Synthetic studies on the antibiotic natural product ripostatin A have been carried out with the aim to construct the C9-C10 bond by a nickel(0)-catalyzed coupling reaction of an enyne and an epoxide, followed by rearrangement of the resulting dienylcyclopropane intermediate to afford the skipped 1,4,7-triene. A cyclopropyl enyne fragment corresponding to C1-C9 has been synthesized in high yield...

From our recent work on the three-dimensional structure of epoxide hydrolases we theoretically deduced the likelihood of a two-step catalytic mechanism that we and others have subsequently experimentally confirmed. Analysis of the rate of the two steps by us and by others show that the first step-responsible for removal of the reactive epoxide from the system-works extraordinarily fast (typical...

Some cytochrome P450 enzymes epoxidize unsaturated substrates, but this activity has not been described for the steroid hydroxylases. Physiologic steroid substrates, however, lack carbon-carbon double bonds in the parts of the pregnane molecules where steroidogenic hydroxylations occur. Limited data on the reactivity of steroidogenic P450s toward olefinic substrates exist, and the study of occu...

Cytochrome P450 (CYP) epoxygenases metabolize arachidonic acid into epoxyeicosatrienoic acids (EETs), which play an important role in blood pressure regulation, protection against ischemia-reperfusion injury, angiogenesis, and inflammation. Epoxide hydrolases metabolize EETs to their corresponding diols (dihydroxyeicosatrienoic acids; DHETs) which are biologically less active. Microsomal epoxid...

The tumorigenicity of the (+)- and (-)-enantiomers of the diastereomeric bay-region benz(a)anthracene 3,4-diol-1,2-epoxides was evaluated in two mouse tumor models. In an initiation-promotion experiment on mouse skin, a single topical application of 0.1 or 0.4 mumol of the benz(a)anthracene diol-epoxides was followed by 25 weeks of promotion with 12-O-tetradecanoylphorbol-13-acetate. Of the fou...

Administration of the antioxidant 2(3)-tert-butyl-4-hydroxyanisole (BHA) in the diet caused a marked increase in the specific activity of epoxide hydratase (EC 4.2.1.63) in hepatic microsomes of CD-1 mice. The increases in epoxide hydratase activities produced by BHA were far greater (11-fold) than were those produced by the administration of well-known enzyme inducers such as 3-methylcholanthr...

Administrationof the antioxidant 2(3)-tert-butyl-4-hy droxyanisole(BHA)in the diet causeda markedincrease in the specific activity of epoxide hydratase (EC 4.2.1.63) in hepatic microsomesof CD-i mice. The increases in epoxide hydratase activities produced by BHA were far greater (11-fold)than were those producedby the admin istrationof well-knownenzymeinducerssuchas 3-meth ylcholanthrene,phenob...

Dual-curing is a processing technology based in the combination of two polymerization processes and proper selection formulation. This methodology allows preparation intermediate materials with tailored characteristics, which can be viscous-liquids or rubbery solids according to their application. Once applied, second stage performed leading high crosslinked network. Usually, different monomers...

A simple method for the synthesis of new bio-based silane coupling agents (SCAs) with a terpene aromatic core by functionalization cheap, natural eugenol and its sulfur derivatives using hydrosilylation C=C bonds HSi(OEt)3, followed nucleophilic substitution reactions OH/SH groups is presented. The obtained alkoxysilanes possess different polymer-reactive functionalities (alkenyl, epoxide, thii...