Nisin is a small gene-encoded antimicrobial protein produced by Lactococcus lactis that contains unusual dehydroalanine and dehydrobutyrine residues. The reactivity of these residues toward nucleophiles was explored by reacting nisin with a variety of mercaptans. The kinetics of reaction with 2-mercaptoethane-sulfonate and thioglycolate indicated that the reaction pathway includes a binding ste...

In order to characterize aromatization in vivo, an androgen and an estrogen, labeled with different radioactive isotopes, are administered simultaneously, either as a pulse alone or as a pulse followed by a constant infusion of the same radiolabeled steroids. Subsequently, blood samples are obtained at varying time intervals and analyzed for the 3H/14C ratio in nonmetabolized unconjugated estro...

[3H8]Thromboxane Bz was biosynthesized and infused into an unanesthetized monkey. Several urinary metabolites were isolated and their structures elucidated using gas chromatography-mass spectrometry. In addition to the major urinary metabolite, dinor-thromboxane Bz, a series of metabolites resulting from dehydrogenation of the alcohol group at C-11 were identified: 11-dehydro-thromboxane Bz, 11...

In order to characterize aromatization in vivo, an androgen and an estrogen, labeled with different radioactive isotopes, are administered simultaneously, either as a pulse alone or as a pulse followed by a constant infusion of the same radiolabeled steroids. Subsequently, blood samples are obtained at varying time intervals and analyzed for the 3H/14C ratio in nonmetabolized unconjugated estro...

A compound catalyst (RA) consisted of Ni, ZnO and HZSM-5 with functions of reactive adsorption desulfurization (RADS) and olefin aromatization for fluid catalytic cracking (FCC) gasoline upgrading was prepared. X-ray powder diffraction (XRD), temperature-programmed reduction and low-temperature N2 adsorption were used to characterize the properties of the catalysts. Performance evaluation by FC...

An enzyme which catalyzes the aromatization of cyclohexanecarboxyl coenzyme A has been isolated from whole liver as well as from liver mitochondria. Incubation of the soluble, partially purified enzyme with cyclohexanecarboxyl-CoA produces cyclohexene-l-carboxyl-CoA, benzoyl-CoA, and a polar compound which has not. been further characterized. All three isomers of cyclohexenecarboxyl-CoA are con...

Background. Increased platelet thromboxane (TX)A2 production has been described in type IIa hypercholesterolemia. To verify the relevance of these capacity-related measurements to the actual rate of TXA2 biosynthesis in vivo, we studied the urinary excretion of its major enzymatic metabolites in 46 patients with type hIa hypercholesterolemia and 20 age-matched controls. Methods and Results. Uri...

and 11-dehydro-thromboxane B2 (TXB2) excretion rates were measuredaspreviouslydescribed.4Thestudyprotocolwasapproved by the local ethics committee, and patients provided written informed consent. The effects of LAGB surgery were assessed using FriedmanandWilcoxontests forpairedsamples.TheSpearmanrank correlation test and stepwisemultiple linear regression analysis (using log-transformed data) w...

20-Hydroxyecdysone, the arthropod moulting hormone, was biotransformed by the fungus Curvularia lunata NRRL 2178 to the rare ecdysteroid, 2-dehydro-3-epi-20-hydroxyecdysone, and the novel 3alpha,9alpha-cyclo ecdysteroid analogue, (20R,22R)-3beta,14alpha,20,22,25-pentahydroxy-3alpha,9alpha-cyclo-5beta-cholest-7-en-2,6-dione in 14 and 44% yields, respectively. Ponasterone A and pterosterone were ...