Conformationally restricted homotryptamines. 2. Indole cyclopropylmethylamines as selective serotonin reuptake inhibitors

Organocatalytic Reductive Amination of the Chiral Formylcyclopropanes: Scope and Applications

We developed a sustainable three-component reductive amination protocol for the chemoselective coupling of optically active functionally rich donor-acceptor carbonyl-cyclopropanes with various amines under 10 mol % of diphenyl phosphate in the presence of Hantzsch ester as a hydride source. The catalytic selective reductive C-N coupling has wide advantages like no epimerization, no ring opening, large substrate scope, generating only mono N-alkylation products and simultaneously resulting in chiral cyclopropane-containing amines possessing many applications in the medicinal chemistry. In this article, we have shown the synthetic applications of reductive C-N coupling reaction to make chiral α-carbonyl-cyclopropane containing amines 8, double C-N coupled cyclopropane-amines 10, unusual C-N/C-C coupled cyclopropane-amines 12, chiral tert-butylsulfinamide containing cyclopropanes 14/15, and functionally rich chiral cyclopropane-fused N-heterocycles 16/18/19. Many of these chiral cyclopropane-amines 5-19 can serve as building blocks for the synthesis of drug-like small molecules, natural products, pharmaceuticals, and their analogues.

Elucidation of Pharmacological Mechanism Underlying the Anti-Alzheimer's Disease Effects of Evodia rutaecarpa and Discovery of Novel Lead Molecules: An In Silico Study

Alzheimer's disease (AD) is a brain disease with a peculiarity of multiformity and an insidious onset. Multiple-target drugs, especially Chinese traditional medicine, have achieved a measure of success in AD treatment. Evodia rutaecarpa (Juss.) Benth. (Wuzhuyu, WZY, i.e., E. rutaecarpa), a traditional Chinese herb, has been identified as an effective drug to cure migraines. To our surprise, our in silico study showed that rather than migraines, Alzheimer's disease was the primary disease to which the E. rutaecarpa active compounds were targeted. Correspondingly, a behavioral experiment showed that E. rutaecarpa extract could improve impairments in learning and memory in AD model mice. However, the mechanism underlying the way that E. rutaecarpa compounds target AD is still not clear. For this purpose, we employed methods of pharmacology networking and molecular docking to explore this mechanism. We found that E. rutaecarpa showed significant AD-targeting characteristics, and alkaloids of E. rutaecarpa played the main role in binding to the key nodes of AD. Our research detected that E. rutaecarpa affects the pathologic development of AD through the serotonergic synapse signaling pathway (SLC6A4), hormones (PTGS2, ESR1, AR), anti-neuroinflammation (SRC, TNF, NOS3), transcription regulation (NR3C1), and molecular chaperones (HSP90AA1), especially in the key nodes of PTGS2, AR, SLCA64, and SRC. Graveoline, 5-methoxy-N, N-dimethyltryptamine, dehydroevodiamine, and goshuyuamide II in E. rutaecarpa show stronger binding affinities to these key proteins than currently known preclinical and clinical drugs, showing a great potential to be developed as lead molecules for treating AD.

Assessment of Paroxetine Molecular Interactions with Selected Monoamine and γ-Aminobutyric Acid Transporters

Thus far, many hypotheses have been proposed explaining the cause of depression. Among the most popular of these are: monoamine, neurogenesis, neurobiology, inflammation and stress hypotheses. Many studies have proven that neurogenesis in the brains of adult mammals occurs throughout life. The generation of new neurons persists throughout adulthood in the mammalian brain due to the proliferation and differentiation of adult neural stem cells. For this reason, the search for drugs acting in this mechanism seems to be a priority for modern pharmacotherapy. Paroxetine is one of the most commonly used antidepressants. However, the exact mechanism of its action is not fully understood. The fact that the therapeutic effect after the administration of paroxetine occurs after a few weeks, even if the levels of monoamine are rapidly increased (within a few minutes), allows us to assume a neurogenic mechanism of action. Due to the confirmed dependence of depression on serotonin, norepinephrine, dopamine and γ-aminobutyric acid levels, studies have been undertaken into paroxetine interactions with these primary neurotransmitters using in silico and in vitro methods. We confirmed that paroxetine interacts most strongly with monoamine transporters and shows some interaction with γ-aminobutyric acid transporters. However, studies of the potency inhibitors and binding affinity values indicate that the neurogenic mechanism of paroxetine's action may be determined mainly by its interactions with serotonin transporters.

Recent advances in the catalytic cyclopropanation of unsaturated compounds with diazomethane

The main achievements and development trends of the past 10–15 years related to the catalytic cyclopropanation of unsaturated compounds with diazomethane are integrated and analyzed. The attention is focused on the most efficient catalysts based on palladium compounds. Data on the effects of substrate structure and nature of catalyst components on the regio- and stereoselectivity of these reactions are systematized. Characteristic features of safe methods for diazomethane generation are considered, including the use of membrane technologies and continuous-flow and in situ preparation methods, which have prospects for industrial application.

The bibliography includes 281 references.

Hybrid molecules inhibiting myeloperoxidase activity and serotonin reuptake: a possible new approach of major depressive disorders with inflammatory syndrome

Objectives

Major depressive disorder (MDD) is accompanied with an imbalance in the immune system and cardiovascular impairments, such as atherosclerosis. Several mechanisms have been pointed out to underlie this rather unexpected association, and among them the activity of myeloperoxidase (MPO). The aim of our study was to find compounds that inhibit both MPO and serotonin transporter (SERT) for treating MDD associated with cardiovascular diseases.

Methods

SERT inhibition was assessed with measuring of [3H]-serotonin uptake using HEK-293 MSR cells. MPO inhibition was determined by taurine chloramine test on 3-(aminoalkyl)-5-fluoroindole derivatives and on clinically relevant antidepressants. All kinetic measurements were performed using a temperature-controlled stopped-flow apparatus (model SX-18 MV). Promising lead compounds were docked onto SERT 3D structure modelled using the LeuT structure complexed to tryptophan (PDB code 3F3A). Their toxicological profile was also assessed.

Key findings

3-(aminoalkyl)-5-fluoroindole derivative with 5 carbons on the side chain and paroxetine showed the best activity on both MPO and SERT at the nanomolar range. Paroxetine was found to be the first irreversible MPO inhibitor at nanomolar concentrations.

Conclusions

Our results put forward the first hybrid molecule (compound 25) and drug (paroxetine) that can be especially used in MDD associated with inflammatory syndrome.

Conformationally restricted homotryptamines. Part 6: indole-5-cycloalkyl methylamines as selective serotonin reuptake inhibitors

Racemic 5-(trans-2-aminomethylcyclopropyl)indoles, 5-(trans-2-aminomethylcyclopentyl) indoles, and 5-(cis-2-aminomethylcyclopentyl)indoles were synthesized and evaluated as selective serotonin reuptake inhibitors. These analogs followed SAR trends similar to those previously reported for 3-cycloalkyl substituted indoles. The most potent analogs exhibited single digit nanomolar inhibition at the human serotonin transporter but were 10-fold less active than the previously reported compounds.

Antidepressant potential of nitrogen-containing heterocyclic moieties: An updated review

Depression is currently the fourth leading cause of disease or disability worldwide. Antidepressant is approved for the treatment of major depression (including paediatric depression), obsessive-compulsive disorder (in both adult and paediatric populations), bulimia nervosa, panic disorder and premenstrual dysphoric disorder. Antidepressant is a psychiatric medication used to alleviate mood disorders, such as major depression and dysthymia and anxiety disorders such as social anxiety disorder. Many drugs produce an antidepressant effect, but restrictions on their use have caused controversy and off-label prescription a risk, despite claims of superior efficacy. Our current understanding of its pathogenesis is limited and existing treatments are inadequate, providing relief to only a subset of people suffering from depression. Reviews of literature suggest that heterocyclic moieties and their derivatives has proven success in treating depression.

Synthesis of 7-azaserotonin: its photophysical properties associated with excited state proton transfer reaction

We report the synthesis of 3-(2-aminoethyl)-5-ol-1H-pyrrolo[2,3-b]pyridine (7-azaserotonin), which may potentially serve as an agonist or antagonist of serotonin receptors. In alcohols, the solvent (e.g., ethanol) catalyzed proton-transfer reaction takes place for 7-azaserotonin in the excited state, resulting in dual emission. Conversely, excited-state deprotonation takes place in neutral aqueous solution. The unique excitation behavior makes 7-azaserotonin versatile as a potential bioprobe.

Conformationally restricted homotryptamines. Part 4: Heterocyclic and naphthyl analogs of a potent selective serotonin reuptake inhibitor

A series of hybrid molecules containing the cyclopropylmethylamino side chain found in homotryptamine (1S,2S)-2c and an isosteric heteroaryl or naphthyl core were prepared and their binding affinities for the human serotonin transporter determined. The most potent isosteres were CN-substituted naphthalenes. These results demonstrate that isosteric aromatic cores which lack an H-bond donor site may be substituted for the indole nucleus without substantial loss in hSERT binding.

Conformationally restricted homotryptamines 3. Indole tetrahydropyridines and cyclohexenylamines as selective serotonin reuptake inhibitors

A series of indole tetrahydropyridine and indole cyclohexenylamines was prepared, and their binding affinities at the human serotonin transporter (SERT) were determined. In particular, a nitrile substituent at the C5 position of the indole ring gave potent SERT activity. The stereochemistry of the N,N-dimethylamine substituent was determined for the most potent indole cyclohexenylamine, 6a. The enantiomers of 6a were energy minimized and compared to other conformationally restricted SSRIs. Compound 6a was found to give a dose-response similar to the SSRI fluoxetine in microdialysis studies in rats.

Asymmetric synthesis of orthogonally protected trans-cyclopropane γ-amino acids via intramolecular ring closure

The synthesis of enantiomerically-enriched trans-cyclopropane amino- and hydroxy-acids can be achieved by intramolecular ring closure in moderate to good yields. The optically active cyclopropane precursors are easily prepared in a short sequence from inexpensive, commercially available olefins and tert-butyl acetate. Several leaving groups and bases were compared for the cyclopropanation step, showing that the diphenylphosphinate and tosyl leaving groups give the best results when used in combination with either LDA or NaHMDS.