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Ether lipids, such as plasmalogens, are peroxisome-derived glycerophospholipids in which the hydrocarbon chain at the sn-1 position of the glycerol backbone is attached by an ether bond, as opposed to an ester bond in the more common diacyl phospholipids. This seemingly simple biochemical change has profound structural and functional implications. Notably, the tendency of ether lipids to form non-lamellar inverted hexagonal structures in model membranes suggests that they have a role in facilitating membrane fusion processes. Ether lipids are also important for the organization and stability of lipid raft microdomains, cholesterol-rich membrane regions involved in cellular signaling. In addition to their structural roles, a subset of ether lipids are thought to function as endogenous antioxidants, and emerging studies suggest that they are involved in cell differentiation and signaling pathways. Here, we review the biology of ether lipids and their potential significance in human disorders, including neurological diseases, cancer, and metabolic disorders.

The structural requirements of strigolactones (SLs) involved in germination induction of root parasitic plants and hyphal branching in arbuscular mycorrhizal (AM) fungi have been extensively studied. However, our knowledge of the requirements of SLs involved in shoot branching inhibition in plants is still limited. To address this question, we investigated the structure-activity relationships of SLs in shoot branching inhibition in rice and Arabidopsis. SLs possess a four-ring structure, with a tricyclic lactone (ABC-rings) connected to a methylbutenolide part (D-ring) via an enol ether bridge. Here, we show that the the (R) configuration at C-2', which determines the steric position of the D-ring relative to the enol ether olefin bond, is critical for the hormonal activity in rice. Replacement of the enol ether moiety by an alkoxy or imino ether resulted in a severe reduction in biological activity in rice. Moreover, yeast two-hybrid experiments using a possible SL receptor, DWARF14 (D14), and a repressor in the SL signaling pathway, DWARF53 (D53), showed that D14 can interact with D53 in the presence of (2'R) stereoisomers of SLs, but not (2'S) stereoisomers, suggesting that the stereostructure of SLs is crucial for the interaction of these proteins. When GR5, an AB-ring-truncated analog, was applied to the hydroponic culture medium, strong inhibition of shoot branching was observed both in rice and in Arabidopsis. However, GR5 was only weakly active when directly applied to the axillary buds of Arabidopsis. Our results indicate that the difference in plant species and application methods greatly influences the apparent SL biological activity., (© The Author 2015. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

This paper reports a novel method for the preparation of chiral stationary phases (CSPs) using an acridino-18-crown-6 ether selector as a model compound. Chiral stationary phase (R,R)-CSP- 2A: was obtained by in situ continuously recirculating the solution of carboxyl-substituted acridino-18-crown-6 ether (R,R)- 4: , dicyclohexylcarbodiimide and 3-(triethoxysilyl)propylamine through a high-performance liquid chromatography (HPLC) column containing blank silica gel in elevated pressure and temperature. The enantiomer separating ability of chiral stationary phase (R,R)-CSP- 2A: was investigated by HPLC using mixtures of enantiomers of 1-(1-naphthyl)ethylamine hydrogen perchlorate, 1-(2-naphthyl)ethylamine, 1-(4-bromophenyl)ethylamine and 1-(4-nitrophenyl)ethylamine hydrogen chloride. The best results were found for the separation of the mixtures of enantiomers of Br-PEA., (© The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)

Heat-treated (120 °C for 120 min) rice flour showed high affinity to oil (oil-binding ability). This oil-binding ability could be observed by shaking the heat-treated rice flour (2.0 g), oil (4.0 mL), and water (20 mL) vigorously in a test tube, and the oil bound to the rice flour sank into the water. To examine the time-dependent levels of the oil-binding ability, rice flour was heat-treated at 120 °C for 10, 20, 40, 60, and 120 min, and the precipitated volume of oil/rice flour complex increased with an increase of the heating time. The oil-binding ability of the rice flour was not affected by the treatments with diethyl ether or boiled chloroform/methanol (2:1) solutions, which suggested no relationship to the oil in the rice flour, but was lost upon alkali (0.2% NaOH solution) or pepsin treatment, which suggested its relationship to the rice proteins.

We describe the syntheses of the proposed structure of diphenyl ether oxyneolignan, apteniol A and its derivatives. The diphenyl ether moiety of proposed apteniol A was formed via Ullmann ether synthesis, but the spectral data of the synthesized apteniol A did not agree with that in previous studies. The dimethyl ester derivative of the proposed apteniol A was found to enhance neurite outgrowth in PC12 cells and inhibit antigen-induced degranulation in RBL-2H3 cells.

The xanthene dyes, erythrosine, phloxine, and rose bengal, were adsorbed to charred cellulose granules. The charred cellulose granules were preliminarily steeped in ionic (NaOH, NaCl, KOH, KCl, and sodium dodecyl sulfate (SDS)), nonionic (glucose, sucrose, and ethanol), and amphipathic sucrose fatty acid ester (SFAE) solutions, and adsorption tests on the dye to the steeped and charred cellulose granules were conducted. Almost none of the dye was adsorbed when the solutions of ionic and amphipathic molecules were used, but were adsorbed in the case of steeping in the nonionic molecule solutions. Thin-layer chromatography (TLC) and the Fourier transform infra-red (FT-IR) profiles of SFAE which was adsorbed to the charred cellulose granules and extracted by ethyl ether suggested the presence of hydrophobic sites on the surface of the charred cellulose granules. We confirmed that the xanthene dyes could bind to the charred cellulose granules by ionic and hydrophobic bonds.

HPLC and TLC methods were developed for separation and detection of some amphetamine analogs: methamphetamine (MA); 3,4-methylenedioxymethamphetamine (MDMA, "ecstasy"); and 3,4-methylenedioxy-N-ethylamphetamine (MDEA) in spiked plasma samples. The methods are based on purple chromogens formed by displacement reaction of these secondary aliphatic amine-bearing drugs with 7,7,8,8-tetracyanoquinodimethane at 80 degrees C for 25 min. For HPLC, both normal phase (silica gel) and RP (C18) columns were used. With the former, good detection limits in plasma were obtained with a 6 min run: 70, 100, and 500 ng/mL for MDMA, MA, and MDEA, respectively. For TLC, hexane-chloroform (1 + 9) and benzene-diethyl ether-petroleum ether (40-60 degrees)-acetonitrile-ethyl methyl ketone (2 + 3.5 + 3.5 + 0.5 + 0.5) were used as mobile phases for silica gel 60 TLC and cyano-bonded silica gel HPTLC plates, respectively. The former offered more sensitive results than the latter. Influence of evaporation steps on recovery and interferences for the HPLC and TLC methods were investigated. The developed methods are selective, simple, and easily applicable.

Background and Aims: Partial hybrids with female-parent-type phenotypes and chromosome numbers but altered genomic compositions have been reported in wide crosses of several plants. In order to introgress desirable genes from a wild relative, Isatis indigotica (a dye and medicinal plant; 2n = 14), into Brassica crops, intertribal sexual hybridizations were carried out with B. rapa (2n = 20), and the resulting hybrids and their progenies were characterized., Methods: Using genomic in situ hybridization (GISH) and amplified fragment length polymorphism (AFLP), chromosomal/genomic components of the hybrids and their progenies were analysed., Key Results: Many hybrid plants were obtained from the mature seeds harvested from the B. rapa x I. indigotica cross, and these exhibited different morphological traits. However, the majority of them did not survive and only three plants grew to maturity. These three hybrids showed poor growth and much smaller stature than the two parents, but had some morphological traits and chemical composition of I. indigotica. One plant had 2n = 10, the haploid chromosome number of B. rapa, and was absolutely sterile. The other two plants had 20 and 22 somatic chromosomes and were male sterile but produced seeds following pollinations with B. rapa. All back-cross progenies over several generations maintained a B. rapa-type phenotype and also displayed some variations in morphological characters and fatty acid compositions. They were all 2n = 20 and showed good seed-set. The hybrid with 2n = 22 produced some progeny plants with 2n = 21 and 2n = 22. GISH detected two chromosomes of I. indigotica in the hybrid with 2n = 22 but none in the one with 2n = 20. AFLP bands specific for I. indigotica, novel for two parents or absent in B. rapa, were detected in the two hybrids and their progenies. These progeny plants were novel B. rapa types with an altered genomic constitution or alien additions., Conclusions: Complete or partial chromosome elimination and diploidization with genomic rearrangements were considered to lead to the formation of partial hybrids in this cross.

Low molecular weight alcohols including fusel oil were determined using diethyl ether extraction and capillary gas chromatography. Twelve kinds of alcohols were successfully resolved on the HP-FFAP (polyethylene glycol) capillary column. The diethyl ether extraction method was very useful for the analysis of alcohols in alcoholic beverages and biological samples with excellent cleanliness of the resulting chromatograms and high sensitivity compared to the direct injection method. Calibration graphs for all standard alcohols showed good linearity in the concentration range used, 0.001-2% (w/v) for all alcohols. Salting out effects were significant (p < 0.01) for the low molecular weight alcohols methanol, isopropanol, propanol, 2-butanol, n-butanol and ethanol, but not for the relatively high molecular weight alcohols amyl alcohol, isoamyl alcohol, and heptanol. The coefficients of variation of the relative molar responses were less than 5% for all of the alcohols. The limits of detection and quantitation were 1-5 and 10-60 microg/L for the diethyl ether extraction method, and 10-50 and 100-350 microg/L for the direct injection method, respectively. The retention times and relative retention times of standard alcohols were significantly shifted in the direct injection method when the injection volumes were changed, even with the same analysis conditions, but they were not influenced in the diethyl ether extraction method. The recoveries by the diethyl ether extraction method were greater than 95% for all samples and greater than 97% for biological samples.

The acyclic nucleoside phosphonate cidofovir (CDV) and its closely related analogue (S)-9-(3-hydroxy-2-phosphonylmethoxypropyl)-adenine ([S]-HPMPA) have been reported to have activity against many adenovirus (AdV) serotypes. A new series of orally active ether lipid-ester prodrugs of CDV and of (S)-HPMPA that have slight differences in the structure of their lipid esters were evaluated, in tissue-culture cells, for activity against 5 AdV serotypes. The results indicated that, against several AdV serotypes, the most active compounds were 15-2500-fold more active than the unmodified parent compounds and should be evaluated further for their potential to treat AdV infections in humans.

Infection with human cytomegalovirus (HCMV) can cause serious complications in bone-marrow and solid-organ transplant recipients, and current therapies are not optimal. We evaluated 2 orally active ether lipid ester analogues of cidofovir (CDV)--hexadecyloxypropyl-CDV (HDP-CDV) and octadecyloxyethyl-CVD (ODE-CDV)--in severe combined immunodeficient mice in which either human fetal retinal tissue or human fetal thymus and liver tissue had been implanted and was later infected with HCMV. Our results indicate that orally administered treatment with either HDP-CDV or ODE-CDV is 4-8-fold more active, on a molar basis, than is intraperitoneally administered CDV. These data suggest that HDP-CDV and ODE-CDV should be further evaluated as potential antiviral agents for treatment of HCMV infection.

Benzodiazepines are common drugs that cause intoxication. Benzodiazepines and their metabolites can be converted by hydrolysis in acid to the corresponding benzophenones, which are easier to be separated from matrices because of their hydrophobic properties. In this study, a new separation technique called solid-phase microextraction (SPME), which can integrate extraction, concentration, sampling and sample introduction into one single procedure, has been employed to extract the products of benzodiazepines from urine after acid hydrolysis. The extracts were determined by gas chromatography with electron-capture detection (GC-ECD). The hydrolysis conditions were optimized by a statistic orthogonal design. Factors influencing direct-immersion (DI)-SPME process were also checked and chosen experimentally. The method was evaluated with spiked human urine samples. The recoveries of nine benzodiazepines ranged from 1 to 25%, with the highest for oxazolam and the lowest for bromazepam. The calibration curves were linear from 10 to 500 ng/mL for oxazolam, haloxazolam, flunitrazepam, nimetazepam, and clonazepam and from 20 to 1000 ng/mL for the others except bromazepam. The detection limits were 2-20 ng/mL for most drugs tested. The intraday and interday coefficients of variation of the developed method were within 10 and 17%, respectively. In addition, the utility of the method was confirmed by determining two ingested benzodiazepines (flunitrazepam and oxazolam) in a volunteer's urine; urine flunitrazepam was still detectable 32 h after a therapeutic dose (1.2 mg) of the drug. Finally, the DI-SPME was compared with the conventional liquid-liquid extraction with regard to detection limits and extraction efficiency of the analytes. By DI-SPME, more amounts of analytes could be introduced into GC column than by conventional liquid-liquid extraction, and thus lower detection limits of the analytes were reached, although benzophenone recoveries by DI-SPME were rather low.

An original, simple, specific, and rapid high-performance liquid chromatography assay for the determination of dapsone and monoacetyldapsone in human plasma is presented. The procedure consists of extracting the drugs and the internal standard (phenacetin) from 1 mL plasma with ethyl ether at alkaline pH. A liquid chromatograph equipped with a reversed-phase 5-microm C8 analytical column was used. The drugs were eluted with a mixture of water and methanol (70:30, v/v). Flow rate and wavelength were set at 1 mL/min and 286 nm, respectively. The precision, linearity, and limit of quantitation of the method were within acceptable limits. The method was considered adequate and has been used for the determination of the acetylator phenotype in population studies.

A gas-liquid chromatographic method with an electron-capture detector was applied for 2,4-dichlorophenoxyacetic acid (2,4-D) determination in the serum and brain tissue of rats acutely intoxicated with the dimethylamine salt of 2,4-D. After extraction with ethyl ether, 2,4-D derivatization was performed using 2-chloroethanol and BCI3. The average recovery values found for serum and brain tissue were 98.5 +/- 4.8 and 93.3 +/- 7.5, respectively. The sensitivity limit of the method was 250 ng/mL for serum and 300 ng/g for brain tissue. The toxic effects of 2,4-D in rats were observed within one-half hour after its oral administration. Results suggest that the toxic mechanism of 2,4-D is related to an action on the central nervous system.