MCF-7 Tumor Cell Lines Research Articles

New piericidin derivatives from the marine-derived streptomyces sp. SCSIO 40063 with cytotoxic activity

Two new piericidins A5 (1) and G1 (2), a previously synthesized piericidin G2 (3), and two known piericidins A1 (4) and A2 (5) were isolated from the marine-derived Streptomyces sp. SCSIO 40063. The structures of 1-5 were elucidated by HRESIMS, 1 D, 2 D NMR data analyses and comparisons with the known compounds. Compound 2 showed moderate cytotoxicities against four human tumor cell lines SF-268, MCF-7, HepG2 and A549 with IC50 values between 10.0 and 12.7 μM.

New quinoxaline derivatives as VEGFR-2 inhibitors with anticancer and apoptotic activity: Design, molecular modeling, and synthesis

New series of [1,2,4]triazolo[4,3-a]quinoxalin-4(5H)-one and [1,2,4]triazolo[4,3-a]quinoxaline derivatives have been designed, synthesized, and biologically assessed for their anti-proliferative activities against two selected tumor cell lines MCF-7 and HepG2. Comparing to sorafenib (IC50 = 2.17 ± 0.13 and 3.51 ± 0.21 µM against MCF-7 and HepG2, respectively), compound 25d, 25e, 25i, and 27e exhibited the highest activities against the examined cell lines with IC50 values extending from 4.1 ± 0.4 to 11.7 ± 1.1 µM. Furthermore, VEGFR-2 inhibitory activities were assessed for all the synthesized compounds as potential mechanisms for their anti-proliferative activities. Compounds 25d, 25e, 25i, and 27e displayed prominent inhibitory efficiency versus VEGFR-2 kinase with IC50 value ranging from 3.4 ± 0.3 to 6.8 ± 0.5 nM. Fascinatingly, the results of VEGFR-2 inhibitory assays were matched with that of the cytotoxicity data, where the most potent anti-proliferative derivatives exhibited promising VEGFR-2 inhibitory activities. Further studies displayed the ability of compound 25d to induce apoptosis in HepG2 cells and can arrest the growth of such cells at the G2/M phase. Also, compound 25d produced a significant increase in the level of BAX/Bcl-2 ratio (3.8-fold), caspase- 3 (1.8-fold), and caspase-9 (1.9-fold) compared to the control cells. Molecular docking studies were carried out to investigate the possible binding interaction inside the active site of the VEGFR-2.

Acridone alkaloids and flavones from the leaves of Citrus reticulata

A new acridone alkaloid, reticarcidone A (1), decorated with an oxygenated isopentenyl group between C-1 and C-2, was isolated from the leaves of Citrus reticulata Blanco, together with nine known acridone alkaloids (2–10) and fifteen flavones compounds (11–25). The structure of those compounds were confirmed by analysis of comprehensive 1D and 2D NMR, and MS data. Reticarcidone A (1) was the first pyrano[2,3-a]acridone isolated from the genus Citrus. Some of these compounds showed moderated cytotoxicity against the five human tumor cell lines MCF-7, SMMC-7721, HL-60, A549 and SW480.

Ultrasound assisted synthesis and cytotoxicity evaluation of known 2′,4′-dihydroxychalcone derivatives against cancer cell lines

This work reports on the development of an efficient and ecofriendly ultrasound assisted method for the high yield synthesis (70.0–94.0%) of eighteen oxyalkylated derivatives of 2′,4′-dihydroxychalcone. Synthesized compounds were subjected to in vitro biological assays against HT-29 (colorectal), MCF-7 (breast), and PC-3 (prostate) human tumor cell lines, these cell lines are among the ten most aggressive malignancies diagnosed in the world. Cytotoxicity evaluations showed that four of the synthesized compounds exhibited moderate to very high toxic activity against MCF-7 (IC50 = 8.4–34.3 μM) and PC-3 (IC50 = 9.3–29.4 μM) – comparable to 5-fluorouracil (IC50 16.4–22.3 μM). The same compounds only showed moderate activity against HT-29 (IC50 15.3–36.3 μM), closer to daunorubicin (IC50 15.1 μM). Next, although selectivity index (SI) of compounds was weak, compound 18 exhibited a remarkable and selective cytotoxic activity (5.8–10.57) against cancer cells. Outside of these, most compounds significantly reduced cell survival, increased reactive oxygen species (ROS) and caspase activity, and decreased mitochondrial membrane permeability. In this sense, a portion of anti-proliferative activity is due to apoptosis. Notwithstanding, due to its remarkable response, chalcone 18 may be a potential alternative as a chemotherapeutic anti-carcinogen.

Setosphlides A\u2013D, New Isocoumarin Derivatives from the Entomogenous Fungus Setosphaeria rostrate LGWB-10

Investigation of the entomogenous fungus Setosphaeria rostrate LGWB-10 from Harmonia axyridis led to the isolation of four new isocoumarin derivatives, setosphlides A–D (1–4), and four known analogues (5–8). Their planar structures and the relative configurations were elucidated by comprehensive spectroscopic methods. The absolute configurations of isocoumarin nucleus for 1–4 were elucidated by their ECD spectra. The C-10 relative configurations for the pair of C-10 epimers (1 and 2) were established by comparing the magnitude of the computed 13C NMR chemical shifts (Δδcalcd.) with the experimental 13C NMR values (Δδexp.) for the epimers. All of the isolated compounds (1–8) were evaluated for their cytotoxicities against four human tumor cell lines MCF-7, MGC-803, HeLa, and Huh-7.Graphic

Chemical composition, antiproliferative and antioxidant attributes of ethanolic extract of resinous sediment from Etlingera elatior (Jack.) inflorescence

The ethanolic extract of resinous sediment (EERS) of Etlingera elatior young inflorescence was examined for its anticancer effect and potential antioxidant activity. The anticancer effect of the EERS was evaluated on four human cancer cell lines, HCT 116, HT-29, Hela, and MCF-7, using the MTT assay. GC-MS analysis showed that the main components found in the EERS were nonyl cyclopropane (4.44%), 1-tetradecane (3.66%), cyclotetradecane (2.41%), cyclododecane (1.92%), and 1-decene (1.72%). The antioxidant activity was determined through different methods. High amounts of TPC and TFC in the EERS were found. Moderate antioxidant capacity of the EERS was detected by DPPH and ABTS assays, with EC50 values of 44.19 and 56.61 μg/mL and a high FRAP value of 281.79 nmol Fe+2 equivalent/mg extract. In the MTT assay, the EERS showed potent anticancer activity, with IC50 values of 19.82, 37.001, 50.49, and 53.29 μg/mL against HT-29, HCT 116, Hela, and MCF-7 tumour cell lines, respectively. Moreover, the results were comparable to or less potent than the standard reference drug, 5-fluorouracil. The results showed that the EERS of Etlingera elatior inflorescence contained a high amount of polyphenols and flavonoids, which may to the selective antiproliferative effects towards colon cancer in vitro

Antioxidant and Antitumor Properties of Wild Blueberry (Sideroxylon mascatense)

Background: Sideroxylon mascatense is a wild blueberry plant that traditionally known as “boot” in Oman. Studies on health beneficial effects of this fruit are very limited. Aims and Objectives: This study aimed to evaluate the antioxidant and antitumor properties of Sideroxylon mascatense under different drying methods. Materials and Methods: Freeze (−20°C) and air drying (60 and 90°C) methods were used. The antioxidant potential properties were evaluated using DPPH and ABTS assay. Moreover, the antitumor activities of blueberry extracts were determined using Alamar blue assay. Results: The results of this study revealed that a blueberry extract at 20 mg powder/mL provided the maximum amount of vitamin C, reaching a value of 19.45 mg/100 g dry-basis in the flesh dried at 60°C and 14.24 mg/100 g dry-basis in seed dried at 90°C. The freeze-dried blueberry exhibited the highest percentage of free radical scavenging activity (DPPH) from both fruit flesh (50.8%) and seeds (39.4%) at a concentration of 20 mg/mL indicating a higher antioxidant activity. There was no significant difference in the ability of blueberry extracts to scavenge radical cations (ABTS+) at various concentrations of extracts. However, there was a 40% reduction of ABTS+ radical formation in blueberry flesh extracts obtained from freeze-dried berry at a concentration of 20 mg/mL. On the other hand, blueberry seeds showed variation in the scavenging activity of the ABTS+ radical of 38% after different processing methods. Breast MCF7 and ovarian Ov2008 tumor cell lines were the most sensitive to the dried blueberry. The 50% growth inhibition (IC50) of the freeze-dried blueberry extract at both cell lines was 64 and 69 μg/mL, respectively. Conclusion: Our findings indicated a potent antioxidant activity of Sideroxylon mascatense, but further research is required to isolate the active compounds in the fruit and test their effects in an experimental animal model.

Synthesis, Characterization, Antimicrobial and Anticancer Activity of New Bidentate Schiff Base Ligand and their Transition Metal(II) Complexes

The metal(II) complexes were synthesized by addition of corresponding MCl2 (M = Mn2+, Ni2+, Cu2+ and Zn2+) with 1,2-bis(1H-pyrrol-2-ylmethylene)diazane in methanol. The ligand acts as a bidentate as confirmed from the mass, IR, UV, NMR and EPR spectral studies. The Schiff base ligand forms hexa-coordinated complexes having octahedral geometry for Mn(II), Ni(II), Zn(II) and Cu(II) complexes. The metal complexes showed an excellent antimicrobial activity spectrum in vitro against both Gram-negative (Klebsiella pneumoniae and Acinetobacter baumannii), Gram-positive (Staphylococcus aureus and Enterococcus faecalis) and human pathogenic bacteria isolates. To find the binding affinity with protein BSA kinase, for that molecular docking studies were also carried for all the four synthesized metal(II) complexes. The anticancer activity of the synthesized metal(II) complexes was also screened against the three human tumor cell lines MCF7 human breast adenocarcinoma cell line, CaSki human caucasian cervical epidermoid carcinoma and HCT116 human colon cancer cell lines. The present study showed that Zn(II) complex showed potent inhibition by the ratio of 80% as compared to the inhibition in the normal cells (L-6).

Chemical Composition, Antioxidant and Anticancer Activities of Leptocarpha rivularis DC Flower Extracts.

An evaluation of antioxidant and anticancer activity was screened in Leptocarpha rivularis DC flower extracts using four solvents (n-hexane (Hex), dichloromethane (DCM), ethyl acetate (AcOEt), and ethanol (EtOH)). Extracts were compared for total extract flavonoids and phenol contents, antioxidant activity (2,2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH), ferric reducing antioxidant potential (FRAP), total reactive antioxidant properties (TRAP) and oxygen radical absorbance capacity (ORAC)) across a determined value of reduced/oxidized glutathione (GSH/GSSG), and cell viability (the sulforhodamine B (SRB) assay). The most active extracts were analyzed by chromatographic analysis (GC/MS) and tested for apoptotic pathways. Extracts from Hex, DCM and AcOEt reduced cell viability, caused changes in cell morphology, affected mitochondrial membrane permeability, and induced caspase activation in tumor cell lines HT-29, PC-3, and MCF-7. These effects were generally less pronounced in the HEK-293 cell line (nontumor cells), indicating clear selectivity towards tumor cell lines. We attribute likely extract activity to the presence of sesquiterpene lactones, in combination with other components like steroids and flavonoids.

Second generation of Casiopeinas®: A joint experimental and theoretical study

Herein, we present the synthesis, characterization, DFT calculations and in vitro evaluation of antiproliferative activity against HeLa and MCF-7 cancer tumor cell lines of three novel second generation Casiopeinas® complexes. These compounds are characterized by the substitution of the usual negatively charged secondary ligand with a neutral bidentate ligand (2AMB = 2-aminomethylbenzimidazole), in order to improve both hydrophilicity and antiproliferative activity. Geometry for the compounds in this study assumes that complexes present a five-coordination number with a square pyramidal geometry, in which two bidentate ligands are in the plane and a nitrate anion is bonded in the axial position. Among analyzed complexes, only [Cu(4,7-dimethyl-1,10-phenanthroline)(2AMB)(NO3)]NO3 is shown to be more effective than the referenced cisplatin drug, against both HeLa and MCF-7 tumor cell lines. Finally, for studied compounds, structure–activity relationships are strongly determined by either the calculated molar volume (V) or the redox potential (E1/2) of CuII/CuI of the complexes. These results aim to encourage further joint experimental theoretical studies, not only to describe biological activity, but also to predict it.

Synthesis, Characterization and Biological Evaluation of Magnolol and Honokiol Derivatives with 1,3,5-Triazine of Metformin Cyclization.

Herein, we sought to evaluate the contribution of the 1,3,5-triazine ring through the metformin cyclization unit to the biological activity of magnolol and honokiol-conjugates. One of the phenolic OH groups of magnolol or honokiol was replaced by a 1,3,5-triazine ring to further explore their synthesis and medicinal versatility. In this study, a robust procedure of three steps was adopted for the synthesis of magnolol and honokiol derivatives by alkylation of potassium carbonate with a 1,3,5-triazine ring. To our knowledge, this is the first report to connect one of the phenolic OH positions of magnolol or honokiol to a 1,3,5-triazine ring cyclized by metformin. The structural characterization of three new compounds was carried out via spectroscopic techniques, i.e., 13C NMR, 1H NMR, and HRMS. Surprisingly, these compounds showed no cytotoxicity against RAW 264.7 macrophages but significantly inhibited the proliferation of MCF-7 (human breast cancer cells), HepG2 (human hepatoma cells), A549 (human lung carcinoma cells), and BxPC-3 (human pancreatic carcinoma cells) tumor cell lines. Furthermore, the compounds also significantly inhibited the release of inflammatory cytokines, including nitric oxide (NO), tumor necrosis factor-α (TNF-α), and interleukin-1β (IL-1β) in the lipopolysaccharide (LPS)-activated mouse cells (RAW 264.7). Among them, compound 2 demonstrated promising broad-spectrum antiproliferative potential with half inhibitory concentration (IC50) values ranging from 5.57 to 8.74 µM and it significantly decreased caspase-3 and Bcl-2 expression in HepG2 cells. These interesting findings show that derivatization of magnolol and honokiol with 1,3,5-triazine affects and modulates their biological properties.

New Trends for Antimalarial Drugs: Synergism between Antineoplastics and Antimalarials on Breast Cancer Cells.

Chemotherapy plays a key role in breast cancer therapy, but drug resistance and unwanted side effects make the treatment less effective. We propose a new combination model that combines antineoplastic drugs and antimalarials for breast cancer therapy. Cytotoxic effects of two antineoplastic agents alone and in combination with several antimalarials on MCF-7 tumor cell line was evaluated. Different concentrations in a fixed ratio were added to the cultured cells and incubated for 48 h. Cell viability was evaluated using MTT and SRB assays. Synergism was evaluated using the Chou-Talalay method. The results indicate doxorubicin (DOX) and paclitaxel (PTX) alone at concentrations of their IC50 and higher are cell growth inhibitors. Mefloquine, artesunate, and chloroquine at concentrations of their IC50 demonstrate anti-cancer activity. In combination, almost all antimalarials demonstrate higher ability than DOX and PTX alone to decrease cell viability at concentrations of IC50 and lower than their IC50. The combination of chloroquine, artesunate and mefloquine with DOX and PTX was synergic (CI < 1). The combination of DOX and mefloquine after 48 h incubation demonstrated the highest cytotoxicity against MCF-7 cells, and the combination of DOX and artesunate was the most synergic. These results suggest antimalarials could act synergistically with DOX/PTX for breast cancer therapy.

Fused isoselenazolium salts suppress breast cancer cell growth by dramatic increase in pyruvate-dependent mitochondrial ROS production

The development of targeted drugs for the treatment of cancer remains an unmet medical need. This study was designed to investigate the mechanism underlying breast cancer cell growth suppression caused by fused isoselenazolium salts. The ability to suppress the proliferation of malignant and normal cells in vitro as well as the effect on NAD homeostasis (NAD+, NADH, and NMN levels), NAMPT inhibition and mitochondrial functionality were studied. The interactions of positively charged isoselenazolium salts with the negatively charged mitochondrial membrane model were assessed. Depending on the molecular structure, fused isoselenazolium salts display nanomolar to high micromolar cytotoxicities against MCF-7 and 4T1 breast tumor cell lines. The studied compounds altered NMN, NAD+, and NADH levels and the NAD+/NADH ratio. Mitochondrial functionality experiments showed that fused isoselenazolium salts inhibit pyruvate-dependent respiration but do not directly affect complex I of the electron transfer system. Moreover, the tested compounds induce an immediate dramatic increase in the production of reactive oxygen species. In addition, the isoselenazolothiazolium derivative selectively binds to cardiolipin in a liposomal model. Isoselenazolium salts may be a promising platform for the development of potent drug candidates for anticancer therapy that impact mitochondrial pyruvate-dependent metabolism in breast cancer cells.

Cytotoxic ergostane-type steroids from Ganoderma lingzhi

Two new ergostane-type steroids (1 and 2) have been isolated from the fruiting body of a medicinal macro fungus Ganoderma lingzhi. The structures including the absolute configurations of them were elucidated by a combination of different spectroscopic analyses especially 13C NMR and ECD calculations. Compound 2 features an unusual 1,2-dioxolane moiety. Our bioassays revealed that the two steroids showed remarkable cytotoxicity against human A549 (lung) and MCF-7 (breast) tumor cell lines, with IC50 values ranging from 5.15 to 8.57 μg/mL.

Ultrasound Assisted Extraction of Phenolic Compounds from a Jujube By-Product with Valuable Bioactivities

Jujube plant is a potential source of polyphenols with biological propreties. The purpose of this study was to investigate the application of ultrasound technique for extracting phenolic compounds (TPC) from seeds of Zizyphus lotus under optimization conditions based on response surface methodology. A maximum TPC, total flavonoids content (TFC), and total condensed tannins content (TTC) of 2383.10 ± 0.87 mg GAE/100g, 486.50 ± 0.38 mg QE/100g and 15,787.10 ± 0.10 mg CE/100g, respectively obtained under ethanol concentration 50.16%, sonication temperature 29.01 °C, sonication time 15.94 min and solvent-to-solid ratio 34.10:1 mL/g. The optimized extract was then evaluated for its antioxidant, antiacethylcholinesterase, antihypercholesterolemia, and antiproliferative activities. The results showed that ultrasound method is a green and safe method that can be used to effectively extract TPC from jujube seeds. The biological activity of Zizyphus extract exhibited a very good antioxidant against DPPH (EC50 = 0.39 µg/mL) and FRAP (1670.42 ± 6.5 mg/100 g). Additionally, it possesses acetylcholinesterase (AChE) inhibitory effect (IC50 = 0.93 ± 0.01 mg/mL) and HMGR inhibition (45.41%) using 100 µg/mL. The extract significantly inhibits cell proliferation on the MCF-7 and HepG2 tumor cell lines with an IC50 values of &lt;0.05 and 3 ± 0.55 mg/mL, respectively. Therefore, the ultrasound method can be considered a method for obtaining a significant anticancer activity with respect to the lines and therefore makes it possible to recover a maximum of phenolic compounds in less time with an AChE and HMGR inhibitory activity. Thus, it can be suggested that Zls extract is a promising fruit for the development of supplementary dietary due to its potential behaviour as nutraceutical.

Design of Novel 4-Aminobenzofuroxans and Evaluation of Their Antimicrobial and Anticancer Activity.

A series of novel 4-aminobenzofuroxan derivatives containing aromatic/aliphatic amines fragments was achieved via aromatic nucleophilic substitution reaction of 4,6-dichloro-5-nitrobenzofuroxan. The quantum chemistry calculations were performed to identify the factors affecting the regioselectivity of the reaction. The formation of 4-substituted isomer is favored both by its greater stability and the lower activation barrier. Antimicrobial activity of the obtained compounds has been evaluated and some of them were found to suppress effectively bacterial biofilm growth. Fungistatic activity of 4-aminobenzofuroxans were tested on two genetically distinct isolates of M. nivale. The effect of some benzofuroxan derivatives is likely to be more universal against different varieties of M. nivale compared with benzimidazole and carbendazim. Additionally, their anti-cancer activity in vitro has been tested. 4-aminofuroxans possessing aniline moiety showed a high selectivity towards MCF-7 and M-HeLa tumor cell lines. Moreover, they exhibit a significantly lower toxicity towards normal liver cells compared to Doxorubicin and Tamoxifen. Thus, benzofuroxans containing aromatic amines fragments in their structure are promising candidates for further development both as anti-cancer and anti-microbial agents.

ST09, A Novel Curcumin Derivative, Blocks Cell Migration by Inhibiting Matrix Metalloproteases in Breast Cancer Cells and Inhibits Tumor Progression in EAC Mouse Tumor Models.

Purpose: Curcumin is known for its anticancer and migrastatic activity in various cancers, including breast cancer. Newer curcumin derivatives are being explored to overcome limitations of curcumin like low bioavailability, stability, and side effects due to its higher dose. In this study, the synthesis of ST09, a novel curcumin derivative, and its antiproliferative, cytotoxic, and migrastatic properties have been explored both in vitro and in vivo. Methods: After ST09 synthesis, anticancer activity was studied by performing standard cytotoxicity assays namely, lactate dehydrogenase (LDH) release assay, 3-(4, 5-dimethylthiazol-2-yl)-2–5-diphenyletrazolium bromide (MTT), and trypan blue exclusion assay. Annexin-FITC, cell cycle analysis using flow cytometry, and Western blotting were performed to elucidate cell death mechanisms. The effect on the inhibition of cell migration was studied by transwell migration assay. An EAC (Ehrlich Ascites carcinoma) induced mouse tumor model was used to study the effect of ST09 on tumor regression. Drug toxicity was measured using aspartate aminotransferase (AST), alanine aminotransferase (ALT), blood urea nitrogen (BUN), and flow-cytometry based lymphocyte count. Histological analysis was performed for assessment of any tissue injury post ST09 treatment. Results: ST09 shows an approximate 100-fold higher potency than curcumin, its parent compound, on breast tumor cell lines MCF-7 and MDA-MB231. ST09 arrests the cell cycle in a cell type-specific manner and induces an intrinsic apoptotic pathway both in vitro and in vivo. ST09 inhibits migration by downregulating matrix metalloprotease 1,2 (MMP1,2) and Vimentin. In vivo, ST09 administration led to decreased tumor volume in a mouse allograft model by boosting immunity with no significant drug toxicity. Conclusion: ST09 exhibits antiproliferative and cytotoxic activity at nanomolar concentrations. It induces cell death by activation of the intrinsic pathway of apoptosis both in vitro and in vivo. It also inhibits migration and invasion. This study provides evidence that ST09 can potentially be developed as a novel antitumor drug candidate for highly metastatic and aggressive breast cancer.

NDV-D90 inhibits 17β-estradiol-mediated resistance to apoptosis by differentially modulating classic and nonclassic estrogen receptors in breast cancer cells.

Newcastle disease virus (NDV) is endowed with the oncolytic ability to kill tumor cells, while rarely causing side effects in normal cells. Both estrogen receptor α (ERα) and the G protein estrogen receptor (GPER) modulate multiple biological activities in response to estrogen, including apoptosis in breast cancer (BC) cells. Here, we investigated whether NDV-D90, a novel strain isolated from natural sources in China, promoted apoptosis by modulating the expression of ERα or the GPER in BC cells exposed to 17β-estradiol (E2). We found that NDV-D90 significantly killed the tumor cell lines MCF-7 and BT549 in a time- and dose-dependent manner. We also found that NDV-D90 exerted its effects on the two cell lines mainly by inducing apoptosis but not necrosis. NDV-D90 induced apoptosis via the intrinsic and extrinsic signaling pathways in MCF-7 cells (ER-positive cells) during E2 exposure not only by disrupting the E2/ERα axis and enhancing GPER expression but also by modulating the expression of several apoptosis-related proteins through ERα-and GPER-independent processes. NDV-D90 promoted apoptosis via the intrinsic signaling pathway in BT549 cells (ER-negative cells), possibly by impairing E2-mediated GPER expression. Furthermore, NDV-D90 exerted its antitumor effects in vivo by inducing apoptosis. Overall, these results demonstrated that NDV-D90 promotes apoptosis by differentially modulating the expression of ERα and the GPER in ER-positive and negative BC cells exposed to estrogen, respectively, and can be utilized as an effective approach to treating BC.

Synthesis, Spectroscopic Characterization, Structural Studies, and In Vitro Antitumor Activities of Pyridine-3-carbaldehyde Thiosemicarbazone Derivatives

Eight new thiosemicarbazone derivatives, 6-(1-trifluoroethoxy)pyridine-3-carbaldehyde thiosemicarbazone (1), 6-(4′-fluorophenyl)pyridine-3-carbaldehyde thiosemicarbazone (2), 5-chloro-pyridine-3-carbaldehyde thiosemicarbazone (3), 2-chloro-5-bromo-pyridine-3-carbaldehyde thiosemicarbazone (4), 6-(3′,4′-dimethoxyphenyl)pyridine-3-carbaldehyde thiosemicarbazone (5), 2-chloro-5-fluor-pyridine-3-carbaldehyde thiosemicarbazone, (6), 5-iodo-pyridine-3-carbaldehyde thiosemicarbazone (7), and 6-(3′,5′-dichlorophenyl)pyridine-3-carbaldehyde thiosemicarbazone (8) were synthesized, from the reaction of the corresponding pyridine-3-carbaldehyde with thiosemicarbazide. The synthesized compounds were characterized by ESI-Mass, UV-Vis, IR, and NMR (1H, 13C, 19F) spectroscopic techniques. Molar mass values and spectroscopic data are consistent with the proposed structural formulas. The molecular structure of 7 has been also confirmed by single crystal X-ray diffraction. In the solid state 7 exists in the E conformation about the N2-N3 bond; 7 also presents the E conformation in solution, as evidenced by 1H NMR spectroscopy. The in vitro antitumor activity of the synthesized compounds was studied on six human tumor cell lines: H460 (lung large cell carcinoma), HuTu80 (duodenum adenocarcinoma), DU145 (prostate carcinoma), MCF-7 (breast adenocarcinoma), M-14 (amelanotic melanoma), and HT-29 (colon adenocarcinoma). Furthermore, toxicity studies in 3T3 normal cells were carried out for the prepared compounds. The results were expressed as IC50 and the selectivity index (SI) was calculated. Biological studies revealed that 1 (IC50 = 3.36 to 21.35 μM) displayed the highest antiproliferative activity, as compared to the other tested thiosemicarbazones (IC50 = 40.00 to &gt;582.26 μM) against different types of human tumor cell lines. 1 was found to be about twice as cytotoxic (SI = 1.82) than 5-fluorouracile (5-FU) against the M14 cell line, indicating its efficiency in inhibiting the cell growth even at low concentrations. A slightly less efficient activity was shown by 1 towards the HuTu80 and MCF7 tumor cell lines, as compared to that of 5-FU. Therefore, 1 can be considered as a promising candidate to be used as a pharmacological agent, since it presents significant activity and was found to be more innocuous than the 5-FU anticancer drug against the 3T3 mouse embryo fibroblast cells.

Isolation and Cytotoxicity of Isocoumarins from the Entomogenous Fungus Setosphaeria sp.

A new isocoumarin compound named setosphacohol A (1), together with six known ones, alternariol (2), isoaltenuene (3), phomasatin (4), alternariol 5-O-methyl ether (5), 1-deoxyrubralactone (6), and rubralactone (7), was isolated from the entomogenous fungus Setosphaeria sp. The structure of the new compound was elucidated by analysis of the 1D and 2D spectroscopic data as well as MS. Compounds 2, 5, 6 showed moderate cytotoxicity against six human tumor cell lines MCF-7, MGC-803, H1975, Huh-7, A549, and HeLa with IC50 values ranging from 23.04 to 96.91 μg·mL–1.