Five alkynyl phosphate esters have been synthesized as probes of the active site structure of phosphotriesterase. These compounds have the potential to be converted by the enzyme to a highly reactive ketene intermediate which can then react with an active site nucleophile causing irreversible inhibition of the enzyme by formation of an inactive covalent adduct. All five compounds completely ina...

BACKGROUND Organophosphorous (OP) pesticides are associated with reduced fetal growth in animals, but human studies are inconsistent. OBJECTIVES We pooled data from four cohorts to examine associations of prenatal OP exposure with birth weight (n = 1,169), length (n = 1,152), and head circumference (n = 1,143). METHODS Data were from the CHAMACOS, HOME, Columbia, and Mount Sinai birth cohor...

A variety of compounds related to the 5'-terminal "cap" (m7GpppN) of eukaryotic mRNA's were chemically synthesized and tested as inhibitors of reovirus mRNA binding to wheat germ ribosomes. Under our conditions of mRNA binding to ribosomes, 7-methyl-, 7-ethyl-, and 7-benzyl-GDP, but not GDP, decreased stable initiation complex formation by 70 to 80% at a concentration of 0.1 mM indicating that ...

Studies on the in vivo and in vitro disposition of 4,4'-[14C]-methylenebis(N,N-dimethyl)benzamine (reduced Michler's ketone, RMK) were performed. Osborne-Mendel rats retained, after 24 hr, 78% of a p.o. dose of [14C]RMK. At 24 hr after an i.p. dose, fat, liver, and intestine represented major sites for deposition of radioactivity. The major urinary metabolite of RMK, representing 36% of the tot...

The stability of o-5,5-dimethyl-A’-thiazoline-4-carboxylic acid has been studied under various conditions. In 10 mu cacodylate, pH 6.5, and at 55”C, o-5,5-dimethyld’-thiazoline-4-carboxylic acid (at concentrations lower than 1 mu) is hydrolyzed into N-formyl-n-penicillamine with a half-life of 3 to 4 min. On this basis, it is very unlikely that D-5,5dimethyl-AZ-thiazoline-4-carboxylic acid coul...

The nature of molybdenum cofactor in the bacterial enzyme dimethyl sulfoxide reductase has been investigated by application of alkylation conditions that convert the molybdenum cofactor in chicken liver sulfite oxidase and milk xanthine oxidase to the stable, well-characterized derivative [di(carboxamidomethyl)]molybdopterin. The alkylated pterin obtained from dimethyl sulfoxide reductase was s...

The near-limit oscillatory behaviors on wick flames of dimethyl carbonate (DMC) with trimethyl phosphate (TMP) additions have been investigated experimentally. experiments were conducted under a burner in conjunction the limiting oxygen concentration test (wick-LOC), and fuels selected as typical examples electrolyte solvents organophosphorus compounds (OPCs) for lithium-ion batteries. oscillat...