Oligonucleotides can bind as third strands of DNA in a sequence-specific manner in the major groove in homopurine/homopyrimidine stretches in duplex DNA. Here we use a 10-base triplex-forming oligonucleotide linked to a psoralen derivative at its 5' end to achieve site-specific, targeted mutagenesis in an intact, double-stranded lambda phage genome. Site-specific triplex formation delivers the ...

Psoralen photochemotherapy [psoralen ultraviolet A (PUVA)] plays an important part in dermatological therapeutics, being an effective and generally safe treatment for psoriasis and other dermatoses. In order to maintain optimal efficacy and safety, guidelines concerning best practice should be available to operators and supervisors. The British Photodermatology Group (BPG) have previously publi...

1,2-Dioxetanes, efficient chemical sources of triplet excited carbonyl compounds, were observed to be genotoxic in isolated DNA, bacteria, and cultured mammalian cells. In superhelical DNA of bacteriophage PM2, various alkyl- and hydroxyalkyl-substituted dioxetanes (1) induced predominantly endonuclease-sensitive base modifications and only few single strand breaks. With a specific endonuclease...

Five new podocarpane-type trinorditerpenes were isolated from the bark of Taiwania cryptomerioides. Structures of 1beta, 14-dihydroxy-13-methoxy-6,8,11,13-podocarpatetraene (1), 1beta, 14-dihydroxy-13-methoxy-8,11,13-podocarpatriene (2), 13-hydroxy-12-methoxy-8,11,13-podocarpatrien-3-one (3), 14-hydroxy-13-methoxy-1,8,11,13-podocarpatetraen-3-one (4), and 13-methoxy-8,12-podocarpatriene-11,14-d...

When chromatin is photoreacted with psoralen, crosslinks occur preferentially in the linker DNA between nucleosomes. The pattern of these crosslinks can be analysed by exonuclease digestion of random DNA fragments, since the exonucleases tested stop at sites of psoralen-crosslinks. Further digestion of these fragments with Sl-nuclease leads to DNA fragments of nucleosomal and polynucleosomal si...

In contrast to all previous results with many derivatives of 4-dimethylaminoazobenzene, the ingestion by the rat of 3-methoxy-4-aminoazobenzene or its N-monomethyl or N,N-dimethyl derivatives was found to induce high incidences of squamouscell carcinomas of the ear duct. $-Methoxy-4-aminoazobenzene also induced low incidences of adenocarcinomas in the small intestine and mammary gland. In addit...

Introduction: GTS-21 ((3E)-3-[(2,4-dimethoxyphenyl)methylene]-3,4,5,6tetrahydro-2,3’-bipyridine), a partial α7 nicotinic acetylcholine receptor agonist drug, has recently been shown to improve cognition in schizophrenia and Alzheimer’s disease. One of its two major demethylated metabolites, 4-OH-GTS-21, has been suggested to contribute to its therapeutic effects. Methods: We labeled GTS-21 in t...

You ask a great question and it?s fantastic that your curiosity led you to a Foxy fact-finding mission! For those unfamiliar with the drug, "Foxy" and "Foxy Methoxy" are nicknames for 5methoxy-N,N-diisopropyltryptamine, (or 5-MeO-DIPT). It falls under the class of tryptamines, which can be found in both naturally-occurring and synthetic forms. While some naturallyoccurring tryptamines are neuro...