Abstract Selective syntheses of coumarin and benzofuran derivatives were achieved via HClO4-mediated intermolecular annulation using phenols α-methoxy-β-ketoesters. Coumarins are formed under dehydrated conditions, whereas benzofurans in the presence water. In synthetic process benzofurans, α-methoxy-β-ketoesters converted into α-methoxyacetophenones, methoxy group is an important element annul...

Treatment of 4-heptafluoroisopropyl-2-methoxy-3,5,6-trifluropyridine (4 ) with aqueous ammonia in THF gave 2-amino-3,5-difluoro-4-heptafluoroisopropyl- 6-methoxy pyridine (5) in 7 1% yield. Chlorination of this amine with 'ButOCl at -16°C gave an unstable product, namely 2-dichloroarnino-3,5- difluoro-4-heptafluoroisopropyl-6-methoxy pyridine (6). Iodine-catalysed rearrangement of this dic...

Psoralens bind to DNA noncovalently and upon exposure to near UV (320-400 nm) light produce covalent adducts. Thymidine residues in DNA, especially those at 5'-TpA-3' sequences, are most susceptible to the photochemical reaction. This property of the reaction and the recent advances in oligonucleotide synthesis and separation has enabled us to construct DNA fragments containing psoralen adducts...

The ability to stimulate recombination in a site-specific manner in mammalian cells may provide a useful tool for gene knockout and a valuable strategy for gene therapy. We previously demonstrated that psoralen adducts targeted by triple-helix-forming oligonucleotides (TFOs) could induce recombination between tandem repeats of a supF reporter gene in a simian virus 40 vector in monkey COS cells...

objective(s) anxiety is a common disorder which afflicts many people in any society and is often accompanied by physiological sensations such as tachycardia, chest pain, shortness of breath, insensitivity, etc. the purpose of present study was to evaluate the putative anxiolytic-like effects of phencyclidine ('-('-phenylcyclohexyl) piperidine, cas 956-90-1, pcp, i) and its methyl and ...

BACKGROUND Release of exosomes have been shown to play critical roles in drug resistance by delivering cargo. Targeting the transfer of exosomes from resistant cells to sensitive cells may be an approach to overcome some cases of drug resistance. METHOD In this study, we investigated the potential role of exosomes in the process of psoralen reverse multidrug resistance of MCF-7/ADR cells. Exo...

a Veterinary Toxicology and Entomology Research Laboratory, Agricultural Research, Science and Education Administration, U.S. Department o f Agriculture, College Station, TX 77840, b Western Regional Research Laboratory, Agricultural Research, Science and Education Administration, U.S. Department o f Agriculture, Berkeley, CA 94710, and c Department o f Entomology, University o f California, Ri...

Triple-helical DNA can be formed by oligonucleotides that bind as third strands of DNA in a sequencespecific manner in the major groove in homopurine/homopyrimidine stretches in duplex DNA. Such triple helix-forming oligonucleotides have been used to inhibit gene expression by blocking transcription factor access to promoter sites in transient expression assays. In an alternative approach to ge...

Many commonly used drugs, such as psoralen and cisplatin, can generate a very unique type of DNA damage, namely ICL (interstrand cross-link). An ICL can severely block DNA replication and transcription and cause programmed cell death. The molecular mechanism of repairing the ICL damage has not been well established. We have studied the role of XPF (xeroderma pigmentosum group F) protein in psor...