On-Line Synthesis of Pseudopeptide Library Incorporating a Benzodiazepinone Turn Mimic: Biological Evaluation on MC1 Receptors

Facile synthesis of 1,4-benzodiazepine-2,5-diones and quinazolinones from amino acids as anti-tubercular agents

A family of 1,4-benzodiazepine-2,5-diones and quinazolinones with diverse substituents at C-3 position are synthesized by novel, simple and convenient methodology using H₂PtCl₆as catalyst and were all screened for anti-TB activity.

Stereoselective Synthesis of Benzo[e][1,4]oxazino[4,3-a][1,4]diazepine-6,12-diones with Two Diversity Positions

Herein, we report a stereoselective formation of tetrahydro-6H-benzo[e][1,4]oxazino[4,3-a][1,4]diazepine-6,12(11H)-diones. Their preparation consisted in solid-phase synthesis of linear intermediates starting from polymer-supported Ser(tBu)-OH. Using various 2-nitrobenzoic acids and bromoketones, the key intermediates were obtained in five steps and subjected to trifluoroacetic acid-mediated cleavage from the resin, followed by stereoselective reduction with triethylsilane. Subsequent catalytic hydrogenation of the nitro group and cyclization yielded the target compounds with full retention of the C^12a stereocenter configuration.

1,4-Thienodiazepine-2,5-diones via MCR (II): scaffold hopping by Gewald and Ugi-deprotection-cyclization strategy

A second scaffold of 1,4-thienodiazepine-2,5-diones was discovered and is synthetically accessible from Gewald 2-aminothiophenes via Ugi-Deprotection-Cyclization (UDC) strategy. This approach yielded hybrid peptidomimetic diazepine structures with six points of diversity introduced from readily available starting materials. A virtual compound library (N = 50 000) was generated and evaluated for chemical space distribution and drug-like properties.

Beta-turn secondary structure and melanocortin ligands

The melanocortin pathway has emerged during this past decade as an important target area for the discovery and development of therapeutic agents related to obesity and type 2 diabetes. This peptide-G-protein coupled receptor (GPCR) pathway has evolved from peptide-based ligands to small molecules possessing a variety of different molecular scaffolds. Herein, we summarize the originating hypothesis of the importance of the reverse beta-turn secondary structure for agonist ligand potency at the melanocortin receptors and how that information was utilized for the discovery of small molecules based upon this type of turn structure.

Three-component synthesis of 1,4-diazepin-5-ones and the construction of gamma-turn-like peptidomimetic libraries

The parallel synthesis of gamma-turn-inspired peptidomimetic libraries has been demonstrated through two approaches toward the preparation of 1,4-diazepin-5-ones. In the first approach, 1,4-diazepin-5-ones scaffolds were prepared on gram scale and subsequently diversified to produce libraries. In a second approach, libraries of 1,4-diazepin-5-ones were produced directly through a three-component strategy that maximizes the diversity obtained in a single step.

Parallel Synthesis of a Lipopeptide Library by Hydrazone-Based Chemical Ligation

alpha-Melanocyte-stimulating hormone (alpha-MSH) is an endogeneous linear tridecapeptide with potential application for the modulation of skin tanning. To evaluate the interest of introducing a lipid moiety onto this peptide, we developed an efficient chemoselective parallel method to prepare a large series of analogues of alpha-melanocortin with high purity, varying the nature or the relative position of the lipid moiety. Two sets of building blocks containing lipidic alpha-oxo-aldehydes or alpha-hydrazinoacetyl peptides were combined to obtain a 102-membered library of amphiphilic alpha-MSH analogues. This library was pharmacologically tested at 1 x 10(-7) M for the ability to induce AMPc production in M4Be melanoma cell line after stimulation of the human melanocortin MC1 receptor. Among theses lipopeptides, 84 compounds exhibited an AMPc induction higher than Melitane, a patented alpha-MSH agonist. These results provide strong evidence of the interest of introduction of a lipid tail for the pharmacomodulation of bioactive peptides.