Genomics and Transcriptomics of the green mussel explain the durability of its byssus.

Mussels, which occupy important positions in marine ecosystems, attach tightly to underwater substrates using a proteinaceous holdfast known as the byssus, which is tough, durable, and resistant to enzymatic degradation. Although various byssal proteins have been identified, the mechanisms by which it achieves such durability are unknown. Here we report comprehensive identification of genes involved in byssus formation through whole-genome and foot-specific transcriptomic analyses of the green mussel, Perna viridis. Interestingly, proteins encoded by highly expressed genes include proteinase inhibitors and defense proteins, including lysozyme and lectins, in addition to structural proteins and protein modification enzymes that probably catalyze polymerization and insolubilization. This assemblage of structural and protective molecules constitutes a multi-pronged strategy to render the byssus highly resistant to environmental insults.

Thermal cyclization of nonconjugated aryl-yne-carbodiimide furnishing a dibenzonaphthyridine derivative.

The reagent-free C(2)-C(7) thermal cyclization of a nonconjugated aryl-yne-carbodiimide yielded a dibenzo[b,g][1,8]naphthyridine derivative, whose congeners are known to possess fascinating pharmacological properties. This is the first heteroaromatic compound prepared by the thermal cycloaromatization of "nonconjugated" aryl-ynes.

Synthesis and DNA cleaving activity of water-soluble non-conjugated thienyl tetraynes.

Water-soluble non-conjugated thienyl tetraynes (3-6) were synthesized and their DNA cleaving activity was evaluated using electrophoresis, atomic force microscopy (AFM) and Escherichia coli (E. coli) transformation techniques. The amino-functionalized compound 4 was shown to possess an activity to cleave plasmid DNA by both electrophoresis and E. coli transformation techniques. AFM also showed a cleavage of the circular DNA into a linear form with a formation of burst-star-shaped architectures, which were envisaged to be cross-linked DNA oligomers.

Green mussel Perna viridis L.: attachment behaviour and preparation of antifouling surfaces.

The green mussel Perna viridis LINNE can be kept in simulated seawater for more than 6 months in good condition. The mussel forms many threads by secreting an adhesive protein from the foot, and attaches with more than 50 byssal threads, which makes most mussels clump together. In order to investigate the preparation of the antifouling surfaces toward green mussels, the attachment of mussels was tested using glass surfaces modified with silane coupling agents, together with non-treated material surfaces such as glass and silicone. The correlation between the attachment percentage and the mean number of the secreted byssus was highly significant, indicating that the mussel selects a favorable surface prior to the secretion of byssus. The relationships between the mussel attachment and the surface chemical parameters (surface free energy (sfe) and its dispersion and polar components) were examined based on a working hypothesis, which we have previously reported. The result of statistical regression test indicated that a certain correlation was found between the dispersion component and the mussel attachment, while the polar component did not correlate to the mussel attachment. The present surface chemical approach provided an additional clue for the preparation of ecologically clean antifouling materials that takes into account the combination of the wettability of both the marine adhesive proteins (MAP) and the modified surfaces.

Copper(I) ion mediated self-organization of molecular rectangular boxes from 1,2-Bis(2-pyridylethynyl)benzene Ligands with bulky substituents.

The reaction of chiral 1,2-bis(2-pyridylethynyl)benzene ligands with copper(I) ions in dichloromethane at room temperature gives rise to the formation of molecular rectangular boxes in high yields. The structures of these complexes were confirmed by X-ray crystallographic analysis. The compound CL1 crystallizes in the triclinic space group P1, with a = 13.707(4) A, b = 14.891(3) A, c = 12.030(1) A, alpha = 101.65(2) degrees, beta = 115.08(2) degrees, gamma = 97.66(1) degrees, V = 2110.8(2) A(3), Z = 1 (T = 288 K). The compound CL2 crystallizes in the triclinic space group P1, with a = 13.539(4) A, b = 14.755(2) A, c = 11.951(2) A, alpha = 101.70(1) degrees, beta = 115.11(1) degrees, gamma = 97.44(2) degrees, V = 2053.8(8) A(3), Z = 1 (T = 198 K). The formation of box-type structure is caused by steric hindrance between bulky substituents of the ligands.

Highly active Pd(II) catalysts with trans-bidentate pyridine ligands for the Heck reaction.

[reaction: see text] The air-, water-, and heat-stable palladium(II) complexes 2a and 2b are prepared by the reaction of palladium(II) salts with the new trans-bidentate nitrogen ligands, 1,2-bis(2-pyridylethynyl)benzenes. The structure of complex 2a has been confirmed by X-ray structure analysis. The complexes efficiently catalyze the Heck olefination of aryl iodides and provide a good yield under phosphine-free conditions. The reaction is very sensitive to the nature of the chelating ligand.

A novel water-soluble Hantzsch 1,4-dihydropyridine compound that functions in biological processes through NADH regeneration.

A novel Hantzsch 1,4-dihydropyridine derivative could function in an organic solvent-free solution, and thus it could function in biological systems. These functions can be accomplished through regeneration of the reduced form of nicotinamine adenine dinucleotide (NADH), an essential compound for living organisms. The results obtained here demonstrate the usefulness of a water-soluble Hantzsch 1,4-dihydropyridine derivative and its wide applicability as a chemical energy source, which drives various biological processes efficiently.