Synthesis and evaluation of a UMI-77-based fluorescent probe for selective detecting Mcl-1 protein and imaging in living cancer cells.

Development of efficient fluorescent probes for detecting the overexpressed Mcl-1 protein in living cells is imperative for the diagnosis and treatment of cancers. In this paper, a new UMI-77 based fluorescent probe (DNSH), was synthesized and characterized. DNSH bound to the hydrophobic pockets of Mcl-1 protein tightly and the binding affinity was 20-fold higher than that of previous developed Mcl-1 probe. DNSH exhibited specific fluorescence response to Mcl-1 protein rather than other proteins. In the presence of Mcl-1 protein, fluorescence emission of DNSH can be switched on. Furthermore, fluorescence colocalization experiment demonstrated that DNSH can be successfully used for imaging mitochondrial Mcl-1 protein in human prostate cancer cells without a washing process. These results showed that DNSH may find useful applications in biological research such as tracking Mcl-1 protein in living biological specimens.

Synthesis of the novel PARP-1 inhibitor AG-690/11026014 and its protective effects on angiotensin II-induced mouse cardiac remodeling.

We previously identified AG-690/11026014 (6014) as a novel poly(ADP-ribose) polymerase-1 (PARP-1) inhibitor that effectively prevented angiotensin II (Ang II)-induced cardiomyocyte hypertrophy. In the present study, we reported a new synthesis route for 6014, and investigated its protective effects on Ang II-induced cardiac remodeling and cardiac dysfunction and the underlying mechanisms in mice. We designed a new synthesis route to obtain a sufficient quantity of 6014 for this in vivo study. C57BL/6J mice were infused with Ang II and treated with 6014 (10, 30, 90 mg·kg-1·d-1, ig) for 4 weeks. Then two-dimensional echocardiography was performed to assess the cardiac function and structure. Histological changes of the hearts were examined with HE staining and Masson's trichrome staining. The protein expression was evaluated by Western blot, immunohistochemistry and immunofluorescence assays. The activities of sirtuin-1 (SIRT-1) and the content of NAD+ were detected with the corresponding test kits. Treatment with 6014 dose-dependently improved cardiac function, including LVEF, CO and SV and reversed the changes of cardiac structure in Ang II-infused mice: it significantly ameliorated Ang II-induced cardiac hypertrophy evidenced by attenuating the enlargement of cardiomyocytes, decreased HW/BW and LVW/BW, and decreased expression of hypertrophic markers ANF, BNP and ß-MHC; it also prevented Ang II-induced cardiac fibrosis, as implied by the decrease in excess accumulation of extracellular matrix (ECM) components collagen I, collagen III and FN. Further studies revealed that treatment with 6014 did not affect the expression levels of PARP-1, but dose-dependently inhibited the activity of PARP-1 and subsequently restored the activity of SIRT-1 in heart tissues due to the decreased consumption of NAD+ and attenuated Poly-ADP-ribosylation (PARylation) of SIRT-1. In conclusion, the novel PARP-1 inhibitor 6014 effectively protects mice against AngII-induced cardiac remodeling and improves cardiac function. Thus, 6014 might be a potential therapeutic agent for heart diseases..

Synthesis, characterization and antioxidant activity of some new thiazolidin-4-one derivatives.

AIM: To design new thiazolidin-4-ones derivatives and to evaluate their potential antioxidant effects using in vitro methods. MATERIAL AND METHODS: New ethyl esters of the 2-(R-phenyl)-4-oxo-thiazolidin-3-yl propionic acid were synthesized using "one step reaction" between different aromatic aldehydes, thioglycolic acid and beta-alanine ethyl ester hydrochloride. The antioxidant potential of the synthesized compounds was evaluated using the DPPH radical scavenging assay and phosphomolybdenum method. RESULTS: Eight thiazolidine-4-one derivatives were obtained in good yields and high purity. The structure of the synthesized compounds was confirmed using IR spectroscopy. The evaluation of antioxidant activity showed that 2-[(4-NO2)-phenyl]-4-oxo-thiazolidin-3-yl propionic acid ethyl ester (compound 16) was the most active compound. For this derivative the DPPH radical scavenger activity (I% = 91.63% +/- 0.77) and the total antioxidant capacity (absorbance = 1.0691 +/- 0.0763) were similar with that of ascorbic acid used as standard antioxidant. CONCLUSIONS: The antioxidant activity of the thiazolidine-4-one derivatives depends on the nature of the phenyl ring substituents, the NO2 and OH radicals having the most significant influence.

Synthesis and in vitro evaluation of West Nile virus protease inhibitors based on the 2-{6-[2-(5-phenyl-4H-{1,2,4]triazol-3-ylsulfanyl)acetylamino]benzothiazol-2-ylsulfanyl}acetamide scaffold.

In recent years, clinical symptoms resulting from West Nile virus (WNV) infection have worsened in severity, with an increased frequency in neuroinvasive diseases among the elderly. As there are presently no successful therapies against WNV for use in humans, continual efforts to develop new chemotherapeutics against this virus are highly desired. The viral NS2B-NS3 protease is a promising target for viral inhibition due to its importance in viral replication and its unique substrate preference. In this study, a WNV NS2B-NS3 protease inhibitor with a 2-{6-[2-(5-phenyl-4H-[1,2,4]triazol-3-ylsulfanyl)acetylamino]benzothiazol-2-ylsulfanyl}acetamide scaffold was identified during screening. Optimization of this initial hit by synthesis and screening of a focused compound library with this scaffold led to the identification of a novel uncompetitive inhibitor (1 a24, IC50 =3.4±0.2 µM) of the WNV NS2B-NS3 protease. Molecular docking of 1 a24 into the WNV protease showed that the compound interferes with productive interactions of the NS2B cofactor with the NS3 protease and is an allosteric inhibitor of the WNV NS3 protease.

Structure-based bioisosterism design, synthesis and biological evaluation of novel 1,2,4-triazin-6-ylthioacetamides as potent HIV-1 NNRTIs.

The development of new HIV-1 non-nucleoside reverse transcriptase inhibitors (NNRTIs) offers the possibility of generating novel chemical entities of increased potency. Previous investigations in our laboratory resulted in the discovery of several novel series of arylazolylthioacetanilides as potent NNRTIs. In this study, based on the structure-based bioisosterism strategy, novel 1,2,4-triazin-6-yl thioacetamide derivatives were designed, synthesized and evaluated for their anti-HIV activity in MT-4 cells. Among them, the most promising compound was 8b15 with double-digit nanomolar activity against wild-type HIV-1 (EC(50)=0.018±0.007 µM) and moderate activity against the double mutant strain RES056 (EC(50)=3.3±0.1 µM), which indicated that 1,2,4-triazin-6-yl thioacetamide can be used as a novel scaffold to develop a new class of potent NNRTIs active against both wild-type and drug-resistant HIV-1 strains. In addition, preliminary structure-activity relationship (SAR) and molecular modeling results are also briefly discussed, which provide some useful information for the further design of novel NNRTIs.

Synthesis and in vitro antimicrobial activity of novel 2-(3-oxo-1,3-diarylpropylthio)acetic acid derivatives.

A series of novel 2-(3-oxo-1,3-diarylpropylthio)acetic acid derivatives (3a-l) were prepared by base catalyzed addition of thioglycolic acid to chalcones (1a-l). The antibacterial activities of synthesized compounds were screened against human pathogenic microorganisms by employing the disk-diffusion technique. For the active compounds, also minimum inhibitory concentrations (MICs) were determined.

Structure-activity relationship of a broad-spectrum insect odorant receptor agonist.

Agonism of insect odorant receptor (OR) cation channels may represent a new strategy for the manipulation of destructive insect olfactory-driven behaviors. We have explored the chemical space around VUAA1, the first in class agonist of the obligate OR co-receptor ion channel (Orco), and describe novel compound analogues with increased potency across insect taxa. Functional analyses reveal several of these VUAA1 structural analogues display significantly greater potency as compared to the activity of the previously described active compounds in mobility-based behavioral assays on mosquito larvae.

Synthesis of biocompatible gelatinated thioglycolic acid-capped CdTe quantum dots ("jelly dots").

Semiconductor luminescent Quantum Dots (QDs) constitute a growing area of research for biological imaging and other biomedical applications. One of the main challenges is to provide QDs with a biocompatible and easy to functionalize surface while retaining the core optical properties. Gelatine is an excellent candidate for that purpose as it is a very common natural polymer, highly biocompatible and bearing various functional groups. Here we present a simple, one-pot method for manufacturing gelatinated QDs with chosen optical properties.

Discovery and synthesis of hydronaphthoquinones as novel proteasome inhibitors.

Screening efforts led to the identification of PI-8182 (1), an inhibitor of the chymotrypsin-like (CT-L) activity of the proteasome. Compound 1 contains a hydronaphthoquinone pharmacophore with a thioglycolic acid side chain at position 2 and thiophene sulfonamide at position 4. An efficient synthetic route to the hydronaphthoquinone sulfonamide scaffold was developed, and compound 1 was synthesized in-house to confirm the structure and activity (IC(50) = 3.0 ± 1.6 µM [n = 25]). Novel hydronaphthoquinone derivatives of 1 were designed, synthesized, and evaluated as proteasome inhibitors. The structure-activity relationship (SAR) guided synthesis of more than 170 derivatives revealed that the thioglycolic acid side chain is required and the carboxylic acid group of this side chain is critical to the CT-L inhibitory activity of compound 1. Furthermore, replacement of the carboxylic acid with carboxylic acid isosteres such as tetrazole or triazole greatly improves potency. Compounds with a thio-tetrazole or thio-triazole side chain in position 2, where the thiophene was replaced by hydrophobic aryl moieties, were the most active compounds with up to 20-fold greater CT-L inhibition than compound 1 (compounds 15e, 15f, 15h, 15j, IC(50) values around 200 nM, and compound 29, IC(50) = 150 nM). The synthetic iterations described here not only led to improving potency in vitro but also resulted in the identification of compounds that are more active such as 39 (IC(50) = 0.44 to 1.01 µM) than 1 (IC(50) = 3.54 to 7.22 µM) at inhibiting the proteasome CT-L activity in intact breast cancer cells. Treatment with 39 also resulted in the accumulation of ubiquitinated cellular proteins and inhibition of tumor cell proliferation of breast cancer cells. The hit 1 and its analogue 39 inhibited proteasome CT-L activity irreversibly.

Synthesis and brain antihypoxic activity of some aliphatic and arylaliphatic amides of caffeine-8-thioglycolic acid.

The synthesis of some aliphatic and arylaliphatic amides of caffeine-8-thioglycolic acid was studied. The structures of synthesized compounds were proved by micro-analyses, IR- and 1H NMR data. Values of acute p.o. and i.p. toxicity in mice show lower toxicity compared to caffeine. Declines in spontaneous locomotor activity support the idea of depressive CNS activity of the compounds. Two compounds exhibited brain antihypoxic activity (5a and 5b against haemic and circulatory hypoxia, respectively).

2-[(Carboxymethyl)sulfanyl]-4-oxo-4-arylbutanoic acids selectively suppressed proliferation of neoplastic human HeLa cells. A SAR/QSAR study.

A series of twenty alkyl-, halo-, and methoxy-aryl-substituted 2-[(carboxymethyl)sulfanyl]-4-oxo-4-arylbutanoic acids were synthesized. The new compounds, called CSAB, suppressed proliferation of human cervix carcinoma, HeLa cells, in vitro in a concentration range of 0.644 to 29.48 microM/L. Two compounds exhibit antiproliferative activity in sub-micromolar concentrations. Five compounds act in low micromolar concentrations (<2 microM/L). The most active compounds exert lower cytotoxicity toward healthy human peripheral blood mononuclear cells (PBMC and PBMC+PHA) (selectivity indexes > 10). A strong structure-activity relationship, using estimated log P values and BCUT descriptors, was observed.

Synthesis and characterization of thiomers of polyaspartamide type.

Synthesis of poly[alpha,beta-(N-2-hydroxyethyl-DL-aspartamide)]-thioglycolic acid (PHEA-TGA) conjugate as a new polyaspartamide thiomer is described. The parent polymer PHEA is chemically modified by introducing sulphydryl-bearing compound thioglycolic acid. By varying the reaction conditions several batches of PHEA-TGA conjugates were prepared and analyzed. Tensile studies revealed that total work of adhesion of PHEA-TGA increased more than twice compared to the unmodified polymer. Microparticles prepared from the thiolated polymer preserved its bioadhesive properties.

Thioglycolic acid and pyrazole derivatives of 4(3H)-quinazolinone: synthesis and antimicrobial evaluation.

New derivatives of 4(3H)-quinazolinone were synthesized and evaluated for their antibacterial and antifungal activity. The derivatives are: 3-Aryl-2-[3-aryl-1-(carboxymethylthio)-3-oxopropyl)]-4(3H)-quinazolinones 2a-f; 3-Aryl-2-(3-aryl-1H-pyrazol-5-yl)-4(3H)-quinazolinones 3a-f; 3-Aryl-2-(1,3-diaryl-1H-pyrazol-5-yl)-4(3H)-quinazolinones 4a-f; 3-Aryl-2-(3-aryl-1-thiocarbamoyl-1H-pyrazol-5-yl)-4(3H)-quinazolinones 5a-f; 3-Aryl-2-[3-aryl-1-(carboxymethylthio)-3-hydroxyiminopropyl)]-4(3H)- quinazolinones 6a-f; and 3-Aryl-2-[3-aryl-1-(carboxymethy- lthio)-3-thiocarbamoyliminopropyl)]-4(3H)-quinazolinones 7a-f. Some of the tested compounds showed activity comparable to that of the standard references used.

[Effect of novel derivatives of 1,2,4-triazolyl-5-mercaptoacetic acid on the reductase activity in the liver microsomes in adult and old rats with immobilization-induced stress]. / Izuchenie osobennostei vliianiia novykh proizvodnykh 1,2,4-trazolil-5-merkaptouksusnoi kisloty na aktivnost' reduktaz mikrosom pecheni vzroslykh i starykh krys pri immobilizatsionnom stresse.

The effect of 3-(4-pyridyl)-1,2,4-triazolyl-5-mercaptoacetic acid morpholinium salt (rumosol) and potassium salt (drug 2) on the liver microsomal reductase activity was studied in adult (aged 10-12 months) and old (22-25 months) Wistar rats under immobilization stress conditions. In the group of adult rats, both drugs showed comparable moderate inhibiting effect. In the group of old rats, rumosol injections produced the reductase activation up to a level characteristic of the intact old animals.

Thiolated polymers--thiomers: development and in vitro evaluation of chitosan-thioglycolic acid conjugates.

The aim of this study was to improve mucoadhesive properties of chitosan by the covalent attachment of thiol moieties to this cationic polymer. Mediated by a carbodiimide, thioglycolic acid (TGA) was covalently attached to chitosan. This was achieved by the formation of amide bonds between the primary amino groups of the polymer and the carboxylic acid group of TGA. Dependent on the pH-value and the weight ratio of polymer to TGA during the coupling reaction the resulting thiolated polymers, the so-called thiomers, displayed 6.58, 9.88, 27.44, and 38.23 micromole thiol groups per gram polymer. Tensile studies carried out with these chitosan-TGA conjugates on freshly excised porcine intestinal mucosa demonstrated a 6.3-, 8.6-, 8.9-, and 10.3-fold increase in the total work of adhesion (TWA) compared to the unmodified polymer, respectively. In contrast, the combination of chitosan and free unconjugated TGA showed almost no mucoadhesion. These data were in good correlation with further results obtained by another mucoadhesion test demonstrating a prolonged residence time of thiolated chitosan on porcine mucosa. The swelling behavior of all conjugates was thereby exactly in the same range as for an unmodified polymer pretreated in the same way. Furthermore, it could be shown that chitosan-TGA conjugates are still biodegradable by the glycosidase lysozyme. According to these results. chitosan-TGA conjugates represent a promising tool for the development of mucoadhesive drug delivery systems.

Synthesis and antimicrobial activity of some 1,2,4-triazole-3-mercaptoacetic acid derivatives.

Ethyl 5-(2-furyl)-4-ethyl-1,2,4-triazole-3-mercaptoacetate (2), 5-(2-furyl)-4-ethyl-1,2,4-triazole-3-mercaptoacetic acid hydrazide (3) and a series of new N-alkylidene/arylidene-5-(2-furyl)-4-ethyl-1,2,4-triazole-3-mercaptoacetic acid hydrazides (4a-f) were synthesized and evaluated for in vitro antibacterial activity against Staphylococcus aureus ATCC 6538. Staphylococcus epidermidis ATCC 12228, Klebsiella pneumoniae ATCC 4352, Pseudomonas aeruginosa ATCC 1539, Escherichia coli ATCC 8739, Shigella flexneri, Salmonella typhi, Proteus mirabilis and antifungal activity against Candida albicans ATCC 10231 using the disk diffusion and microdilution methods. Compound 4f showed antibacterial activity against some bacteria. The in vitro antimycobacterial activity of the new compounds against Mycobacterium tuberculosis H37Rv was evaluated employing the BACTEC 460 radiometric system. The highest inhibition observed was 61% at > 6.25 microg/ml.

Use of dithiodiglycolic acid as a tether for cationic lipids decreases the cytotoxicity and increases transgene expression of plasmid DNA in vitro.

Two major barriers that limit cationic lipids in gene delivery are low transfection efficiency and toxicity. In the present studies, we used dithiodiglycolic acid as a new tether for the polar and hydrophobic domains of a cationic lipid, cholesteryl hemidithiodiglycolyl tris(aminoethyl)amine (CHDTAEA). We compared the transfection activity and toxicity of CHDTAEA with its nondisulfide analogue and cholesteryl N-(dimethylaminoethyl) carbamate (DC-Chol). The liposomes of CHDTAEA had more than 2 orders of magnitude greater transfection activity than DC-Chol in CHO cells and 7 times greater transfection activity in SKnSH cells. CHDTAEA also demonstrated much less toxicity than the other two lipids. Dithiodiglycolic acid may act as an excellent linker in the application of cationic lipid syntheses.

Synthesis, DNA cleavage and cytotoxicity of some novel cyclic peptide-2,6-dimethoxyhydroquinone-3-mercaptoacetic acid conjugates containing D-amino acids.

This paper reports an ongoing study of the use of small-ring-size cyclic peptides as carriers of a potential antitumor agent: 2,6-dimethoxyhydroquinone-3-mercaptoacetic acid (DMQ-MA). Three new cyclic tripeptide-DMQ-MA conjugates--cyclo[D-Val-Lys(DMQ-MA)-gamma-aminobutyric acid (GABA)-], cyclo[Val-Lys(DMQ-MA)-GABA-] and cyclo[D-Val-D-Lys(DMQ-MA)-GABA-]--were synthesized. The isomeric cyclic tripeptide-DMQ-MA conjugates were designed and synthesized to study the effect of stereoisomerism of the conjugates on cytotoxicity. The cyclic peptides were synthesized by coupling protected amino acids in solution and the final cyclization performed by the pentafluorophenyl ester method as described previously. After removing the lysyl-Z protecting group of the cyclic peptides the conjugation was achieved by reacting with the pentafluorophenyl ester of DMQ-MA. Electron spin resonance (ESR) studies of these three cyclic tripeptide-DMQ-MA conjugates showed that hydroxyl radicals were generated as a non-linear function of L-ascorbic acid (AH2) concentration. The IC50 of the cyclic tripeptide-DMQ-MA conjugates against a human pulmonary carcinoma cell line (PC-9 cells) under the synergistic activation of AH2 ranges from 0.4 to 1.6 microM, which is significantly lower than the parent compound DMQ-MA (6.1 microM). Agarose gel electrophoresis showed that DMQ-MA and these cyclic peptide-DMQ-MA conjugates are capable of cleaving supercoiled plasmid DNA to open circular and linear forms, even in the absence of AH2. The effects of enantiomeric and diastereomeric variations of these cyclic tripeptide-DMQ-MA conjugates on the cytotoxicity against PC-9 cells were discussed.

Synthesis and antibacterial activity of thioglycolic amino acid derivatives and dipeptides containing the 2-methyl-3,4-dihydroquinazolin-4-one moiety.

3-(2'-Chloroethyl)-2-methyl-3,4-dihydroquinazolin-4-one (I) was reacted with sodio (sodium thioglycolate) in dry dioxane and yielded compound II. By using thionyl chloride, this compound was converted to the corresponding acid chloride (III). The prepared acyl chloride (III) was allowed to interact with different alpha-amino acids such as Gly, L-Ala, L-B-Phe, DL-Asp, L-Glu, L-Thr and L-Val to give new amino acid derivatives (IVa-g). A selected C-terminal derivative of glycine (IVa) was converted into acid chloride (V). The acid chloride formed was reacted with L-Ala, L-B-Phe, DL-Asp, L-Glu, L-Thr and L-Val and yielded the new dipeptides VIa-f. The structures of the synthesized compounds were elucidated by elemental analysis and IR spectra. The prepared peptides were tested for their antimicrobial activities by comparison with tetra-cycline as a reference compound.

Synthesis and free radical scavenging properties of the enantiomers of erdosteine.

The synthesis of enantiomers R and S of erdosteine, a derivative of homocysteine-gamma-thiolactone, and the NMR studies for the determination of the enantiomeric excess with chiral shift reagent on the more soluble ethyl esters, are described. Pharmacological data relative to the free radical scavenging properties of the R and S enantiomers are reported. In particular, it has been documented that the S isomer is more effective than R isomer in protecting mice against lethal doses of paraquat (substance able to form free radicals when administered by i.p. route).