Asymmetrical 2,6-bis(benzylidene)cyclohexanones: Synthesis, cytotoxic activity and QSAR study

Discovery of new pyridine heterocyclic hybrids; design, synthesis, dynamic simulations, and in vitro and in vivo breast cancer biological assays

Pyridine is a nitrogen bearing heterocyclic scaffold that shows a wide range of biological activities. The pyridine nucleus has become an interesting target for medicinal chemistry researchers worldwide. Several pyridine derivatives exhibited good anticancer effects against diverse cell lines. Therefore, to explore new anticancer pyridine entities, novel pyridine derivatives were designed and synthesized and evaluated for their anticancer abilities in vitro and in vivo. All of the target compounds were evaluated against three different human cancer cell lines (Huh-7, A549 and MCF-7) via MTT assay. Most of the compounds exhibited significant cytotoxic activities. Compounds 3a, 3b, 5a and 5b showed superior antiproliferative activities to Taxol. Where, compound 3b showed IC₅₀ values of 6.54, 15.54 and 6.13 μM compared to Taxol (6.68, 38.05, 12.32 μM) against Huh-7, A549 and MCF-7, respectively. Also, tubulin polymerization assay was carried out. The most potent compounds 3a, 3b, 5a and 5b could significantly inhibit tubulin polymerization with IC₅₀ values of 15.6, 4.03, 6.06 and 12.61 μM, respectively. Compound 3b exhibited the highest tubulin polymerization inhibitory effect with an IC₅₀ value of 4.03 μM compared to combretastatin (A-4) (1.64 μM). Molecular modeling studies of the designed compounds confirmed that most of the compounds made the essential binding interactions compared to the reference compound which assisted in the prediction of the structure requirements for the detected anticancer activity. Finally, in vivo studies showed that compound 3b could significantly inhibit breast cancer.

Synthesis of small molecules targeting paclitaxel-induced MyD88 expression in triple-negative breast cancer cell lines

Acquired paclitaxel (PTX) chemoresistance in triple-negative breast cancer (TNBC) can be inferred from the overexpression of toll-like receptor 4 (TLR4) and myeloid differentiation primary response 88 (MyD88) proteins and the activation of the TLR4/MyD88 cascading signalling pathway. Finding a new inhibitor that can attenuate the activation of this pathway is a novel strategy for reducing PTX chemoresistance. In this study, a series of small molecule compounds were synthesised and tested in combination with PTX against TNBC cells. The trimethoxy-substituted compound significantly decreased MyD88 overexpression and improved PTX activity in MDA-MB-231^TLR4+ cells but not in HCC^TLR4- cells. On the contrary, the trifluoromethyl-substituted compound with PTX synergistically improved the growth inhibition in both TNBC subtypes. The fluorescence titrations indicated that both compounds could bind with MD2 with good and comparable binding affinities. This was further supported by docking analysis, in which both compounds fit perfectly well and form some critical binding interactions with MD2, an essential lipid-binding accessory to TLR4 involved in activating the TLR-4/MyD88-dependent pathway.

In-Vitro and In-Silico Evaluations of Heterocyclic-Containing Diarylpentanoids as Bcl-2 Inhibitors Against LoVo Colorectal Cancer Cells

In the present study, we investigated the in-vitro anti-cancer potential of six diarylpentanoids against a panel of BRAF- and KRAS-mutated colorectal cancer cell lines including T84, SW620, LoVo, HT29, NCI-H508, RKO, and LS411N cells. Structure-activity relationship study suggested that the insertions of tetrahydro-4H-thiopyran-4-one and brominated phenyl moieties are essential for better cytotoxicity. Among the evaluated analogs, 2e has been identified as the lead compound due to its low IC50 values of approximately 1 µM across all cancer cell lines and high chemotherapeutic index of 7.1. Anti-proliferative studies on LoVo cells showed that 2e could inhibit cell proliferation and colony formations by inducing G2/M cell cycle arrest. Subsequent cell apoptosis assay confirmed that 2e is a Bcl-2 inhibitor that could induce intrinsic cell apoptosis by creating a cellular redox imbalance through its direct inhibition on the Bcl-2 protein. Further molecular docking studies revealed that the bromophenyl moieties of 2e could interact with the Bcl-2 surface pocket through hydrophobic interaction, while the tetrahydro-4H-thiopyran-4-one fragment could form additional Pi-sulfur and Pi-alkyl interactions in the same binding site. In all, the present results suggest that 2e could be a potent lead that deserves further modification and investigation in the development of a new Bcl-2 inhibitor.

Synthesis of novel spirobibenzopyrans as potent anticancer leads inducing apoptosis in HeLa cells

Spirobibenzopyrans are an unexplored class of therapeutics. We report the anticancer activity of novel spirobibenzopyrans, synthesized by a one-pot reaction and extensively characterized. Structure of one of the spirobibenzopyran has been determined by the single crystal XRD technique. The in vitro anticancer activity of these derivatives across the NCI 60-cell line panel was evaluated and for the first time their mechanism of action against HeLa cells was probed via cell morphology analysis and cell cycle analysis. They were determined to be apoptosis inducers with cell cycle arrest in G₀/G₁ and S phase suggesting CDK-4 protein inhibition and the inhibition of DNA replication. The DNA inhibition was studied and confirmed using the alkaline comet assay for the compound CHX-4MO-SAL showing S phase inhibition. Further, conformity with the in silico Lipinski's score signify the potential of spirobibenzopyrans as anticancer leads.

An Operationally Simple and Efficient Synthesis of 7-Benzylidene-substitutedphenyl- 3,3a,4,5,6,7-hexahydro-2H-indazole by Grinding Method

BACKGROUND

An eco-friendly, operationally simple and efficient reaction is shown between various 2,6-bis-(substituted-benzylidene)-cyclohexanones and differently substituted hydrazine in the presence of acetic acid.

METHODS

The reaction between various 2,6-bis-(substituted-benzylidene)-cyclohexanones and differently substituted hydrazine in the presence of acetic acid afforded 7-Benzylidene-substituted-phenyl-3,3a,4,5,6,7- hexahydro-2H-indazole in 74 to 92 % yield in short reaction time using the grindstone technique.

RESULTS AND DISCUSSION

The notable advantages of this method include mild synthetic conditions, weak acid catalysis, and non-hazardous solvent which make this method environmentally safer.

CONCLUSION

In conclusion, we have developed an efficient, simple and eco-friendly method for the synthesis of 7-Benzylidene-substituted-phenyl-3,3a,4,5,6,7-hexahydro-2H-indazole by grinding technique. The notable benefits of this method are waste minimization, no organic solvent required, simple procedure, easy work-up, and clean reaction profile.

Diarylpentanoids with antitumor activity: A critical review of structure-activity relationship studies

Diarypentanoids are commonly considered as monocarbonyl analogues of curcumin. Since the discovery of this compound in 1962, twenty one diarylpentanoids have been isolated and almost 600 synthetic analogues with antitumor activity have been synthesized. This review reports the exploitation of diarylpentanoids to develop curcumin analogues with improved antitumor activity over the last two decades. The mechanism of action and structure-activity relationship (SAR) studies are also highlighted. More importantly, structural features for the antitumor activity that may guide the design of new and more effective diarylpentanoids are also proposed.

Overview of recent developments of pyrazole derivatives as an anticancer agent in different cell line

Pyrazole is a five-membered aromatic heterocyclic ring with two adjacent nitrogen atoms C₃H₃N₂H.The presence of this nucleus in pharmacological agents of various therapeutic categories gifts a broad spectrum of biological activities and pharmaceuticals that contain pyrazole like celecoxib (anti-inflammatory), CDPPB (antipsychotic), Rimonabant (anti-obesity), Difenamizole, (Analgesic), Betazole (H2 receptor agonist), Fezolamide (Antidepressant), etc… The pharmacological potential of the pyrazole fraction is proved in many publication where they synthesized and evaluated pyrazoles against several biological agents. The aim of this article review is to survey recent works linking pyrazole structures to anticancer activities corresponding to 9 different type of cancer.

Insights on the synthesis of asymmetric curcumin derivatives and their biological activities

Curcumin is a small organic molecule with pleiotropic biological activities. However, its multiple structural-pharmacokinetic challenges prevent its development into a clinical drug. Various structural modifications have been made to improve its drug profile. In this review, we focus on the methods adopted in the synthesis of asymmetric curcumin derivatives and their biological activities and forecast the future of this exciting class of compounds in the field of medicine.

Synthesis and X-ray study of dispiro 8-nitroquinolone analogues and their cytotoxic properties against human cervical cancer HeLa cells

A series of unique dispiro analogues containing an oxindole pyrrolidine 8-nitroquinolone hybrid has been obtained through a one-pot three-component 1,3-dipolar cycloaddition of azomethine ylides generated in situ from the condensation of isatins and benzylamine with (E)-3-arylidene-2,3-dihydro-8-nitro-4-quinolones. The structures of the newly synthesized compounds were characterized by using different spectroscopic techniques and by X-ray diffraction studies of their regio- and stereochemistry. All the synthesized compounds were screened for in vitro cytotoxic activity against the human cervical cancer cell line HeLa. The compounds have exhibited potent inhibition against human cervical cancer cells and insignificant toxicity to normal cells. The compounds 6d, 6a, 6h, 6b, and 6e induced apoptosis of HeLa cells, through ROS influx. The expression levels of proteins involved in the mitochondrion-related pathways were detected, and Western blot analysis showed that apoptosis occurred via activation of caspase-3.

Design, synthesis and cytotoxic effects of curcuminoids on HeLa, K562, MCF-7 and MDA-MB-231 cancer cell lines

Background

Curcumin is one of the leading compound extracted from the dry powder of Curcuma longa (Zingiberaceae family), which possess several pharmacological properties. However, in vivo administration exhibited limited applications in cancer therapies.

Results

Twenty-four curcumin derivatives have synthesized, which comprises cyclohexanone 1–10, acetone 11–17 and cyclopentanone 18–24 series. All the curcuminoids were synthesized by the acid or base catalyzed Claisen Schmidt condenstion reactions, in which β-diketone moiety of curcumin was modified with mono-ketone. These curcuminoids 1–24 were screened against HeLa, K562, MCF-7 (an estrogen-dependent) and MDA-MB-231 (an estrogen-independent) cancer cell lines. Among them, acetone series 11–17 were found to be more selective and potential cytotoxic agents. The compound 14 was exhibited (IC₅₀ = 3.02 ± 1.20 and 1.52 ± 0.60 µg/mL) against MCF-7 and MDA-MB-231 breast cancer cell lines. Among the cyclohexanone series, the compound 4 exhibited (IC₅₀ = 11.04 ± 2.80, 6.50 ± 01.80, 8.70 ± 3.10 and 2.30 ± 1.60 µg/mL) potential cytotoxicity against four proposed cancer cell lines, respectively. All the curcucminoids were characterized with the detailed ¹H NMR, IR, UV–Vis, and mass spectroscopic techniques. The structure of compound 4 was confirmed by using the single X-ray crystallography. Additionally, we are going to report the first time spectral data of (2E,6E)-2,6-bis(2-methoxybenzylidene)cyclohexanone (1). Structure–activity relationships revealed that the mono-carbonyl with 2,5-dimethoxy substituted curcuminoids could be an essential for the future drugs against cancer diseases.

Conclusions

Curcuminoids with diferuloyl(4-hydroxy-3-methoxycinnamoyl) moiety with mono carbonyl exhibiting potential cytotoxic properties. The compound 14 was exhibited (IC₅₀ = 3.02 ± 1.20 and 1.52 ± 0.60 µg/mL) against MCF-7 and MDA-MB-231 breast cancer cell lines.

Synthesis, anticancer evaluation, and molecular docking studies of some novel 4,6-disubstituted pyrazolo[3,4-d]pyrimidines as cyclin-dependent kinase 2 (CDK2) inhibitors

A novel series of 4,6-disubstituted pyrazolo[3,4-d]pyrimidines (7-43) bearing various anilines at C-4 position and thiophenethyl or thiopentane moieties at C-6 position have been designed and synthesized by molecular hybridization approach. All the synthesized compounds were evaluated for in vitro CDK2/cyclin E and Abl kinase inhibitory activity as well as anti-proliferative activity against K-562 (chronic myelogeneous leukemia), and MCF-7 (breast adenocarcinoma) cell lines. The structure-activity relationship (SAR) studies revealed that compounds with thiophenethyl group at C-6 with mono-substituted anilines at C-4 exhibited better CDK2 inhibitory activity compared to alkyl group (thiopentane) at C-6 and di-substituted anilines at C-4 of the scaffold. In particular, compounds having 2-chloro, 3-nitro and 4-methylthio aniline groups at C-4 displayed significant enzymatic inhibitory activity against CDK2 with single digit micromolar IC₅₀ values. The in silico molecular docking studies suggested possible binding orientation and the binding energies were in agreement with the observed SAR as well as experimental results. In addition, some of the synthesized compounds showed anti-proliferative effects against K-562 and MCF-7 cancer cell lines with IC₅₀ values in a micromolar range. Thus, the synthesized compounds could be considered as new anticancer hits for further lead optimization.

Design, Synthesis and Docking Studies of Flavokawain B Type Chalcones and Their Cytotoxic Effects on MCF-7 and MDA-MB-231 Cell Lines

Flavokawain B (1) is a natural chalcone extracted from the roots of Piper methysticum, and has been proven to be a potential cytotoxic compound. Using the partial structure of flavokawain B (FKB), about 23 analogs have been synthesized. Among them, compounds 8, 13 and 23 were found in new FKB derivatives. All compounds were evaluated for their cytotoxic properties against two breast cancer cell lines, MCF-7 and MDA-MB-231, thus establishing the structure–activity relationship. The FKB derivatives 16 (IC₅₀ = 6.50 ± 0.40 and 4.12 ± 0.20 μg/mL), 15 (IC₅₀ = 5.50 ± 0.35 and 6.50 ± 1.40 μg/mL) and 13 (IC₅₀ = 7.12 ± 0.80 and 4.04 ± 0.30 μg/mL) exhibited potential cytotoxic effects on the MCF-7 and MDA-MB-231 cell lines. However, the methoxy group substituted in position three and four in compound 2 (IC₅₀ = 8.90 ± 0.60 and 6.80 ± 0.35 μg/mL) and 22 (IC₅₀ = 8.80 ± 0.35 and 14.16 ± 1.10 μg/mL) exhibited good cytotoxicity. The lead compound FKB (1) showed potential cytotoxicity (IC₅₀ = 7.70 ± 0.30 and 5.90 ± 0.30 μg/mL) against two proposed breast cancer cell lines. It is evident that the FKB skeleton is unique for anticancer agents, additionally, the presence of halogens (Cl and F) in position 2 and 3 also improved the cytotoxicity in FKB series. These findings could help to improve the future drug discovery process to treat breast cancer. A molecular dynamics study of active compounds revealed stable interactions within the active site of Janus kinase. The structures of all compounds were determined by ¹H-NMR, EI-MS, IR and UV and X-ray crystallographic spectroscopy techniques.

The in vivo anti-tumor effect of curcumin derivative (2E,6E)-2,6-bis(4-hydroxy-3-methoxybenzylidene)cyclohexanone (BHMC) on 4T1 breast cancer cells

BHMC possessedin vitroandin vivoantitumor effect on 4T1 triple negative breast cancer cells.

Synthesis and biological evaluation of 1,3,4,5-tetrasubstituted pyrazole derivatives

We report a solvent-free synthesis of novel 1,3,4,5-tetrasubstituted pyrazoles and investigate their inhibitory activity against soybean 15-lipoxygenase. It was revealed that all synthesized compounds exhibited good activity, and among them, 3-(furan-2-yl)-1,4,5-triphenyl-1H-pyrazole (5j) showed 10 times stronger inhibitory activity in comparison to the reference drug quercetin.

Recent advances of cytotoxic chalconoids targeting tubulin polymerization: Synthesis and biological activity

Since microtubules have an important role in mitosis and other vital cellular functions, tubulin-targeting chemotherapy has been received growing attention in anticancer drug design and development. It was found that a number of naturally occurring compounds including distinct chalcones exert their effect by inhibition of tubulin polymerization. After the identification of tubulin polymerization as potential target for chalcone-type compounds, extensive researches have been made to design and synthesis of new anti-tubulin chalconoids. Although diverse chalcones have found to be potent anticancer agents but in the present review, we focused on the recently reported tubulin polymerization inhibitors from chalcone origin and related synthetic compounds, and their detailed synthetic methods and biological activities.

Design, synthesis, and biological evaluation of new series of 2-amido-1,3,4-thiadiazole derivatives as cytotoxic agents

A series of novel 1,3,4-thiadiazole derivatives bearing an amide moiety were designed, synthesized, and evaluated for their in vitro antitumor activities against HL-60, SKOV-3 and MOLT-4 human tumor cell lines by MTT assay. Ethyl 2-((5-(4-methoxybenzamido)-1,3,4-thiadiazol-2-yl)thio)acetate (5f) showed the best inhibitory effect against SKOV-3 cells, with an IC50 value of 19.5 μm. In addition, the acridine orange/ethidium bromide staining assay in SKOV-3 cells suggested that the cytotoxic activity of 5f occurs via apoptosis.

Synthesis and in vitro antiproliferative activity of novel pyrazolo[3,4-d]pyrimidine derivatives

A novel series of pyrazolo[3,4-d]pyrimidine derivatives were designed, synthesized and evaluated for their antiproliferative activity.

In vitro biocompatibility evaluation of biscoumarin based random copolyesters

Copolyester CP5 exhibits cytocompatible properties toward a normal cell line (Vero cells) and requires 13-fold higher concentration in comparison with Hep-2 cells.

Recent developments in biological activities of chalcones: a mini review

Chalcones represent key structural motif in the plethora of biologically active molecules including synthetic and natural products. Synthetic manipulations of chalcones or their isolation from natural sources are being investigated worldwide for the development of more potent and efficient drugs for the treatment of several dreadful diseases such as cancer, diabetes, HIV, tuberculosis, malaria etc. Over the past few years, a large volume of research papers and review articles highlighting the significance of chalcone derivatives has been compiled in the literature. The present review article focuses on the recent developments (2010-2014) on various pharmacological and medicinal aspects of chalcones and their analogues.

Synthesis and cytotoxic evaluation of some new[1,3]dioxolo[4,5-g]chromen-8-one derivatives

Background

Homoisoflavonoids are naturally occurring compounds belong to flavonoid classes possessing various biological properties such as cytotoxicity. In this work, an efficient strategy for the synthesis of novel homoisoflavonoids, [1,3]dioxolo[4,5-g]chromen-8-ones, was developed and all compounds were evaluated for their cytotoxic activities on three breast cancer cell lines.

Methods

Our synthetic route started from benzo[d][1,3]dioxol-5-ol which was reacted with 3-bromopropanoic acid followed by the reaction of oxalyl chloride to afford 6,7-dihydro-8H-[1,3]dioxolo[4,5-g]chromen-8-one. The aldol condensation of the later compound with aromatic aldehydes led to the formation of the title compounds. Five novel derivatives 4a-e were tested for their cytotoxic activity against three human breast cancer cell lines including MCF-7, T47D, and MDA-MB-231 using the MTT assay.

Results

Among the synthesized compounds, 7-benzylidene-6,7-dihydro-8H-[1,3]dioxolo[4,5-g]chromen-8-one (4a) exhibited the highest activity against three cell lines. Also the analysis of acridine orange/ethidium bromide staining results revealed that 7-benzylidene-6,7-dihydro-8H-[1,3]dioxolo[4,5-g]chromen-8-one (4a) and 7-(2-methoxybenzylidene)-6,7-dihydro-8H-[1,3]dioxolo[4,5-g]chromen-8-one (4b) induced apoptosis in T47D cell line.

Conclusion

Finally, the effect of methoxy group on the cytotoxicity of compounds 4b-4d was investigated in and it was revealed that it did not improve the activity of [1,3]dioxolo[4,5-g]chromen-8-ones against MCF-7, T47D, and MDA-MB-231.

Synthesis and In vitro cytotoxic activity evaluation of (E)-16-(substituted benzylidene) derivatives of dehydroepiandrosterone

Background and the purpose of the study

Modified androsterone derivatives are class of steroidal compounds with potential anticancer properties. Various steroidal derivatives containing substitution at position 16 have shown diversified pharmacological activities. In the present study, a new series of cytotoxic 16-(substituted benzylidene) derivatives of dehydroepiandrosterone (DHEA) were synthesized and evaluated against three different cancer cell lines.

Methods

The cytotoxic 16-(substituted benzylidene) derivatives of DHEA were synthesized via aldol condensation of DHEA with corresponding benzaldehyde derivatives. The cytotoxic activity of synthesized derivatives was evaluated against three different cancer cells including KB, T47D and SK-N-MC cell lines by MTT reduction colorimetric assay.

Results

The results indicated that 16-(substituted benzylidene) derivatives of DHEA could be served as a potent anti-cancer agent. The 3-cholro benzylidene derivatives of DHEA was the most potent synthesized derivative especially against KB and T47D cell lines (IC₅₀ values were 0.6 and 1.7 μM; respectively).

Conclusion

The cytotoxic potential of novel benzylidene derivatives of DHEA is mainly attributed to the position and nature of the substituted group on the benzylidene pendant.

Synthesis and cytotoxic properties of novel (E)-3-benzylidene-7-methoxychroman-4-one derivatives

Background and the purpose of the study

There has been increscent interest in the field of cancer chemotherapy by discovery and development of novel agents with high efficacy, low toxicity, and minimum side effects. In order to find new anticancer agents, we replaced the pyrazolone part of well-known cytotoxic agent SJ-172550 with 7-methoxychroman-4-one. Thus, a novel series of 3-benzylidene-4-chromanones were synthesized and tested in vitro against human cancer cell lines.

Methods

The title compounds were prepared by condensation of 7-methoxychroman-4-one with suitable aldehydes in appropriate alcohol in the presence of gaseous HCl. The antiproliferative activity of target compounds were evaluated against MDA-MB-231 (breast cancer), KB (nasopharyngeal epidermoid carcinoma) and SK-N-MC (human neuroblastoma) cell lines using MTT assay.

Results

Although the direct analog of SJ-172550 (compound 5d) did not show any cytotoxic activity against tested cell lines, but 2-(2-chloro-6-methoxyphenoxy)acetic acid methyl ester analog 5c showed some activity against MDA-MB-231 and SK-N-MC cells. Further modification of compound 5c resulted in the 3-chloro-4,5-dimethoxybenzylidene derivative 5b which demonstrated better cytotoxic profile against all tested cell lines (IC₅₀ values = 7.56–25.04 μg/ml).

Conclusion

The results demonstrated that the cytotoxic activity of compound 5b against MDA-MB-231 and SK-N-MC cells is more than etoposide. Therefore, compound 5b prototype could be considered as novel cytotoxic agent for further developing new anticancer chemotherapeutics.

Halogenated flavanones as potential apoptosis-inducing agents: synthesis and biological activity evaluation

A series of halogenated flavanones were synthesized from 2-hydroxychalcones and tested for their cytotoxicity against a panel of human cancer cell lines. Among the synthesized compounds, 3',7-dichloroflavanone (2d) showed the highest activity against MCF-7, LNCaP, PC3, Hep-G2, KB and SK-N-MC cells. However, 3',6-dichloroflavanone (2g) with IC(50) value of 2.9 ± 0.9 μM was the most potent compound against MDA-MB-231 cells, being approximately 12 times more active than etoposide as reference drug. According to the flow-cytometric analysis, compound 2g can induce apoptosis by 66.19 and 21.37% in PC3 and MDA-MB-231 cells, respectively. The results of acridine orange/ethidium bromide staining and TUNEL assay suggested that the cytotoxic activity of this compound in PC3 and MDA-MB-231 cells occurs via apoptosis.

Synthesis of novel quinoline-2-one based chalcones of potential anti-tumor activity

Novel quinoline-2-one based chalcones were synthesized from a Claisen-Schmidt condensation by using the couple KOH/1,4-dioxane as reaction medium. A relatively stable aldol was isolated and identified as the intermediate species in the formation of the target chalcones. Nine of the obtained compounds were in vitro screened by the US National Cancer Institute (NCI) for their ability to inhibit 60 different human tumor cell lines. Products 16c, 16d, 16h and 27 exhibited the highest activity, being compound 27 the most active, displaying remarkable activity against 50 human tumor cell lines, thirteen of them with GI(50) values ≤1.0 μM, being the HCT-116 (Colon, GI(50) = 0.131 μM) and LOX IMVI (Melanoma, GI(50) = 0.134 μM) the most sensitive strains. Compound 27 was referred to in vivo acute toxicity and hollow fiber assay by the Biological Evaluation Committee of the NCI. The acute toxicity study indicated that compound 27 was well tolerated intraperitoneally (150 mg/kg/dose) by athymic nude mice. This compound may possibly be used as lead compound for developing new anticancer agents.