Demonstration of remarkable biological effect of 3-deoxy-steroid confused the view about the mechanism of action of steroid,2) 3) while it has long been believed that the oxygen function at C-3 of steroid molecule is closely related to the mechanism of steroid action.1) 17a-Ethyny1-4-estrene-178-ol (ethynyl-estrenol) is one such compound which has no oxygen function at C-3 and shows remerkable ...

Regio- and stereoselective insertion of the terminal ethynyl functions of 4-ethynylstilbene, the E and Z isomers of 4,4'-bis(ethynylphenyl)ethene and a backbone-rigidified cyclohexenyl derivative of the Z isomer into the Ru-H bond of the complex RuClH(CO)(P(i)Pr(3))(2) provides the corresponding vinyl ruthenium complexes, which have been characterized spectroscopically and by X-ray crystallogra...

Clickable oligonucleotides with ethynyl residues in the 5-position of pyrimidines ((eth)dC and (eth)dU) or the 7-position of 7-deazaguanine ((eth)c(7)G(d)) are hydrated during solid-phase oligonucleotide synthesis and workup conditions. The side products were identified as acetyl derivatives by MALDI-TOF mass spectra of oligonucleotides and by detection of modified nucleosides after enzymatic p...

The N = 7 ← 6 to 11 ← 10 pure rotational transitions of CCH, X2Σ+, were measured in the laboratory between 611 and 961 GHz. The radical was produced in a dc glow discharge of a mixture of helium and acetylene. The electron spin-rotation splitting was resolved. The new line frequencies were fit together with previously published data, providing greatly improved spectroscopic constants, such as B...

The antitumor 3'-ethynyl nucleosides, 1-(3-C-ethynyl-beta-D-ribopentofuranosyl)cytosine (ECyd) and 1-(3-C-ethynyl-beta-D-ribopentofuranosyl)uridine (EUrd), are potent inhibitors of RNA polymerases and show excellent antitumor activity against various human solid tumors in xenograft models. ECyd is being investigated in phase I clinical trials as a novel anticancer drug possessing a unique antit...

The reaction between the ethynyl radical, C2H (X S), and methylacetylene (X A18), which yields ethynylallene, pentadiyne, and butadiyne, has been studied at the density functional ~B3LYP/6-3111G**! and coupled cluster ~coupled-cluster single double perturbative triple/ cc-pVTZ! levels of theory. These results agree with data from crossed molecular beam experiments where ethynylallene ~10! and p...

A new tetracobalt(III) cubane 1, carrying functionalized peripheral ethynyl groups, was prepared. Cubane 1 catalyses photoinduced water oxidation, indicating that the ethynyl groups do not negatively affect the catalytic properties of the Co cubane assembly. In contrast, the quantum yield for water oxidation (0.36) is significantly increased with respect to the prototype, simplest species.

Degeneration of the dopaminergic nigrostriatal system and of noradrenergic neurons in the locus coeruleus are important pathological features of Parkinson's disease. There is an urgent need to develop therapies that slow down the progression of neurodegeneration in Parkinson's disease. In the present study, we tested whether the highly specific metabotropic glutamate receptor 5 antagonist, 3-[(...