Sex dimorphism in European sea bass (Dicentrarchus labrax L.): New insights into sex-related growth patterns during very early life stages.

The European sea bass (Dicentrarchus labrax) exhibits female-biased sexual size dimorphism (SSD) early in development. New tagging techniques provide the opportunity to monitor individual sex-related growth during the post-larval and juvenile stages. We produced an experimental population through artificial fertilization and followed a rearing-temperature protocol (~16°C from hatching to 112 days post-hatching, dph; ~20°C from 117 to 358 dph) targeting a roughly balanced sex ratio.

New ligands of the ghrelin receptor based on the 1,2,4-triazole scaffold by introduction of a second chiral center.

Introducing a second chiral center on our previously described 1,2,4-triazole, allowed us to increase diversity and elongate the 'C-terminal part' of the molecule. Therefore, we were able to explore mimics of the substance P analogs described as inverse agonists. Some compounds presented affinities in the nanomolar range and potent biological activities, while one exhibited a partial inverse agonist behavior similar to a Substance P analog.

Heating and microwave assisted SPPS of C-terminal acid peptides on trityl resin: the truth behind the yield.

Despite correct purity of crude peptides prepared on trityl resin by Fmoc/tBu microwave assisted solid phase peptide synthesis, surprisingly, lower yields than those expected were obtained while preparing C-terminal acid peptides. This could be explained by cyclization/cleavage through diketopiperazine formation during the second amino acid deprotection and third amino acid coupling. However, we provide here evidence that this is not the case and that this yield loss was due to high temperature promoted hydrolysis of the 2-chlorotrityl ester, yielding premature cleavage of the C-terminal acid peptides.

Supported oligomethionine sulfoxide and Ellman's reagent for cysteine bridges formation.

A large number of bioactive peptides are cyclized through a disulfide bridge. This structural feature is very important for both bioactivity and stability. The oxidation of cysteine side chains is challenging not only to avoid intermolecular reaction leading to oligomers and oxidation of other residues but also to remove solvents and oxidant such as dimethyl sulfoxide.

Recycling the versatile Pipecolic linker.

The Pipecolic linker is a new highly versatile handle which immobilizes on solid support through a carboxylic acid function a wide range of amines, alcohols, and hydrazines. The anchoring step on pipecolic resin is very easy and efficient, and compounds are released with high purities upon acidic treatment. During this treatment, an oxazolonium intermediate is hydrolyzed, yielding the cleavage of ester or amide bond and the release of free carboxylic acid of the starting linker.

New trisubstituted 1,2,4-triazole derivatives as potent ghrelin receptor antagonists. 3. Synthesis and pharmacological in vitro and in vivo evaluations.

Ghrelin receptor ligands based on trisubstituted 1,2,4-triazole structure were synthesized and evaluated for their in vitro binding and biological activity. In this study, we explored the replacement of the alpha-aminoisobutyryl moiety by aromatic or heteroaromatic groups. Compounds 5 and 34 acted as potent in vivo antagonists of hexarelin-stimulated food intake.

On-line synthesis of pseudopeptide library incorporating a benzodiazepinone turn mimic: biological evaluation on MC1 receptors.

Alpha melanocyte stimulating hormone (alpha-MSH) is a widely distributed hormone. This tridecapeptide exhibits various biological activities mediated through different receptors. alpha-MSH binds to the melanocortin-1 receptor (MC1-R), mainly expressed in keratinocytes and melanocytes, inducing melanogenesis and anti-inflammatory processes.

Electrospray mass spectrometry of 2-aminotroponimines and 2-aminotropones.

A series of aminotroponimine and aminotropone derivatives were studied by electrospray mass spectrometry. MS and MS/MS data were acquired according to automated procedures. In the case of mono- and di-halogenated compounds, their specific behavior upon collisionally-activated dissociation conditions provided rapid structural assignments through inexpensive isotopic labeling MS/MS experiments.