The first total synthesis of bussealin E, a natural product with a unique cycloheptadibenzofuran scaffold, is reported. A strategy inspired by a proposed biosynthesis was employed whereby a diphenylpropane derivative underwent an oxidative phenolic coupling to forge the tetracyclic ring system. The synthesis of the diphenylpropane featured a key sp2-sp3 Hiyama coupling between a vinyldisiloxane...

The mechanism of the formation of [C,Hs]' ions by hydrogen rearrangement in the molecular ions of 1-phenylpropane and 1,3-diphenylpropane has been investigated by looking at the effects of CH,O and CF, substituents in the meta and para positions on the relative abundances of the corresponding ions and on the appearance energies. The formation of [C,H,]' ions from 1,3-diphenylpropane is much enh...

Hydrogen migrations in the molecular ions of 1,3-diphenylpropane, preceding the fragmentations to [C7H,]' and [C,H& ions, have been investigated by use of deuterated derivatives. By comparing the distribution of deuterium labels in the [C,(H, D)Jt products from metastable molecular ions with the distribution patterns calculated for various exchange models, it is shown that the H migrations occu...

The endocrine-disrupting activities of bisphenol A (BPA) and 19 related compounds were comparatively examined by means of different in vitro and in vivo reporter assays. BPA and some related compounds exhibited estrogenic activity in human breast cancer cell line MCF-7, but there were remarkable differences in activity. Tetrachlorobisphenol A (TCBPA) showed the highest activity, followed by bis...

Bisphenol-A (4,4'-dihydroxy-2,2-diphenylpropane, BPA, or BPA-A) and its derivatives, when exposed to humans, may affect functions of multiple organs by specific binding to the human estrogen-related receptor γ (ERRγ). We carried out atomistic molecular dynamics (MD) simulations of three ligand compounds including BPA-A, 4-α-cumylphenol (BPA-C), and 2,2-diphenylpropane (BPA-D) binding to the lig...

Using trans-diphenylpropane oxide (tDPPO) as a substrate, we measured epoxide hydrolase (EH) activity in subcellular fractions of Alternaria alternata f. sp. lycopersici (Aal), a fungus that produces host-specific toxins. The activity was mainly (> 99.5%) located in the soluble fraction (100,000 x g supernatant) with the optimum pH at 7.4. An increase of toxin production between days 3 and 9 fo...

In this study we examined estrogenic activity of styrene oligomers after metabolic activation by rat liver microsomes. Trans-1,2-diphenylcyclobutane (TCB), cis-1,2-diphenylcyclobutane (CCB), 1,3-diphenylpropane, 2,4-diphenyl-1-butene, 2,4,6-triphenyl-1-hexene, and 1-alpha-phenyl-4ss-(1 -phenylethyl)tetralin were negative in the yeast estrogen screening assay and estrogen reporter assay using es...