Dynamics of indole-3-acetic acid and indole-3-ethanol during development and germination of Pinus sylvestris seeds

Indole-3-acetic acid (IAA) and indole-3-ethanol (IEt) were identified in immature seeds of Pinus sylvestris L. by combined gas chromatography-mass spectrometry. Indole-3-methanol was tentatively identified using multiple ion monitoring. Anatomical investigations of seeds, as well as measurements of free and alkali-hydrolysable IAA and IEt, were made during seed development and germination. Levels of free IAA and IEt decreased during seed development. In the later stages of seed maturation most IAA and IEt were present in alkali-hydrolysable forms. Bound IAA and bound IEt rapidly decreased during germination, while levels of free IAA and IEt increased dramatically for a short period.     

Methods for determination of lipid peroxidation in biological samples

Interest in the pathological consequences of lipid peroxidation has led to the development of a number of analytical approaches to the quantitation of products. However, the various analytical methodologies employed often do not measure the same chemical classes of products, and apparent discrepencies have been observed, particularly in studies of lipid peroxidation in biological systems. This review provides a brief discussion of some of the strengths and weakness of methods currently used for the determination of lipid peroxidation in biological tissues.     

Generation and esterification of electrophilic fatty acid nitroalkenes in triacylglycerides

Electrophilic fatty acid nitroalkenes (NO₂-FA) are products of nitric oxide and nitrite-mediated unsaturated fatty acid nitration. These electrophilic products induce pleiotropic signaling actions that modulate metabolic and inflammatory responses in cell and animal models. The metabolism of NO₂-FA includes reduction of the vinyl nitro moiety by prostaglandin reductase-1, mitochondrial β-oxidation, and Michael addition with low molecular weight nucleophilic amino acids. Complex lipid reactions of fatty acid nitroalkenes are not well defined. Herein we report the detection and characterization of NO₂-FA-containing triacylglycerides (NO₂-FA-TAG) via mass spectrometry-based methods. In this regard, unsaturated fatty acids of dietary triacylglycerides are targets for nitration reactions during gastric acidification, where NO₂-FA-TAG can be detected in rat plasma after oral administration of nitro-oleic acid (NO₂-OA). Furthermore, the characterization and profiling of these species, including the generation of beta oxidation and dehydrogenation products, could be detected in NO₂-OA-supplemented adipocytes. These data revealed that NO₂-FA-TAG, formed by either the direct nitration of esterified unsaturated fatty acids or the incorporation of nitrated free fatty acids into triacylglycerides, contribute to the systemic distribution of these reactive electrophilic mediators and may serve as a depot for subsequent mobilization by lipases to in turn impact adipocyte homeostasis and tissue signaling events.     

Modeling and optimization of lipase-catalyzed esterification of policosanols with conjugated linoleic acid by response surface methodology

Abstract

The aim of this study was to model the lipase-catalyzed esterification of policosanols with conjugated linoleic acid (CLA) in a solvent-free system to produce wax esters which had a lower melting point than that of their corresponding policosanol forms and to optimize the reaction conditions by response surface methodology (RSM). Novozym 435 was selected as a suitable biocatalyst for the reaction. The molar ratio of substrates (policosanols to CLA) was 1:2. A well-fitting quadratic polynomial regression model for the degree of esterification (DE) of policosanols with CLA was established with regard to temperature (35–65°C), enzyme loading (1–5% of weight of total substrates), and reaction time (10–50 min). Optimal reaction conditions were 61.3°C for temperature, 3.7% for enzyme loading, and 34.1 min for reaction time, and the DE was ? 95 mol% under these conditions. The policosanols and wax esters synthesized under optimal conditions had melting points of 79°C and 57°C, respectively.     

Synthesis,copolymerization and peptide-modification of carboxylic acid-functionalized 3,4-ethylenedioxythiophene (EDOTacid) for neural electrode interfaces

Background

Conjugated polymers have been developed as effective materials for interfacing prosthetic device electrodes with neural tissue. Recent focus has been on the development of conjugated polymers that contain biological components in order to improve the tissue response upon implantation of these electrodes.

Methods

Carboxylic acid-functionalized 3,4-ethylenedioxythiophene (EDOTacid) monomer was synthesized in order to covalently bind peptides to the surface of conjugated polymer films. EDOTacid was copolymerized with EDOT monomer to form stable, electrically conductive copolymer films referred to as PEDOT-PEDOTacid. The peptide GGGGRGDS was bound to PEDOT-PEDOTacid to create peptide functionalized PEDOT films.

Results

The PEDOT-PEDOTacid-peptide films increased the adhesion of primary rat motor neurons between 3 and 9 times higher than controls, thus demonstrating that the peptide maintained its biological activity.

Conclusions

The EDOT-acid monomer can be used to create functionalized PEDOT-PEDOTacid copolymer films that can have controlled bioactivity.

General Significance

PEDOT-PEDOTacid-peptide films have the potential to control the behavior of neurons and vastly improve the performance of implanted electrodes. This article is part of a Special Issue entitled Organic Bioelectronics—Novel Applications in Biomedicine.     

Re-characterization of three conjugated linolenic acid isomers by GC-MS and NMR

Conjugated linolenic acids (CLN) refer to a group of octadecatrienoic acids with three conjugated double bonds. Minor positional and geometrical differences among CLN isomers make their separation and identification difficult. We have used GC-MS and NMR to study three common CLN isomers namely alpha-eleostearic acid, beta-eleostearic acid and punicic acid, finding that some signals of olefinic carbon atoms in NMR spectra were mistakenly assigned in the literature. The present study was therefore undertaken to re-characterize the location of CC double bonds and assign the chemical signals of proton and carbon atoms using (1)H NMR, (13)C NMR, (1)H-(1)H two-dimensional correlation spectra ((1)H-(1)H COSY) and (13)C-(1)H two-dimensional correlation spectra ((13)C-(1)H COSY). The geometrical structure of double bonds in these three CLN isomers was identified using homonuclear decoupling technique.     

Quercetin metabolites inhibit copper ion-induced lipid peroxidation in rat plasma

The oxidative susceptibility of plasma obtained from rats after intragastric administration of quercetin was studied to know whether or not quercetin acts as an in vivo antioxidant after metabolic conversion. Quercetin was raised in the rat blood plasma essentially as glucuronide and/or sulfate conjugates. The plasma obtained from rats after quercetin administration was more resistant against copper sulfate-induced lipid peroxidation than the control plasma on the basis of the accumulation of cholesteryl ester hydroperoxides and the consumption of α-tocopherol. The results strongly suggest that some conjugated metabolites of quercetin act as effective antioxidants when plasma is subject to metal ion-induced lipid peroxidation.     

Almond (Prunus dulcis (Mill.) D.A. Webb) polyphenols: From chemical characterization to targeted analysis of phenolic metabolites in humans

In this paper, a survey of our studies on almond polyphenols including their chemical characterization and further bioavailability in humans is reported. Combination of analytical techniques (LC-DAD/fluorescence, LC/ESI-MS and MALDI-TOF-MS) allowed us, for the first time, the identification of A- and B-type procyanidin, propelargonidin and prodelphinidin polymers in almond skins. Glucuronide, O-methyl glucuronide, sulfate and O-methyl sulfate derivatives of (epi)catechin, as well as the glucuronide conjugates of naringenin and isorhamnetin, and sulfate conjugates of isorhamnetin, together with conjugates of hydroxyphenylvalerolactones were detected in plasma and urine samples after the intake of almond skin polyphenols. In addition, numerous microbial-derived metabolites, including hydroxyphenylpropionic, hydroxyphenylacetic, hydroxycinnamic, hydroxybenzoic and hydroxyhippuric acids were also identified. Depending of the type of metabolite, maximum urinary excretion was attained at different time in comparison to the control group in the course of the 24-h period of urine excretion, allowing us to establish the onset of microbial metabolism.     

共轭亚油酸对草鱼生长、肌肉成分、谷草转氨酶及谷丙转氨酶活性的影响

<正>共轭亚油酸(Conjugated linoleic acid,CLA)是十八碳二烯酸(亚油酸)的同分异构体,其共同特征为两个双键直接通过一个碳-碳单键连接,没有被亚甲基隔开。共轭亚油酸的双