the essential oil of prangos ferulacea (apiaceae) fruits was obtained by hydrodistillation and analyzed by gas chromatography (gc) and gc-mass spectrometery (ms). among the 39 identified constituents accounting for 99.99% of the total oil, the major components were chrysanthenyl acetate (26.53%), limonene (19.59%), alpha pinene (19.50%), delta-3-carene (6.56%), mesitaldehyde (6.09), and germacr...

Interest in the distribution of choline esterase activity between the cells and plasma dates back a dozen years or more, but relatively little investigation has been carried out. In 1928 Galehr and Plattner (1), using a biological assay method, found that there was more choline esterase activity in human blood cells than in serum, and their finding was confirmed by Matthes (2) in 1930. The este...

Lymphocytes from a case of B-cell chronic lymphocytic leukemia (CLI) were obtained in a highly purified state from a therapeutic leukapheresis preparation. The CLL lymphocytes showed a fine, scattered, granular pattern of nonspecific esterase cytochemical reactivity with either a-naphthyl acetate (aNA) or a-naphthyl butyrate (aNB) substrate as opposed to the more focal pattern of control (T) ly...

Leukemic cells from nine cases of acute monocytic leukemia (AMoL) were characterized by multiple differentiation markers. Cells in most cases were phagocytic, carried an Fc receptor, and stained positively for alpha-naphthyl acetate esterase but negatively for naphthol AS-D chloroacetate esterase. However, subtle differences in marker expression were observed which suggested different degrees o...

Horse liver aldehyde dehydrogenase, like other aldehyde dehydrogenases, is capable of hydrolyzing esters such as nitrophenyl acetate. Pre-steady state and burst kinetics were performed using substrate levels of enzyme to determine whether the rate-limiting step occurred prior to or after the formation of an acyl enzyme intermediate. A burst was found by both techniques for the dehydrogenase rea...

A-esterases are calcium-dependent hydrolases that can detoxify the active metabolites (oxons) of organophosphorus insecticides such as chlorpyrifos and parathion. A-esterases from rat liver have previously been shown to hydrolyze chlorpyrifos-oxon but not paraoxon at low substrate concentrations. Two A-esterases were extracted by ammonium sulfate fractionation from solubilized rat liver microso...

Following the development of a histochemical method for demonstrating non-specific esterase (1) in tissue sections by enzymatic hydrolysis of Bnaphthyl acetate, the possibility was explored of developing a similar method for lipase together with convenient calorimetric methods for measuring the activity of both enzymes in blood serum. Interest in the enzymes which hydrolyze carboxylic esters st...

A metagenomic library of surface-water microbes from the Yangtze River in China was constructed, and a novel esterase, designated as EstY, was isolated and characterized. EstY had 423 amino acids with an estimated molecular mass of 44 kDa and pI of 7.28. It hydrolyzed various pnitrophenyl esters (acetate, butyrate, caprate, caprylate, laurate, myristate, and palmitate) and its best substrate wa...

Toxicity and metabolism of t-permethrin were evaluated in two colonies (UF and ARS) of the eastern subterranean termite, Reticulitermes flavipes (Kollar), collected in Gainesville, FL. The UF colony (LC50 = 1.86 micrograms per vial) was approximately twofold more tolerant of t-permethrin than the ARS colony (LC50 = 0.89 microgram per vial) at the LC50. The synergists piperonyl butoxide and S,S,...