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.     

Synthesis and <Emphasis Type="Italic">in Vitro</Emphasis> cytotoxic activities of 2-alkyl-2,3-dihydro-1<Emphasis Type="Italic">H</Emphasis>-2,6-diazacyclopenta[<Emphasis Type="Italic">b</Emphasis>]anthracene-5,10-diones

A series of 2-alkyl-2,3-dihydro-1H-2,6-diazacyclopenta[b]anthracene-5,10-diones (4a–f) was synthesized and their in vitro cytotoxic activities were evaluated against six human cancer cell lines (HCT15, SK-OV-3, SNB19, A549, MCF7 and MCF7/ADR). They all appeared to be less potent than doxorubicin against all doxorubicin sensitive human cancer cell lines tested. However, these compounds retained considerable cytotoxic activity against the doxorubicin-resistant cell line MCF7/ADR, implying their therapeutic potential to treat doxorubicin-resistant tumors. The most active compound 4c was equipotent with doxorubicin against HCT15 cell line.     

Isoflavanones from Desmodium oxyphyllum and their cytotoxicity

Two new isoflavanones, (3R)-7-hydroxy-4′-methoxy-5-methoxycarbonyl-isoflavanone (1) and (3R)-8-hydroxy-4′-methoxy-7-methoxycarbonyl-isoflavanone (2), together with seven known isoflavanones (3–9) were isolated from Desmodium oxyphyllum of the Leguminosae family. Their structures were elucidated by spectroscopic methods, including extensive 1D and 2D NMR techniques. Compound 1 showed good cytotoxicity against NB4 and SHSY5Y cell lines with IC₅₀ values of 3.1 and 2.5 μM; compound 2 exhibited cytotoxicity against PC3 cell lines with a IC₅₀ value of 3.6 μM; compound 4 showed cytotoxicity against A549 and SHSY5Y cell lines with IC₅₀ values of 3.6 and 2.8 μM; and compound 5 displayed cytotoxicity against NB4, SHSY5Y, and MCF7 cell lines with IC₅₀ values of 2.6, 3.8, and 2.8 μM, respectively. Other compounds also showed moderate cytotoxicity for some tested cell lines with IC₅₀ values between 5.4 and 8.8 μM.     

Leucanone A and naamine J,glycerol ether lipid and imidazole alkaloid from the marine sponge Leucandra sp.

Chemical investigation on CH₂Cl₂ extract of the marine sponge Leucandra sp. afforded two new compounds named leucanone A (1) and naamine J (2), together with eight known compounds (3–10). Their structures were elucidated on the basis of NMR spectroscopic analyses, and comparing with the literature. The cytotoxic activities of the compounds were evaluated against four cancer cell lines, and compound 2 showed mild cytotoxic activities against MCF-7, A549, HeLa, and PC9 cancer cell lines with IC₅₀ values in the range of 20.1–45.3 μM.     

Adlumiceine methyl ester,a new alkaloid from Fumaria vaillantii

A new alkaloid, adlumiceine methyl ester (1), together with two known alkaloids, parfumine (2) and N-methylhydrastine methyl ester (3), was isolated from aerial parts of Fumaria vaillantii. The structures of compounds were determined by 1D/2D NMR and MS data. All three compounds were tested for cytotoxic activity against PC3 and MCF7 cell lines using Alamar blue assay. The tested compounds showed no significant cytotoxic activity (IC₅₀>50 μM) against PC3 and MCF7 cell lines.     

Synthesis,structural studies,and cytotoxic evaluation of novel ursolic acid hybrids with capabilities to arrest breast cancer cells in mitosis

Some novel chemically modified frameworks of ursolic acid have been designed and synthesized. The key step was the cycloaddition of azidopropyl-3β-hydroxy-urs-12-en-28-oate with the appropriate C28 propargyl esters of ursolic, corosolic, asiatic, oleanolic, and betulinic acid under Click reaction conditions, and the products were obtained in 74–84% yields. In view of their intriguing structural diversity, they have been subjected to detailed 1D and 2D NMR studies and their structures are thoroughly assigned. The synthesized compounds were screened for their anticancer potential against two human breast cancer cell lines (MCF-7 & MDA-MB-231) using sulforhodamine B cell proliferation assay. The GI₅₀ data revealed that the synthesized compounds exhibit highly potent activities against the two tested cell lines. Interestingly, the synthesized compounds showed selectivity and higher activity against MDA-MB-231 cell line than MCF-7. Among the tested compounds, compound 17 is the most potent one with GI₅₀ value of 1.4 ± 0.1 μM and showed 2.9 times more activity than the standard doxorubicin against MDA-MB-231. In addition, 17 arrests cells in mitotic phase of cell cycle, resulting in a change in cell phenotype. In view of the selective and highly promising activity against breast cancer cell lines, these compounds can serve as promising leads for further development.     

Synthesis and cytotoxic evaluation of N-(4-methoxy-1H-benzo[d]imidazol-7-yl)-arylsulfonamide and N-aryl-(4-methoxy-1H-benzo[d]imidazol)-7-sulfonamide analogs of combretastatin A-4

Two series of novel benzoimidazole sulfonamides as combretastatin A-4 analogs were synthesized. The cytotoxicities of the title compounds were evaluated against five different cancer cell lines. Among the tested compounds, four compounds displayed cytotoxicities against the HCT8 cell line. Compound 6a has shown the strongest potency against the tested human tumor cell lines with an IC₅₀ value ranging from submicromolar to micromolar level.     

Diterpenoids from the roots of Euphorbia fischeriana

Six tigliane-type diterpenoids (1–6) were isolated from the roots of Euphorbia fischeriana. Their structures were elucidated by various spectral analyses. Among them, compounds 1 and 3 were new, and compounds 2, 4, and 5 were naturally obtained for the first time. All compounds were tested against two human cancer cell lines, MDA-MB-231 and HepG2, and one human immortalized cell line, and only compound 6 showed cytotoxicity for MDA-MB-231 cells with an IC₅₀ value of 6.694 μM.     

Two new eudesmanolides from Inula racemosa

Two new eudesmane-type sesquiterpene lactones were isolated from the roots of Inula racemosa and their structures were elucidated as 3β-hydroxy-11α,13-dihydroalantolactone (1) and 11α-hydroxy-eudesm-5-en-8β,12-olide (2). Their cytotoxic activities against five human cancer cell lines had been tested and compound 2 exhibited weak cytotoxic activity against BEL-7402 and HCT-8 cell lines. The anti-inflammatory activities were also tested, but neither of them showed any activities.     

Synthesis of 2-Fluoro N10-Substituted Acridones and Their Cytotoxicity Studies in Sensitive and Resistant Cancer Cell Lines and Their DNA Intercalation Studies

A series of 2-fluoro N¹⁰-substituted acridone derivatives with varying alkyl side chain length with propyl, butyl substitution, and a tertiary amine group at the terminal end of the alkyl side chain were synthesized and screened against cancer cell lines SW 1573, SW 1573 2R 160 (P-gp substrate) which are non-small lung cancer cell lines, MCF-7, MCF-7/MR (BCRP substrate) are breast cancer cell lines, 2008 WT, 2008MRP1, 2008MRP2, 2008MRP3 are ovarian cancer cell lines, and human embryo kidney cell lines like HEK293, HEK293 MRP4, and HEK293 MRP5i. The propyl-series compounds showed lipophilicity in the range of 1.93 to 4.40 and the butyl series in the range of 2.37 to 4.78. The compounds 4 , 7 , and 8 showed good cytotoxicity against the 60 human cancer cell line panel of the National Cancer Institute, USA. The compounds 14 and 15 showed a better cytotoxicity in most of the cancer cell lines compared to other compounds tested. The DNA-binding properties of the compounds were evaluated based on their affinity or intercalation with CT-DNA measured with absorption titration. The compound 11 bearing planar tricyclic ring linked with a butyl methylpiperazino side chain showed the highest binding affinity with a binding constant (K_i) of 10.38×10 M^–1. Evaluation of the compounds in cell lines with an overexpression of various multidrug resistance-related protein (MRP), P-glycoprotein (P-gp), or Breast Cancer Resistance Protein (BCRP) showed that all compounds are not substrates for any of these transporters.     

Chemical constituents of the red alga Laurencia tristicha

Six new sesquiterpenes, 10-hydroxy-epiaplysin (1), 10-hydroxy-aplysin (2), 10-hydroxy-debromoepiaplysin (3), aplysin-9-ene (4), epiaplysinol (5) and debromoepiaplysinol (6), together with 13 known compounds (7–19), have been isolated from the red alga Laurencia tristicha. The structures of 1–6 were determined by spectroscopic methods including IR, EI-MS, HREI-MS, and 1D and 2D NMR techniques. All compounds were obtained from this species for the first time and were tested for cytotoxic activities against several human cancer cell lines including lung adenocarcinoma (A549), stomach cancer (BGC-823), hepatoma (Bel 7402), colon cancer (HCT-8) and HeLa cell lines. Compound 6 showed selective cytotoxicity against HeLa cell line with IC₅₀ 15.5 μM, cholest-5-en-3β,7α-diol (14) was toxic to all tested cell lines with IC₅₀ values of 16.8, 5.1, 0.5, 0.5, and 0.3 μM, respectively, and other compounds were inactive (IC₅₀>10 μg/ml).     

Cytotoxic lignans from the barks of Juglans mandshurica

Phytochemical investigation of the barks of Juglans mandshurica Maxim led to the isolation, purification, and identification of one new lignan named Juglansol A (1), along with nine known compounds (2–10). Their structures were determined by the results of UV, IR, CD, HRESIMS, 1D, and 2D NMR spectroscopic analysis. Compounds 1–10 were evaluated for their cytotoxicities against A549, HepG2, Hep3B, Bcap-37, and MCF-7 cell lines. The results showed that compound 2 possessed stronger cytotoxicities against the tested tumor cell lines compared with positive control 5-fluorouracil.     

Design,synthesis, docking study and cytotoxic activity evaluation of some novel letrozole analogs

Background

Breast cancer is the most common type of female cancer. One class of hormonal therapy for breast cancer drugs -non steroidal aromatase inhibitors- are triazole analogues. In this work, some derivatives of these drugs was designed and synthesized. All synthesized compounds were evaluated for their cytotoxic activities on breast cancer cell lines (MDA-MB-231, T47D and MCF-7).

Methods

Our synthetic route for designed compounds started from 4-bromotolunitrile which was reacted with 1H-1,2,4-triazole to afford 4-(4-cyanobenzyl)-1,2,4-triazole. The reaction of later compound with aromatic aldehydes led to formation of the designed compounds. Eleven novel derivatives 1a-k were tested for their cytotoxic activities on three human breast cancer cell lines.

Results

Among the synthesized compound, 4-[2-(3-chlorophenyl)-1-(1H-1,2,4-triazol-1-yl)ethenyl]benzonitrile (1c) showed the highest activity against MCF-7 and MDA-MB-231 cell lines and 4-[2-(4-methoxyphenyl)-1-(1H-1,2,4-triazol-1-yl)ethenyl]benzonitrile (1 h) exhibited highest activity against T47D cell line. According to cytotoxic activities results, compound 4-[2-(4-dimethylamino)-1-(1H-1,2,4-triazol-1-yl)ethenyl]benzonitrile (1 k) showed comparative activity against T47D and MDA-MB-231 cell lines with compound (1 h) and our reference drug Etoposide.

Conclusion

In the process of anti-cancer drug discovery, to find new potential anti-breast cancer agents, we designed and synthesized a novel series of letrozole analogs. Cytotoxicity evaluation revealed that compounds (1c) and (1 k) were the most potent compounds with comparative activity with Etoposide. The results revealed that π-π interactions are responsible for the enzyme inhibitions of compounds (1 c) and (1 k).Keyword: Breast cancer, Non-steroidal aromatase inhibitor, Cytotoxic activity     

Two new compounds from the green peel of Juglans mandshurica

A new cyclic diarylheptanoid (1) and a new flavone glucoside (2), along with seven known compounds, were isolated from the green peel of Juglans mandshurica. Their structures were elucidated based on extensive spectroscopic analyses. Moreover, the cytotoxicity against NCI-H460, A549, and K562 cancer cells of compounds 1–6 was evaluated. The results showed that compound 3 exhibited moderate inhibitory potency against the growth of three cell lines.     

Four new diterpenoids isolated from the Euphorbia rapulum

Four new diterpenoids named 1-epi-9-hydroxydepressin (1), 1-epi-8-hydroxydepressin (2), 2,13,9-trihydroxy-labda-8(17),12(E),14-triene (3) and tagalsin I (4) were isolated from Euphorbia rapulum. The structures of these compounds were elucidated by means of various spectroscopic methods. All the isolated compounds were evaluated for cytotoxic activities against HepG2, MCF-7, and C6 cell lines, and compound 4 showed moderate selective activity against MCF-7 cell line with an IC₅₀ value of 31.8 μM.     

Cytotoxic and antiproliferative constituents from Dictyota ciliolata,Padina sanctae-crucis and Turbinaria tricostata

Context: The hexane extracts of Dictyota ciliolata Sonder ex Kützing (Dictyotaceae), Padina sanctae-crucis Børgesen (Dictyotaceae), and Turbinaria tricostata E.S. Barton (Sargassaceae) were found to exhibit cytotoxic and antiproliferative activities in vitro. Bioactive compounds responsible for these activities have not been studied in detail for these species and phytochemical studies are very limited.

Objective: Isolate, evaluate, and elucidate the bioactive constituents of D. ciliolata, P. sanctae-crucis, and T. tricostata.

Materials and methods: Bioassay-guided cytotoxicity fractionations using the Hep-2 cell line of the hexane extracts from these brown algae were analyzed using various chromatographic techniques. Cytotoxic and antiproliferative activities of all isolated compounds were also evaluated on a panel of cell lines (KB, Hep-2, MCF-7, and SiHa). Furthermore, their selectivity index, the ratio of cytotoxicity on normal cells to cancer cells, was evaluated using the HEK-293 cell line.

Results: Four compounds were isolated from studied species: two sterol, fucosterol (1) and 24ξ-hydroperoxy-24-vinylcholesterol (2); and two diterpenes, pachydictyol A (3) and dictyol B acetate (4). The major bioactive components of the hexane extracts of T. tricostata and P. sanctae-crucis were compounds 1 and 2 (with CC₅₀ varying around 3.1–25.6?µg/mL) on cell lines tested. Whereas compounds 1, 3, and 4 showed cytotoxic activity against cancer cell lines (CC₅₀ varying between 14.8 and 41.2?µg/mL) and were major bioactive constituents of hexane extract of D. ciliolata. Compounds 1 and 4 showed antiproliferative activity on MCF-7 (IC₅₀?=?43.3?µg/mL for compound 1 and 38.3?µg/mL for compound 2) and SiHa (IC₅₀?=?43.3?µg/mL for compound 1 and 38.3?µg/mL for compound 2) cell lines.

Conclusion: This study is the first investigation on the bioactive components of D. ciliolata, P. sanctae-crucis, and T. tricostata. Although compounds 1–3 were described previously, the pharmacological activity of compound 4 is presented here for the first time.     

Synthesis and cytotoxic activities of a series of novel N-methyl-bisindolylmaleimide amide derivatives

A novel series of N-methyl-bisindolylmaleimides were synthesized and evaluated for their inhibitory activities against nine tumor cell lines. Some of the compounds showed an interesting activity against the tested cell lines. The most potent compounds 5e and 5j displayed antiproliferative activity with 50% inhibitory concentration values in the μM range against some tested cell lines.     

Cytotoxic effects of neolignans from Saururus cernuus (Saururaceae) against prostate cancer cells

In this study, five neolignans were isolated from Saururus cernuus—threo-dihydroguaiaretic acid ( 1 ), threo-austrobailignan-6 ( 2 ), threo-austrobailignan-5 ( 3 ), verrucosin ( 4 ), and saucernetin ( 5 )—and have their cytotoxic effects evaluated in prostate cancer cell lines (PC3 and DU145). Initially, using an in silico approach, tested compounds were predicted to be absorbed by the gastrointestinal tract, be able to permeate the blood–brain barrier and did not show any alert in PAINS (pan-assay structures interference). In vitro assays showed that compounds 2 , 4 , and 5 reduced cell viability of DU145 cell line at 100 μmol/L after 48 h while compounds 1 and 3 showed to be inactive at the same conditions. Furthermore, compounds 4 and 5 reduced cell number as early as in 24 h at 50 μmol/L and compound 2 showed effects at 100 μmol/L in 24 h against both cancer cell lines PC3 and DU145. Studies using flow cytometry were conducted and indicated that compound 4 induced strong necrosis and apoptosis whereas compound 5 induced strong necrosis. Otherwise, less active compound 2 did not show evidence of induction of apoptosis or necrosis, suggesting that its mechanism of action involves inhibition of cell proliferation. In conclusion, compounds 4 and 5 have been shown to be promising cytotoxic agents against prostate cancer cell lines and can be used as a starting point for the development of new drugs for the treatment of prostate cancer.     

Two new cassane-type diterpenes from the seeds of Caesalpinia crista

Two new cassane-type diterpenes, phangininoxys D and E (1 and 2), together with five known compounds were isolated from the seeds of Caesalpinia crista Linn. The structures of these compounds were elucidated by means of various spectroscopic analyses. All the isolated compounds were evaluated for cytotoxicity activities against HeLa, HT-29 and KB cell lines, and compound 7 showed moderate selective activities against KB cell line with an IC₅₀ value of 17.1 μM.     

Two new casbane diterpenoids from the roots of Euphorbia pekinensis

From the roots of Euphorbia pekinensis, two new casbane diterpenoids, named pekinenins A (1) and B (2), were isolated. Their structures were elucidated as 18-hydroxy-1βH,2αH-casba-3E,7E,11E-trien-5-one (1), 5α-methoxy-1βH,2αH-casba-3Z,7E,11E-trien-18-oic acid (2) by a combination of 1D and 2D NMR spectroscopy and mass spectrometry. In the cytotoxicity assay of the two new compounds against Hela, MCF-7, and C6 human cancer cell lines, compound 1 showed moderate cytotoxic activity against two human cancer cell lines, Hela and C6, with IC₅₀ values of 42.97 and 50.00 μM, respectively.