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A new amide, named dehydropropylpantothenamide (1), was obtained by a co-culture of Nocardia tenerifensis IFM 10554T in the presence of the mouse macrophage-like cell line J774.1 in modified Czapek-Dox (mCD) medium. Compound 1 was synthesized from D-pantothenic acid calcium salt in 6 steps. The absolute configuration of natural compound 1 was determined by comparisons of the optical rotation and CD spectra of synthetic 1. In the present study, a new method for producing secondary metabolites was demonstrated using a "co-culture" in which the genus Nocardia was cultured in the presence of an animal cell line.

Two new aminocyclitol amide derivatives, nabscessins A (1) and B (2), were isolated from the culture broth of a pathogenic actinomycete species, Nocardia abscessus IFM 10029T. The structures of nabscessins A and B were elucidated by spectral studies, and the compounds showed antifungal activity against Cryptococcus neoformans, with IC50 values of 32 and 16 μg/mL, respectively.

The Hes1 dimer inhibitor, agalloside (2), which can accelerate the differentiation of neural stem cells is described. Six natural products, including one new natural product, which bind to Hes1 were rapidly isolated by a developed "target protein oriented natural products isolation" (TPO-NAPI) method using Hes1-immobilized beads. Of the six compounds, 2 inhibited Hes1 dimer formation at both the protein- and cellular level. Neural stem cells treated with 2 differentiated to neurons with longer neurites than cells treated with varproic acid or retinoic acid. Moreover, 2 exhibited specificity for neurons. This promotion of differentiation was supported by an increase in the mRNA expression of the proneural genes, Mash1 and Ngn2, which were inhibited by Hes1.

Two new phenazine derivatives, aotaphenazine (1) and 5,10-dihydrophencomycin (2), were isolated from the ethyl acetate extract of Streptomyces sp. IFM 11694. In addition, the known 1-phenazinecarboxylic acid (3), phencomycin (4) and 1,6-phenazinedicarboxylic acid (5) were identified. The structures of the isolated compounds (1-5) were characterized by spectroscopic methods including NMR and mass spectrometry data. Compound 1 showed the ability to overcome tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) resistance at concentration of 12.5 μM. Aotaphenazine (1) enhanced the levels of apoptosis inducing proteins DR4, DR5, p53 and also decreased the levels of cell survival protein Bcl-2 in TRAIL-resistant human gastric adenocarcinoma (AGS) cells in a dose-dependent manner.

The ability of TRAIL to selectively induce apoptosis in cancer cells while sparing normal cells makes it an attractive target for the development of new cancer therapy. In search of bioactive natural products for overcoming TRAIL-resistance from natural resources, we previously reported a number of active compounds. In our screening program on natural resources targeting overcoming TRAIL-resistance, activity-guided fractionations of the extract of Xanthium strumarium led to the isolation of five sesquiterpene compounds (1-5). 11α,13-dihydroxanthinin (2) and 11α,13-dihydroxanthuminol (3) were first isolated from natural resources and xanthinosin (1), desacetylxanthanol (4), and lasidiol p-methoxybenzoate (5) were known compounds. All compounds (1-5) showed potent TRAIL-resistance overcoming activity at 8, 20, 20, 16, and 16 μM, respectively, in TRAIL-resistant AGS cells. Compounds 1 and 5 enhanced the levels of apoptosis inducing proteins DR4, DR5, p53, CHOP, Bax, cleaved caspase-3, cleaved caspase-8, and cleaved caspase-9 and also decreased the levels of cell survival protein Bcl-2 in TRAIL-resistant AGS cells in a dose-dependent manner. Compound 1 also enhanced the levels of DR4 and DR5 proteins in a time-dependent manner. Thus, compounds 1 and 5 were found to induce both extrinsic and intrinsic apoptotic cell death. Compound 1 also exhibit TRAIL-resistance overcoming activity in DLD1, DU145, HeLa, and MCF7 cells but did not decrease viability in non-cancer HEK293 cells up to 8 μM.

The Wnt signal pathway modulates numerous biological processes, and its aberrant activation is related to various diseases. Therefore, inhibition of the Wnt signal may provide an effective (or efficient) strategy for these diseases. Cell-based luciferase assay targeting the Wnt signal (TOP assay) revealed that Hibiscus ficulneus extract inhibited the Wnt signal. The activity-guided isolation of the MeOH extract of H. ficulneus stems yielded four known (1-4) lignans along with myriceric acid (5). Compounds 1-4 potently inhibited the Wnt signal with TOPflash IC50 values of 1.0, 4.5, 6.3, and 1.9 μM, respectively. Compound 1 exhibited cytotoxicity against both Wnt-dependent (HCT116) and Wnt-independent (RKO) cells. Western blot analysis showed that 1 decreased the expression of full, cytosolic and nuclear β-catenin along with c-myc in STF/293 cells. Our results suggested that 1 may have inhibited the Wnt signal by decreasing β-catenin levels.

The isolation and evaluation of inhibitors of Fanconi F protein (FANCF) – hairy and enhancer of split 1 (Hes1) complex are described. A high-throughput screening assay for small-molecule inhibitors of the FANCF–Hes1 complex was realized. Successful complex formation between fluorophore (Cy3)-labeled human FANCF and immobilized rat or human HES1 on a microplate was established. Screening of our plant extract library using this system resulted in the isolation of eight natural products, including two new flavonoid glycosides (3 and 4), from Wrightia religiosa. Of these compounds, 3, 5, and 7 showed potent inhibition of the FANCF–Hes1 complex formation. Compound 7 disrupted the FANCF–Hes1 complex more efficiently than the Hes1 dimer.

Purpose : To investigate the in vitro anti-proliferative effect and mechanism of action of Moringa oleifera Lam. leaf extract on human colon carcinoma HCT116 cell line. Methods : M. oleifera leaves were extracted with methanol. It was fractionated by Sephadex LH-20 column chromatography. Several fractions were identified by thin layer chromatography (TLC), proton nuclear magnetic resonance (1H NMR) and mass spectrometry (MS). The growth inhibitory activity and mechanism of action of the extracts in HCT116 colon cancer cells were investigated by 3-(4, 5-dimethylthiazolyl-2)-2,5-diphenyltetrazolium bromide (MTT) assay and Western blotting. Results : Successive fractions from M. oleifera leaf crude extracts by column chromatography were combined into four pooled batches (MOL1 - MOL4) according to their absorbance at 260 nm and TLC pattern. MOL2 and MOL3 contain astragalin and isoquercetin, respectively. The results from MTT assay indicated that cell proliferation was significantly (p < 0.05) inhibited in a concentration-dependent fashion, especially by MOL2, MOL3 and MOL4. MOL2 and MOL3 exhibited a stronger cell growth inhibition than their major ingredients. The anti-proliferative activity of MOL2 - MOL4 in HCT116 colon cancer cells was mediated by downregulation of ERK1/2 phosphorylation. Conclusion : M. oleifera leaf extract has a strong anti-proliferative activity which is exerted by decreasing ERK1/2 phosphorylation. Thus, the extract has a potential for use in cancer chemoprevention. Keywords : Moringa oleifera , Anti-proliferation, Colon cancer, AKT, ERK1/2 phosphorylation, Chemoprevention

Three new isobenzofuran derivatives, named elmonin (1), elmenols A (2) and B (3), have been isolated from the ethyl acetate extract of the Streptomyces sp. IFM 11490. The structures of compounds 1–3 were established using extensive spectroscopic data analyses, including 1D and 2D NMR spectroscopy. The relative configuration of 2 was confirmed by single-crystal X-ray diffraction. Compounds 1 and 3 showed moderate cytotoxicity against the human gastric adenocarcinoma (AGS) cell line.

Chemical investigations of the ethyl acetate extract of Streptomyces sp. IFM 11490 have led to the isolation of six new angucycline metabolites, named elmenols C–H (1–6), along with the previously reported elmonin (7) and elmenols A (8) and B (9). The known LS1924A (10), 6-deoxy-8-methylrabelomycin (11), tetrangulol methyl ether (12) and angucyclinone (13) were additionally identified. The structures of the isolated compounds were elucidated by means of spectroscopic methods including UV, IR, HRESIMS, and 1D and 2D NMR. Compounds 1–6 were evaluated for their abilities to overcome tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) resistance in human gastric adenocarcinoma (AGS) cells. Compounds 5 (10 μm) and 6 (50 μm) in combination with TRAIL showed moderate activity in sensitizing TRAIL-resistant AGS cells.

A new bis-aporphine alkaloid, cerasoidine (1), was isolated from the root extract of Polyalthia cerasoides together with the known bis-aporphine bidebiline E (2) during screening for compounds with Wnt signal inhibitory activities. The structure of cerasoidine (1) was established by X-ray analysis and shown by chiral HPLC analyses and electronic circular dichroism to be a 57:43 mixture of R(-)- and S(+)-atropisomers. Bidebiline E (2) exhibited inhibition of transcriptional activity of TCF/β-catenin with an IC50 value of 20.2 μM and was also found to inhibit Wnt signaling by decreasing nuclear β-catenin.

Heronamides are a class of potent antifungal metabolites produced by marine-derived actinomycetes. The number of hydroxy groups and the stereochemistry of the two hydroxylated methine carbons are important for the activity of heronamide C, whereas the effect of the hydrocarbon chains is not known. In this study, the stereochemistry and the biological activity of BE-14106, another member of the heronamide class of antibiotics, isolated from an actinomycete Actinoalloteichus cyanogriseus IFM 11549 was investigated. Spectroscopic analysis coupled with photo- and O2-induced conversion revealed that BE-14106 and the heronamides had the same stereochemistry. BE-14106 showed potent growth inhibition against fission yeast cells with an MIC value of 0.50 μM (0.21 μg/mL), being 4 times less potent than heronamide C, which revealed the importance of the structure of the hydrocarbon tail for the activity.

One new alkyl sulfonic acid derivative, sulfotanone (1), and the known panosialin wA (2) were isolated from the methanolic extract of mycelium of Streptomyces sp. 11694. The structure of the new compound (1) was established by a combination of spectroscopic techniques, including HRESIMS, IR, 1D and 2D NMR measurements. Compound 1 (40 µM) in combination with TRAIL showed synergistic activity in sensitizing TRAIL-resistance in human gastric adenocarcinoma cell lines.

TRAIL is a potent inducer of apoptosis in most cancer cells, but not in normal cells, and therefore has deserved intense interest as a promising agent for cancer therapy. In the search for bioactive natural products for overcoming TRAIL-resistance, we previously reported a number of active compounds. In our screening program on natural resources targeting overcoming TRAIL-resistance, activity-guided fractionation of the MeOH extract of Datura stramonium leaves led to the isolation of three alkaloids – scopolamine (1), trigonelline (2), and tyramine (3). Compounds 1, 2, and 3 exhibited TRAIL-resistance overcoming activity at 50, 150, and 100 μM, respectively in TRAIL-resistant AGS cells.

The antibiotic β-indomycinone was isolated from Streptomyces sp. IFM11607 by cytotoxicity-guided fractionation against human gastric adenocarcinoma AGS cells, and the geometry of its Δ17,18-double bond was revised from E to Z based on the coupling constant.

Biosynthesis of rabbit red cell carbonic anhydrase isozyme B and C was demonstrated in reticulocyte cell-free lysates by the specific immunoprecipitin reaction. Using this homologous protein synthesis system, it was found that 10−5 to 10−7 M thyroxine preferentially inhibited the synthesis of carbonic anhydrase B isozyme without affecting that of C isozyme. These results suggested that this inhibitory action of the protein synthesis by thyroxine may be responsible for the decreased level of the B type isozymes in human hyperthyroidism or experimental hyperthyroidism of rabbits.

Zinc deficiency states were produced in rabbit erythrocytes by experimentally induced bleeding anemia and hemolytic anemia. Parallel decreases in total zinc levels and the contents for major zinc protein, carbonic anhydrase I and II isozymes were observed in the erythrocytes. During the process of the anemias the zinc status in the erythrocytes varied remarkably and the relative increase of zinc ions other than that derived from carbonic anhydrase was observed, suggesting that the former zinc ions play an important role in forming a zinc pool in the erythrocytes under the anemic conditions.

A sensitive and specific radioimmunoassay method for human erythrocyte carbonic anhydrase B was developed using a solid-phase technique. The assay was found to be sensitive for the detection of nanogram amounts of the enzyme in incubation mixtures. Iodination of it gave rise to a loss of antigenicity and a solid-phase assay technique using antibody-coated paper discs was employed in order to exclude the chemical modification or conformational changes of the enzyme. The levels of carbonic anhydrase B in the erythrocytes of newborn infants and in some biological fluids were determined.

Levels of rabbit erythrocyte carbonic anhydrase B and C isozymes were determined in experimental hyperthyroidism using a quantitative immunologic technique. Levels of erythrocyte 2,3-diphosphoglycerate and protein binding iodine were simultaneously determined. Thyroxine and 3,5,3'-triiodothyronine were administered to rabbits orally for 30 days. A significant decrease in carbonic anhydrase B type was observed after 30 days, although no significant change was observed in carbonic anhydrase C type. These findings suggest that the steady state level of carbonic anhydrase B type in red cells is affected by thyroid hormone more readily than that of carbonic anhydrase C type. The level of red cell 2,3-diphosphoglycerate increased markedly after 10 days of treatment, corresponding to the increase of protein binding iodine. The clinical or pathologic significances were discussed in relation to the changes in the levels of these isozymes and 2,3-diphosphglycerate in red cells.