In Drosophila oogenesis, the development of a mature oocyte depends on having properly developed ring canals that allow cytoplasm transport from the nurse cells to the oocyte. Ring canal assembly is a step-wise process that transforms an arrested cleavage furrow into a stable intercellular bridge by the addition of several proteins. Here we describe a new gene wc named cheerio that provides a c...

An efficient synthetic method of 1,3-bis(arylethynyl)isobenzofurans is developed. Nucleophilic addition of alkynyllithium to benzocyclobutenone and subsequent oxidative ring cleavage of the four-membered ring gave a keto-aldehyde, which, in turn, accepted the second nucleophile to produce isobenzofurans after acid treatment.

The functions of the actin-myosin-based contractile ring in cytokinesis remain to be elucidated. Recent findings show that in the fission yeast Schizosaccharomyces pombe, cleavage furrow ingression is driven by polymerization of cell wall fibers outside the plasma membrane, not by the contractile ring. Here we show that one function of the ring is to spatially coordinate septum cell wall assemb...

On deprotonation, 1-arylindazolium salts form 1-arylindazol-3-ylidenes which rearrange spontaneously via ring cleavage, ring closure and subsequent proton transfer to substituted 9-aminoacridines. By contrast, the N-heterocyclic carbene of 2-phenylindazolium cannot rearrange similarly and was trapped by sulfur.

Hydrolysis of cyanuric acid, melamine, melem, atrazine and melamine-formaldehyde resin was found to be catalyzed by an A1203 catalyst. The reactions occur irreversibly with cleavage of the s-triazine ring between 240 and 450°C. The s-triazine-ring is hydrolyzed to ammonia and carbon dioxide, and the substituted groups to the corresponding molecules by addition of hydrogen.

Cyclobutanols undergo an oxidative ring expansion with Co(acac)2 and triplet oxygen to give 1,2-dioxanols. The formation of alkoxy radical drives the regioselective cleavage on more substituted side before insertion molecular oxygen. reaction is particularly effective secondary cyclobutanols but works also certain tertiary alcohols. Further substitution neutral nucleophiles under catalytic Lewi...

This study examined the ligninase-catalysed degradation of lignin model compounds representing the arylglycerol ,-aryl ether substructure, which is the dominant one in the lignin polymer. Three dimeric model compounds were used, all methoxylated in the 3and 4-positions of the arylglycerol ring (ring A) and having various substituents in the ,-ether-linked aromatic ring (ring B), so that competi...

The possibility for Au(III) σ-cyclopropyl complexes to undergo ring-opening and give π-allyl was interrogated. transformation first evidenced within (P,C)-cyclometalated complexes, it occurs hours at –50°C. It then generalized other ancillary ligands. With (N,C)-cyclometalated the rearrangement room temperature while proceeds already –80°C with a dicationic (P,N)-chelated complex. Density Funct...

in this note we introduce the notion of weak mccoy rings as a generalization of mccoy rings, and investigate their properties. also we show that, if is a semi-commutative ring, then is weak mccoy if and only if is weak mccoy.