Let $G$ be a finite group. The prime graph of $G$ is a graph $Gamma(G)$ with vertex set $pi(G)$, the set of all prime divisors of $|G|$, and two distinct vertices $p$ and $q$ are adjacent by an edge if $G$ has an element of order $pq$. In this paper we prove that if $Gamma(G)=Gamma(G_2(5))$, then $G$ has a normal subgroup $N$ such that $pi(N)subseteq{2,3,5}$ and $G/Nequiv G_2(5)$.

Oligodeoxynucleotide N3'-->P5' phosphoramidates are promising candidates for antisense therapeutics, as well as for diagnostic applications. We recently reported a new method for the synthesis of these oligonucleotide analogs which makes use of a phosphoramidite amine-exchange reaction in the key coupling step. We report herein an improved set of monomers that utilize a more reactive, hindered ...

Fink and Fink (1) have shown that Neurospora crassa mycelia convert thymidine to the uracil and cytdsine of RNA without fragmentation of the pyrimidine ring. A cell-free system from Neurospora catalyzes several reactions which appear (l-3) to be involved in this pathway effecting the removal of the methyl group of thymidine. These reactions are the conversions of thymidine to thymine ribonucleo...

The substitution of a hydroxyl group by a fluorine atom in a potential drug is an efficient reaction that can, in principle, improve its pharmacological properties. Herein, the synthesis of the novel compound 5'-fluoro-5'-deoxyacadesine (5'-F-AICAR), a strict analogue of AICAR that cannot be 5'-phosphorylated to ZMP by cellular kinases, is reported.

5-Hydroxymethylcytosine (hmC) was recently detected as the sixth base in mammalian tissue at so far controversial levels. The function of the modified base is currently unknown, but it is certain that the base is generated from 5-methylcytosine (mC). This fuels the hypothesis that it represents an intermediate of an active demethylation process, which could involve further oxidation of the hydr...

Fluorescent or biotin labelling of an oligonucleotide at it's 5'-end usually involves two steps. First, a N-protected aminoalkyl phosphoramidite derivative (as for instance Aminolink 2 from Applied Biosystems) is added to the 5'-end of an oligonucleotide during automated DNA synthesis. After removal of all protecting groups the NHS ester of an appropriate fluorescent dye or biotin is coupled to...