Publications by authors named "Junko Takashima"

Rat hepatoma Reuber H-35 cells produce a unique compound designated as Fr.B-25, a 2-cell stage-specific inhibitor of the cleavage of preimplantation mouse embryos cultured in vitro. Here, we identified Fr.

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A new iridoid glycoside, citrifoside (1), and a new anthraquinone, 1,5,15-trimethylmorindol (2), together with 24 known compounds, were isolated from the leaves of Morinda citrifolia. The structures of the new compounds were elucidated by spectral data. 1,5,15-Trimethylmorindol (2) did not show significant cytotoxic activity by itself but showed cytotoxicity when combined with tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), while citrifoside (1) did not show any activity even with TRAIL.

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Four new flavonoids, brosimacutins J-M (1 - 4), were isolated from the bark of Brosimum acutifolium Huber together with a known flavan, brosimine A (5). The structures of compounds 1-4 were elucidated by spectroscopic means. 27 constituents of this plant including compounds 1-5 were evaluated for their cytotoxic activity against murine leukemia P388 cells.

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1. Diacylglycerol kinase (DG kinase) is a key enzyme in vascular contraction; however, alterations of the regulatory mechanisms in vascular dysfunction are poorly understood. In this study, the effect of a novel DG kinase inhibitor, stemphone, on vascular contraction was investigated.

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Four new triterpenoids with various skeletons, maytefolins A-C (1-3) and uvaol-3-caffeate (4), were isolated from the leaves of a Brazilian medicinal plant, Maytenus ilicifolia, together with five known triterpenoids. Of these triterpenoids only erythrodiol exhibited significant cytotoxicity against KB/S, KB/VJ300, and KU 19-20 cells.

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The effect of the thromboxane A(2) analog 9,11-dideoxy-11alpha, 9alpha-epoxymethanoprostaglandin F(2alpha) (U46619) on spontaneous phasic contractions in the mouse portal vein was studied. U46619 induced concentration-dependent (1-100 nM) increases in amplitude, frequency, and contractile period (ON-time) of the contraction. Both amplitude and ON-time were enhanced significantly under high-glucose (HG; 4-fold greater than normal) conditions.

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Nine new flavonoids, brosimacutins A-I (1-9), and four known flavonoids were isolated from the bark of Brosimum acutifolium, a Brazilian folk medicine ("Mururé"). Their structures were elucidated by spectroscopic methods, including 2D NMR. Brosimacutins A-I possess differentially functionalized isoprene units at C-8.

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Two new flavonolignans, mururins A and B ( 1 and 2), and a new lignan, mururin C ( 3), were isolated from the bark of Brosimum acutifolium Huber together with three known lignans. Their structures were elucidated by spectroscopic means and chemical modifications. They were tested for protein kinase A (PKA) and protein kinase C (PKC) inhibitory activity.

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A new rotenoid, derrisin (1), together with 10 known rotenoids (2-11) were isolated from the roots of Derris malaccensis Plain. The structure of 1 was elucidated by spectroscopic analysis. Nine of the isolated rotenoids (3-11) showed antibacterial activity against Helicobacter pylori.

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