀ = 7.92, 8.35, 8.51, 9.59, and 13.06 μM, respectively, relative to sorafenib ( III ; IC₅₀ = 10.99 μM). Also, compounds 6j, 9a, 6m , and 6s (IC₅₀ = 15.21, 16.96, 17.68, and 18.15 μM, respectively) are the most potent compounds against the UO‐31 cell line. Further evaluation of the effect of the synthesized candidates on VEGFR‐2 in the HepG2 cell line demonstrated that compounds 6j and 6l exhibit VEGFR‐2 inhibitory activity of 87% and 84%, respectively, relative to sorafenib ( III ; 92%). In silico docking of the synthesized hits into the binding site of VEGFR‐2 showed their ability to perform the main binding interactions with the key amino acids in the binding site. Studying the in silico predicted ADME (absorption, distribution, metabolism, and excretion) parameters for the synthesized thiouracils demonstrated that they have favorable pharmacokinetic and drug‐likeness properties. These results demonstrate that the 2,4‐disubstituted thiouracils 6 and 9 have not only favorable antiangiogenic and antiproliferative activity but also satisfy the criteria required for the development of orally bioavailable drugs. Consequently, they represent a biologically active scaffold that should be further optimized for future discovery of potential hits.     

Synthesis and Antitumor Activity of Novel Nitrogen Mustard‐Linked Chalcones

A series of nitrogen mustard‐linked chalcones were synthesized and evaluated for their antitumor activity in vitro against the K562 and HepG2 cell lines. The aldol condensation of [N,N‐bis(chloroethyl)‐3‐amino]‐acetophenone ( 2 ) with aromatic aldehydes afforded the nitrogen mustard‐linked chalcones. Among the analogs tested, compounds 5e and 5k exhibited significant anti‐proliferation activities against K562 cells with IC₅₀ values of 2.55 and 0.61 µM, respectively, which revealed higher cell toxicity than the standard drugs cisplatin (IC₅₀ > 200 µM) and adriamycin (IC₅₀ = 14.88 µM). The methoxyl and N,N‐dimethyl groups on the B‐ring of the chalcone frame enhanced the inhibitory activities against both the K562 and HepG2 cell lines. The structure–activity relationship study indicated that the inhibitory activities significantly varied with the position(s) and species of the substituted group(s).     

Design,synthesis, and biological evaluation of novel 1,2‐diaryl‐4‐substituted‐benzylidene‐5(4H)‐imidazolone derivatives as cytotoxic agents and COX‐2/LOX inhibitors

A new series of 1,2‐diaryl‐4‐substituted‐benzylidene‐5(4H)‐imidazolone derivatives 4a–l was synthesized. Their structures were confirmed by different spectroscopic techniques (IR, ¹H NMR, DEPT‐Q NMR, and mass spectroscopy) and elemental analyses. Their cytotoxic activities in vitro were evaluated against breast, ovarian, and liver cancer cell lines and also normal human skin fibroblasts. Cyclooxygenase (COX)‐1, COX‐2 and lipoxygenase (LOX) inhibitory activities were measured. The synthesized compounds showed selectivity toward COX‐2 rather than COX‐1, and the IC₅₀ values (0.25–1.7 µM) were lower than that of indomethacin (IC₅₀ = 9.47 µM) and somewhat higher than that of celecoxib (IC₅₀ = 0.071 µM). The selectivity index for COX‐2 of the oxazole derivative 4e (SI = 3.67) was nearly equal to that of celecoxib (SI = 3.66). For the LOX inhibitory activity, the new compounds showed IC₅₀ values of 0.02–74.03 µM, while the IC₅₀ of the reference zileuton was 0.83 µM. The most active compound 4c (4‐chlorobenzoxazole derivative) was found to have dual COX‐2/LOX activity. All the synthesized compounds were docked inside the active site of the COX‐2 and LOX enzymes. They linked to COX‐2 through the N atom of the azole scaffold, while C?O of the oxazolone moiety was responsible for the binding to amino acids inside the LOX active site.

     

Design and synthesis of 2‐phenyl benzimidazole derivatives as VEGFR‐2 inhibitors with anti‐breast cancer activity

Three new series of 2‐phenyl benzimidazole‐based derivatives were designed, synthesized, and evaluated for their in vitro cytotoxic activity against breast cancer (MCF‐7) cell lines. Three compounds 8 , 9 , and 15 showed high cytotoxic activities, with IC₅₀ values of 3.37, 6.30, and 5.84 μM, respectively, while they showed comparable cytotoxicity to the standard drug doxorubicin against human normal cells, including nontumorigenic breast epithelial cell line (MCF‐10F), skin fibroblast cell line (BJ), and lung fibroblast cell line (MRC‐5). Six of the synthesized compounds were screened against vascular endothelial growth factor receptor 2 (VEGFR‐2) where compounds 8 , 9 , 12 , and 15 exhibited an outstanding potency in comparison with sorafenib, with IC₅₀ values of 6.7–8.9 nM. Molecular docking study assessed the good binding patterns of the most potent compounds with the reported conserved amino acids of VEGFR‐2 active site.     

Design,synthesis, in silico and antiproliferative evaluation of novel pyrazole derivatives as VEGFR‐2 inhibitors

As the blockade of the VEGFR‐2 signaling pathway is a viable approach in cancer therapy, the present study focuses on a series of pyrazole based VEGFR‐2 inhibitors that were designed on the basis of the hybridization approach, supported by docking and in silico computational studies. The designed compounds were synthesized through facile synthetic methods and the structures were confirmed by ¹H NMR, ¹³C NMR, MS and elemental analysis. The compounds were screened for in vitro antiproliferative activity against the HT‐29 (human colon cancer) and MCF‐7 (human breast cancer) cell lines by MTT assay. The compounds were also studied for in vitro inhibitory activity against VEGFR‐2 kinase. Among all the tested compounds, compound 6h emerged as a potent agent in the antiproliferative study against HT‐29 and MCF‐7 cells, with IC₅₀ values of 2.36 and 6.59 μM, respectively. Moreover, the same compound exhibited the highest VEGFR‐2 inhibitory activity with an IC₅₀ value of 1.89 μM. In docking studies, the designed compounds showed similar and essential key interactions as those of known VEGFR‐2 inhibitors. The present study may lead to new molecules in the development of anticancer agents targeting VEGFR‐2.     

Synthesis and Evaluation of Benzophenone O‐Glycosides as α‐Glucosidase Inhibitors

The first total synthesis of benzophenone O‐glycosides (iriflophenone 2‐O‐α‐L ‐rhamnopyranoside: 1 and aquilarisinin: 2 ) isolated from the leaves of Aquilaria sinensis and related new derivatives ( 3 – 12 ) was accomplished through suitable protecting group manipulations and glycosylation starting from commercially available L ‐rhamnose, D ‐glucose, D ‐galactose, D ‐mannose, D ‐xylose, and 1,3,5‐trihydroxybenzene. All synthesized benzophenone O‐glycosides were evaluated for their inhibitory activities against α‐glucosidase. Of these, benzophenone O‐glycosides 4 and 10 exhibited the most potent inhibitory activity in vitro against α‐glucosidase with IC₅₀ values of 168.7 ± 13.9 and 210.1 ± 23.9 µM, respectively, when compared with that of the positive control acarbose with an IC₅₀ value of 569.3 ± 49.7 µM.     

Synthesis and cytotoxicity evaluation of novel podophyllotoxin derivatives

Seven benzylamino derivatives of podophyllotoxin 8a–8g were synthesized and their chemical structures were confirmed by IR, ¹H‐NMR, ¹³C‐NMR and ESI‐MS spectral analyses. Their abilities to inhibit the growth of cancer cells A549, HCT‐116 and HepG2, were investigated by MTT assay. Compound 8b possessed the highest cytotoxicity on cancer cell lines with average IC₅₀ values of 3.8 µM. All we synthetic compounds were cytotoxic against three cancer cell lines at the micromolar range, indicating podophyllotoxin derivatives with structural modification of benzylamino possess potent antitumor activity.     

Synthesis of new arylazopyrazoles as apoptosis inducers: Candidates to inhibit proliferation of MCF‐7 cells

New 4‐arylazo‐3,5‐diamino‐1H‐pyrazole derivatives substituted in the 4‐aryl ring with the acetyl moiety were designed and synthesized. The antiproliferative activity of the novel arylazopyrazoles was examined against the MCF‐7 cell line. Among all target compounds, 8b (IC₅₀ 3.0 µM) and 8f (IC₅₀ 4.0 µM) displayed higher cytotoxicity as compared with the reference standard imatinib (IC₅₀ 7.0 µM). Further studies to explore the mechanism of action were performed on the most active hit of our library, 8b , via anti‐CDK2 kinase activity. It demonstrated good inhibitory effects for CDK2 (IC₅₀ 0.24 µM) with 62.5% inhibition, compared with imatinib. The cell cycle analysis in the MCF‐7 cell line revealed apoptosis induction by 8b and cell cycle arrest at the S phase. Docking in the CDK2 active site and pharmacophore modeling confirmed the affinity of 8b to the CDK2 active site. Absorption, distribution, metabolism, and excretion studies revealed that our target compounds are orally bioavailable, with no permeation through the blood–brain barrier.     

Design and synthesis of pyrazole–pyrazoline hybrids as cancer‐associated selective COX‐2 inhibitors

In continuation of our previous work on cancer and inflammation, 15 novel pyrazole–pyrazoline hybrids ( WSPP1 – 15 ) were synthesized and fully characterized. The formation of the pyrazoline ring was confirmed by the appearance of three doublets of doublets in ¹H nuclear magnetic resonance spectra exhibiting an AMX pattern for three protons (H_A, H_M, and H_X) of the pyrazoline ring. All the synthesized compounds were screened for their in vitro anticancer activity against five cell lines, that is, MCF‐7, A549, SiHa, COLO205, and HepG2 cells, using the MTT growth inhibition assay. 5‐Fluorouracil was taken as the positive control in the study. It was observed that, among them, WSPP11 was found to be active against A549, SiHa, COLO205, and HepG2 cells, with IC₅₀ values of 4.94, 4.54, 4.86, and 2.09 µM. All the derivatives were also evaluated for their cytotoxicity against HaCaT cells. WSPP11 was also found to be nontoxic against normal cells (cell line HaCaT), with an IC₅₀ value of more than 50 µM. The derivatives were also evaluated for their in vitro anti‐inflammatory activity by the protein (egg albumin) denaturation assay and the red blood cell membrane stabilizing assay, using diclofenac sodium and celecoxib as standard. Compounds that showed significant anticancer and anti‐inflammatory activities were further studied for COX‐2 inhibition. The manifestation of a higher COX‐2 selectivity index of WSPP11 as compared with other derivatives and an in vitro anticancer activity against four cell lines further established that compounds that were more selective toward COX‐2 also exhibited a better spectrum of activity against various cancer cell lines.     

Design,synthesis, and cytotoxic evaluation of novel furo[2,3‐b]quinoline derivatives

A number of novel furo[2,3‐b]quinoline derivatives were designed and synthesized by introducing benzyl ether, benzoate, and benzenesulfonate to 6‐position of furo[2,3‐b]quinoline and their chemical structures were confirmed by ESI‐MS, ¹H NMR, and ¹³C NMR spectra. All target compounds were evaluated in vitro against four human cancer cell lines (HCT‐116, MCF‐7, U2OS, and A549) by MTT method. Cytotoxic assay showed that compounds 8a , 8e , 10a , 10b, and 10c exhibited more potent cytotoxicities compared to 2‐bromine‐6‐hydroxy‐furo‐[2,3‐b]quinoline ( 7 ). Compound 10c exhibited higher antiproliferative activity (IC₅₀ values ranging from 4.32 to 24.96 μm ) against four human cancer cell lines (HCT‐116, MCF‐7, U2OS, and A549) and weak cytotoxicity on normal cell HL‐7702, which suggested that 10c might be an ideal anticancer candidate. Compounds 8a , 10a , 10b showed good selectivities to MCF‐7 and HCT‐116, which could be considered as ideal selective candidates for further study. The SARs showed that the introduction of the benzyl ether and benzenesulfonate could significantly improve cytotoxicities, while the benzoate failed to enhance potency obviously.     

Design,synthesis, and biological evaluation of novel 3‐(thiophen‐2‐ylthio)pyridine derivatives as potential multitarget anticancer agents

A series of novel 3‐(thiophen‐2‐ylthio)pyridine derivatives as insulin‐like growth factor 1 receptor (IGF‐1R) inhibitors was designed and synthesized. IGF‐1R kinase inhibitory activities and cytotoxicities against HepG2 and WSU‐DLCL2 cell lines were tested. For all of these compounds, potent cancer cell proliferation inhibitory activities were observed, but not through the inhibition of IGR‐1R. Selected compounds were further screened against various kinases. Typical compound 22 (50% inhibitory concentration [IC₅₀] values, HepG2: 2.98 ± 1.11 μM and WSU‐DLCL2: 4.34 ± 0.84 μM) exhibited good inhibitory activities against fibroblast growth factor receptor‐2 (FGFR2), FGFR3, epidermal growth factor receptor, Janus kinase, and RON (receptor originated from Nantes), with IC₅₀ values ranging from 2.14 to 12.20 μM. Additionally, the cell‐cycle analysis showed that compound 22 could arrest HepG2 cells in the G1/G0 phase. Taken together, all the experiments confirmed that the compounds in this series were multitarget anticancer agents worth further optimizing.