A new furanoid diterpene, 15,16-epoxy-12-oxo-8(17), 13(16), 14-labdatrien-20,19-olide (1) was isolated from an ethanolic extract of Potamogeton nodosus. Its structure was elucidated by the usual spectroscopic methods, including 2D NMR techniques. Compound 1 was found to exhibit moderate inhibitory activity against a number of both Gram-positive and Gram-negative bacteria.
View Article and Find Full Text PDFTrichothecene mycotoxins such as deoxynivalenol, 4,15-diacetoxyscirpenol, and T-2 toxin, are potent protein synthesis inhibitors for eukaryotic organisms. The 3-O-acetyl derivatives of these toxins were shown to reduce their in vitro activity significantly as assessed by assays using a rabbit reticulocyte translation system. The results suggested that the introduction of an O-acetyl group at the C-3 position in the biosynthetic pathway works as a resistance mechanism for Fusarium species that produce t-type trichothecenes (trichothecenes synthesized via the precursor trichotriol).
View Article and Find Full Text PDFBiosci Biotechnol Biochem
July 2016
Pestalotiopsis theae is known to be a causal fungus for tea gray blight disease. Pesthetoxin was isolated from P. theae as a potent leaf-necrosis substance against tea.
View Article and Find Full Text PDFTwo new indole derivatives were isolated as free radical scavengers from the MeOH extract of Agrocybe cylindracea. The structures of these compounds were determined to be 6-hydroxy-1H-indole-3-carboxaldehyde (1) and 6-hydroxy-1H-indole-3-acetamide (2) on the basis of spectroscopic studies. Compounds 1 and 2 inhibited lipid peroxidation in rat liver microsomes, with IC50 values of 4.
View Article and Find Full Text PDFNew melanin synthesis inhibitors (MR566A and B) and six related known isocyanocyclopentenes were isolated from the fermentation broth of Trichoderma harzianum, and their structures were elucidated by spectroscopic methods. The structures of novel isocyanides, MR566A (1) and B (2), were elucidated as 1-(3-chloro-1,2-dihydroxy-4-isocyano-4-cyclopenten-1-yl)etha nol, 1-(1,2,3-trihydroxy-3-isocyano-4-cyclopenten-1-yl)ethanol, respectively. The structure of novel oxazole, MR93B (9), was elucidated as 4-[(1Z)-3-hydroxy-2-hydroxymethyl-1-propen-1-yl]oxazole.
View Article and Find Full Text PDFA strain of streptomycete isolated from a soil sample was found to produce a novel amino acid metabolite. The compound was purified from the culture fluid by chromatography, using cation exchange resin, a synthetic adsorbent, and finally by preparative HPLC with a reverse-phase column. The structure of the compound was established as N(delta)-(5-methyl-4-oxo-2-imidazolin-2-yl)-L-ornithine on the basis of an analysis of the spectral data and chemical degradation.
View Article and Find Full Text PDFSNA-8073-B, an inhibitor of prolyl endopeptidase isolated from the broth filtrate of Streptomyces sp. SNA-8073, is a new isotetracenone antibiotic. It was purified by ethyl acetate extraction, silica gel column chromatography and high performance liquid chromatography on ODS column.
View Article and Find Full Text PDFStatement Of Problem: For complete denture wearers the tongue plays an important role in the retention and stability of dentures and has a great influence on masticatory function.
Purpose Of Study: The purpose of this study was to elucidate the relationship between tongue motor behavior and masticatory function.
Material And Methods: Thirty healthy, normal adult dentates, 10 normal elderly dentates, and 20 complete denture wearers whose dentures were constructed by the same methods and materials were selected.
A new pollen growth inhibitor, named simplicissin, was isolated from Penicillium cf. simplicissimum (Oudemans) Thorn No. 410, and its structure was established by spectroscopic methods including 2D NMR.
View Article and Find Full Text PDFTwo lipid peroxidation inhibitors, designated as betulinans A (1) and B (2), were isolated from the MeOH extract of Lenzites betulina. The structures of these compounds have been determined to be 2,5-diphenyl-3,6-dimethoxy-p-benzoquinone and 2-phenyl-3-methoxy-[1H-2-benzopyran][4,3-e][p]benzoquinone, respectively, on the basis of various spectral data. Betulinans A and B inhibited lipid peroxidation with IC50 values of 0.
View Article and Find Full Text PDFThree new sesquiterpene ortho-naphthoquinones, davidianones A, B and C, together with four known compounds, mansonones E, F, H and I, were isolated from the root bark of Ulmus davidiana. On the basis of spectral data including pulse field gradient two-dimensional NMR spectroscopy, the structures of new compounds were established as 3-hydroxymethyl-6,9-dimethylnaphtho(1,8-b,c)pyran-7,8-dione, 6-methoxycarbonyl-3,9-dimethylnaphtho(1,8-b,c)pyran-7,8-dione, 6-dimethoxymethyl-3,9-dimethylnaphtho(1.8-b,c)pyran-7,8-d ion e, respectively.
View Article and Find Full Text PDFThree new dihydroflavonols, gericudranins A-C were isolated from the stem bark of Cudrania tricuspidata. They were identified as 6,8-di-p-hydroxybenzyltaxifolin, 8-p-hydroxybenzyltaxifolin and 6-p-hydroxybenzyltaxifolin, respectively, by means of spectral studies. These compounds were cytotoxic to human tumor cell lines, such as CRL 1579 (skin), LOX-IMVI (skin), MOLT-4F (leukemia), KM12 (colon) and UO-31 (renal) in culture, with ED50 values of 2.
View Article and Find Full Text PDFPercept Psychophys
April 1995
We determined the relative effectiveness and tradeoffs among central, peripheral, and abrupt onset cues in directing attention to a potential target character. Central cues were arrows located at the fixation point, whereas peripheral cues were arrows occurring about 3 degrees away from fixation, near the location of a potential target. These were contrasted with the abrupt onset of an ambiguous part of a character, which later was filled in to reveal a target or a distractor item.
View Article and Find Full Text PDFWe investigated the in vivo selective anti-inflammatory effect of L-156,602, which was first identified as a preferential delayed-type hypersensitivity-suppressant in our screening program and first reported to be a C5a antagonist. The agent most profoundly suppressed footpad edema 4 h after elicitation by concanavalin A (con A) and also caused a significantly impaired response after a further 20 h. Footpad edema induced by either serotonin, carrageenan or zymosan was not much influenced by the agent.
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