Design and pharmacophore modeling of biaryl methyl eugenol analogs as breast cancer invasion inhibitors

In-vitro anti-Mycobacterium tuberculosis effect of Eugenol

BACKGROUND/OBJECTIVES

Mycobacterium tuberculosis, the causative agent of tuberculosis has developed resistance to most of the available antimicrobials. Therefore research on the detection of new antimicrobials against Mycobacterium tuberculosis is needed urgently. Essential oils extracted from plants have been shown to have anti-Mycobacterium tuberculosis effect in in-vitro experiments. Essential oil contains many chemicals and any one or more than one chemical may have the anti-Mycobacterium tuberculosis effect. Eugenol is one such chemical in the essential oil and the anti-Mycobacterium tuberculosis effect of eugenol is investigated.

METHODS

The anti-Mycobacterium tuberculosis effect of eugenol was evaluated against H37Rv and twelve clinical isolates of Mycobacterium tuberculosis in the BD BACTEC MGIT instrument using different volumes of eugenol.

RESULTS

H37Rv and all the twelve clinical isolates of Mycobacterium tuberculosis were inhibited by eugenol. The minimal inhibitory concentration of H37Rv was 2.5 μl (2.67 mg) and those of the clinical isolates of Mycobacterium tuberculosis ranged from to 2.5 μl (2.67 mg) to 10 μl (10.68 mg).

CONCLUSION

Eugenol has anti-Mycobacterium tuberculosis effect in the in-vitro BD BACTEC MGIT method.

Control of ER-positive breast cancer by ERα expression inhibition, apoptosis induction, cell cycle arrest using semisynthetic isoeugenol derivatives

New semi-synthetic effective and safe anticancer agents isoeugenol derivatives were synthesized, characterized, and screened for their cytotoxic activity against MCF-7. Moreover, their selective cytotoxicity was assessed against MCF-10A. Three derivatives, 2, 8 and 10 were significantly more active than the reference drug 5-FU with IC₅₀ values of 6.59, 8.07 and 9.63 and 30.93 μM, respectively. Also interestingly, these derivatives demonstrated some degree of selectivity to cancer cells over normal cells. Furthermore, derivative 2 was subjected to other in vitro experiments against MCF-7 where it inhibited colony formation by 87.5% and lowered ERα concentration to 395.7 pg/mL compared to 1129 pg/mL in untreated control cells. In continuation of the investigation, the apoptotic activity of compound 2, was assessed where it significantly enhanced total apoptotic cell death by 9.16-fold (18.70% compared to 1.64% for the untreated MCF-7 control cells) and arrested the cell cycle at the G2/M phase. Furthermore, the molecular mechanism of apoptotic activity was investigated at both the gene (RT-PCR) and protein (western plotting) levels where upregulation of pro-apoptotic and down regulation of anti-apoptotic genes was detected. Additionally, compound 2 treatment enhanced the antioxidant (GSH, CAT, SOD) activities. Finally, in vivo experiments verified the effective anticancer activity of compound 2 through inhibition of tumor proliferation by 47.6% compared to 22.9% for 5-FU and amelioration of the hematological, biochemical, and histopathological examinations near normal. In effect, compound 2 can be viewed as a promising semi-synthetic derivative of isoeugenol with some degree of selectivity for management of breast cancer through apoptotic induction and ERα downregulation.

A New Chalcone Derivative with Promising Antiproliferative and Anti-Invasion Activities in Glioblastoma Cells

Glioblastoma (GBM) is the most common and most deadly primary malignant brain tumor. Current therapies are not effective, the average survival of GBM patients after diagnosis being limited to few months. Therefore, the discovery of new treatments for this highly aggressive brain cancer is urgently needed. Chalcones are synthetic and naturally occurring compounds that have been widely investigated as anticancer agents. In this work, three chalcone derivatives were tested regarding their inhibitory activity and selectivity towards GBM cell lines (human and mouse) and a non-cancerous mouse brain cell line. The chalcone 1 showed the most potent and selective cytotoxic effects in the GBM cell lines, being further investigated regarding its ability to reduce critical hallmark features of GBM and to induce apoptosis and cell cycle arrest. This derivative showed to successfully reduce the invasion and proliferation capacity of tumor cells, both key targets for cancer treatment. Moreover, to overcome potential systemic side effects and its poor water solubility, this compound was encapsulated into liposomes. Therapeutic concentrations were incorporated retaining the potent in vitro growth inhibitory effect of the selected compound. In conclusion, our results demonstrated that this new formulation can be a promising starting point for the discovery of new and more effective drug treatments for GBM.

Wild Italian Hyssopus officinalis subsp. aristatus (Godr.) Nyman: From Morphological and Phytochemical Evidences to Biological Activities

Three specimens of H. officinalis subsp. aristatus were collected in three areas of the Abruzzo region (Italy) and subjected to macroscopic and microscopic observation to support their botanical identification. The essential oils (EOs) obtained from the aerial parts of the samples were characterized with the object to define their phytochemical and pharmaceutical biology profile. They highlight three different chemotypes, including one never seen in previous literature (CIV17-EO, distilled from sample harvested in 2017 at Civitaretenga), that showed a fingerprinting with the predominance of (-)-limonen-10-yl-acetate (67.9%). In 2017 European Food Safety Authority (EFSA) reported the genotoxicity of similar compounds, therefore, to dismiss any safety concern for the CIV17-EO use as flavouring substance, the Ames test was performed with no evidence of mutagenic activity. Safety of use coupled with chemical characterization of this new chemotype set the stage for a better standardization of H. officinalis EOs. The ethanolic extracts, on the other hand, with qualitatively similar chemical profiles in which caftaric, chlorogenic and rosmarinic acid were the main molecules, showed interesting antioxidant activity and a slight cytotoxicity towards the A549 cell line that could indicate a starting point for the evaluation of an additional preventive tool for maintaining health status.

Pterygota alata (Roxb.) R.Br. Bark Fraction Induced Intrinsic Apoptotic Pathway in 4T1 Cells by Decreasing Bcl-2 and Inducing Bax Expression

BACKGROUND AND OBJECTIVE

Pterygota alata (Roxb.) R.Br. bark extract has been studied to have cytotoxic activity on 4T1 cells. This study was conducted to determine the cytotoxic activity of several fractions of Pterygota alata (Roxb.) R.Br. bark against 4T1 breast cancer cells and to investigate the most active fractions on Bcl-2 and Bax expressions.

MATERIALS AND METHODS

The bark of Pterygota alata (Roxb.) R.Br. was extracted using 80% methanol and was fractionated into fractions of n-hexane, chloroform, ethyl acetate, n-butanol and insoluble n-butanol with liquid-liquid partition. Cytotoxic tests were performed using the MTT method and expressions of Bax and Bcl-2 on 4T1 breast cancer cells were detected with immunocytochemical staining. Identification of compounds in the most active fraction using GC-MS.

RESULTS

The results showed that the most active fraction was the insoluble fraction of n-butanol (IFB) with an IC50 of 15.14 μg mL-1. IFB also decreases the expression of Bcl-2 and increases the expression of Bax.

CONCLUSION

It can be concluded that Pterygota alata (Roxb.) R.Br. bark has the potential to be developed for medical use, especially for breast cancer therapy.

Synthesis of Eugenol Derivatives and Evaluation of their Antifungal Activity Against Fusarium solani f. sp. piperis

BACKGROUND

Fusarium solani f. sp. piperis is a phytopathogen that causes one of the most destructive diseases in black pepper crops, resulting in significant economic and crop production losses. Consequently, the control of this fungal disease is a matter of current and relevant interest in agriculture.

OBJECTIVE

The objective was to synthesize eugenol derivatives with antifungal activity.

METHODS

In this study, using bimolecular nucleophilic substitution and click chemistry approaches, four new and three known eugenol derivatives were obtained. The eugenol derivatives were characterized and their antifungal and cytotoxic effects were evaluated.

RESULTS

Eugenol derivative 4 (2-(4-allyl-2-methoxyphenoxy)-3-chloronaphthalene-1,4-dione) was the most active against F. solani f. sp. piperis and showed acceptable cytotoxicity. Compound 4 was two-fold more effective than tebuconazole in an antifungal assay and presented similar cytotoxicity in macrophages. The in silico study of β-glucosidase suggests a potential interaction of 4 with amino acid residues by a cation-π interaction with residue Arg177 followed by a hydrogen bond with Glu596, indicating an important role in the interactions with 4, justifying the antifungal action of this compound. In addition, the cytotoxicity after metabolism was evaluated as a mimic assay with the S9 fraction in HepG2 cells. Compound 4 demonstrated maintenance of cytotoxicity, showing IC50 values of 11.18 ± 0.5 and 9.04 ± 0.2 μg mL-1 without and with the S9 fraction, respectively. In contrast, eugenol (257.9 ± 0.4 and 133.5 ± 0.8 μg mL-1), tebuconazole (34.94 ± 0.2 and 26.76 ± 0.17 μg mL-1) and especially carbendazim (251.0 ± 0.30 and 34.7 ± 0.10 μg mL-1) showed greater cytotoxicity after hepatic biotransformation.

CONCLUSION

The results suggest that 4 is a potential candidate for use in the design of new and effective compounds that could control this pathogen.

Chalcone derivatives targeting mitosis: synthesis, evaluation of antitumor activity and lipophilicity

This study describes the synthesis of a series of chalcones, including pyrazole and α,β-epoxide derivatives, and evaluation of their cell growth inhibitory activity in three human tumor cell lines, as well as their lipophilicity using liposomes as a biomimetic membrane model. Structure-activity and structure-lipophilicity relationships were established for the synthetized chalcones. From this work, nine chalcones (3, 5, 9, 11, 15-19) showing suitable drug-like lipophilicity with potent growth inhibitory activity were identified, being the growth inhibitory effect of compounds 15-17 associated with a pronounced antimitotic effect. Compounds 15-17 affected spindle assembly and, as a consequence, arrested cells at metaphase in NCI-H460 cells, culminating in cell death. Amongst the compounds tested, compound 15 exhibited the highest antimitotic activity as revealed by mitotic index calculation. Moreover, 15 was able to enhance chemosensitivity of tumor cells to low doses of paclitaxel in NCI-H460 cells. The results indicate that 15 exerts its antiproliferative activity by affecting microtubules and causing cell death subsequently to a mitotic arrest, and thus has the potential for antitumor activity.

Identification of Essential 2D and 3D Chemical Features for Discovery of the Novel Tubulin Polymerization Inhibitors

Background:

Tubulin polymerization inhibitors interfere with microtubule assembly and their functions lead to mitotic arrest, therefore they are attractive target for design and development of novel anticancer compounds.

Objective:

The proposed novel and effective structures following the use of three-dimensionalquantitative structure activity relationship (3D-QSAR) pharmacophore based virtual screening clearly demonstrate the high efficiency of this method in modern drug discovery.

Method:

Combined computational approach was applied to extract the essential 2D and 3D features requirements for higher activity as well as identify new anti-tubulin agents.

Results:

The best quantitative pharmacophore model, Hypo1, exhibited good correlation of 0.943 (RMSD=1.019) and excellent predictive power in the training set compounds. Generated model AHHHR, was well mapped to colchicine site and three-dimensional spatial arrangement of their features were in good agreement with the vital interactions in the active site. Total prediction accuracy (0.92 for training set and 0.86 for test set), enrichment factor (4.2 for training set and 4.5 for test set) and the area under the ROC curve (0.86 for training set and 0.94 for the test set), the developed model using Extended Class FingerPrints of maximum diameter 4 (ECFP_4) was chosen as the best model.

Conclusion:

Developed computational platform provided a better understanding of requirement features for colchicine site inhibitors and we believe the results of this study might be useful for the rational design and optimization of new inhibitors.

Eugenol and derivatives activity against Mycobacterium tuberculosis, nontuberculous mycobacteria and other bacteria

AIM

To evaluate (i) the in vitro activity of eugenol (EUG) and three derivatives against Mycobacterium tuberculosis (Mtb), nontuberculous mycobacteria (NTM) and other bacteria, (ii) the EUG and antituberculosis drugs combinatory effect and (iii) the EUG and its derivatives cytotoxicity.

MATERIALS & METHODS

Minimum inhibitory concentration of the compounds were determined by resazurin microtiter or broth microdilution assay and the drug interaction between EUG and antituberculosis drugs by resazurin drug combination microtiter. The cytotoxicity was carried out in macrophages, HeLa and VERO cells. Results: EUG and derivatives displayed activity and synergic effect of EUG combined with rifampicin, isoniazid, ethambutol, and pyrazinamide in Mtb including multidrug-resistant isolates, with more selectivity to bacillus than macrophages, HeLa and VERO cells (selective index from 0.65 to 31.4). EUG derivatives (4-allyl-2-methoxyphenyl acetate, 4-allyl-2-methoxyphenyl benzoate, and 4-allyl-2-methoxyphenyl 4-nitrobenzoate) were more active against nontuberculous mycobacteria than EUG. EUG and derivatives exhibited low activity in other Gram-positive and -negative bacteria.

CONCLUSION

EUG and its derivatives show activity against Mycobacterium spp. and synergic effect of EUG combined with antituberculosis drugs against Mtb.

Heck Transformations of Biological Compounds Catalyzed by Phosphine-Free Palladium

The development and optimization of synthetic methods leading to functionalized biologically active compounds is described. Two alternative pathways based on Heck-type reactions, employing iodobenzene or phenylboronic acid, were elaborated for the arylation of eugenol and estragole. Cinnamyl alcohol was efficiently transformed to saturated arylated aldehydes in reaction with iodobenzene using the tandem arylation/isomerization sequential process. The arylation of cinnamyl alcohol with phenylboronic acid mainly gave unsaturated alcohol, while the yield of saturated aldehyde was much lower. Catalytic reactions were carried out using simple, phosphine-free palladium precursors and water as a cosolvent, following green chemistry rules as much as possible.

Aqueous protocol for allylic arylation of cinnamyl acetates with sodium tetraphenylborate using a Bedford-type palladacycle catalyst

Allylic arylation using 0.002 mol% of a Bedford-type palladacycle catalyst is described under mild reaction conditions.

Perspectives on medicinal properties of natural phenolic monoterpenoids and their hybrids

Carvacrol, thymol and eugenol belong to a class of naturally presenting phenols with a ten-carbon unit, which are present in essential oils of many plants. These versatile molecules are incorporated as useful ingredients in many food products and find applications in agricultural, pharmaceutical, fragrance, cosmetic, flavor and other industries. They are wide ranging of biological and pharmaceutical activities: anti-inflammatory, antimicrobial, analgesic, anticancer and antioxidant. This review summarizes pharmacological and medicinal activities of these phytochemicals and their synthetic hybrids.

Cobalt-Catalyzed Reductive Cross-Coupling Between Styryl and Benzyl Halides

A simple and efficient protocol for the direct reductive cross-coupling between alkenyl and benzyl halides using a Co/Mn system has been developed. This reaction proceeds smoothly in the presence of [CoBr₂ (PPh₃ )₂ ] as the catalyst, with NaI as an additive in acetonitrile with a broad scope of functionalized alkenyl and benzyl halides. Different functional groups are tolerated on both coupling partners, thus, significantly extending the general scope of transition-metal-catalyzed benzylation of alkenyl halides. Moderate to excellent yields were also obtained. From a mechanistic point of view, a radical chain mechanism was proposed. This reaction is stereospecific and some studies suggest the retention of the double-bond configuration.

γ-Tocotrienol reversal of epithelial-to-mesenchymal transition in human breast cancer cells is associated with inhibition of canonical Wnt signalling

OBJECTIVES

Frizzled-7 (FZD7) receptor-dependent activation of the canonical Wnt/β-catenin pathway plays a crucial role in epithelial-to-mesenchymal transition (EMT) and breast cancer metastasis. FZD7 and its co-receptor, low-density lipoprotein receptor-related protein 6 (LRP6), are highly expressed in MDA-MB-231 and T-47D breast cancer cells, and endogenous ligands for FZD7 include Wnt3a and Wnt5a/b. γ-Tocotrienol, a natural isoform of vitamin E, inhibits human breast cancer cell proliferation and EMT. Here, studies have been conducted to investigate the role of the canonical Wnt pathway in mediating inhibitory effects of γ-tocotrienol on EMT in human breast cancer cells.

MATERIALS AND METHODS

MDA-MB-231, T-47D and MCF-10A cells were maintained in serum-free defined media containing selected doses of γ-tocotrienol. Cell viability was determined using the MTT colorimetric assay, Western blot analysis was used to measure protein expression and the wound-healing assay was employed to study cell mobility and migration. Immunohistochemical fluorescence staining visualized expression and localization of EMT cell markers.

RESULTS

γ-Tocotrienol was found to induce dose-responsive inhibition of MDA-MB-231 and T-47D cell growth at doses that had no effect on immortalized normal MCF-10A mammary epithelial cells. These growth inhibitory effects were associated with suppression in canonical Wnt signalling, reversal of EMT and significant reduction in breast cancer cell motility.

CONCLUSIONS

γ-Tocotrienol suppression of metastatic breast cancer cell proliferation and EMT was associated with suppression of the canonical Wnt/β-catenin signalling pathway.

Pincer-Nickel-Catalyzed Allyl-Aryl Coupling between Allyl Methyl Ethers and Arylzinc Chlorides

The P,N,N-pincer nickel complex [Ni(Cl){N(2-Ph2PC6H4)(2'-Me2NC6H4)}]-catalyzed allyl-aryl coupling was studied. The reaction of allyl methyl ethers, including (1-methoxyallyl)arenes and (3-methoxyprop-1-en-1-yl)arenes, with arylzinc chlorides afforded linear (E)-alkenes in high yields, whereas the reaction of (E)-1-methoxytridec-2-ene with p-Me2NC6H4ZnCl generated a mixture of linear and branched alkenes.

Continuous ion-exchange resin catalysed esterification of eugenol for the optimized production of eugenyl acetate using a packed bed microreactor

A green scalable flow-synthesis process for the production of eugenyl acetate, an eugenol derivative with potential applications in food and medicinal chemistry, was developed.

Hydrazone-palladium-catalyzed allylic arylation of cinnamyloxyphenylboronic acid pinacol esters

Allylic arylation of cinnamyloxyphenylboronic acid pinacol esters 3, which have arylboronic acid moiety and allylic ether moiety, using a hydrazone 1d-Pd(OAc)2 system proceeded and gave the corresponding 1,3-diarylpropene derivatives 4 with a phenolic hydroxyl group via a selective coupling reaction of the π-allyl intermediate to the boron-substituted position of the leaving group.

Direct olefination of benzaldehydes into 1,3-diarylpropenes via a copper-catalyzed heterodomino Knoevenagel-decarboxylation-Csp3-H activation sequence

Copper-catalyzed direct olefination of benzaldehydes into unsymmetrical 1,3-diarylpropenes by a novel domino Knoevenagel-decarboxylation-Csp³-H activation sequence using simpler substrates like benzaldehydes.

Combretastatin A-4 inspired novel 2-aryl-3-arylamino-imidazo-pyridines/pyrazines as tubulin polymerization inhibitors, antimitotic and anticancer agents

Novel 2-aryl-3-arylamino-imidazo-pyridines/pyrazines that exhibit potent tubulin polymerization inhibition, anticancer activity, anti-migration of cancer cells, chromosomal damage, and apoptosis have been developed.