Electron flying qubits are envisioned as potential information links within a quantum computer, but also promise-like photonic approaches-to serve as self-standing quantum processing units. In contrast to their photonic counterparts, electron-quantum-optics implementations are subject to Coulomb interactions, which provide a direct route to entangle the orbital or spin degree of freedom. However, controlled interaction of flying electrons at the single-particle level has not yet been established experimentally.
View Article and Find Full Text PDFSingle-electron sources, formed by a quantum dot (QD), are key elements for realizing electron analogue of quantum optics. We develop a new type of single-electron source with functionalities that are absent in existing sources. This source couples with only one lead.
View Article and Find Full Text PDFMany factors regulate the expression of specialised secondary metabolite biosynthetic gene clusters, which have been recognised as important for the discovery of novel microbial natural products. A cosmid library based on genomic DNA of the marine-derived Streptomyces puniceus Act1085 was constructed and screened to identify a short gene cluster similar to the nonactin biosynthetic cluster. The ORFs of the gene cluster isolated had high amino acid sequence identity, from 82% to 96%, with corresponding ORFs of the nonactin biosynthetic gene cluster from S.
View Article and Find Full Text PDFJ Microbiol Biotechnol
August 2017
Seven flavonoids were isolated from via repetitive column chromatography and high-performance liquid chromatography. The chemical structures of these compounds were identified by spectroscopic analysis and comparison with values reported in the literature. Among the flavonoids tested, 7-hydroxy-6-methoxyflavanone () and formononetin () exhibited strong inhibitory activity against SrtA, with IC values of 46.
View Article and Find Full Text PDFChemical investigation of a halophilic actinomycete strain belonging to the genus inhabiting a hypersaline saltern led to the discovery of new 18-membered macrolides with nitrile functionality, borrelidins C-E (-), along with a previously reported borrelidin (). The planar structures of borrelidins C-E, which are new members of the rare borrelidin class of antibiotics, were elucidated by NMR, mass, IR, and UV spectroscopic analyses. The configurations of borrelidines C-E were determined by the interpretation of ROESY NMR spectra, J-based configuration analysis, a modified Mosher's method, and CD spectroscopic analysis.
View Article and Find Full Text PDFCandida albicans hyphal formation is inhibited by a quorum-sensing molecule, farnesoic acid, which accumulates in the medium as the cells proliferate. We recently showed that Pho81 is essential for the inhibition of hyphal growth by farnesoic acid. Here, we describe a newly identified regulator, Hot1, which increases the expression of PHO81.
View Article and Find Full Text PDFTerrelumamides A (1) and B (2), two new lumazine-containing peptides, were isolated from the culture broth of the marine-derived fungus Aspergillus terreus. From the results of combined spectroscopic and chemical analyses, the structures of these compounds were determined to be linear assemblies of 1-methyllumazine-6-carboxylic acid, an amino acid residue and anthranilic acid methyl ester connected by peptide bonds. These new compounds exhibited pharmacological activity by improving insulin sensitivity, which was evaluated in an adipogenesis model using human bone marrow mesenchymal stem cells.
View Article and Find Full Text PDFPenicillipyrones A (1) and B (2), two novel meroterpenoids, were isolated from the marine-derived fungus Penicillium sp. On the basis of the results of combined spectroscopic analyses, these compounds were structurally elucidated to be sesquiterpene γ-pyrones from a new skeletal class derived from a unique linkage pattern between the drimane sesquiterpene and pyrone moieties. Compound 2 elicited significant induction of quinone reductase.
View Article and Find Full Text PDFHerqueiazole (1), herqueioxazole (2), and herqueidiketal (3), polyaromatic metabolites with a novel skeletal class, were isolated from the marine-derived fungus Penicillium sp. Based on the combined spectroscopic analyses, the structures of 1 and 2 were determined to be the first examples of pyrrole- and oxazole-containing phenalenone compounds, respectively, whereas 3 possessed a novel skeleton with a highly oxidized naphthoquinone moiety. Compound 3 exhibited moderate cytotoxicity and significant inhibitory activity against sortase A.
View Article and Find Full Text PDFNa(+)/K(+)-adenosine triphosphatase (ATPase) inhibitors have considerable therapeutic potential against some heart diseases like congestive heart failure and cardiac arrhythmias. Through bioassay-guided separation of the leaf extract of Laurus nobilis, six acylated kaempferol glycosides (compounds 1-6) were isolated. Their structures were determined on the basis of spectroscopic analysis and comparison with reported data.
View Article and Find Full Text PDFOxazole-containing macrolides (1-5) isolated from the marine sponge Chondrosia corticata were evaluated for their actin depolymerizing activities by monitoring fluorescent intensity of pyrene F-actin. These studies led to the identification of (19Z)-halichondramide (5) as a new actin depolymerizing agent. The actin depolymerizing activity by (19Z)-halichondramide (5) was four times more potent than that of halichondramide (1).
View Article and Find Full Text PDFBioorg Med Chem Lett
December 2010
Guided by the inhibitory activities of indole-containing natural products against isocitrate lyase (ICL) from Candida albicans and sortase A (SrtA) from Staphylococcus aureus, a series of compounds structurally analogous to natural products were synthesized. Eight SrtA inhibitors and an ICL inhibitor having higher activities than the natural products were discovered by screening the enzyme inhibitory activities of synthesized compounds. Among the SrtA inhibitors discovered, six exhibited higher activities than p-hydroxymercuribenzoic acid, which suggests that these compounds have great potential as alternative antibacterial agents.
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