Pearson correlation between sperm qualitative parameters and metabolites identified in turkey fresh semen, at 32, 44 and 56 weeks of male age.

<p>Pearson correlation between sperm qualitative parameters and metabolites identified in turkey fresh semen, at 32, 44 and 56 weeks of male age.</p

Age-dependent changes in metabolic profile of turkey spermatozoa as assessed by NMR analysis

<div><p>Metabolic profile of fresh turkey spermatozoa at three different reproductive period ages, namely 32, 44 and 56 weeks, was monitored by Nuclear Magnetic Resonance (NMR) spectroscopy and correlated to sperm quality parameters. The age-related decrease in sperm quality as indicated by reduction of sperm concentration, sperm mobility and osmotic tolerance was associated to variation in the level of specific water-soluble and liposoluble metabolites. In particular, the highest levels of isoleucine, phenylalanine, leucine, tyrosine and valine were found at 32 weeks of age, whereas aspartate, lactate, creatine, carnitine, acetylcarnitine levels increased during the ageing. Lipid composition also changed during the ageing: diunsaturated fatty acids level increased from 32 to 56 weeks of age, whereas a reduction of polyunsaturated fatty acids content was observed at 56 weeks. The untargeted approach attempts to give a wider picture of metabolic changes occurring in ageing suggesting that the reduction of sperm quality could be due to a progressive deficiency in mitochondrial energy producing systems, as also prompted by the negative correlation found between sperm mobility and the increase in certain mitochondrial metabolites.</p></div

Age-dependent changes in metabolic profile of turkey spermatozoa as assessed by NMR analysis - Fig 2

<p>^<b>1</b><b>H NMR spectra of aqueous (A) and organic extracts (B) of turkey spermatozoa at 32 weeks of age.</b> Assignments: 1, Ala; 2, Asp; 3, Gln; 4, Glu; 5, Gly; 6, Ile; 7, Leu; 8, Phe; 9, Tyr; 10, Val; 11, Acetate; 12, Citrate; 13, Formate; 14, Fumarate; 15, Lactate; 16, Ac-carnitine; 17, AMP; 18, Carnitine; 19, Creatine; 20, Glucose; 21, Myo-inositol; 22, CHO; 23, DUFA; 24, UFA; 25, PUFA; 26, PC; 27, PE; 28, SMN. For details see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0194219#sec002" target="_blank">Methods</a> section.</p

Metabolites identified by NMR in fresh spermatozoa from 32, 44 and 56 weeks old turkey male.

<p>Mean values ± SE.</p

Effect of turkey male ages on sperm quality parameters.

<p>Mean values ± SE (n = 5) for sperm concentration (a), sperm mobility (b), sperm viability (c) and SOT (d) were evaluated at 32, 44 and 56 weeks of age. For details see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0194219#sec002" target="_blank">Methods</a> section. * indicates significant differences (P < 0.05).</p

Synthesis of a Double-Spanned Resorc[4]arene via Ring-Closing Metathesis and Calculation of Aggregation Propensity

Ring-closing metathesis (RCM) catalyzed by a second-generation Grubbs catalyst has been used to synthesize resorc[4]­arenes <b>2b</b>–<b>5b</b> starting from undecenyl resorc[4]­arene <b>1b</b> fixed in the cone conformation. X-ray diffraction analysis of the major metathesis product, <b>3b</b> (50% yield), revealed a cavity-shaped architecture resembling a basket, endowed with a large intramolecular space (∼10 Å) and a strong propensity to self-assemble as a supramolecular trio of heterochiral dimers. This prompted us to investigate the aggregation propensity of basket <b>3b</b> in THF/water solution by UV–visible spectroscopy. The cavitation Gibbs free-energy change (ΔΔ<i>G</i>_cav = 4.78 kcal mol^–1) associated with the self-assembly of macrocycle <b>3b</b> was calculated as a measure of the solvophobic interactions involved in the process

Metabolic profile of different Italian cultivars of hazelnut (<i>Corylus avellana</i>) by nuclear magnetic resonance spectroscopy

<div><p>High-resolution proton NMR spectroscopy was performed on three Italian hazelnut cultivars, Tonda di Giffoni, Mortarella and Tonda Gentile Romana, and it allowed to define their metabolic profile. The hazelnuts were grown in the same pedoclimatic conditions in the Monti Cimini (Latium) area. The samples were obtained by using a modified Bligh–Dyer extraction protocol which did not give rise to artefacts arising from the demolition of macromolecular structures such as proteins and polysaccharides. Metabolites belonging to different chemical classes (amino acids, organic acids, carbohydrates, lipids and miscellaneous compounds) were identified and quantified. The three cultivars were discriminated by means of univariate (ANOVA) and multivariate (PCA) statistical analysis.</p></div

Reaction of Nitrosonium Cation with Resorc[4]arenes Activated by Supramolecular Control: Covalent Bond Formation

Resorc­[4]­arenes <b>1</b> and <b>2</b>, which previously proved to entrap NO⁺ cation within their cavities under conditions of host-to-guest excess, were treated with a 10-fold excess of NOBF₄ salt in chloroform. Kinetic and spectral UV–visible analyses revealed the formation of isomeric 1:2 complexes as a direct evolution of the previously observed event. Accordingly, three-body <b>1</b>–(NO⁺)₂ and <b>2</b>–(NO⁺)₂ adducts were built by MM and fully optimized by DFT calculations at the B3LYP/6-31G­(d) level of theory. Notably, covalent nitration products <b>4</b>,<b> 5</b> and <b>6</b>,<b> 7</b> were obtained by reaction of NOBF₄ salt with host <b>1</b> and <b>2</b>, respectively, involving macrocycle ring-opening and insertion of a nitro group in one of the four aromatic rings. In particular, compounds <b>4</b> and <b>6</b>, both containing a trans-double bond in the place of the methine bridge, were oxidized to aldehydes <b>5</b> and <b>7</b>, respectively, after addition of water to the reaction mixture. Calculation of the charge and frontier orbitals of the aromatic donor (HOMO) and the NO⁺ acceptor (LUMO) clearly suggests an ipso electrophilic attack by a first NO⁺ unit on the resorcinol ring, mediated by the second NO⁺ unit

<i>cis</i>-4-Amino‑l‑proline Residue As a Scaffold for the Synthesis of Cyclic and Linear Endomorphin‑2 Analogues: Part 2

Recently, we reported synthesis and activity of a constrained cyclic analogue of endomorphin-2 (EM-2: Tyr-Pro-Phe-Phe-NH₂) and related linear models containing the <i>cis</i>-4-amino-l-proline (cAmp) in place of native Pro². In the present article, the adopted rationale is the possible modulation of the receptor affinity of the cAmp containing EM-2 analogues by assigning a different stereochemistry to the Phe³ and Phe⁴ residues present in the ring. Thus, eight more analogues with different absolute configuration at the chiral center of the aromatic residues in positions 3 and 4 have been synthesized and their opioid activity examined. The stereochemical change at the α-carbon atoms leads to a meaningful enhancement of the affinity and activity toward μ opioid receptors with respect to the prototype compound <b>9</b>: e.g., <b>9a</b>, <i>K</i>_<i>i</i>^μ = 63 nM, GPI (IC₅₀) = 480 nM; <b>9b</b>, <i>K</i>_<i>i</i>^μ = 38 nM, GPI (IC₅₀) = 330 nM

Conversion of the Mycotoxin Patulin to the Less Toxic Desoxypatulinic Acid by the Biocontrol Yeast Rhodosporidium kratochvilovae Strain LS11

The infection of stored apples by the fungus Penicillium expansum causes the contamination of fruits and fruit-derived products with the mycotoxin patulin, which is a major issue in food safety. Fungal attack can be prevented by beneficial microorganisms, so-called biocontrol agents. Previous time-course thin layer chromatography analyses showed that the aerobic incubation of patulin with the biocontrol yeast Rhodosporidium kratochvilovae strain LS11 leads to the disappearance of the mycotoxin spot and the parallel emergence of two new spots, one of which disappears over time. In this work, we analyzed the biodegradation of patulin effected by LS11 through HPLC. The more stable of the two compounds was purified and characterized by nuclear magnetic resonance as desoxypatulinic acid, whose formation was also quantitated in patulin degradation experiments. After R. kratochvilovae LS11 had been incubated in the presence of ¹³C-labeled patulin, label was traced to desoxypatulinic acid, thus proving that this compound derives from the metabolization of patulin by the yeast. Desoxypatulinic acid was much less toxic than patulin to human lymphocytes and, in contrast to patulin, did not react in vitro with the thiol-bearing tripeptide glutathione. The lower toxicity of desoxypatulinic acid is proposed to be a consequence of the hydrolysis of the lactone ring and the loss of functional groups that react with thiol groups. The formation of desoxypatulinic acid from patulin represents a novel biodegradation pathway that is also a detoxification process