Isosteres of natural phosphates. 6. The preparation and properties of Lysophosphotidic acid

We herein report the first chemical synthesis of phosphonic acid analogues of lysophosphatidic acid. The racemic isosteric analogues, 4-acyloxy-3-hydroxybutyl-1-phosphonic acids, of lyso-phosphatidic acid were prepared by both catalytic and hydride reductions of the 4-acyloxy-3-oxobutyl-1-phosphonic acids, a general method for the preparation of the latter having been reported previously. The lysophosphatidic acids have been found to substrates for lysophosphatidic acid acyl transferase, and may be acylated chemically to yield phosphotidic acids. The latter reaction is of use in the preparation of differentially acylated phosphatidic acids.     

Hydroxylated glutamic acids in Phlox,lepidium and Rheum species

The two diastereoisomers, (2S,4R)-4-hydroxyglutamic acid and (2S,4S)-4-hydroxyglutamic acid, occur in characteristic concentration ratios in Phlox species. The second of these compounds is the principal free amino acid in the green parts of the plants. The presence of (2S,4R)-4-hydroxyglutamic acid in plants is reported for the first tiine. No other 4-substituted acidic amino acids were detected in the Phlox species analysed, although special attention was paid to the possible presence of 4-hydroxy-4-methylglutamic acids which have previously been reported in plants. It was found, however, that both diastereoisomers of (2S)-4-hydroxy-4-methylglutamic acid co-exist in Ledenbergia roseoaenea and also in Pandanus veitchii. Although the presence of 3,4-dihydroxyglutamic acids in green parts of Lepidium sativum and Rheum rhaponticum has been previously reported, we were not able to detect or isolate any of the possible diastereoisomers from the green parts or seeds of these plants. We did isolate glutathione which was found to have some properties in common with those reported for the dihydroxy compounds.     

trans-Monounsaturated Acids in a Marine Bacterial Isolate

A sedimentary bacterial isolate has been shown to contain trans-monounsaturated fatty acids (6% of the total fatty acids). The ratio of trans- to cis-acids in this isolate was in the range 3.2 to 7.6. The identification of trans-monounsaturated acids in a marine bacterium implied that the trans-acids which have been reported in recent sediments could derive, in whole or part, from direct bacterial input.     

Long chain esters of Virola species

The esters of n-fatty acids and ω-hydroxy n-fatty acids of β-sitosterol, D-glucose and ferulic acid (trans and cis) as well as β-sitosterol, fatty acids and β-sitosteryl-β-D-glucoside were isolated from three Virola species and identified by optical data and chemical reactions. A novel series of acidic esters derived from C₂₂C₂₉ ω-hydroxy fatty acids and cis- and trans-ferulic acid is reported for the first time. These compounds also occurred as the corresponding diester 1-monoglycerides whereas the ω-hydroxy acids themselves were also present as the corresponding glucosyl esters.     

Percentage recovery of free fatty acids from bovine muscle lipids by nonchromatographic techniques

The inability of silicic acid to completely separate the neutral lipids from phospholipids has been reported by several investigators (1,2). Hornstein et al. (3) increased the polarity of the solvent system and reported a clean separation of the phospholipid fraction by adsorption on activated silicic acid. Studies on bovine lipids by Hood and Allen (2) utilized acid-washed Florisil to separate the lipid fractions claiming that silicic acid incompletely separates the free fatty acids from the phospholipids. Work performed in this laboratory (4) on bovine lipids confirmed that phospholipids could be effectively separated from free fatty acids by adsorption on silicic acid by incorporating the solvent system described by Hornstein et al. (3). The liquid-liquid partition procedure of Hamilton and McDonald (5) was also found to be sensitive enough to partition the extremely small amount of free fatty acids from the esterified fatty acids. This paper provides evidence for the effectiveness of these methods in separating the frec fatty acids by incorporating an internal standard [1-¹⁴C]palmitic acid.     

Biochemical and Genetic Characterization of the Two-Peptide Bacteriocin Enterocin 1071 Produced by Enterococcus faecalis FAIR-E 309

The structural genes for the two-peptide bacteriocin enterocin 1071 (Ent1071) in Enterococcus faecalis FAIR-E 309 were cloned. DNA sequence analysis showed that the enterocin 1071A (Ent1071A) peptide of strain FAIR-E 309 differed by two amino acids from the Ent1071A reported for E. faecalis BFE 1071 (E. Balla, L. M. T. Dicks, M. Du Toit, M. J. van der Merwe, and W. H. Holzapfel, Appl. Environ. Microbiol. 66:1298-1304, 2000), while the Ent1071B gene encoded identical peptides in these strains. However, resequencing of ent1071A from E. faecalis BFE 1071 showed that the Ent1071A peptide sequence reported previously was incorrect in two amino acids. Also, ent1071B in E. faecalis FAIR-E 309 encoded a prepeptide that was three amino acids shorter than that previously reported for E. faecalis BFE 1071 Ent1071B. A presumptive immunity gene (eni1071) was located downstream of the bacteriocin structural genes. This gene was cloned into the heterologous host E. faecalis ATCC 19433 and was shown to confer immunity. A truncated ABC transporter gene was located upstream of the Ent1071 structural genes.     

15-oxo-zoapatlin,a diterpene lactone from Viguiera maculata

The isolation of a new diterpene lactone and two known diterpenoid acids from the aerial parts of Viguiera maculata is reported.     

Sterols and fatty acids of the red tide flagellates Heterosigma akashiwo and Chattonella antiqua (Raphidophyceae)

The fatty acids and sterols of the raphidophyte flagellates, Heterosigma akashiwo (Australian and Plymouth strains) and Chattonella antiqua (Japanese strain) are reported. The major sterol of both species is 24-ethylcholesterol, which is more commonly associated with higher plants and has rarely been reported in unicellular algae. C. antiqua also contained 24-dihydrozymosterol [cholest-8(9)-en-3β-ol], which is also uncommon in marine algae. The major fatty acids in both raphidophytes are 16:0, 18:4ω3, 20:5ω3, 16:1ω7 and 14:0. Polyunsaturated fatty acids accounted for 46–50% of the total fatty acids in both species. The fatty acid 18:5ω3 was detected in H. akashiwo, but not in C. antiqua. This acid is found in some dinoflagellates and Prymnesiophycean algae, but this is the first report of its presence in the Raphidophyceae. The lipid distributions obtained for H. akashiwo and C. antiqua provide unique signature profiles for use in taxonomic, food-web and organic geochemical studies. The fatty acid and sterol distributions of these two raphidophytes justify their assignment to a separate class within the ‘brown algal’ line.     

The triterpenoid acids of Schinus molle

From the acidic fraction of the oleoresin obtained from the berries of Schinus molle was isolated isomasticadienonic, isomasticadienonalic, masticadienonic and 3-epi-isomasticadienolic acids. In addition the new 3-epi-isomasticadienolalic acid was isolated. Both isomasticadienonalic and 3-epi-isomasticadienolalic acids had an aldehydic group attached to C-20. The absolute configuration of this centre was established. The PMR study of the isolated compounds, of their reduction products and O-acetyl derivatives is reported.     

Fatty acids of Pinus elliottii tissues

The total fatty constituents of slash pine (Pinus elliottii) tissue cultures, seeds and seedlings were examined by GLC and MS. Qualitatively, the fatty acid composition of these tissues was very similar to that reported for other pine species. The fatty acid contents of the tissue cultures resembled that of the seedling tissues. In addition to the fatty acids common to botanical materials, Δ⁵-C₁₈ and -C₂₀ nonmethy lene-interrupted polyunsaturated acids were present in low relative abundances. The branched-chain C₁₇ acid reported for several other Pinus species was confirmed as the anteiso isomer.     

Variability in fatty acids and fatty aldehydes in different organs of two prosobranch gastropod mollusks

The distribution of fatty acids and fatty aldehydes of total lipids in mantle, foot and digestive gland of two prosobranch gastropod mollusks, Bellamya bengalensis and Pila globosa, from India were studied. The individual volatile compounds, e.g., acids and aldehydes, were separated by serially coupled capillary columns with different polarity stationary phase and identified by gas chromatography-mass spectrometry. Saturated fatty acids were the main components and vary from 48–60%, monoenic are 18–30%, while polyunsaturates vary between 21–33%. The digestive glands of both the snail species contained cyclopropane fatty acids, not previously reported in gastropods.     

Diterpene resin acids from the needle oleoresin of pinus strobus

The resin acid components of P. strobus needles were isolated, and the major constituents identified as labdenoic diterpenes. In addition to anticopalic and strobic acids previously reported in the needles, 3-oxoanticopalic, 3β-acetoxyanticopalic, 3β-hydroxyanticopalic acids and the 8α-hydroxy derivative of anticopalic acid were found along with two new compounds. The structures of the two new compounds, a cycloanticopalic acid and an abcoanticopalic acid, were determined by NMR. The composition of the diterpene resin acids was obtained for several samples of P. strobus needles from provenance tests.     

A comparison of lipid components of the fresh and dead leaves and pneumatophores of the mangrove Avicennia marina

The component hydrocarbons, sterols, alcohols, monobasic, α,ω-dibasic and ω-hydroxy acids of the fresh hand decayed leaves and the pneumatophores of the mangrove Avicennia marina are reported in detail. From the quantitative comparisons which can be drawn, relative changes in the lipid classes occurring during leaf decay can be highlighted. These base-line data are important to our understanding of inputs to marine intertidal sediments. During leaf decay the only significant changes were a reduction in the total absolute concentrations of monobasic acids due largely to a decrease in concentration of the C₁₈ polyunsaturated fatty acids, and an enhancement of the concentrations of the long-chain monobasic acids, ω-hydroxy acids and α,ω-dibasic acids. This resistance to degradation shown by the cutin derived acids (α,ω-dibasic, ω-hydroxy and long-chain monobasic acids) relative to the cellular and wax derived lipids may allow these cutin components to be used as quantitative markers of A. marina in mangrove associated sediments.     

Substrate specificity of fatty-acyl-CoA ligase in liver microsomes

The substrate specificity of fatty-acyl-CoA ligase in liver microsomes has been studied in a system in which fatty acids are present initially as complexes with unilamellar vesicles of phosphatidylcholine. The latter were prepared by cosonication of phospholipids and different fatty acids. As compared with previous studies of the enzyme the activity of acyl-CoA ligase is several-fold higher for assays carried out with fatty acid substrates added as components of a bilayer. This was true for all fatty acids studied. Also as compared with data reported previously in the literature there was a systematic relationship between the structure of fatty acids, activity at V_max for synthesis of acyl-CoA and avidity of binding to the ligase. Activity at V_max was greatest for lauric acid and decreased with increasing chain length. The apparent avidity of enzyme for fatty acids was greatest for octanoic acid and decreased as chain length increased.     

δ-Lactones of polyhydroxy-C26 acids in Eupatorium pilosum

Isolation and structure determination of the δ-lactones of Z-5,7,9,11-tetrahydroxy- and Z-5,7,9,11,15-pentahydroxyhexacos-2-enoic acids from Eupatorium pilosum is reported. The flavones salvigenin and cirsimaritin were also found.     

Occurrence of 2-hydroxy acids in microalgae

2-Hydroxy acids were believed to be absent in algae until this study, in which the analysis of microalgae belonging to Chlorophyta (Chlamydomonas reinhardtii and Chlorella pyrenoidosa), Rhodophyta (Cyanidium caldarium M-8 and Cyanidium caldarium RK-1) and Cyanophyta (Anbaena variabilis, Anacystis nidulans, Oscillatoria species and Phormidium foveolarum) is reported. 2-Hydroxy adds with carbon chain lengths of C₁₆-C₂₆, were found in all the algal samples studied, ranging in concentrations from 4.0 to 320μg/g dry alga. The dominant constituents are 2-hydroxyhexadecanoic, 2-hydroxynonadecanoic, 2-hydroxyhexacosanoic and a branched 2-hydroxy-C₁₉ acid. The distribution patterns of the acids differed significantly among the algal samples. Hence 2-hydroxy acids may be useful for the classification of algal species as well as being an important source of 2-hydroxy acids in the natural environment.     

Fatty acids. Part 50. 13C nuclear magnetic resonance studies of olefinic fatty acids and esters

The ¹³C-NMR spectra of 48 cis alkenoic acids and esters (C₈–C₂₀), 18 trans alkenoic acids and esters (C₉–C₁₈), and 26 polyenoic acids and esters (C₁₈–C₂₂) are reported and interpreted. The characteristic features of such spectra which permit structural assignments to be made are discussed.     

Alkaloids and olefinic acids from Cryptocarya amygdalina

From the bark of Cryptocarya amygdalina two new olefinic acids with a tetracyclo(4.3.0^2.4.0^3.7) non-8-enemoiety are reported. From the same source the benzylisoquinoline alkaloids orientaline and laudanidine are also reported.     

Amino acid analysis by gas-liquid chromatography on a single column

A gas-liquid chromatography procedure for analysis of protein amino acids is described. Amino acids are esterified to their n-propyl esters then acylated to their heptafluorobutyryl (HFB) derivatives. These reactions were carried out in a single tube at 100°C. A simple steam-heating apparatus was constructed that heats only the bottom of the reaction vessel. Only 10 min were needed for esterification and 20 min for acylation, respectively. The resulting products, N-HFB-n-propyl esters of amino acids, were chromatographed on a single column. The amino acid compositions of chymotrypsinogen A and casein were analyzed by the present method, and the results were compared with those obtained by ion-exchange chromatography reported previously.     

Rapid Gas Chromatographic Technique for Presumptive Detection of Clostridium botulinum in Contaminated Food

A simple gas-liquid chromatography end-product assay is reported for butyric and other short-chain fatty acids as presumptive indicators of Clostridium botulinum contamination in food.