Design,Synthesis, and Cytotoxic Activity of 3‐Aryl‐N‐hydroxy‐2‐(sulfonamido)propanamides in HepG2, HT‐1080, KB,and MCF‐7 Cells

A new series of (sulfonamido)propanamides ( 6a1 – 6a13 , 6b1 – 6b15 , 7c1 – 7c5 , 6d1 – 6d5 , 6e1 – 6e6 ) was designed and synthesized. All the synthesized compounds were characterized by NMR and mass spectrometry. The target compounds were evaluated for their in vitro cytotoxic activity against hepatocellular carcinoma (HepG2), fibrosarcoma (HT‐1080), mouth epidermal carcinoma (KB), and breast adenocarcinoma (MCF‐7) cell lines with the sulforhodamine B (SRB) assay, with gemcitabine and mitomycin C as positive controls. Most of these compounds exhibit a more potent cytotoxic effect than the positive control group on various cancer cell lines and the most potent compound, 6a7 , shows the IC₅₀ values of 29.78±0.516 μm , 30.70±0.61 μm , and 64.89±3.09 μm in HepG2, HT‐1080, KB, and MCF‐7 cell lines, respectively. Thus, these compounds with potent cytotoxic activity have potential for development as new chemotherapy agents.     

Evaluation of cytotoxic effects of 7-dehydrocholesterol on melanoma cells

Ultraviolet radiation is the main cause of skin cancers, and melanoma is the most serious form of tumor. There is no therapy for advanced-stage melanoma and its metastasis because of their high resistance to various anticancer therapies. Human skin is an important metabolic organ in which occurs photoinduced synthesis of vitamin D3 from 7-dehydrocholesterol (7-DHC). 7-DHC, the precursor of cholesterol biosynthesis, is highly reactive and easily modifiable to produce 7-DHC-derived compounds. The intracellular levels of 7-DHC or its derivatives can have deleterious effects on cellular functionality and viability. In this study we evaluated the effects on melanoma cell lines of 7-DHC as such and for this aim we used much care to minimize 7-DHC modifications. We found that from 12 to 72 h of treatment 82–86% of 7-DHC entered the cells, and the levels of 7-DHC-derived compounds were not significant. Simultaneously, reactive oxygen species production was significantly increased already after 2 h. After 24 h and up to 72 h, 7-DHC-treated melanoma cells showed a reduction in cell growth and viability. The cytotoxic effect of 7-DHC was associated with an increase in Bax levels, decrease in Bcl-2/Bax ratio, reduction of mitochondrial membrane potential, increase in apoptosis-inducing factor levels, unchanged caspase-3 activity, and absence of cleavage of PARP-1. These findings could explain the mechanism through which 7-DHC exerts its cytotoxic effects. This is the first report in which the biological effects found in melanoma cells are mainly attributable to 7-DHC as such.     

Synthesis and cytotoxic activity of N-[(alkylamino)alkyl]carboxamide derivatives of 7-oxo-7H-benz[de]anthracene, 7-oxo-7H-naphtho[1,2,3-de]quinoline, and 7-oxo-7H-benzo[e]perimidine

7-Oxo-7H-naphtho[1,2,3-de]quinoline-11-carboxamides and analogues were prepared and evaluated for in vitro and in vivo antitumor activity. Chromophore variations included 'deaza' (7-oxo-7H-benz[de]anthracene) and 'diaza' (7-oxo-7H-benzo[e]perimidine) analogues, and side chain variations included chiral alpha-methyl compounds. The naphthoquinolines were the most cytotoxic, with IC(50) values of 5-20 nM, and showed the strongest DNA binding, with high selectivity for G-C rich DNA. The chiral alpha-methyl analogues were 10-20-fold more cytotoxic than the parent des-methyl compound. Both enantiomers provided substantial growth delays against s.c. colon 38 tumors in mice, with the R-enantiomer more active than the S (tumor growth delays of >35 and 12 days, respectively).     

Impairment of the cytotoxic and oxidative activities of 7 beta-hydroxycholesterol and 7-ketocholesterol by esterification with oleate

Atherosclerosis involves inflammatory processes, as well as cytotoxic and oxidative reactions. In atherosclerotic plaques, these phenomena are revealed by the presence of dead cells, oxidized lipids, and oxidative DNA damage, but the molecules triggering these events are still unknown. As 7 beta-hydroxycholesterol and 7-ketocholesterol, which are present at elevated concentrations in atherosclerotic lesions, are strongly cytotoxic and pro-oxidative, their effects were determined on cell death, superoxide anion and nitric oxide production, lipid peroxidation, and oxidative DNA damage. 7-Ketocholesterol- and 7 beta-hydroxycholesterol-induced cell death leads to a loss of mitochondrial potential, to increased permeability to propidium iodide, and to morphological nuclear changes (swelling, fragmentation, and/or condensation of nuclei). These effects are preceded by the formation of cytoplasmic monodansylcadaverine-positive structures and are associated with a rapid enhancement of cells overproducing superoxide anions, a decrease in cells producing nitric oxide, lipid peroxidation (formation of malondialdehyde and 4-hydroxynonenal adducts, low ratio of [unsaturated fatty acids]/[saturated fatty acids]) as well as oxidative DNA damage (8-oxoguanine formation). Noteworthy, none of the cytotoxic features previously observed with 7 beta-hydroxycholesterol and 7-ketocholesterol were noted with cholesterol, 7 beta-hydroxycholesteryl-3-oleate and 7-ketocholesteryl-3-oleate, with the exception of a slight increase in superoxide anion production with 7 beta-hydroxycholesteryl-3-oleate. This finding supports the theory that 7 beta-hydroxycholesterol and 7-ketocholesterol could induce cytotoxic and oxidative processes observed in atherosclerotic lesions and that esterification of these compounds may contribute to reducing atherosclerosis progression.     

Theophylline-7-acetic acid derivatives with amino acids as anti-tuberculosis agents

A series of amides were synthesized by condensation of theophylline-7-acetic acid and eight commercially available amino acid methyl ester hydrochlorides. Consecutive hydrolysis of six of the amido-esters resulted in the formation of corresponding amido-acids. The newly synthesized compounds were evaluated for their in vitro activity against Mycobacterium tuberculosis H37Rv. The activity varied depending on the amino acid fragments and in seven cases exerted excellent values with MICs 0.46–0.26 μM. Assessment of the cytotoxicity revealed that the compounds were not cytotoxic against the human embryonal kidney cell line HEK-293T. The theophylline-7-acetamides containing amino acid moieties appear to be promising lead compounds for the development of antimycobacterial agents.     

Synthesis and cytotoxic activity of novel C7-functionalized spongiane diterpenes

Based on two lead cytotoxic spongiane diterpenes, a new series of C7-oxygenated derivatives were synthesized and evaluated for their antitumor activity in vitro against the cancer cell lines HeLa and HEp-2. In general, introduction of either hydroxyl or acetoxy groups at C-7 did not improve the resultant cytotoxicity, while the presence of a butyrate ester led to more active compounds (CC(50)=4.0-9.5 microM).     

Synthesis of 7-oxo-7H-naphtho[1,2,3-de]quinoline derivatives as potential anticancer agents active on multidrug resistant cell lines

Following our earlier finding that tetracyclic anthraquinone analogs with a fused pyridone ring exhibit cytotoxic activity toward multidrug resistant tumor cells, a series of new potential antitumor agents, 7-oxo-7H-naphtho[1,2,3-de]quinoline derivatives (3, 6-8, 10-12, 14, 15, and 18), bearing one or two basic side chains and various substituents at the pyridone ring, have been synthesized. The compounds have been obtained from 1-amino-4-chloroanthraquinone or 1-aminoanthraquinone by cyclization with diethyl malonate and the subsequent reactions of the key intermediates 2, 4, and 17. The compounds exhibited cytotoxic activity toward sensitive human leukemia cell line HL-60 and against its resistant sublines HL-60/VINC (MDR1 type) and HL-60/DX (MRP1 type).     

Synthesis and in vitro antiproliferative evaluation of some ring B abeo-sterols

Using cholesterol, β-sitosterol, dehydroisoandrosterone and pregnenolone as starting materials, a series of 5(6→7)abeo-sterols with different substituted groups and various side chains were synthesized and the antiproliferative activity of these compounds against HeLa, SMMC 7404 and MGC 7901 cells was investigated. The results revealed that the presence of a cholesterol-type side chain was very important for their cytotoxicity, and in particular a thiosemicarbazone at the C-6 position significantly enhanced the antiproliferative activity of these compounds. Although the elimination of 5-hydroxyl has no an obvious effect on their cytotoxic function, removal of the hydroxyl at the C-3 position decreased markedly the antiproliferative activity of the compounds. Some compounds have similar cytotoxic capability as cisplatin does.     

6-Arylamino-7-chloro-quinazoline-5,8-diones as novel cytotoxic and DNA topoisomerase inhibitory agents

A series of 6-arylamino-7-chloro-quinazoline-5,8-diones were prepared and evaluated for their in vitro cytotoxicity in cultured human cancer cell lines A549 (lung cancer), Col2 (colon cancer), and SNU-638 (stomach cancer). The preliminary structure-activity relationship has been described for providing further development of potent antitumor agents. To further investigate the cytotoxic mechanism, the effects of test compounds on DNA topoisomerase I and II activities have been assessed.     

Synthesis and biological evaluation of 7-azaindole derivatives, synthetic cytokinin analogues

Cytokinins, N6-substituted adenine derivatives, are plant hormones playing important roles in various processes in plant development. Furthermore, cytokinins and their derivatives are able to control mammalian cell apoptosis and differentiation. The aim of our study was the synthesis of 7-azaindole derivatives as cytokinin analogues with the Hartwig-Buchwald coupling reaction in order to evaluate their biological properties on human myeloblastic leukaemia cells (HL-60 cell line). All these compounds presented a cytotoxic activity on HL-60 cells especially the 4-phenylaminopyrrolo[2,3-b]pyridine and the 4-phenethylaminopyrrolo[2,3-b]pyridine.     

Hormetic/Cytotoxic Effects of Nigella sativa Seed Alcoholic and Aqueous Extracts on MCF-7 Breast Cancer Cells Alone or in Combination with Doxorubicin

In this study, we investigate the possible cytotoxic effects of different Nigella sativa seed extracts on human MCF-7 breast cancer cells and screening the effects of a wide range of extracts concentrations and their application as an adjuvant therapy to doxorubicin. The results obtained showed that the cytotoxic solvent dimethyl sulfoxide can be used for permeation assay in concentration range 697.5–0.341 mmol/ml without affecting the viability of MCF-7 cells. N. sativa lipid extract is cytotoxic to MCF-7 cells with LC₅₀ of 2.72 ± 0.232 mg/ml, while its aqueous extract cytotoxicity exhibited when the applied concentration is high as ≈ 50 mg/ml. The results of this study reveal for the first time that low concentrations of aqueous extract of the seed has a hormetic rather than cytotoxic effect. It is also possible to use cell culture medium or bovine serum to dilute the oil extract for the permeation assay. In conclusion, N. sativa aqueous extract should not be used as antitumor compound by its own. The oil is a promising antitumor compound and its cytotoxicity was greatly enhanced with its nanoemulsion formulation. Antitumor activity of doxorubicin was enhanced, as a function of time, when N. sativa extracts were involved as adjunct therapeutic compounds. Adding doxorubicin to the prepared lipid nanoemulsion has a beneficial impact to their bioactivity. These doxorubicin—N. sativa lipid nanoemulsion are promising and potential therapeutic modality.     

Design,synthesis and molecular modeling of new 4-phenylcoumarin derivatives as tubulin polymerization inhibitors targeting MCF-7 breast cancer cells

A new set of 4-phenylcoumarin derivatives was designed and synthesized aiming to introduce new tubulin polymerization inhibitors as anti-breast cancer candidates. All the target compounds were evaluated for their cytotoxic effects against MCF-7 cell line, where compounds 2f, 3a, 3b, 3f, 7a and 7b, showed higher cytotoxic effect (IC₅₀?=?4.3–21.2?μg/mL) than the reference drug doxorubicin (IC₅₀?=?26.1?μg/mL), additionally, compounds 1 and 6b exhibited the same potency as doxorubicin (IC₅₀?=?25.2 and 28.0?μg/mL, respectively). The thiazolidinone derivatives 3a, 3b and 3f with potent and selective anticancer effects towards MCF-7 cells (IC₅₀?=?11.1, 16.7 and 21.2?μg/mL) were further assessed for tubulin polymerization inhibition effects which showed that the three compounds were potent tubulin polymerization suppressors with IC₅₀ values of 9.37, 2.89 and 6.13?μM, respectively, compared to the reference drug colchicine (IC₅₀?=?6.93?μM). The mechanistic effects on cell cycle progression and induction of apoptosis in MCF-7 cells were determined for compound 3a due to its potent and selective cytotoxic effects in addition to its promising tubulin polymerization inhibition potency. The results revealed that compound 3a induced cell cycle cessation at G2/M phase and accumulation of cells in pre-G1 phase and prevented its mitotic cycle, in addition to its activation of caspase-7 mediating apoptosis of MCF-7 cells. Molecular modeling studies for compounds 3a, 3b and 3f were carried out on tubulin crystallography, the results indicated that the compounds showed binding mode similar to the co-crystalized ligand; colchicine. Moreover, pharmacophore constructed models and docking studies revealed that thiazolidinone, acetamide and coumarin moieties are crucial for the activity. Molecular dynamics (MD) studies were carried out for the three compounds over 100?ps. MD results of compound 3a showed that it reached the stable state after 30?ps which was in agreement with the calculated potential and kinetic energy of compound 3a.     

Redox Cycling in MCF-7 Human Breast Cancer Cells by Antitumor Agents Based on Mitozantrone

In a series of hydroxyethylaminoalkylaminoanthraquinones (AQ's) based on mitozantrone, 1-AQ (340%) and 1,8-AQ (137%) stimulated basal rate NADPH oxidation (72 + 18pmol min^-lmg S9 protein^-1) whilst 1,4-AQ, 1,5-AQ and mitozantrone had no effect. A similar trend was observed for O_2? generation (measured as nmol acet. cyt c reduction min-¹ mg protein^-1) by these compounds in MCF-7 S9 fraction: 1-AQ (9.5) and 1,8-AQ (7.9), whilst 1,5-AQ, 1,4-AQ and mitozantrone showed no significant effect. All the AQs including mitozantrone were cytotoxic to MCF-7 cells in a dose dependent manner with EC₅₀ values as follows: 1-AQ (0.01 μm) > doxorubicin (0.4μM) > mitozantrone (0.6μM) > 1,8-AQ (2.O μM) > 1,5-AQ (4.0μM) > 1,4-AQ (8,0 μM). Thus the redox active AQs were also the most cytotoxic. Mitozantrone however was not redox active but was more cytotoxic than all but 1-AQ hence it would appear that factors other than free radical generation contribute to the antitumor activity of this group of compounds.     

Synthesis and antiproliferative evaluation of 7-aminosubstituted pyrroloiminoquinone derivatives

Coupling of five amines on the 7-methoxy-1,3,4,5-tetrahydropyrrolo[4,3,2-de]quinoline core was achieved and afforded, in particular, an opened analogue of the natural alkaloid wakayin. Evaluation of cytotoxic activity of compounds 2, 10-13 on L1210 cells afforded IC50 in the range 0.25 5.3 microM.     

First synthesis of 7alpha- and 7beta-amino-DHEA, dehydroepiandrosterone (DHEA) analogues and preliminary evaluation of their cytotoxicity on Leydig cells and TM4 Sertoli cells

Efficient syntheses of new DHEA analogues, and their apoptotic and necrotic effects on Leydig cells and TM4 Sertoli cells are described. The key step in the synthetic strategy of 7-amino-DHEA derivatives involves a bromination on C-7 position to give an epimeric mixture of bromides which were substituted by azides and reduced to give 7alpha- and 7beta-amino-3beta-hydroxyandrost-5-en-17-ones. No cytotoxic effect induced by apoptosis mechanism was observed on Leydig and TM4 Sertoli cells by treatment with these amino-DHEA analogues. A necrotic effect was induced only in TM4 Sertoli cells. The best activity was obtained with 7alpha,beta-amino-androst-5-en-3beta-ol and 7beta-amino-3beta-hydroxy-androst-5-en-17-one.     

Synthesis,Cytotoxicity and Antimicrobial Evaluation of New Coumarin‐Tagged β‐Lactam Triazole Hybrid

A series of coumarin‐tagged β‐lactam triazole hybrids ( 10a – 10o ) were synthesized and tested for their cytotoxic activity against MDA‐MB‐231 (triple negative breast cancer), MCF‐7 (estrogen receptor positive breast cancer (ER+)) and A549 (human lung carcinoma) cancer cell lines including one normal cell line, HEK‐293 (human embryonic kidney). Two compounds 10b and 10d exhibited substantial cytotoxic effect against MCF‐7 cancer cell lines with IC₅₀ values of 53.55 and 58.62 μm , respectively. More importantly, compounds 10b and 10d were non‐cytotoxic against HEK‐293 cell lines. Structure–activity relationship (SAR) studies suggested that the nitro and chloro group at the C‐3 position of phenyl ring are favorable for anticancer activity, particularly against MCF‐7 cell lines. Furthermore, antimicrobial evaluation of these compounds revealed modest inhibition of examined pathogenic strains with compounds 10c and 10i being the most promising antimicrobial agents against Pseudomonas aeruginosa and Candida albicans, respectively.     

Biological Screening of Polyphenol Derivatives for Anti-Proliferative,Anti-Apoptotic and Anti-Migrative Activities in Human Breast Cancer Cell Lines MCF-7

Breast cancer is known as the most common type of invasive cancer in women. It is well-known that phenolic compounds play an important role in the treatment of this disease. This study hypothesized that isoeugenol based two polyphenolic compounds 1 and 2 exerts its anti-proliferative effects through the induction of apoptosis and cell migration arrest on human breast cancer cell. Based on this hypothesis, the study aimed to investigate the anti-proliferative, anti-migrative effects of these compounds and their possible basic molecular mechanisms of action in MCF-7 cell lines. As a result, isoeugenol-based compounds 1 and 2 showed anti-proliferative, anti-apoptotic and anti-migrative effects in MCF-7 breast cancer cells. This result was supported by molecular analyzes and it was determined that there were changes in the expression of some gene regions involved in apoptosis and migration. Additionally, it was a remarkable result that cell viability inhibition did not occur in healthy breast tissue cells and no cytotoxic effect was observed. The existence of such a differentiation between cancer cells and healthy cells significantly increases the potential of these compounds to be used as chemotherapeutic drug active ingredients without side effects.     

Expression of ATP binding cassette-transporter ABCG1 prevents cell death by transporting cytotoxic 7beta-hydroxycholesterol

Oxysterols result from cholesterol by enzymatic or oxidative processes. Some exert cytotoxic effects leading to necrosis or apoptosis. Detoxification of these compounds mainly occurs in the liver and requires transport from peripheral tissues towards it. Some ATP-binding cassette transporters are involved in export of cytotoxic compounds. In the current study, we investigated whether ABC transporter family member G1 (ABCG1) may be involved in oxysterol transport, since its gene expression is highly responsive to oxysterol loading. TetOff HeLa cells stably expressing ABCG1 showed decreased mass uptake of 7beta-hydroxycholesterol (7beta-HC) whereas that of other physiologically relevant oxysterols was unaffected. Application of 7beta-HC to ABCG1 expressing cells induced hyperpolarization of mitochondrial membrane potential and production of reactive oxygen species, indicating energy consumption by the ATP-binding cassette transporter when it is activated by its correct substrate. Our study points to detoxification as one of potential cellular functions of ABCG1. We assume that ABCG1 protects against 7beta-HC-induced cell death, an important role in prevention of neurodegenerative and cardiovascular disease.     

Syntheses and antiproliferative activities of rebeccamycin analogues bearing two 7-azaindole moieties

As a part of structure-activity relationship studies on rebeccamycin analogues, compounds containing two aza-indole moieties were synthesized bearing either a methyl group or a hydrogen atom on the imide nitrogen. The azaindole substructures were expected to enhance the cytotoxicity toward tumor cell lines through stronger hydrogen bonding with the target enzyme(s). The cytotoxicities of compounds 8, 10 and 19 against a panel of tumor cell lines were examined and compared with those of rebeccamycin, dechlorinated rebeccamycin 2 and N-methylated analogue A. Their effect on the L1210 cell cycle was also evaluated. Compound 19, having an imide NH function had the strongest cytotoxicity towards L1210 cells and induced the largest accumulation of cells in the G2+M phases of the cell cycle. In contrast to their non-aza analogues, which were cytotoxic for all the cell lines tested, diaza compounds 10 and 19 showed selectivity for some cell lines.     

Synthesis of new pyridothienopyrimidinone derivatives as Pim-1 inhibitors

Four series of pyridothienopyrimidin-4-one derivatives were designed and prepared to improve the pim-1 inhibitory activity of the previously reported thieno[2,3-b]pyridines. Significant improvement in the pim-1 inhibition and cytotoxic activity was achieved using structure rigidification strategy via ring closure. Six compounds (6c, 7a, 7c, 7d, 8b and 9) showed highly potent pim-1 inhibitory activity with IC₅₀ of 4.62, 1.18, 1.38, 1.97, 8.83 and 4.18?μM, respectively. Four other compounds (6b, 6d, 7b and 8a) showed moderate pim-1 inhibition. The most active compounds were tested for their cytotoxic activity on three cell lines [MCF7, HCT116 and PC3]. Compounds 7a [the 2-(2-chlorophenyl)-2,3-dihydro derivative] and 7d [the 2-(2-(trifluoromethyl)-phenyl)-2,3-dihydro derivative] displayed the most potent cytotoxic effect on the three cell lines tested consistent with their highest estimated pim-1 IC₅₀ values.