Hydroxylation-Induced Migration: The NIH Shift

Abstract

have been discussed by Cameron (32), Johnson (33), Manley (34), and Matsuoka et al. (35).On the basis of the rather crude x-ray positional data that were available in the fall of 1966, Sandage made a photographic survey of a 4by 4-degree region surrounding Cyg XR-2. Subsequently, more accurate information was provided by the ASE-MIT group, which led to an identification of Cyg XR-2 with a 16th-magnitude blue star noted on the Palomar plates. If the identification is confirmed, Cyg XR-2 and Sco XR-1 will be "charter members" of a newly recognized class of stars, located in our own galaxy, whose x-ray luminosities considerably exceed their optical outputs. References and Notes 1. The 1967 Texas Symposium had a registration of approximately 650 persons. The organizing committee and sponsoring organizations consisted of A. have been discussed by Cameron (32), Johnson (33), Manley (34), and Matsuoka et al. (35).On the basis of the rather crude x-ray positional data that were available in the fall of 1966, Sandage made a photographic survey of a 4by 4-degree region surrounding Cyg XR-2. Subsequently, more accurate information was provided by the ASE-MIT group, which led to an identification of Cyg XR-2 with a 16th-magnitude blue star noted on the Palomar plates. If the identification is confirmed, Cyg XR-2 and Sco XR-1 will be "charter members" of a newly recognized class of stars, located in our own galaxy, whose x-ray luminosities considerably exceed their optical outputs.References and Notes 1. The 1967 Texas Symposium had a registration of approximately 650 persons. The organizing committee and sponsoring organizations consisted of A.

Metabolic pathways of decabromodiphenyl ether (BDE209) in rainbow trout (Oncorhynchus mykiss) via intraperitoneal injection

“…It was once suspected that hydroxylation of PBDEs was mediated by cytochrome P450 enzymes, which could account for direct hydroxylation or hydroxylation via a 1,2-shift. In addition, the 1,2-shift mechanism proceeded via an arene oxide intermediate (Guroff et al, 1967;Jerina and Daly, 1974). Moreover, previous studies suggested that orthosubstituted OH-BDEs were formed from naturally occurring compounds in marine ecosystems (Teuten et al, 2005), while meta-or para-substituted OH-BDEs could originate from the biotransformation of synthetic BDEs (Malmberg et al, 2005;Hamers et al, 2008).…”

The metabolism of orally administered l‐DOPA in Parkinsonism

“…We would even postulate that its presence is indicative of a sufflicient production of DHPPA or VPA to interfere with the normal metabolism of tyrosine. The major metabolite of tyrosine metabolism is p-hydroxyphenylpyruvic acid (p-HPPA) which is normally further metabolized by p-HPPA-oxidase (La Du, 1966), undergoing the recently described "NIH shift " (Guroff, Daly, Jerina, Renson, Witkop & Udenfriend, 1967), to 2,5-dihydroxy,phenylacetic acid (homogentisic acid). Our finding of an increased output of the immediate reduction product of p-HPPA, p-HPLA, which tends to correlate with VLA output, suggests to us that DHPPA or VPA may compete with p-HPPA for p-HPPA-oxidase.…”

Conversion of 7-Dehydrocholesterol to 7-Ketocholesterol Is Catalyzed by Human Cytochrome P450 7A1 and Occurs by Direct Oxidation without an Epoxide Intermediate

“…A comparison can be made with hydroxylation of aryl compounds and the 1,2-"NIH shift" (i.e. p to m shift of hydrogen due to a 4-keto intermediate) (58), although in the case of aryl compounds, the epoxides are often unstable, and demonstrating a "non-epoxide" mechanism is difficult. Precedent also exists for 1,2-halide migration in the conversion of vinyl halides to carbonyls without the intermediary of epoxides (38,59).…”