Vancomycin resistance plasmids in enterococci carry the genes vanH and vanA, which encode enzymes catalyzing, respectively, the reduction of 2-keto acids to 2-D-hydroxy acids and the addition of D-hydroxy acids to D-alanine. It has therefore been postulated that resistant cells produce peptidoglycan precursors that terminate in the depsipeptide D-alanine-2-D-hydroxy acid rather than the dipepti...

Melting points and heats of fusion were determined for 13 hydroxy acids and their lithium salts with chain lengths ranging from 14 to 24 carbons. Included were hydroxy acids prepared from two unusual plant sources, Lesquerella sp. and Crambe abyssinica. Upper melting point temperatures, transition entropies, and heat capacity changes of the lithium salts on heating and cooling suggest that many...

The lipids from the electric organ of the ray, Torpedo marmorata, have been isolated and characterized. The major lipids were cholesterol, choline phospholipids, ethanolamine phospholipids, and sphingomyelins. The major fatty acids of ethanolamine phospholipids were 18:1, 18:0, 22:6, and 20:4. More than 50% of the acids in choline phospholipids were 16:0. The sphingomyelins consisted of five ma...

Tydemania expeditionis Weber-van Bosse (Udoteaceae) is a weakly calcified green alga. In the present paper, liquid chromatography coupled with photodiode array detection and electrospray mass spectrometry was developed to identify the fingerprint components. A total of four triterpenoid sulfates and three hydroxy fatty acids in the ethyl acetate fraction of the crude extract were structurally c...

Sphingomyelin, ceramide, cerebroside, and cerebroside sulfate from beef brain were isolated by column chromatography in quantitative yield and in pure form. The fatty acid composition of each sphingolipid was determined by gas-liquid chromatography (GLC). Sphingomyelin contained only nonhydroxy fatty acids, while cerebroside, cerebroside sulfate, and ceramide contained both nonhydroxy and hydro...

A new method is described for the isolation of nearly pure total cerebrosides from fresh brain. Florisil columns are used to separate the cerebroside hydroxy and normal acids, in the form of their esters, and to separate the saturated and unsaturated esters of each group. The esters within each class are determined by gas chromatography, the hydroxy esters being run as the methyl ethers. Yields...

Lanosterol is a precursor for cholesterol, which synthesized primarily in the liver pathway often described as mevalonate or HMG-CoA reductase pathway. The first two steps (formation of acetoacetyl CoA and mitochondrial generation (S)-3-hydroxy-3-methylglutaryl-CoA) are also associated with oxidation fatty acids.

Two strains of Bacteroides asaccharolyticus and two strains of Bacteroides fragilis were analyzed for total fatty acid, total lipid fatty acid, and total bound fatty acid profiles. Extracted lipids and defatted cell residues were subjected to sequential alkaline and acid methanolyses to distinguish ester- and amide-linked fatty acids in each fraction. In the lipid fractions, all the ester-linke...

A Beijerinckia strain designated strain B1 was shown to oxidize benz[a]anthracene after induction with biphenyl, m-xylene, and salicylate. Biotransformation experiments showed that after 14 h a maximum of 56% of the benz[a]anthracene was converted to an isomeric mixture of three o-hydroxypolyaromatic acids. Nuclear magnetic resonance and mass spectral analyses led to the identification of the m...