Kinetic analyses of the irreversible inhibition of L-tyrosine and L-phenylalanine transport in Bacillus subtilis by phenylalanine chloromethyl ketone revealed that the inhibition was due to an affinity labeling process. Phenylalanine chloromethyl ketone is a competetive inhibitor of L-tyrosine and L-phenylalanine transport. The K, values for irreversible inhibition of L-tyrosine and L-phenylala...

The morphology and molecular conformation of Langmuir-Blodgett deposited and floating monolayers of a selection of straight chain (eicosanoic acid, EA), iso (19-methyl eicosanoic acid, 19-MEA), and anteiso (18-methyl eicosanoic acid, 18-MEA) fatty acids have been investigated by Vibrational Sum Frequency Spectroscopy (VSFS), AFM imaging, and the Langmuir trough. While the straight chain fatty a...

The germicidal potency of quatemary ammonium compounds is known to depend mainly on the chemical structure of the cation, the nature of the anion having little if any effect (Glassman, 1948). The relation of structure of the cation to bactericidal activity has been studied extensively insofar as chain length of the hydrophobic or hydrocarbon group is concerned. In compounds with only one long c...

D-amino acids are valuable building blocks for the synthesis of biologically active compounds and pharmaceuticals. The asymmetric chiral amino from prochiral ketones using stereoselective enzymes is a well-known but far exhausted approach large-scale production. Herein, we investigated pyridoxal-5′-phosphate-dependent acid transaminase Haliscomenobacter hydrossis as potential biocatalyst enzyma...

Organic acids from w heat ( Triticum aestivum), rye (Secale cereale), and barley (Hordeum vulgare, var. “G erbel” and “ Igri” ) were analysed by gas c h ro m a to g ra p h y -m ass spectrom etry. Two carboxylic acid fractions were obtained by chrom atography on Sephadex LH 20: frac­ tion A contained m ainly aliphatic acids, fraction B contained m ainly arom atic acids. The identified com pounds...

Freshly isolated cotyledons from 10-day developing pea (Pisum sativum) seeds were fed radiolabeled precursors for 5 hours, and the specific radioactivity of the free and total protein amino acids was determined using a dansylation procedure. When the seven most abundant amino acids in phloem exudate of pea fruits (asparagine, serine, glutamine, homoserine, alanine, aspartate, glycine) were fed ...

The lipophilic composition of wild Arbutus unedo L. berries, collected from six locations in Penacova (center of Portugal), as well as some general chemical parameters, namely total soluble solids, pH, titratable acidity, total phenolic content and antioxidant activity was studied in detail to better understand its potential as a source of bioactive compounds. The chemical composition of the li...

BACKGROUND Three-ring polyamides containing N-methylimidazole and N-methylpyrrole amino acids bind sequence-specifically to double-helical DNA by forming side-by-side complexes in the minor groove. Simple pairing rules relate the amino-acid sequence of a pyrrole-imidazole polyamide to its expected DNA target site, and polyamides that target a wide variety of DNA sequences have been synthesized....

Lipids active in biological systems demonstrate a broad range of behavior in water, from hydrocarbons which are insoluble, to molecules such as bile salts that possess potent detergent properties and interact with water rather dynamically. The purpose of this paper is to describe some of the physical properties of lipids with respect to their inter— action with aqueous systems, and to classify ...

Polygonum capitatum (Polygonaceae) exists in rural areas of Southwest China and some other Asian countries. Its aerial part or whole herbal plant has been used as a Miao ethnomedicine against urinary system diseases, infections, pyelonephritis, diarrhea, so on. The progress phytochemical research on P. over the past decades is summarized. Two hundred three chemical constituents that have isolat...