Nucleophile-Triggered π-Topological Transformation: A New Synthetic Approach to Near-Infrared-Emissive Rhodamines.

We describe a π-topological transformation-based synthetic method for the preparation of a new type of near-infrared (NIR)-emissive rhodamine dye called Polymethine-embedded Rhodamine Fluorophore (PeR Fluor). In contrast to conventional NIR-emissive dyes that require tedious synthetic steps and/or a high cost, linear fully π-conjugated PeR Fluor can be regioselectively prepared in one step by mixing different nucleophiles with ABPXs, a family of rhodamines with a cross-conjugated structure. PeR Fluor exhibits bright NIR fluorescence emission and high photostability owing to the cooperative π-electron system of rhodamines and polymethine scaffolds.

Visualization of the photodegradation of a therapeutic drug by chemometric-assisted fluorescence spectroscopy.

The fluorescence spectral fingerprint, also known as the excitation-emission matrix (EEM), is used to assess and visualize therapeutic drug photodegradation in combination with chemometrics. Examination of EEM-parallel factor analysis (PARAFAC) data showed that an individual component was easily separated from a mixture of photogenerated products of a heterocyclic pharmacophore, in this case, phenothiazine drugs (PTZs). Detailed investigations of both structure-EEM relationships and kinetics revealed that the components extracted from EEM-PARAFAC could be quantitatively attributed to such photogenerated products as phenothiazine sulfoxide and carbazole derivatives.

Bridged eosin Y: a visible and near-infrared photoredox catalyst.

Herein, a new NIR photoredox catalyst, bridged eosin Y (BEY), has been developed. Its detailed structure and NIR optical properties are clarified by using various spectroscopic methods, X-ray single-crystal structure analysis and DFT calculations. In addition, we demonstrate the photoreaction in colored reagents and high-concentration suspensions to show the advantage of NIR photoredox-catalyzed reactions.

Structure-activity Relationship of Indomethacin Derivatives as IDO1 Inhibitors.

Background/aim: Indoleamine 2,3-dioxygenase (IDO) is regarded as an important molecular target for cancer immune therapy. This study aimed to examine the IDO1 inhibitory activity of newly synthesized indomethacin derivatives to develop an IDO1 inhibitor.

Materials And Methods: The inhibitory effects of indole-containing compounds against recombinant human IDO1 (rhIDO1) were evaluated.

Synthesis and anticancer activity of bis(2-arylimidazo[1,2-]pyridin-3-yl) selenides and diselenides: the copper-catalyzed tandem C-H selenation of 2-arylimidazo[1,2-]pyridine with selenium.

Most heteroaryl selenides and diselenides are biologically active, with some reported to act as antioxidants and show activities that are medicinally relevant; hence, the development of efficient methods for their synthesis is an important objective. Herein, a simple method for the synthesis of selenides and diselenides bearing imidazo[1,2-]pyridine rings and their anticancer activity are described. The double C-H selenation of imidazo[1,2-]pyridine with Se powder was catalyzed by CuI (10 mol %) ligated with 1,10-phenanthroline (10 mol %) at 130 °C under aerobic conditions.

Synthesis, antitumor activity, and cytotoxicity of 4-substituted 1-benzyl-5-diphenylstibano-1H-1,2,3-triazoles.

Trisubstituted 5-organostibano-1H-1,2,3-triazoles (3a-f) were synthesized by the Cu-catalyzed azide-alkyne cycloaddition of various ethynylstibanes (1) with benzylazide (2) in the presence of CuBr (5 mol%) under aerobic conditions. The reaction of 5-stibanotriazoles with HCl afforded C5-unsubstituted 1,2,3-triazoles (4a-f). The antitumor activity of trisubstituted 5-organostibano-1H-1,2,3-triazoles (3a-f) and their 5-unsubstituted 1,2,3-triazoles (4a-f) were evaluated in several tumor cell lines.

Structure-cytotoxicity relationship of methacrylate-based resin monomers as evaluated by an anti-oxidant responsive element-luciferase reporter assay.

To investigate the chemical structure-cytotoxicity relationship of methacrylate-based resin monomers, we studied their effects on anti-oxidant responsive element (ARE)-mediated transcription. HepG2 cells stably expressing an ARE-regulated luciferase reporter gene were cultured for 6 h with various concentrations of several resin monomers and subjected to a luciferase assay. The doseresponse curves observed for hydrophobic monomers with different hydrocarbon chains (MMA, EMA, PMA and BMA) began to rise at concentrations between 0.

Improvement of the antitumor activity of poorly soluble sapacitabine (CS-682) by using Soluplus® as a surfactant.

Sapacitabine (CS-682 or CYC682; 1-[2-C-cyano-2-deoxy-β-D-arabino-pentfuranosyl]N4-palmitoyl cytosine), a novel antitumor 2'-deoxycytidine analogue, shows a marked reduction in the water solubility because of the fatty acid side chain on the N4 group of the cytosine moiety. Poor water solubility is one of the important reasons why sapacitabine does not exert maximum antitumor activity. Therefore, we attempted to improve the water solubility of sapacitabine using a novel surfactant, Soluplus®, which consisted of a polyvinyl caprolactam-polyvinyl acetate-polyethylene glycol graft copolymer.

Design and synthesis of indomethacin analogues that inhibit P-glycoprotein and/or multidrug resistant protein without COX inhibitory activity.

We designed and synthesized conformationally restricted analogues and regioisomers of the nonsteroidal anti-inflammatory drug indomethacin. Evaluation of the inhibitory effects of these compounds on COX, P-glycoprotein, and multidrug resistance indicated that NSAIDS modulation of multidrug-resistant P-glycoprotein and multidrug-resistant protein-1 is not associated with COX-1 and COX-2 inhibitory activities.

Indomethacin Analogues that Enhance Doxorubicin Cytotoxicity in Multidrug Resistant Cells without Cox Inhibitory Activity.

Conformationally restricted indomethacin analogues were designed and prepared from the corresponding 2-substituted indoles, which were synthesized by a one-pot isomerization/enamide-ene metathesis as the key reaction. Conformational analysis by calculations, NMR studies, and X-ray crystallography suggested that these analogues were conformationally restricted in the s-cis or the s-trans form due to the 2-substituent as expected. Their biological activities on cyclooxygenase-1 (COX-1) inhibition, cyclooxygenase-2 (COX-2) inhibition, and modulation of MRP-1-mediated multidrug resistance (MDR) are described.

Influence of cytidine deaminase on antitumor activity of 2'-deoxycytidine analogs in vitro and in vivo.

Antitumor 2'-deoxycytidine (dCyd) analogs such as gemcitabine (dFdC), cytarabine (Ara-C), and 2'-C-cyano-2'-deoxy-1-β-d-arabinofuranosylcytosine (CNDAC) are activated by dCyd kinase, whereas cytidine deaminase (CDA) inactivates them by conversion to their uracil forms. To elucidate the relationship between the chemosensitivity to antitumor dCyd nucleosides and CDA expression, we established a stable line of human gastric carcinoma TMK-1 cells constitutively overexpressing CDA (TMK-1/CDA) and examined its chemosensitivity to antitumor dCyd analogs in vitro and in vivo. We observed comparable reactivity for dFdC and Ara-C, and the substrate reactivity of CNDAC to recombinant human CDA was more than 10 times less efficient than those of Ara-C and dFdC.

Synthesis, configurational stability and stereochemical biological evaluations of (S)- and (R)-5-hydroxythalidomides.

The first asymmetric synthesis of (S)- and (R)-5-hydroxythalidomides, one of thalidomide's major metabolites, was achieved using HMDS/ZnBr(2)-induced imidation as a key reaction. 5-Hydroxythalidomide was found to be configurationally more stable than thalidomide at physiological pH. Stereochemical biological effects of thalidomide and 5-hydroxythalidomide on anti-angiogenesis and antitumor activities were also investigated using racemic and pure enantiomers.

Development of an antitumor adenosine analog, 3''-ethynyladenosine.

3'-ethynyladenosine (EAdo) was an adenosine analog with potent antitumor activity against various human tumor cells in vitro. However, EAdo was enzymatically inactivated by adenosine deaminase (ADA) in vitro and in vivo. Therefore, we synthesized two ADA-resistant EAdo derivatives (2-F-EAdo and EAdo-5'-monophosphate, EAMP) and examined their antitumor activities.

Cellular localization and functional characterization of the equilibrative nucleoside transporters of antitumor nucleosides.

Nucleoside transporters play an important role in the disposition of nucleosides and their analogs. To elucidate the relationship between chemosensitivity to antitumor nucleosides and the functional expression of equilibrative nucleoside transporters (ENT), we established stable cell lines of human fibrosarcoma HT-1080 and gastric carcinoma TMK-1 that constitutively overexpressed green fluorescent protein-tagged hENT1, hENT2, hENT3 and hENT4. Both hENT1 and hENT2 were predictably localized to the plasma membrane, whereas hENT3 and hENT4 were localized to the intracellular organelles.

Recent advances in the treatment of peritoneal dissemination of gastrointestinal cancers by nucleoside antimetabolites.

Peritoneal dissemination is the most common cause of metastasis from malignancies in the abdominal cavity. There are no standard treatments for peritoneal dissemination and the results are poor. The reasons for this are as follows: (1) no effective chemotherapeutic agents have been identified or developed; (2) surgical cytoreduction has little effect on survival improvement; and (3) the molecular mechanisms of peritoneal dissemination have not been clarified and no therapy against the target molecules has been developed.

In vitro sensitivity to platinum-derived drugs is associated with expression of thymidylate synthase and dihydropyrimidine dehydrogenase in human lung cancer.

Thymidylate synthase (TS) and dihydropyrimidine dehydrogenase (DPD) are critical enzymes in nucleic acid metabolism. Proliferating cell nuclear antigen (PCNA) is a specific protein that is correlated with proliferative activity of cells. The TS gene has a variable number of tandem repeats (VNTR) in its 5'-untranslated region and a single nucleotide polymorphism (SNP) in the VNTR area.

Effects of pioglitazone vs glibenclamide on postprandial increases in glucose and triglyceride levels and on oxidative stress in Japanese patients with type 2 diabetes.

To investigate the relationship between insulin resistance, postprandial hyperglycemia, postprandial hyperlipidemia, and oxidative stress in type 2 diabetes, changes in postprandial glucose, triglyceride, and nitrotyrosine levels vs baseline after diet loading were examined in type 2 diabetic patients given pioglitazone (PG) or glibenclamide (GB). Twenty-four outpatients with type 2 diabetes treated with oral PG for 6 mo (BMI, 26.3 +/- 0.

The yeast eIF4E-associated protein Eap1p attenuates GCN4 translation upon TOR-inactivation.

Amino acid-starved yeast activates the eIF2alpha kinase Gcn2p to suppress general translation and to selectively derepress the transcription factor Gcn4p, which induces various biosynthetic genes to elicit general amino acid control (GAAC). Well-fed yeast activates the target of rapamycin (TOR) to stimulate translation via the eIF4F complex. A crosstalk was demonstrated between the pathways for GAAC and TOR signaling: the TOR-specific inhibitor rapamycin activates Gcn2p.

Synthesis of a biotin-conjugate of phosmidosine O-ethyl ester as a G1 arrest antitumor drug.

This paper deals with the synthesis of a stable biotin-phosmidosine conjugate molecule 3 that is required for isolation of biomolecules that bind to phosmidosine (1). It was found that introduction of a biotin residue into the 6-N position of phosmidosine could be carried out by reaction of an N7-Boc-7,8-dihydro-8-oxoadenosine derivative 13 with phenyl chloroformate followed by displacement with a diamine derivative 6 along with the simultaneous removal of the Boc group and one of the two phenoxycarbonyl groups and the successive condensation with an N-tritylated biotin derivative 5. The condensation of an N-prolylphosphorodiamidite derivative 4 with an appropriately protected 7,8-dihydro-8-oxoadenosine derivative 17 having the biotin residue gave the coupling product 18, which was deprotected to give the biotin-phosmidosine (O-ethyl ester) conjugate 3.

[Treatment results of peritoneal dissemination from gastric cancer by neoadjuvant intraperitoneal-systemic chemotherapy].

Unlabelled: No standard treatment exists for peritoneal dissemination from gastric cancer. We reviewed our experience using a novel treatment consisting of peritonectomy and intraoperative chemo-hyperthermic peritoneal perfusion (CHPP). Records of all patients who underwent CHPP and cytoreductive surgery from 1992 to 2001 were reviewed.

A crucial role of uridine/cytidine kinase 2 in antitumor activity of 3'-ethynyl nucleosides.

The antitumor 3'-ethynyl nucleosides, 1-(3-C-ethynyl-beta-D-ribopentofuranosyl)cytosine (ECyd) and 1-(3-C-ethynyl-beta-D-ribopentofuranosyl)uridine (EUrd), are potent inhibitors of RNA polymerases and show excellent antitumor activity against various human solid tumors in xenograft models. ECyd is being investigated in phase I clinical trials as a novel anticancer drug possessing a unique antitumor action. ECyd and EUrd require the activity of uridine/cytidine kinase (UCK) to produce the corresponding active metabolite.

Synthesis of chemically stabilized phosmidosine analogues and the structure--activity relationship of phosmidosine.

Phosmidosine is known to have potent antitumor activity and the unique property of stopping cell growth at the G(1) phase in the cell cycle. However, this natural product having N-prolylphosphoramidate and O-methyl ester linkages on the 5'-phosphoryl residue is unstable under basic conditions and even during the chemical synthesis due to its inherent methyl transfer activity. To find stable derivatives of phosmidosine, a variety of phosmidosine analogues 1a-d replaced by longer alkyl groups in place of the methyl group on the phosphoramidate linkage were synthesized by reaction of alkyl N-(N-tritylprolyl)phosphorodiamidite derivatives 7a-d with an 8-oxoadenosine derivative 4 protected with acid-labile protecting groups.

The molecular targets of antitumor 2'-deoxycytidine analogues.

Most antitumor 2'-deoxycytidine (dCyd) analogues, such as Ara-C (1-beta-arabinofuranosylcytosine) and gemcitabine (2'-deoxy-2',2'-difluolo-cytidine), have common antitumor mechanisms and metabolic pathways. These nucleosides are transported into tumor cells via specific nucleoside transporters (NT), and then phosphorylated toward each monophosphate form by dCyd kinase. Finally, tri-phosphate forms are enzymatically produced and efficiently inhibit DNA synthesis.

Rapamycin-induced translational derepression of GCN4 mRNA involves a novel mechanism for activation of the eIF2 alpha kinase GCN2.

When starved for amino acids, Saccharomyces cerevisiae accumulates uncharged tRNAs to activate its sole eukaryotic initiation factor (eIF) 2alpha kinase GCN2. Subsequent phosphorylation of eIF2alpha impedes general translation, but translationally derepresses the transcription factor GCN4, which induces expression of various biosynthetic genes to elicit general amino acid control response. By contrast, when supplied with enough nutrients, the yeast activates the target of rapamycin signaling pathway to stimulate translation initiation by facilitating the assembly of eIF4F.