96558-72-4Relevant academic research and scientific papers
Total synthesis of (±)-cis-trikentrin B via intermolecular 6,7-indole aryne cycloaddition and Stille cross-coupling
Chandrasoma, Nalin,Brown, Neil,Brassfield, Allen,Nerurkar, Alok,Suarez, Susana,Buszek, Keith R.
, p. 913 - 917 (2013/02/25)
An efficient total synthesis of the annulated indole natural product (±)-cis-trikentrin B was accomplished by means of a regioselectively generated 6,7-indole aryne cycloaddition via selective metal-halogen exchange from a 5,6,7-tribromoindole. The unaffected C-5 bromine was subsequently used for a Stille cross-coupling to install the butenyl side chain and complete the synthesis. This strategy provides rapid access into the trikentrins and the related herbindoles, and represents another application of this methodology to natural products total synthesis. The required 5,6,7-indole aryne precursor was prepared using the Leimgruber-Batcho indole synthesis.
Synthesis of polybrominated diphenyl ethers and their capacity to induce CYP1A by the Ah receptor mediated pathway
Chen,Konstantinov,Chittim,Joyce,Bols,Bunce
, p. 3749 - 3756 (2007/10/03)
Polybrominated diphenyl ethers (PBDEs) have become widely distributed as environmental contaminants due to their use as flame retardants. Their structural similarity to other halogenated aromatic pollutants has led to speculation that they might share toxicological properties such as hepatic enzyme induction. In this work we synthesized a number of PBDE congeners, studied their affinity for rat hepatic Ah receptor through competitive binding assays, and determined their ability to induce hepatic cytochrome P-450 enzymes by means of EROD (ethoxyre-sorufin-O-deethylase) assays in human, rat, chick, and rainbow trout cells. Both pure PBDE congeners and commercial PBDE mixtures had Ah receptor binding affinities 10-2-10-5 times that of 2,3,7,8-tetrachlorodibenzo-p-dioxin. In contrast with polychlorinated biphenyls, Ah receptor binding affinities of PBDEs could not be related to the planarity of the molecule, possibly because the large size of the bromine atoms expands the Ah receptor's binding site. EROD activities of the PBDE congeners followed a similar rank order in all cells. Some congeners, notably PBDE 85, did not follow the usual trend in which strength of Ah receptor binding affinity paralleled P-450 induction potency. Use of the gel retardation assay with a synthetic oligonucleotide indicated that in these cases the liganded Ah receptor failed to bind to the DNA recognition sequence.
