A Novel Tetramethylpyrazine Chalcone Hybrid- HCTMPPK, as a Potential Anti-Lung Cancer Agent by Downregulating MELK.

Purpose: Lung adenocarcinoma currently ranks the leading causes of cancer-related mortality worldwide. Many anti-inflammation herbs, like tetramethylpyrazine, have shown their anti-tumor potentials. Here, we evaluated the role of a novel chalcone derivative of tetramethylpyrazine ((E) -1- (E) -1- (2-hydroxy-5-chlorophenyl) -3- (3,5,6-trimethylpyrazin-2-yl) -2-propen-1, HCTMPPK) in lung adenocarcinoma. Methods: The effects of HCTMPPK on cell proliferation, apoptosis, and invasion were investigated by in-vitro assays, including CCK-8, colony formation assay, flow cytometry, transwell assay, and wound-healing assay. The therapeutic potential of HCTMPPK in vivo was evaluated in xenograft mice. To figure out the target molecules of HCTMPPK, a network pharmacology approach and molecular docking studies were employed, and subsequent experiments were conducted to confirm these candidate molecules. Results: HCTMPPK effectively suppressed the proliferative activity and migration, as well as enhanced the apoptosis of A549 cells in a concentration-dependent manner. Consistent with this, tumor growth was inhibited by HCTMPPK significantly in vivo. Regarding the mechanisms, HCTMPPK down-regulated Bcl-2 and MMP-9 and up-regulating Bax and cleaved-caspase-3. Subsequently, we identified 601 overlapping DEGs from LUAD patients in TCGA and GEO database. Then, 15 hub genes were identified by PPI network and CytoHubba. Finally, MELK was verified to be the HCTMPPK targeted site, through the molecular docking studies and validation experiments. Conclusion: Overall, our study indicates HCTMPPK as a potential MELK inhibitor and may be a promising candidate for the therapy of lung cancer.

Synthesis, Characterization, Antioxidant, and Anticancer Activity against Colon Cancer Cells of Some Cinnamaldehyde-Based Chalcone Derivatives.

The purpose of the current investigation was to produce cinammaldehyde-based chalcone derivatives (3a-k) to evaluate their potential effectiveness as antioxidant and inhibitory agents versus human Caco-2 cancer cells. The findings obtained using the DPPH assay showed that compound 3e had the highest effective antioxidant activity with the best IC50 value compared with the other compounds. Moreover, the cytotoxic findings revealed that compound 3e was the best compound for inhibiting Caco-2 development in contrast to all other produced derivatives, with the lowest IC50 concentration (32.19 ± 3.92 µM), and it also had no detrimental effects on healthy human lung cells (wi38 cells). Exposure of Caco-2 cells with this IC50 value of compound 3e resulted in a substantial rise in the number of early and late cells that are apoptotic with a significant comet nucleus when compared with control cells employing the annexin V/PI and comet evaluations, respectively. Furthermore, qRT-PCR and ELISA examinations indicated that compound 3e significantly altered the expression of genes and their relative proteins related to apoptosis in the treated Caco-2 cells, thus significantly inhibiting Caco-2 growth through activating Caspase-3 via an intrinsic apoptotic pathway. As a result, compound 3e could serve as an effective therapy for human colon cancer.

Quinazoline-chalcone hybrids as HDAC/EGFR dual inhibitors: Design, synthesis, mechanistic, and in-silico studies of potential anticancer activity against multiple myeloma.

Two new series of quinazoline-chalcone hybrids were designed, synthesized as histone deacetylase (HDAC)/epidermal growth factor receptor (EGFR) dual inhibitors, and screened in vitro against the NCI 60 human cancer cell line panel. The most potent derivative, compound 5e bearing a 3,4,5-trimethoxyphenyl chalcone moiety, showed the most effective growth inhibition value against the panel of NCI 60 human cancer cell lines. Thus, it was selected for further investigation for NCI 5 log doses. Interestingly, this trimethoxy-substituted analog inhibited the proliferation of Roswell Park Memorial Institute (RPMI)-8226 cells by 96%, at 10 µM with IC50 = 9.09 ± 0.34 µM and selectivity index = 7.19 against normal blood cells. To confirm the selectivity of this compound, it was evaluated against a panel of tyrosine kinase enzymes. Mechanistically, it successfully and selectively inhibited HDAC6, HDAC8, and EGFR with IC50 = 0.41 ± 0.015, 0.61 ± 0.027, and 0.09 ± 0.004 µM, respectively. Furthermore, the selected derivative induced apoptosis via the mitochondrial apoptotic pathway by raising the Bax/Bcl-2 ratio and activating caspases 3, 7, and 9. Also, the flow cytometry analysis of RPMI-8226 cells showed that the trimethoxy-substituted analog produced cell cycle arrest in the G1 and S phases at 55.82%. Finally, an in silico study was performed to explore the binding interaction of the most active compound within the zinc-containing binding site of HDAC6 and HDAC8.

Synthesis, Antimicrobial Activities, and Molecular Modeling Studies of Agents for the Sortase A Enzyme.

Sortase A (SrtA) is an attractive target for developing new anti-infective drugs that aim to interfere with essential virulence mechanisms, such as adhesion to host cells and biofilm formation. Herein, twenty hydroxy, nitro, bromo, fluoro, and methoxy substituted chalcone compounds were synthesized, antimicrobial activities and molecular modeling strategies against the SrtA enzyme were investigated. The most active compounds were found to be T2, T4, and T19 against Streptococcus mutans (S. mutans) with MIC values of 1.93, 3.8, 3.94 µg/mL, and docking scores of -6.46, -6.63, -6.73 kcal/mol, respectively. Also, these three active compounds showed better activity than the chlorohexidine (CHX) (MIC value: 4.88 µg/mL, docking score: -6.29 kcal/mol) in both in vitro and in silico. Structural stability and binding free energy analysis of S.mutans SrtA with active compounds were measured by molecular dynamic (MD) simulations throughout 100 nanoseconds (ns) time. It was observed that the stability of the critical interactions between these compounds and the target enzyme was preserved. To prove further, in vivo biological evaluation studies could be conducted for the most promising precursor compounds T2, T4, and T19, and it might open new avenues to the discovery of more potent SrtA inhibitors.

Current scenario of chalcone hybrids with antibreast cancer therapeutic applications.

Breast cancer, an epithelial malignant tumor that occurs in the terminal ducts of the breast, is the most common female malignancy. Currently, approximately 70%-80% of breast cancer with early-stage, nonmetastatic disorder is curable, but the emergency of drug resistance often leads to treatment failure. Moreover, advanced breast cancer with distant organ metastases is incurable with the available therapeutics, creating an urgent demand to explore novel antibreast cancer agents. Chalcones, the precursors for flavonoids and isoflavonoids, exhibit promising activity against various breast cancer hallmarks, inclusive of proliferation, angiogenesis, invasion, metastasis, inflammation, stemness, and regulation of cancer epigenetics, representing useful scaffolds for the discovery of novel antibreast cancer chemotherapeutic candidates. In particular, chalcone hybrids could act on two or more different biological targets simultaneously with more efficacy, lower toxicity, and less susceptibility to resistance. Accordingly, there is a huge scope for application of chalcone hybrids to tackle the present difficulties in breast cancer therapy. This review outlines the chalcone hybrids with antibreast cancer potential developed from 2018. The structure-activity relationships as well as mechanisms of action are also discussed to shed light on the development of more effective and multitargeted chalcone candidates.

Discovery of a new dihydroeugenol-chalcone hybrid with cytotoxic and anti-migratory potential: A dual-action hit for cancer therapeutics.

Cancer still represents a serious public health problem and one of the main problems related to the worsening of this disease is the ability of some tumors to develop metastasis. In this work, we synthesized a new series of chalcones and isoxazoles derived from eugenol and analogues as molecular hybrids and these compounds were evaluated against different tumor cell lines. This structural pattern was designed considering the cytotoxic potential already known for eugenol, chalcones and isoxazoles. Notably, chalcones 7, 9, 10, and 11 displayed significant activity (4.2-14.5 µM) against two cancer cell lines, surpassing the potency of the control drug doxorubicin. The reaction of chalcones with hydroxylamine hydrochloride provided the corresponding isoxazoles that were inactive against these cancer cells. The dihydroeugenol chalcone 7 showed the most promising results, demonstrating higher potency against HepG2 (CC50: 4.2 µM) and TOV-21G (CC50: 7.2 µM). Chalcone 7 was also three times less toxic than doxorubicin considering HepG2 cells, with a selectivity index greater than 11. Further investigations including clonogenic survival, cell cycle progression and cell migration assays confirmed the compelling antitumoral potential of chalcone 7, as it reduced long-term survival due to DNA fragmentation, inducing cell death and inhibiting HepG2 cells migration. Moreover, in silico studies involving docking and molecular dynamics revealed a consistent binding mode of chalcone 7 with metalloproteinases, particularly MMP-9, shedding light on its potential mechanism of action related to anti-migratory effects. These significant findings suggest the inclusion of compound 7 as a promising candidate for future studies in the field of cancer therapeutics.

Conarubins A-D: Four Monoterpene-Chalcone Conjugates from Conamomum rubidum and Their Anti-inflammatory and Cytotoxic Activities.

Four novel compounds, conarubins A-D (1-4), were isolated from the whole plants of Conamomum rubidum collected in Vietnam. Their structures were elucidated by extensive spectroscopic analyses and by quantum chemical calculations of NMR and ECD. Compounds 1 and 2 were the first examples of monoterpene-monoterpene-chalcone conjugates in nature, whereas compound 4 was an unprecedented monoterpene-substituted chalcone containing a 3,4,5-trioxygenated cyclohexa-2,5-diene-1-one ring. The anti-inflammatory and cytotoxic activities of all isolates were investigated.

Flexibility in the bridge of chalcone derivatives is important for the inhibition of cellular growth.

Chalcones and their derivatives are a privileged scaffold in medicinal chemistry, demonstrating numerous biological activities. These molecules have shown significant potential toward the development of novel cancer therapies. While much is known about modification to the chalcone aryl rings, little is known about conformations of the bridge between the aryl rings. Here we report the synthesis and biological evaluation of a series of molecules with flexible and rigid bridge conformations. Crystal structures of a select group of molecules were determined. Flexibility in the chalcone bridge containing the enone moiety was determined to be important for activity. Screening in three distinct cancer cell lines showed significant differences in the activity between the flexible and rigid conformations. Crystal structures suggest an increase in bond rotation and weakened π-bonding in the flexible chalcone bridge, which may contribute to the stronger anti-proliferative activity.

Fluoroindole chalcone analogues targeting the colchicine binding site of tubulin for colorectal oncotherapy.

Colorectal cancer (CRC) is a common malignancy of the gastrointestinal tract with high morbidity and mortality. Our previous studies have demonstrated that indole-chalcone-based compounds targeting tubulin displayed potential cytotoxicity to CRC cells. Herein, three new series of derivatives were systematically designed and synthesized to explore their structure-activity relationship (SAR) against CRC based on prior research. Among them, a representative fluorine-containing analog (FC116) exerted superior efficacy on HCT116 (IC50 = 4.52 nM) and CT26 (IC50 = 18.69 nM) cell lines, and HCT116-xenograft mice with tumor growth inhibition rate of 65.96% (3 mg/kg). Of note, FC116 could also suppress the growth of organoid models (IC50 = 1.8-2.5 nM) and showed adenoma number inhibition rate of 76.25% at the dose of 3 mg/kg in APCmin/+ mice. In terms of mechanism, FC116 could induce endoplasmic reticulum (ER) stress to produce excess reactive oxygen species (ROS), leading to mitochondrial damage to promote the apoptosis of CRC cells by targeting microtubules. Our results support that indole-chalcone compounds are promising tubulin inhibitors and highlight the potential of FC116 to combat CRC.

Imidazopyridine chalcones as potent anticancer agents: Synthesis, single-crystal X-ray, docking, DFT and SAR studies.

New imidazopyridine-chalcone analogs were synthesized through the Claisen-Schmidt condensation reaction. The newly synthesized imidazopyridine-chalcones (S1-S12) were characterized using spectroscopic and elemental analysis. The structures of compounds S2 and S5 were confirmed by X-ray crystallography. The global chemical reactivity descriptor parameter was calculated using theoretically (DFT-B3LYP-3-211, G) estimated highest occupied molecular orbital and lowest unoccupied molecular orbital values and the results are discussed. Compounds S1-S12 were screened on A-549 (lung carcinoma epithelial cells) and MDA-MB-231 (M.D. Anderson-Metastatic Breast 231) cancer cell lines. Compounds S6 and S12 displayed exceptional antiproliferative activity against lung A-549 cancer cells with IC50 values of 4.22 and 6.89 µM, respectively, compared to the standard drug doxorubicin (IC50 = 3.79 µM). In the case of the MDA-MB-231 cell line, S1 and S6 exhibited exceptionally superior antiproliferative activity with IC50 of 5.22 and 6.50 µM, respectively, compared to doxorubicin (IC50 = 5.48 µM). S1 was found to be more active than doxorubicin. Compounds S1-S12 were tested for their cytotoxicity on human embryonic kidney 293 cells, which confirmed the nontoxic nature of the active compounds. Further molecular docking studies verified that compounds S1-S12 have a higher docking score and interacted well with the target protein. The most active compound S1 interacted well with the target protein carbonic anhydrase II in complex with pyrimidine-based inhibitor, and S6 with human Topo IIα ATPase/AMP-PNP. The results suggest that imidazopyridine-chalcone analogs may serve as new leads as anticancer agents.

Novel Tetrahydro-[1,2,4]triazolo[3,4-a]isoquinoline Chalcones Suppress Breast Carcinoma through Cell Cycle Arrests and Apoptosis.

Chalcones are interesting anticancer drug candidates which have attracted much interest due to their unique structure and their extensive biological activity. Various functional modifications in chalcones have been reported, along with their pharmacological properties. In the current study, novel chalcone derivatives with the chemical base of tetrahydro-[1,2,4]triazolo[3,4-a]isoquinolin-3-yl)-3-arylprop-2-en-1-one were synthesized, and the structure of their molecules was confirmed through NMR spectroscopy. The antitumor activity of these newly synthesized chalcone derivatives was tested on mouse (Luc-4T1) and human (MDA-MB-231) breast cancer cell lines. The antiproliferative effect was evaluated through SRB screening and the MTT assay after 48 h of treatment at different concentrations. Interestingly, among the tested chalcone derivatives, chalcone analogues with a methoxy group were found to have significant anticancer activity and displayed gradient-dependent inhibition against breast cancer cell proliferation. The anticancer properties of these unique analogues were examined further by cytometric analysis of the cell cycle, quantitative PCR, and the caspases-Glo 3/7 assay. Chalcone methoxy derivatives showed the capability of cell cycle arrest and increased Bax/Bcl2 mRNA ratios as well as caspases 3/7 activity. The molecular docking analysis suggests that these chalcone methoxy derivatives may inhibit anti-apoptotic proteins, particularly cIAP1, BCL2, and EGFRK proteins. In conclusion, our findings confirm that chalcone methoxy derivatives could be considered to be potent drug candidates against breast cancer.

Synthesis, in vitro cytotoxicity evaluation and mechanism of 5' monosubstituted chalcone derivatives as antitumor agents.

A series of 5' monosubstituted chalcone derivatives were synthesized to explore their antitumor activity and mechanism of action in vitro. The structures of 5' monosubstituted chalcone derivatives synthesized by reactions such as Suzuki coupling were confirmed by 1H NMR, 13C NMR and MS, and the target compounds were not reported in the literature. The antitumor activity of the aimed compounds was tested by MTT colorimetric method in vitro. Compound 5c has an IC50 value of 1.97 µM for K562 and a value of 2.23 µM for HepG2. Further investigation of the mechanism of action of compound 5c was found to have effects on K562 cell morphology, proliferation, apoptosis, cell cycle, and wound healing of HepG2 cells. The results showed that compound 5c has research value in antitumor activity and mechanism of action in vitro.

Design, synthesis, cytotoxic activities, and molecular docking of chalcone hybrids bearing 8-hydroxyquinoline moiety with dual tubulin/EGFR kinase inhibition.

The present study established thirteen novel 8-hydroxyquinoline/chalcone hybrids3a-mof hopeful anticancer activity. According to NCI screening and MTT assay results, compounds3d-3f, 3i,3k,and3ldisplayed potent growth inhibition on HCT116 and MCF7 cells compared to Staurosporine. Among these compounds,3eand3fshowed outstanding superior activity against HCT116 and MCF7 cells and better safety toward normal WI-38 cells than Staurosporine. The enzymatic assay revealed that3e,3d, and3ihad goodtubulin polymerization inhibition (IC50 = 5.3, 8.6, and 8.05 µM, respectively) compared to the reference Combretastatin A4 (IC50 = 2.15 µM). Moreover,3e,3l, and3fexhibited EGFR inhibition (IC50 = 0.097, 0.154, and 0.334 µM, respectively) compared to Erlotinib (IC50 = 0.056 µM). Compounds3eand3fwere investigated for their effects on the cell cycle, apoptosis induction, andwnt1/ß-cateningene suppression. The apoptosis markers Bax, Bcl2, Casp3, Casp9, PARP1, and ß-actin were detected by Western blot. In-silico molecular docking, physicochemical, and pharmacokinetic studies were implemented for the validation of dual mechanisms and other bioavailability standards. Hence, Compounds3eand3fare promising antiproliferative leads with tubulin polymerization and EGFR kinase inhibition.

Biological evaluation of polycyclic chalcone based acrylamides in human MCF-7 and HeLa cancer cell lines.

Breast and cervical cancer account for the majority of cancer-narrated fatalities among women worldwide, necessitating the development of novel, effective therapeutic ways to combat the disease. In this study, we synthesized 6-methoxy naphthalene and anthracene-based acrylamide chalcone (NBA and ABA) and evaluated its activity for cell multiplication inhibition against two cancer cell lines from humans such as MCF-7 (Human Breast) and HeLa (Cervical) by MTT assay. Physiochemical characterization, such as FT-IR and NMR analyses, validated the synthesized NBA and ABA. Both NBA and ABA have shown antiproliferative action against two cancer cell lines, each with IC50 values of 38.46 and 48.25 µg/mL for HeLa cells and 38.02 and 36.35 µg/mL for MCF-7 cell lines. The results suggest that these acrylamide chalcones for cancer therapy at the lowest concentration. NBA and ABA could prevent cervical and breast cancer in-vitro, and their anti-cancer activity was closely related to methoxy-substituted naphthalene, anthracene ring, α, ß-unsaturated carbonyl and amide group. According to docking data, the NBA and ABA have dock scores ranging from -8.7 to -11.44 kcal/mol. The highest dock score for compound ABA was -11.58 kcal/mol and compound NBA was -10.77 kcal/mol with Braf (5VAM) binding site.

Antimicrobial, Antiproliferative Effects and Docking Studies of Methoxy Group Enriched Coumarin-Chalcone Hybrids.

Methoxy group enriched eight coumarin-chalcone hybrid derivatives were synthesized. Antimicrobial/ antiproliferative activities were tested against eight human pathogenic microorganisms and four cancer cell lines (AGS, HepG2, MCF-7 and PC-3), respectively. Antimicrobial results showed that most of the compounds were almost more active than used standard antibiotics. Cytotoxicity results showed that 2,3,4-trimethoxyphenyl and thiophene containing structures have promising antiproliferative effects against AGS gastric cell lines with ∼5 µg/ml IC50 values. At the same time, 2,4-dimethoxyphenyl bearing derivative exhibited the lowest IC50 values against HepG2 (∼10 µg/ml) and PC-3 (∼5 µg/ml) cell lines. Particularly, the cell viabilities of MCF-7 cell lines were remarkably inhibited by all the compounds with lower IC50 values. Therefore, molecular docking studies between hybrid ligands and quinone reductase-2 enzyme (regulates in MCF-7 cancer cells) were performed. The results demonstrated that all the derivatives can smoothly interact with interested enzyme in agreement with the experimental results. Finally, ADME parameters were studied to reveal drug-likeness potentials of the coumarin-chalcone hybrids.

Chalcones: Potential Chemotherapeutic Compounds and Educational Tools for Closing the Loop in STEM.

The study discussed herein describes the synthesis of halogenated chalcones as potential chemotherapeutics. The synthesis work was conducted by undergraduate students participating in an Organic Chemistry II laboratory course at Tuskegee University, while the biological assays were conducted by students enrolled in a Molecular Biology I laboratory course. Chalcones were synthesized via aldol condensation and purified from hot ethanol. The impetus for the work was the fact that Tuskegee University sits positioned within the Black Belt of Alabama which, in addition to being an area of fertile soil and excellent farmland, is also an area rife with health disparities that particularly affect African-Americans. Breast cancer, specifically triple-negative breast cancer, affects African-American women at a higher rate than any other ethnic group. The work described herein addresses a practical problem [teaching undergraduate students about the interface of synthetic techniques, synthesis of specific classes of compounds, functional groups, and their relation to biological activity], as well an existential problem [the prevalence of breast cancer among African-American women, and the need to develop targeted treatments]. One of the chief aims of this approach of integrating these ideas into our laboratory courses was to facilitate the understanding of translational science, i.e. taking chalcones from benchtop to potential therapies for breast cancer. Another aim of the current approach was to, in essence, create a research problem based course and concomitantly use the results of the experiments performed in the course as a way to address the dearth of research funding that HBCUs typically receive. The pharmacological activities of chalcones and their derivatives are well documented. They are an important class of natural products that occur in edible plant derivatives such as spices, teas, fruits and various vegetables. In vitro studies have shown that chalcones inhibit proliferation of breast cancer cells by inducing apoptosis and blocking cell progression. The synthesis of chalcones with aromatic substituents has been investigated, and electron rich chalcones, i.e., chalcones with donors attached to the aromatic rings, have been studied extensively. The effect that adding electron withdrawing groups to the chalcone structural motif has on the antiproliferation ability of chalcones had been only minimally investigated at the time that our studies were being conducted. We examined the introduction of chlorine to the aromatic system of the chalcone and how these electron withdrawing substituents affect the chalcone's antiproliferative ability. It was discovered that (E)-3-(4-chlorophenyl)-1-phenylprop-2-en-1-one inhibited MDA-MB-231 cell progression in a dose dependent manner and outperformed the unsubstituted (E)-1,3-diphenyl-2-propen-1-one (1) at concentrations ranging from 0 µg/mL to 20 µg/mL. Cell death was determined by MTT assay.

New 1,3,4-oxadiazole-chalcone/benzimidazole hybrids as potent antiproliferative agents.

A series of new 1,3,4-oxadiazole-chalcone/benzimidazole hybrids 9a-o and 10a-k were designed and synthesized as potential antiproliferative agents. Hybrids 9a-o exhibited remarkable antiproliferative activities on different NCI-60 cell lines in a single-dose assay. The antiproliferative activities of the newly synthesized compounds were evaluated against a panel of four human cancer cell lines (A-549, MCF-7, Panc-1, and HT-29). Compounds 9g-i and their oxygen isosteres, 10f-h, exhibited promising antiproliferative activities with IC50 values ranging from 0.80 to 2.27 µM compared to doxorubicin (IC50 ranging from 0.90 to 1.41 µM). Furthermore, the inhibitory potency of these compounds against the epidermal growth factor receptor (EGFR) and BRAFV600E kinases was evaluated using erlotinib as a reference drug. Molecular modeling studies were done to investigate the binding mode of the most active hybrids in the ATP binding site of EGFR.

The synthesis of novel thioderivative chalcones and their influence on NF-κB, STAT3 and NRF2 signaling pathways in colorectal cancer cells.

This study aimed to synthesize new thioderivative chalcones and analyze their impact on the NF-κB, STAT3, EGFR and Nrf2 signaling pathways in colorectal cancer cells. Among the studied compounds, derivatives 4 and 5 decreased the activation of NF-κB and the expression of the target gene COX-2. In the case of STAT3, we observed the inhibition of activation of this signaling pathway after influencing derivative 4. Increased activation of the Nrf2 signaling pathway was demonstrated for derivatives 5 and 7 in DLD-1 and HCT116 cells. The results of this study indicated that new chalcone derivatives, especially compounds 4, 5, and-to some degree-7, possess potential applications in the prevention of colorectal cancer.

Efficient access to domain-integrated estradiol-flavone hybrids via the corresponding chalcones and their in vitro anticancer potential.

Structural modification of the phenolic A-ring of estrogens at C-2 and/or C-3 significantly reduces or eliminates the hormonal effects of the compounds, thus the incorporation of other pharmacophores into these positions can provide biologically active derivatives suitable for new indications, without possessing unwanted side effects. As part of this work, A-ring integration of estradiol with chalcones and flavones was carried out in the hope of obtaining novel molecular hybrids with anticancer action. The syntheses were performed from 2-acetylestradiol-17ß-acetate which was first reacted with various (hetero)aromatic aldehydes in a pyrrolidine-catalyzed reaction in DMSO. The chalcones thus obtained were then subjected to oxidative cyclization with I2 in DMSO to afford estradiol-flavone hybrids in good yields. All newly synthesized derivatives were tested in vitro for cytotoxicity on human malignant cell lines of diverse origins as well as on a non-cancerous cell line, and the results demonstrated that estradiol-flavone hybrids containing a structure-integrated flavone moiety were the most active and cancer cell-selective agents. The minimal inhibitory concentration values (IC50) were calculated for selected compounds (3c, 3d and 3e) and their apoptosis inducing capacity was verified by RT-qPCR (real-time quantitative polymerase chain reaction). The results suggest an important structure-activity relationship regarding estradiol-flavone hybrids that could form a promising synthetic platform and rationale for future drug developments.

Microwave-Assisted Extraction of Anticancer Flavonoid, 2',4'-Dihydroxy-6'-methoxy-3',5'-dimethyl Chalcone (DMC), Rich Extract from Syzygium nervosum Fruits.

2',4'-Dihydroxy-6'-methoxy-3',5'-dimethyl chalcone (DMC) is a biological flavonoid that is present in the fruits of Syzygium nervosum (Ma-Kiang in Thai). Microwave-assisted extraction (MAE), which utilizes microwave radiation to heat the extraction solvent quickly and effectively, was used to recover DMC-rich extract from Syzygium nervosum fruit. To determine the DMC content, a highly accurate and precise HPLC technique was developed. The influences of MAE conditions, including the solid-liquid ratio, microwave power, and microwave duration on the content of DMC, were sequentially employed by a single factor investigation and response surface methodology (RSM) exploratory design. The predicted quadratic models were fitted due to their highly significant (p < 0.0001) and excellent determination coefficient (R2 = 0.9944). The optimal conditions for producing DMC-rich extract were a ratio of sample to solvent of 1:35 g/mL, a microwave power of 350 W, and a microwave time of 38 min. Under the optimal MAE setting, the DMC content reached 1409 ± 24 µg/g dry sample, which was greater than that of the conventional heat reflux extraction (HRE) (1337 ± 37 µg/g dry sample) and maceration (1225 ± 81 µg/g dry sample). The DMC-rich extract obtained from MAE showed stronger anticancer activities against A549 (human lung cancer cells) and HepG2 (human liver cancer cells) than the individual DMC substance, which makes MAE an effective method for extracting essential phytochemicals from plants in the nature.