Synthesis, Pharmacological, and Biological Evaluation of MIF-1 Picolinoyl Peptidomimetics as Positive Allosteric Modulators of D2R
摘要:
This work describes the synthesis and pharmacological evaluation of picolinoyl-based peptidomimetics of melanocyte stimulating hormone release inhibiting factor 1 (MIF-1) as dopamine modulating agents. Eight novel peptidomimetics were tested for their ability to enhance the maximal effect of tritiated N-propylapomorphine ([H-3]-NPA) at dopamine D-2 receptors (D2R). Methyl picolinoyl-L-valyl-L-alaninate (compound 6b) produced a statistically significant increase in the maximal [H-3]-NPA response at 0.01 nM (11.9 +/- 3.7%), which is close to the effect of MIF-1 in this assay at same concentration (18.3 +/- 9.1%). Functional assays measuring cAMP mobilization in the presence of dopamine corroborate the activity of peptidomimetic 6b as a positive allosteric modulator (PAM) of D2R. In this assay, 6b produced a typical bell-shaped dose-response curve similar to that of the parent neuropeptide (18.3 +/- 7.1% for 6b vs 15.4 +/- 5.5% for MIF-1, both at 0.1 nM). Dose-response curves for dopamine in the presence of 6b show EC50 (0.33 +/- 0.21 mu M for 6b vs 0.17 +/- 0.07 pM for MIF-1) and E-max (86.0 +/- 5.4% for 6b vs 93.6 +/- 4.4% for MIF-1) comparable to those of MIF-1, both at 0.01 nM. Furthermore, peptidomimetic 6b was tested for agonist activity at the human D2R and the results show that it displays no intrinsic agonism effect, endorsing its activity as a PAM of D2R. Cytotoxic and neurotoxic assays were performed for peptidomimetic 6b using HEK 293T cells and cortex neurons from 19 day old Wistar-Kyoto rat embryos, respectively, suggesting this analogue displays no toxicity effect in these assays up to 100 mu M. Conformational energy minimization for 6b shows that this peptidomimetic cannot adopt the postulated type-II beta-turn bioactive conformation, endorsing the possibility of an extended bioactive conformation as claimed by other researchers as a second bioactive conformation of MIF-1. Overall, the pharmacological and toxicological profile of peptidomimetic 6b together with its favorable druglike properties and structural simplicity makes it a potential lead compound for further development and optimization.
据报道,有一种新的策略可以通过吡啶甲酰胺辅助的钯催化的C–H键活化反应从脂肪族胺中构建复杂的多环含氮杂环。该反应显示出广泛的底物范围,可用于合成各种氮杂双环支架,包括氮杂环丁烷和托烷类生物碱。该方法在天然存在的(-)-顺式-二甲基乙胺中的应用,这是前所未有的碳-碳键活化,其中涉及的电子对引发了环钯片段的分子内“ S N 2样”置换。第三中心,描述。
Iterative Arylation of Amino Acids and Aliphatic Amines via δ‐C(sp
<sup>3</sup>
)−H Activation: Experimental and Computational Exploration
作者:Srimanta Guin、Pravas Dolui、Xinglong Zhang、Satyadip Paul、Vikas Kumar Singh、Sukumar Pradhan、Hediyala B. Chandrashekar、S. S. Anjana、Robert S. Paton、Debabrata Maiti
DOI:10.1002/anie.201900479
日期:2019.4.16
mostly up to the γ‐position. In the present work, we demonstrate the diverse (hetero)arylation of amino acids and analogous aliphatic amines selectively at the remote δ‐position by tuning the reactivity controlled by ligands. An organopalladium δ‐C(sp3)−H activated intermediate has been isolated and crystallographically characterized. Mechanistic investigations carried out experimentally in conjunction
Highly Efficient Syntheses of Azetidines, Pyrrolidines, and Indolines via Palladium Catalyzed Intramolecular Amination of C(sp<sup>3</sup>)–H and C(sp<sup>2</sup>)–H Bonds at γ and δ Positions
palladium-catalyzed intramolecular amination of C-H bonds at the γ and δ positions of picolinamide (PA) protected amine substrates. These methods feature relatively a low catalyst loading, use of inexpensive reagents, and convenient operating conditions. Their selectivities are predictable. These methods highlight the use of unactivated C-H bond, especially the C(sp(3))-H bond of methyl groups, as functional
Radical C−H Alkylation with Ethers and Unactivated Cycloalkanes toward the Assembly of Tetrasubstituted Amino Acid Derivatives
作者:Marcos San Segundo、Arkaitz Correa
DOI:10.1002/adsc.202200716
日期:2022.9.20
A radical α−C−H alkylation of a collection of N-picolinamide aminoacidderivatives with ethers and cycloalkanes as chemical feedstock is described. This cross-dehydrogenative coupling is distinguished by its reliable scalability and removable auxiliary group, and enables the assembly of a variety of tri- and tetrasubstituted aminoacid compounds.
Pd‐Catalyzed δ‐C(<i>sp</i><sup>3</sup>)−H Thiolation of Amino Acid Derivatives
作者:Andrés García‐Viada、Celia Sánchez‐González、Mario Martínez‐Mingo、Inés Alonso、Nuria Rodríguez、Juan C. Carretero
DOI:10.1002/adsc.202300808
日期:2023.11.21
δ-thiolation of aliphatic α-amino acids catalyzed by a Pd(II)/Ag(I) system. This reaction employs disulfides as thiolating agents and N-COPy as directing group, providing valuable non-proteinogenic amino acid derivatives in moderate to good diastereoselectivities and yields. Remarkably, the method is also suitable for the late-stage functionalization of a dipeptide. Experimental and DFT studies have provided
A novel strategy to construct complex polycyclic nitrogen-containing heterocycles from aliphatic amines via picolinamide-assisted palladium-catalyzed C–H bond activation reaction was reported. The reaction exhibits broad substrate scope for the synthesis of various azabicyclic scaffolds, including azetidines and tropane-class alkaloids. Application of this method to naturally occurring (−)-cis-myrtanylamine
据报道,有一种新的策略可以通过吡啶甲酰胺辅助的钯催化的C–H键活化反应从脂肪族胺中构建复杂的多环含氮杂环。该反应显示出广泛的底物范围,可用于合成各种氮杂双环支架,包括氮杂环丁烷和托烷类生物碱。该方法在天然存在的(-)-顺式-二甲基乙胺中的应用,这是前所未有的碳-碳键活化,其中涉及的电子对引发了环钯片段的分子内“ S N 2样”置换。第三中心,描述。