Keiko Shimanuki

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Pyrrospirones A and B have been isolated from unpolished rice cultures of the endophytic fungus Neonectria ramulariae Wollenw KS-246. Their absolute stereostructures (1 and 2) were elucidated through spectroscopic methods using 1D and 2D NMR techniques and chemical transformations, including the modified Mosher's method. The compounds exhibited cytotoxicity(More)
Endophytes live symptomlessly and intracellularly inside host plants. The interaction of endophytes with host plants has, in particular, received considerable attention. Studies carried out in the last two decades have shown that endophytes are rich sources of structurally diverse natural products with interesting biological activities.1 These studies(More)
Fragile X expression was studied in human-mouse cell hybrids prepared from lymphocytes and fibroblasts obtained from a mentally retarded male. The patient showed a fragile X in 29-35.5% of his lymphocytes in medium 199 (M199) and in M199 plus fluorodeoxyuridine (FdU). One lymphocyte hybrid clone showed no expression in M199 and low expression in M199 + FdU.(More)
Two new cyclic lipopeptides, fusaristatins A (1) and B (2) were isolated from rice cultures of a Fusarium sp. YG-45 in the course of a screening of endophytic fungi. Their structures of 1 and 2 were determined by spectroscopic methods. 2 showed a moderate inhibitory effect on topoisomerases I (IC50: 73 μM) and II (IC50: 98 μM) without cleavable complexes.(More)
Frequency of fragile X expression was investigated before and after cryopreservation (-196 degrees C) in the blood of 4 affected males, 3 fragile X carriers and in a fibroblast cell strain from a fragile X male fetus. The results indicate that there is a significant decrease (p less than 0.05) in the frequency of the fragile X expression in lymphocytes(More)
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