Design,Synthesis, and Anticancer Activity of Novel Benzothiazole Analogues

On the pharmaceutical account of the reported anticancer activity of benzothiazole derivatives, differently substituted benzothiazole derivatives 2a – c to 34a , b , attached at 2‐position to different heterocyclic moieties, were synthesized via different chemical reactions. Thirteen of the newly synthesized compounds were selected by the National Cancer Institute, Bethesda, Maryland, USA, and evaluated for their in vitro antitumor activity against 60 human tumor cell lines in a one‐dose screening panel among which two compounds 4 and 17 showed high activity and were selected for further evaluation in the five‐dose full panel assay, in which compound 4 exerted powerful growth inhibitory activity against all cell lines with GI₅₀ ranging from 0.683 to 4.66 μM/L in addition to excellent lethal activity against most of the cell lines.     

Synthesis of a Novel Series of (E,E)-4,6-bis(styryl)-2-O-Glucopyranosyl-Pyrimidines and Their Potent Multidrug Resistance (MDR) Reversal Activity Against Cancer Cells

A novel series of methoxy or benzyloxy substituted (E,E)-4,6-bis(styryl)-2-O-glucopyranosyl-pyrimidines as curcuminoid analogs were synthesized in four steps with total yields of 21.5% to 33.9%. A549 and HL60 cells were employed for the anticancer activity testing. The results demonstrated that 5a, 5c, and 5e have some inhibitory activity against the HL-60 cell line. Unfortunately, no compound displayed inhibitory activity against A549 except for 5c. MDR reversal activity results demonstrated that compounds 4a (RF = 12.3) and 4b (RF = 18.5) showed strong reversal activity to the P-gp-mediated LCC6MDR cells compared to verapamil (RF = 3.2) and no cytotoxicity to cancer or normal cell lines even at a high concentrations (100 μM).     

Synthesis and Anticancer Properties of New 3-Methylidene-1-sulfonyl-2,3-dihydroquinolin-4(1H)-ones

Quinolinones have been known for a long time as broad-spectrum synthetic antibiotics. More recently, the anticancer potential of this group of compounds has been investigated. Following this direction, we obtained a small library of 3-methylidene-1-sulfonyl-2,3-dihydroquinolin-4(1H)-ones with various substituents at positions 1, 2, 6, and 7 of the quinolinone ring system. The cytotoxic activity of the synthesized analogs was tested in the MTT assay on two cancer cell lines in order to determine the structure–activity relationship. All compounds produced high cytotoxic effects in MCF-7, and even higher in HL-60 cells. 2-Ethyl-3-methylidene-1-phenylsulfonyl-2,3-dihydroquinolin-4(1H)-one, which was over 5-fold more cytotoxic for HL-60 than for normal HUVEC cells, was selected for further tests. This analog was shown to inhibit proliferation and induce DNA damage and apoptosis in HL-60 cells.     

Synthesis and Cytotoxic Activity of Some Novel Dihyrobenzo[h]pyrano[3,2‐c]chromene Derivatives

Three‐component reaction of 4‐hydroxy‐2H‐benzo[h]chromen‐2‐one, aromatic aldehydes, and malononitrile in the presence of 1,4‐diazabicyclo[2.2.2]octane (DABCO) in ethanol at room temperature affords good yields of novel dihyrobenzo[h]pyrano[3,2‐c]chromene derivatives. The synthesized compounds examined by MTT assays for cytotoxic activity in two human cancer cell lines (MOLT‐4, HL‐60). Most of the evaluated compounds showed low inhibitory activity against tumor cell line at micromolar concentrations.     

Study of immobilized and extracellular invertase of lemon balm

Cell suspensions of lemon balm (Melissa officinalis L.) were permeabilized by Tween 20, Tween 80, ethanol, hexadecyltrimethylammonium bromide, and hexadecylpyridinium chloride, and immobilized by glutaraldehyde. The invertase pH optimum was 4.5 at temperature 50°C. The hydrolysis of substrate was linear for 4 h, reaching 60% conversion. The cells had high invertase activity and good stability, and in longterm storage they showed good physicomechanical properties. The culture medium (without cells) was used for the identification and determination of extracellular enzyme activity. Intracellular activity was estimated from the cell suspension. For the lemon balm cell suspension, the intracellular activity accounted for 83.7% of the total activity, and the extracellular one for 12.7%. The intracellular specific activity is 4.2 times higher. Our method permits the rapid, simple, and specific identification and determination of plant invertase. Published in Khimiya Prirodnykh Soedinenii, No. 6, pp. 611-615, November-December, 2008.     

Synthesis and cytotoxic activity of some new 2,6-substituted purines

A seriesof twenty four acyclic unsaturated 2,6-substututed purines 5a-20b were synthesized. These compounds were evaluated for cytotoxic activity against NCI-60 DTP human tumor cell line screen at 10μMconcentration. N?-[(Z)-4'-chloro-2'-butenyl-1'-yl]-2,6-dichloropurine(5a), N?-[4'-chloro-2'-butynyl-1'-yl]-2,6-dichloropurine(10a), N?-[(E)-2',3'-dibromo-4'-chloro-2'-butenyl-1'-yl]-6-methoxypurine(14)and N?-[4'-chloro-2'-butynyl-1'-yl]-6-(4-methoxyphenyl)-purine(19)exhibited highly potent cytotoxic activity with GI?? values in the 1-5 μM range for most human tumor cell lines. Other compounds exhibited moderate activity.     

Synthesis and in vitro antitumor activity of novel naphthyridinone derivatives

A series of naphthyridinone derivatives based on la(a precursor of Voreloxin) were designed and synthesized.Seven compounds having 70%inhibition against HL60 at 30 μmol/L were further evaluated for their in vitro antitumor activity by SRB assay.Results reveal that thiazol-2-yl and 3-aminomethyl-4-benzyloxyimino-3-methylpyrrolidin-l-yl groups are optimal at the N-1 and C-7positions of naphthyridinone core,respectively.10 j exhibits broad-spectrum activity(IC_(50):0.5-6.25 μmol/L) against all of the tested cell lines including Etoposide- and/or la-resistant ones,and is 1.3-fold to 100-fold more potent than the two references against eight of these cell lines.     

Convenient and Scalable Synthesis of 2,3-Dihydroquinazolin-4(1H)-one Derivatives and Their Anticancer Activities

An efficient and mild InBr₃-catalyzed approach to synthesize 2,3-dihydroquinazolin-4(1H)-one derivatives (3a–3aa) has been developed. Notably, all the products were isolated by recrystallization and the reaction is accessible on a gram scale. Moreover, the reactions only require 10–60 min. All the synthesized compounds were evaluated for their in vitro anticancer activity against four human cancer cell lines.     

Mining and visualizing large anticancer drug discovery databases

In order to find more effective anticancer drugs, the U.S. National Cancer Institute (NCI) screens a large number of compounds in vitro against 60 human cancer cell lines from different organs of origin. About 70,000 compounds have been tested in the program since 1990, and each tested compound can be characterized by a vector (i.e., "fingerprint") of 60 anticancer activity, or -[log(GI50)], values. GI50 is the concentration required to inhibit cell growth by 50% compared with untreated controls. Although cell growth inhibitory activity for a single cell line is not very informative, activity patterns across the 60 cell lines can provide incisive information on the mechanisms of action of screened compounds and also on molecular targets and modulators of activity within the cancer cells. Various statistical and artificial intelligence methods, including principal component analysis, hierarchical cluster analysis, stepwise linear regression, multidimensional scaling, neural network modeling, and genetic function approximation, among others, can be used to analyze this large activity database. Mining the database can provide useful information: (a) for the development of anticancer drugs; (b) for a better understanding of the molecular pharmacology of cancer; and (c) for improvement of the drug discovery process.     

Cell sorting by endocytotic capacity in a microfluidic magnetophoresis device

Magnetically labelled cells are finding a wealth of applications for in vitro analysis as well as in vivo treatments. Sorting of cells into subpopulations based on their magnetite loading is an important step in such procedures. Here, we study the sorting of monocytes and macrophages which internalise nanoparticles to different extents based on their endocytotic capacity. Macrophages featured a high endocytotic activity and were found to internalise between 4 and 60 pg of iron per cell. They were successfully sorted into five subpopulations of narrow iron loading distributions via on-chip free-flow magnetophoresis, thus demonstrating the potential of sorting of relatively similarly loaded cells. Monocytes featured a low endocytotic capacity and took on 1 to 4 pg of iron per cell. Mixtures of monocytes and macrophages were successfully sorted within the free-flow magnetophoresis chip and good purity (>88%), efficacy (>60%) and throughput (from 10 to 100 cells s(-1)) could be achieved. The introduced method constitutes a viable tool for studies of endocytotic capacity and sorting/selection of cells based on this functionality.     

Design,Synthesis, and Antipoliferative Activities of Novel Substituted Imidazole-Thione Linked Benzotriazole Derivatives

A new series of benzotriazole moiety bearing substituted imidazol-2-thiones at N1 has been designed, synthesized and evaluated for in vitro anticancer activity against the different cancer cell lines MCF-7(breast cancer), HL-60 (Human promyelocytic leukemia), and HCT-116 (colon cancer). Most of the benzotriazole analogues exhibited promising antiproliferative activity against tested cancer cell lines. Among all the synthesized compounds, BI9 showed potent activity against the cancer cell lines such as MCF-7, HL-60 and HCT-116 with IC₅₀ 3.57, 0.40 and 2.63 µM, respectively. Compound BI9 was taken up for elaborate biological studies and the HL-60 cells in the cell cycle were arrested in G₂/M phase. Compound BI9 showed remarkable inhibition of tubulin polymerization with the colchicine binding site of tubulin. In addition, compound BI9 promoted apoptosis by regulating the expression of pro-apoptotic protein BAX and anti-apoptotic proteins Bcl-2. These results provide guidance for further rational development of potent tubulin polymerization inhibitors for the treatment of cancer.     

Microwave-assisted synthesis of derivatives of khellinone under phase-transfer catalytic conditions

The microwave-assisted synthesis of four new 5-acetyl-4,7-dimethoxy-6-hydroxybenzofuran (khellinone) analogs is described. The structures of the obtained derivatives in the solid state are evaluated on the basis of ¹³C CP/MAS NMR spectra and theoretical calculations at DFT level. A single crystal X-ray diffraction structure is presented for 8-acetyl-7-hydroxy-4-methylcoumarin. 1,4-Bis(5-acetyl-4,7-dimethoxybenzofuran-6-yloxy)butane was evaluated for potential anticancer activity in an in vitro screening panel of 60 human tumor cell lines. Selected leukemia, non-small cell lung cancer, CNS, melanoma, ovarian, and breast cancer cell lines were sensitive to this compound.     

Synthesis and antitumor activity of 3-methyl-4-oxo-3,4-dihydroimidazo [5,1-d][1,2,3,5]tetrazine-8-carboxylates and -carboxamides

Seventeen novel 3-methyl-4-oxo-3,4-dihydroimidazo[5,1-d][1,2,3,5]tetrazine-8-carboxylate and -carboxamide derivatives were synthesized and evaluated for their growth inhibition in seven human solid tumor and a human leukemia HL-60 cell lines. Compound IVa showed more activity than the other compounds and the positive control temozolomide. In the presence of 40 μg/mL of IVa, the survival rate of all tested tumor cells was less than 10%. Esters displayed more potent antitumour activity than amides and temozolomide against HL-60 cells. These compounds also exhibited considerably enhanced water-solubility.     

Biphenyl Ether Analogs Containing Pomalidomide as Small-Molecule Inhibitors of the Programmed Cell Death-1/Programmed Cell Death-Ligand 1 Interaction

New biphenyl-based chimeric compounds containing pomalidomide were developed and evaluated for their activity to inhibit and degrade the programmed cell death-1/programmed cell death- ligand 1 (PD-1/PD-L1) complex. Most of the compounds displayed excellent inhibitory activity against PD-1/PD-L1, as assessed by the homogenous time-resolved fluorescence (HTRF) binding assay. Among them, compound 3 is one of the best with an IC₅₀ value of 60 nM. Using an ex vivo PD-1/PD-L1 blockade cell line bioassay that expresses human PD-1 and PD-L1, we show that compounds 4 and 5 significantly restore the repressed immunity in this co-culture model. Western blot data, however, demonstrated that these anti-PD-L1/pomalidomide chimeras could not reduce the protein levels of PD-L1.     

Synthesis of the new ring system pyrrolizino[2,3-b]indol-4(5H)-one

Derivatives of the new ring system pyrrolizino[2,3-b]indol-4(5H)-one were prepared in four steps starting from substituted benzonitriles bearing a functionalized amino group in the adjacent position. The unsubstituted- and the dimethoxy-pyrrolizinoindolones 5a and 5b exhibited modest activity against the HL-60(TB) human leukemia cell line, whereas the N-methylated dimethoxy-pyrrolizinoindolone 6b showed to be selective against MOLT-4 leukemia, A549/ATCC, HOP-92, and NCI-H460 non-small cell lung cancer, and CAKI-1 renal cancer cell lines.     

Design and efficient synthesis of 2 alpha-(omega-hydroxyalkoxy)-1 alpha,25-dihydroxyvitamin D3 Analogues, including 2-epi-ED-71 and their 20-epimers with HL-60 cell differentiation activity

A concise and efficient synthetic approach to 2 alpha-(omega-hydroxyalkoxy)-1 alpha,25-dihydroxyvitamin D(3) (4a-c), including 2-epi-ED-71, was developed starting from D-glucose as a chiral template for the construction of the 2 alpha-modified A-ring precursors (11a-c). It was found that the best ligand for the bovine thymus vitamin D receptor (VDR) in this series is 4b, which has 1.8 times greater binding affinity for the bovine thymus VDR than that of the natural hormone 1. Interestingly, potency in the induction of HL-60 cell differentiation for 4a-c was almost the same or weaker than that of 1 despite the strong binding affinity for the VDR. Next, we were interested in the "double modification"of 1 based on 4a-c with C20-epimerization, affording 2 alpha-(omega-hydroxyalkoxy)-20-epi-1 alpha,25-dihydroxyvitamin D(3) (20-epi-4a-c). All three 2 alpha-substituted 20-epi analogues of 1 (20-epi-4a-c) exhibited stronger binding affinities for the VDR, and their conformations in the ligand binding domain of VDR were analyzed by molecular modeling. Double-modified analogues of 20-epi-4a-c showed marked HL-60 cell differentiation activity, and 20-epi-4a possesses an activity 58-fold higher than that of the natural hormone 1.     

Synthesis and in vitro antitumor activity of substituted anthracene-1,4-diones

Based on a rational approach, 6-substituted 1,4-anthracenediones were synthesized and found to exhibit potent cytotoxic activity against murine and human leukemic cells. The synthetic sequence includes a double Friedel-Crafts reaction, reductive quinone formation, and selective bromination of the alkyl side chain. A key intermediate, 6-bromomethyl-1,4-anthracenedione (10), was synthesized and converted to various active antitumor agents, including a water-soluble phosphate ester pro-drug. The interconversion reactions include displacement of the bromide with various nucleophiles and basic hydrolysis to the alcohol and subsequent oxidation to provide the aldehyde. Based on their ability to decrease L1210 and HL-60 tumor cell viability, 1,4-dihydroxyanthraquinones are inactive but 1,4-anthracenediones have interesting antitumor activity, which may be abolished by modification of the A-ring and improved by substitution of the C-ring. The cytostatic and cytotoxic activity of the representative compound 10 was verified at the National Cancer Institute in studies on the 60-human tumor cell line panel in the in vitro antitumor screening. A wide spectrum of tumor cells are sensitive to 10 inhibition, and concentrations required to inhibit tumor cell growth by 50% (GI₅₀) at 48 h are <10 nM in HL-60 and MOLT-4 and 37.1 nM in SR leukemia. Preliminary studies suggest that the molecular targets and mechanisms of action of 10 may be different from those of daunomycin.     

Synthesis,Bioactivity, Pharmacokinetic and Biomimetic Properties of Multi-Substituted Coumarin Derivatives

A series of novel multi-substituted coumarin derivatives were synthesized, spectroscopically characterized, and evaluated for their antioxidant activity, soybean lipoxygenase (LOX) inhibitory ability, their influence on cell viability in immortalized human keratinocytes (HaCaT), and cytotoxicity in adenocarcinomic human alveolar basal epithelial cells (A549) and human melanoma (A375) cells, in vitro. Coumarin analogues 4a–4f, bearing a hydroxyl group at position 5 of the coumarin scaffold and halogen substituents at the 3-phenyl ring, were the most promising ABTS^•+ scavengers. 6,8-Dibromo-3-(4-hydroxyphenyl)-4-methyl-chromen-2-one (4k) and 6-bromo-3-(4,5-diacetyloxyphenyl)-4-methyl-chromen-2-one (3m) exhibited significant lipid peroxidation inhibitory activity (IC₅₀ 36.9 and 37.1 μM). In the DCF-DA assay, the 4′-fluoro-substituted compound 3f (100%), and the 6-bromo substituted compounds 3i (80.9%) and 4i (100%) presented the highest activity. The 3′-fluoro-substituted coumarins 3e and 4e, along with 3-(4-acetyloxyphenyl)-6,8-dibromo-4-methyl-chromen-2-one (3k), were the most potent lipoxygenase (LOX) inhibitors (IC₅₀ 11.4, 4.1, and 8.7 μM, respectively) while displaying remarkable hydroxyl radical scavenging ability, 85.2%, 100%, and 92.9%, respectively. In silico docking studies of compounds 4e and 3k, revealed that they present allosteric interactions with the enzyme. The majority of the analogues (100 μΜ) did not affect the cell viability of HaCaT cells, though several compounds presented over 60% cytotoxicity in A549 or A375 cells. Finally, the human oral absorption (%HOA) and plasma protein binding (%PPB) properties of the synthesized coumarins were also estimated using biomimetic chromatography, and all compounds presented high %HOA (>99%) and %PPB (60–97%) values.     

Design,synthesis, and in vitro anticancer screening of novel pyrazolinyl-pyrazole/1, 2, 3-triazole hybrids

Novel hybrids, pyrazolinylpyrazoles, and pyrazolinyltriazoles were designed, synthesized, and screened for their anticancer activity. Eleven compounds were selected by the National Cancer Institute (NCI)/USA for anticancer screening at single high dose (10⁻⁵ M) in full NCI 60 cell panels. Two compounds: 4-aminopyrazole-5-carbonitrile, 5c (NSC-747630/1) and ethyl 4-aminopyrazole-5- carboxylate, 7d (NSC-747634/1) were the most active candidates of the series and were selected for further evaluation at five dose screening as they displayed significant growth inhibition with full panel median growth inhibition (GI₅₀) 5.47 and 2.24 μM, respectively. Both 5c and 7d hybrids exhibited broad spectrum antitumor activity; however 7d showed moderate selectivity (selectivity ratio 3.6) toward leukemia.