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61.
62.
Takaaki Kubota Yuichiro Ishiguro Azusa Takahashi-Nakaguchi Jane Fromont Tohru Gonoi Jun’ichi Kobayashi 《Bioorganic & medicinal chemistry letters》2013,23(1):244-247
Three new polyketides, manzamenones L–N (1–3), have been isolated from an Okinawan marine sponge of the genus Plakortis. The structures of 1–3 were elucidated on the basis of spectroscopic data. Manzamenones L–N (1–3) were new dimeric fatty-acid derivatives consisting of a tetrahydroindenone with three carboxy groups and two hexadecanyl chains. Manzamenones M (2) and N (3) showed antimicrobial activity against several bacteria and fungi. 相似文献
63.
Yohei Takahashi Takaaki Kubota Sunao Yamamoto Jun’ichi Kobayashi 《Bioorganic & medicinal chemistry letters》2013,23(1):117-118
Metachromins are a series of sesquiterpenoid quinones isolated from Okinawan marine sponges. Inhibitory effects of metachromins L–Q (1–6), sesquiterpenoid quinones with an amino acid residue, and their related analogs (7–18) prepared from metachromins A (19) and C (20) against receptor tyrosine kinases EGFR and HER2 were investigated. Two analogs 11 and 12 showed relatively stronger inhibitory activity against EGFR, while metachromins L–Q (1-6) and seven analogs (8, 10, 11, and 15–18) showed inhibitory activities against HER2. 相似文献
64.
Kenji Kano Tomonori Konse Motoko Okada Tanekazu Kubota Sachiko Ibe Tokuji Ikeda 《Bioscience, biotechnology, and biochemistry》2013,77(7):1795-1800
A polarographic method based on the Brdi?ka current (the polarographic catalytic hydrogen evolution current produced by proteins in the presence of cobalt salts) was applied to direct titration of subtilisin BPN′ (S.BPIST) with plasminostreptin (PS) at a concentration level of 10”8 m. The first and second dissociation constants of the S.BPN-PS complex were determined by fitting theoretical curves to the titration data, in which the multiple equilibria involving microscopically distinct forms of S.BPN-PS complex were taken into account. The intrinsic free energy change in the first binding of S.BPN′ to dimeric PS was larger than that in the second binding. The dependence of the microscopic dissociation constants of S.BPN′-PS complex on pH indicates the participation of ionizable groups of pKa 8.0 and 9.4 in the complex formation. The repulsive effect between negatively charged molecules of S.BPN′ and PS in the complex formation at elevated pH is suggested. 相似文献
65.
Kenji Kobata Ikue Takemura Gaku Tago Takayuki Moriya Kaori Kubota Sachie Nakatani 《Bioscience, biotechnology, and biochemistry》2013,77(7):1242-1245
Long-chain N-vanillyl-acylamides (LCNVAs) were generated from plant oils and vanillylamine (VA) by nucleophilic amidation without any catalytic reagents. The resulting LCNVAs varied according to the fatty acid composition of the plant oil used. Therefore, the LCNVAs contained in Capsicum oleoresins were products that were spontaneously generated from the oleoresin during storage. 相似文献
66.
Jun Shimizu Takao Kubota Erika Takada Kenji Takai Naruyoshi Fujiwara Nagisa Arimitsu Yuji Ueda Sueshige Wakisaka Tomoko Suzuki Noboru Suzuki 《PloS one》2016,11(4)
Gut microbiota compositional alteration may have an association with immune dysfunction in patients with Behcet’s disease (BD). We conducted a fecal metagenomic analysis of BD patients. We analyzed fecal microbiota obtained from 12 patients with BD and 12 normal individuals by sequencing of 16S ribosomal RNA gene. We compared the relative abundance of bacterial taxa. Direct comparison of the relative abundance of bacterial taxa demonstrated that the genera Bifidobacterium and Eggerthella increased significantly and the genera Megamonas and Prevotella decreased significantly in BD patients compared with normal individuals. A linear discriminant analysis of bacterial taxa showed that the phylum Actinobacteria, including Bifidobacterium, and the family Lactobacillaceae exhibited larger positive effect sizes than other bacteria in patients with BD. The phylum Firmicutes and the class Clostridia had large effect sizes in normal individuals. There was no significant difference in annotated species numbers (as numbers of operational taxonomic unit; OTU) and bacterial diversity of each sample (alpha diversity) between BD patients and normal individuals. We next assigned each sample to a position using three axes by principal coordinates analysis of the OTU table. The two groups had a significant distance as beta diversity in the 3-axis space. Fecal sIgA concentrations increased significantly in BD patients but did not correlate with any bacterial taxonomic abundance. These data suggest that the compositional changes of gut microbes may be one type of dysbiosis (unfavorable microbiota alteration) in patients with BD. The dysbiosis may have an association with the pathophysiology of BD. 相似文献
67.
We examined the genetic divergence of Platycerus hongwonpyoi Imura & Choe, 1989 in South Korea using the nuclear wingless (Wg) gene, internal transcribed spacer (ITS) region and mitochondrial cytochrome oxidase subunit I (COI) gene. We found no variation in Wg or ITS. Based on COI, P. hongwonpyoi was split into four well defined and one weakly supported clades, which were inferred to have diverged 2.11–1.33 Ma. The Platycerus hongwonpyoi population size seems to have decreased during the past several tens of thousands of years. The divergence times of major clades of P. hongwonpyoi were comparable with those involved in the speciation of certain Japanese species. Frequent overlapping of different clades at the same sites suggests the occurrence of secondary gene flow following differentiation in South Korea. In conclusion, the genus Platycerus underwent strikingly different divergence patterns in South Korea compared with Japan according to the disparate topographies of these two geographical areas. 相似文献
68.
Beckstrom-Sternberg SM Auerbach RK Godbole S Pearson JV Beckstrom-Sternberg JS Deng Z Munk C Kubota K Zhou Y Bruce D Noronha J Scheuermann RH Wang A Wei X Wang J Hao J Wagner DM Brettin TS Brown N Gilna P Keim PS 《PloS one》2007,2(9):e947
Francisella tularensis is the causative agent of tularemia, which is a highly lethal disease from nature and potentially from a biological weapon. This species contains four recognized subspecies including the North American endemic F. tularensis subsp. tularensis (type A), whose genetic diversity is correlated with its geographic distribution including a major population subdivision referred to as A.I and A.II. The biological significance of the A.I - A.II genetic differentiation is unknown, though there are suggestive ecological and epidemiological correlations. In order to understand the differentiation at the genomic level, we have determined the complete sequence of an A.II strain (WY96-3418) and compared it to the genome of Schu S4 from the A.I population. We find that this A.II genome is 1,898,476 bp in size with 1,820 genes, 1,303 of which code for proteins. While extensive genomic variation exists between "WY96" and Schu S4, there is only one whole gene difference. This one gene difference is a hypothetical protein of unknown function. In contrast, there are numerous SNPs (3,367), small indels (1,015), IS element differences (7) and large chromosomal rearrangements (31), including both inversions and translocations. The rearrangement borders are frequently associated with IS elements, which would facilitate intragenomic recombination events. The pathogenicity island duplicated regions (DR1 and DR2) are essentially identical in WY96 but vary relative to Schu S4 at 60 nucleotide positions. Other potential virulence-associated genes (231) varied at 559 nucleotide positions, including 357 non-synonymous changes. Molecular clock estimates for the divergence time between A.I and A.II genomes for different chromosomal regions ranged from 866 to 2131 years before present. This paper is the first complete genomic characterization of a member of the A.II clade of Francisella tularensis subsp. tularensis. 相似文献
69.
Kouichi Kawamura Masashi Kubota Miki Furukawa Yasushi Harada 《Conservation Genetics》2007,8(5):1163-1176
The amago salmon, Oncorhynchus masou ishikawae, is an endemic subspecies of O. masou in Japan. Owing to the extensive stocking of hatchery fish throughout Japan, indigenous populations of O. m. ishikawae are now on the verge of extinction. We examined the genetic effects of stocking hatchery fish on wild populations in the
River Koza, Japan, using microsatellite and mitochondrial DNA (mtDNA) markers. For mtDNA, haplotype mt1, which is common in
wild populations, was present exclusively in isolated wild populations assumed to be unaffected by previous stocking, while
it was never observed in hatchery fish. Genetic diversity was much higher in wild populations in the stocked area, which shared
many mtDNA haplotypes with hatchery fish, than in isolated wild populations with haplotype mt1. Pairwise F
ST estimates based on microsatellites showed significant differentiation among the isolated populations with many microsatellite
loci monomorphic. Significant deviation from Hardy–Weinberg equilibrium was observed in wild populations in the area subject
to stocking, where a Bayesian-based assignment test showed a high level of introgression with hatchery fish. These results
suggest that wild populations with haplotype mt1, which became isolated through anthropogenic environmental change in the
1950–1960s, represent indigenous populations of O. m. ishikawae in the River Koza. They have low genetic diversity, most likely caused by genetic bottlenecks following damming and environmental
deterioration, while stocking of hatchery fish over the past 30 years apparently had a large impact on the genetic structure
of wild populations in the main channel of the River Koza. 相似文献
70.
A key feature of the mammalian brain is its capacity to adapt in response to experience, in part by remodeling of synaptic connections between neurons. Excitatory synapse rearrangements have been monitored in vivo by observation of dendritic spine dynamics, but lack of a vital marker for inhibitory synapses has precluded their observation. Here, we simultaneously monitor in vivo inhibitory synapse and dendritic spine dynamics across the entire dendritic arbor of pyramidal neurons in the adult mammalian cortex using large-volume, high-resolution dual-color two-photon microscopy. We find that inhibitory synapses on dendritic shafts and spines differ in their distribution across the arbor and in their remodeling kinetics during normal and altered sensory experience. Further, we find inhibitory synapse and dendritic spine remodeling to be spatially clustered and that clustering is influenced by sensory input. Our findings provide in vivo evidence for local coordination of inhibitory and excitatory synaptic rearrangements. 相似文献