5-羟色胺(5-HT)和去甲肾上腺素(NE)重摄取抑制剂药效团模型的建立及比较分析

近年来的研究表明, 去甲肾上腺素(NE)能系统和5-羟色胺(5-HT)能系统可能共同参与了抑郁症的发病机制. 采用Catalyst软件的Hypogen方法, 利用22个不同结构类型的5-HT重摄取抑制剂和19个不同结构类型和活性的NE重摄取抑制剂分别建立了5-HT药效团模型和NE药效团模型, 它们的相关系数分别为0.935, 0.844, 这表明所得到的模型能较好地表征重摄取抑制剂化合物的特征; 此外, 我们还选择了四种不同活性的预测集分别对所建立的药效团模型进行检验, 结果表明所建立的药效团模型具有较好的预测能力. 对这两个药效团模型进行了比较分析, 其结果可以为设计高活性的双重5-HT和NE重摄取抑制剂提供依据.     

Advances in the enantioseparation of second-generation antidepressant drugs by electrodriven methods

Stereochemistry is steadily increasing in importance in the development of new drugs, and the availability of pure enantiomer drugs can make therapy safer and more efficacious. In particular, almost all second-generation antidepressant drugs possess one or more chiral centres; however, only some of them are administered as single enantiomers. A fundamental part of the quality control of pharmaceutical formulations is the determination of enantiomeric excess and enantiomeric purity; this is also important for the therapeutic drug monitoring of depressed patients. For this purpose, efficient and reliable analytical methods are needed and electrodriven techniques (most of all CE, CEC and MEKC) are very efficient and inexpensive candidates for the role. In this review, the enantioselective electrodriven methods available for the analysis of second-generation antidepressant are presented and discussed. In particular, the following pharmacological classes of antidepressants will be considered: selective serotonin reuptake inhibitors (fluoxetine, citalopram, paroxetine, sertraline); norepinephrine reuptake inhibitors (reboxetine); serotonin and norepinephrine reuptake inhibitors (venlafaxine, milnacipran, duloxetine); and noradrenergic and specific serotonergic antidepressants (mirtazapine).     

Recent advances in liquid chromatographic methods for the determination of selective serotonin reuptake inhibitors and serotonin norepinephrine reuptake inhibitors

Depression is now the second largest public health burden throughout the world. Selective serotonin reuptake inhibitors (SSRIs) and serotonin norepinephrine reuptake inhibitors (SNRIs) have replaced older antidepressants to become first-line medications to treat this disease with increased remission rates and markedly decreased incidence of severe adverse events. Traditional and modern bioanalytical strategies for SSRI and SNRI determination are being continuously improved. There has also been a recent increase in the use of unconventional sample preparation methods. This review critically evaluates the development of SSRI and SNRI liquid chromatographic analytical methods published between 2014 and mid-2019, with special attention to novel sample preparation methods.     

Quantitation of nicotinamide and serotonin derivatives and detection of flavins in neuronal extracts using capillary electrophoresis with multiphoton-excited fluorescence

Capillary electrophoresis (CE) with multiphoton-excited fluorescence detection (CE-MPE) allows low-background analysis of spectrally distinct fluorophores using a single long-wavelength laser. Extracts were prepared from immortalized rat raphe nuclei neurons, and were analyzed by CE-MPE. Native fluorescence was detected from reduced nicotinamide adenine dinucleotide (NADH) and its phosphorylated form (NADPH), flavin adenine dinucleotide (FAD), flavin mononucleotide (FMN), riboflavin, serotonin, and 5-hydroxytryptophan (5HTrp). Quantitation of exogenous serotonin (taken up by cells) and endogenous NADH and 5HTrp was possible using internal standards or standard addition. This system should be useful to study monamine oxidase inhibitors (MAOIs) and selective serotonin reuptake inhibitors (SSRIs).     

新型5-HT重摄取抑制剂的设计、合成及活性评价

在对已知各种结构类型的5-HT重摄取抑制剂分子结构全面分析的基础上, 建立了SSRIs药效团模型. 基于该模型应用UNITY程序对NCI-3D和Maybridge-3D数据库进行三维结构的限制性查询, 在获得的命中结构的信息指导下, 设计合成了3种全新结构类型的化合物, 并完成了初步的药理活性评价. 这些化合物均显示出不同程度的5-HT重摄取抑制活性, 其中5个化合物显示高抑制活性. 哌嗪取代的二苯脒类化合物的结构新颖, 较好地符合5-HT重摄取抑制剂药效团模型, 与SSRIs类化合物三维定量构效关系研究得到的CoMFA模型有较好的适配性.     

An enantioselective approach to 3-substituted pyrrolidines: Asymmetric synthesis for pyrrolidine core of serotonin norepinephrine reuptake inhibitors (SNRIs)

A novel and efficient synthetic approach to enantiopure 3-substituted pyrrolidine skeleton from readily available (S)-PMB glycidyl ether as a starting material and its application to the asymmetric synthesis of pyrrolidine core 1 of serotonin norepinephrine reuptake inhibitors (SNRIs) 2 and 3 are described. The synthesis utilizes the organocatalyzed asymmetric Michael addition reaction as key step.     

Biocatalytic strategy toward asymmetric β-hydroxy nitriles and γ-amino alcohols

A library of 20 bakers’ yeast reductases, that are overexpressed in Escherichia coli, were screened against a variety of β-keto nitriles. Enzymes from the aldose reductase and the short chain dehydrogenase family displayed activity toward these substrates. All of the seven substrates were reduced with high enantioselectivities and in some cases both antipodes could be synthesized in high ees. These whole-cell reactions afforded gram quantities of asymmetric compounds that could ultimately lead to scaleable and simple synthesis to new drug analogs of serotonin reuptake inhibitors and β-adrenergic blocking agents.     

A simple HPLC method for the simultaneous determination of two selective serotonin reuptake inhibitors and two serotonin-norepinephrine reuptake inhibitors in hair, nail clippings, and cerebrospinal fluid

A novel and simple high-performance liquid chromatography method has been developed for the simultaneous determination of two selective serotonin reuptake inhibitors (fluoxetine and paroxetine) and two serotonin-norepinephrine reuptake inhibitors (venlafaxine and duloxetine) in alternative samples of toxicological interest such as hair, nail clippings, and cerebrospinal fluid (CSF). The separation was achieved on a Hichrom Kromasil 100-5C(18) (250 × 4.6 mm) 5 μm column by using ammonium acetate (0.05 M)-acetonitrile (59:41% v/v) as the mobile phase, delivered isocratically at a flow rate of 1.3 mL/min, within ca. 10 min. Ultraviolet detection at 235 nm was used for monitoring the eluting analytes. Validation was performed in terms of linearity, selectivity, accuracy, precision, and stability. Correlation coefficients were greater than 0.9954. The limits of quantitation ranged between 0.3 and 2.1 ng/μL for all analytes in the liquid matrix (CSF), while the respective values were in the range of 0.3-3.6 ng/mg for solid matrices (hair and nail clippings), with an injection volume of 20 μL. Repeatability and intermediate precision (relative standard deviation, RSD%) were less than 16.6%. The method was successfully applied to actual hair and nail samples from a patient under fluoxetine treatment.     

Magnetic carbon nanotubes modified with 1,4-diazabicyclo[2.2.2] octane are a viable sorbent for extraction of selective serotonin reuptake inhibitors

Carbon nanotubes were modified with magnetite nanoparticles, and 1,4-diazabicyclo[2.2.2]octane (DABCO) was then covalently attached to their surface. The resulting material is shown to be a viable sorbent for the preconcentration of the selective serotonin reuptake inhibitors citalopram, sertraline, fluvoxamine and fluoxetine via ultrasound-assisted magnetic solid phase extraction. The effects of pH value, sorbent dosage, eluent volume and salt concentration were optimized by central composite design and desirability function. The drugs were quantified by HPLC with UV detection. Detection limits are as low as 0.2, 0.25, 0.3, and 0.5 ng mL^?1 for citalopram, sertraline, fluvoxamine and fluoxetine, respectively. The intra-day precisions (RSDs) are <4.0%. The method was applied to the determination of the selective serotonin reuptake inhibitors in plasma samples and gave recoveries of >91%. The sorbent can be reused 12 times without a noticeable decrease in extraction efficiency.

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Graphical abstract Magnetic carbon nanotubes were modified with 1,4-diazabicyclo[2.2.2]octane (DABCO) with ionic liquid framework. Resulting material was used as a reusable and selective sorbent for preconcentration and extraction of antidepressant drugs from plasma samples.

     

Sensitive capillary GC-MS-SIM determination of selective serotonin reuptake inhibitors: reliability evaluation by validation and robustness study

A simple, fast, selective and very sensitive capillary GC-MS method for the simultaneous determination of five antidepressant drugs is described. Fluoxetine, fluvoxamine, citalopram, sertraline and paroxetine belong to the newest and most important drug group termed selective serotonin reuptake inhibitors. Imipramine was used in this method as an internal standard for quantification. Optimum parameters for GC separation were investigated, i.e., flow rate, column head pressure, injector temperature, injection splitless conditions and oven temperature program. MS detection was performed in SIM mode to increase the sensitivity. Stability of the solutions, linear concentration range, accuracy, precision, LOD, LOQ (3.6-41.5 mg/L) and specificity were examined in the presence of excipients for checking the reliability of this method. The robustness was evaluated with a matrix of 15 experiments (seven factors and three levels) using Plackett-Burman fractional factorial experimental design, and Youden and Steiner statistical treatment. The method was applied to the analysis of these antidepressants in nearly all their pharmaceutical formulations, obtaining recoveries between 98.1% and 102.7% with regard to the claimed values.     

Solid-phase microextraction-gas chromatography-mass spectrometry for the analysis of selective serotonin reuptake inhibitors in environmental water

The continuous contamination of surface waters by pharmaceuticals is of most environmental concern. Selective serotonin reuptake inhibitors (SSRIs) are drugs currently prescribed for the treatment of depressions and other psychiatric disorders and then, they are among the pharmaceuticals that can occur in environmental waters. Solid-phase microextraction (SPME) coupled to gas chromatography-mass spectrometry has been applied to the extraction of five SSRIs--venlafaxine, fluvoxamine, fluoxetine, citalopram and sertraline--from water samples. Some of the analytes were not efficiently extracted as underivatized compounds and so, an in situ acetylation step was introduced in the sample preparation procedure. Different parameters affecting extraction efficiency such as extraction mode, fiber coating and temperature were studied. A mixed-level fractional factorial design was also performed to simultaneously study the influence of other five experimental factors. Finally, a method based on direct SPME at 100 degrees C using polydimethylsiloxane-divinylbenzene fibers is proposed. The performance of the method was evaluated, showing good linearity and precision. The detection limits were in the sub-ng/mL level. Practical applicability was demonstrated through the analysis of real samples. Recoveries obtained for river water and wastewater samples were satisfactory in all cases. An important aspect of the proposed method is that no matrix effects were observed. Two of the target compounds, venlafaxine and citalopram, were detected and quantified in a sewage water sample.     

Is the Antidepressant Activity of Selective Serotonin Reuptake Inhibitors Mediated by Nicotinic Acetylcholine Receptors?

It is generally assumed that selective serotonin reuptake inhibitors (SSRIs) induce antidepressant activity by inhibiting serotonin (5-HT) reuptake transporters, thus elevating synaptic 5-HT levels and, finally, ameliorates depression symptoms. New evidence indicates that SSRIs may also modulate other neurotransmitter systems by inhibiting neuronal nicotinic acetylcholine receptors (nAChRs), which are recognized as important in mood regulation. There is a clear and strong association between major depression and smoking, where depressed patients smoke twice as much as the normal population. However, SSRIs are not efficient for smoking cessation therapy. In patients with major depressive disorder, there is a lower availability of functional nAChRs, although their amount is not altered, which is possibly caused by higher endogenous ACh levels, which consequently induce nAChR desensitization. Other neurotransmitter systems have also emerged as possible targets for SSRIs. Studies on dorsal raphe nucleus serotoninergic neurons support the concept that SSRI-induced nAChR inhibition decreases the glutamatergic hyperstimulation observed in stress conditions, which compensates the excessive 5-HT overflow in these neurons and, consequently, ameliorates depression symptoms. At the molecular level, SSRIs inhibit different nAChR subtypes by noncompetitive mechanisms, including ion channel blockade and induction of receptor desensitization, whereas α9α10 nAChRs, which are peripherally expressed and not directly involved in depression, are inhibited by competitive mechanisms. According to the functional and structural results, SSRIs bind within the nAChR ion channel at high-affinity sites that are spread out between serine and valine rings. In conclusion, SSRI-induced inhibition of a variety of nAChRs expressed in different neurotransmitter systems widens the complexity by which these antidepressants may act clinically.     

Coordination of Na(+) by monoamine ligands in dopamine, norepinephrine, and serotonin transporters

The reuptake of neurotransmitters by dopamine, norepinephrine, and serotonin transporters during neuronal transmission requires a sodium gradient. An "ionic mode" of binding proposes that aspartate anchors the ligand's positive charge but ignores the direct role of sodium in ligand binding seen in the only representative structure, the prokaryotic leucine transporter LeuT. Here, we built structural models of human transporters of dopamine, norepinephrine, and serotonin using the LeuT structure. The ligand and sodium-binding sites are highly conserved. We examined the possibilities for ligand binding given the available experimental evidence, including examples of catechol-cation chelates in X-ray structures of protein and other complexes. We conclude that a "chelation mode" of binding with direct interaction between the catechol hydroxyls and sodium is a valid alternative, with consequences for pharmaceutical design. In the modeled serotonin transporter complexes, Y95 is placed where it could select for serotonin through hydrogen bonding to the indole nitrogen.     

Determination of fluoxetine, fluvoxamine, and clomipramine in pharmaceutical formulations by capillary gas chromatography

A simple and fast capillary gas chromatographic method with flame ionization detection is proposed for the simultaneous determination of fluoxetine, fluvoxamine, and clomipramine without a prederivatization. The reported method is the first one that allows the determination of three selective serotonin reuptake inhibitors. Optimal conditions for the quantitative separation were investigated: column head pressure (80 kPa), injector and detector temperatures (260 and 250 degrees C), time and temperature for the splitless step (0.75 min and 60 degrees C), size of sample (2 microL), and oven temperature program, providing analysis times shorter than 10 min. Aspects such as the stability of the solutions, linearity, accuracy, and precision are examined in order to validate this method. Peak purity and detection and quantitation limits are also assessed using mass selective detection. The scope of the validated method is tested in the analysis of pharmaceutical preparations, with recoveries between 97.5 and 102.5% with regard to their nominal contents.     

Enantioselective synthesis of a highly potent selective serotonin reuptake inhibitor. An application of imidazolidinone catalysis to the alkylation of indoles with an alpha,beta-disubstituted alpha,beta-unsaturated aldehyde

The synthesis of the highly potent and selective serotonin reuptake inhibitor 1 (BMS-594726) is described. In the key construction step, an enantioselective alkylation of the indole nucleus with an alpha-branched alpha,beta-unsaturated aldehyde 7 was accomplished utilizing MacMillan's imidazolidinone catalyst 3b. A rationale is presented for the unexpected stereochemical result, as well as the novel reactivity of the alpha-branched substrate. [reaction: see text]     

Fluorescent neuroactive probes based on stilbazolium dyes

A set of spectrally diverse stilbazolium dyes was identified in an uptake assay using cultured brainstem and cerebellum cells isolated from e19 chicks. Pretreatment of cells with indatraline, a monoamine reuptake inhibitor, allowed identification of dyes that may interact with monoamine transporters. Two structurally related, yet spectrally segregated, probes, (E)-1-methyl-4-[2-(2-naphthalenyl)ethenyl]-pyridinium iodide (NEP+, 3A) and (E)-4-[2-(6-hydroxy-2-naphthalenyl)ethenyl]-1-methyl-pyridinium iodide (HNEP+, 4A), were selected and further investigated using HEK-293 cells selectively expressing dopamine, norepinephrine or serotonin transporters. HNEP+ was selectively accumulated via catecholamine transporters, with the norepinephrine transporter (NET) giving the highest response; NEP+ was not transported, though possible binding was observed. The alternate modes of interaction enable the use of NEP+ and HNEP+ to image distinct cell populations in live brain tissue explants. The preference for HNEP+ accumulation via NET was confirmed by imaging uptake in the absence and presence of desipramine, a norepinephrine reuptake inhibitor.     

A Simple Liquid Chromatographic Method for the Simultaneous Determination of Antidepressants in Pharmaceutical Preparations

Fluoxetine (FT), fluvoxamine (FX), sertraline (ST) and trazodone (TD) are new type of antidepressants acting as selective serotonin reuptake inhibitors (SSRIs). In structures, they all have chromophore and can be easily monitored by UV absorption spectrophotometry. A simple isocratic high‐performance liquid chromatographic method with ultraviolet detection (215 nm) was developed for the simultaneous quantification of FT, FX, ST and TD. The determination range of the method is over 10.0–400.0 μM for each drug. The detection limits (S/N = 3, injection 20 μL) are about 0.1 μM for TD, 0.2 μM for FT, FX and ST. The relative standard deviation and relative error of the method for intra‐ and inter‐day analyses of FT, FX, ST and TD were all below 3.7%. Application of the method to the analysis of FT, FX or ST in pharmaceutical product proved feasible. The method could be used for the quality control assay of the analytes in bulk and in formulations.     

Molecular design based on 3D-pharmacophore. Application to 5-HT4 receptor

A definition of a pharmacophore for the 5-HT4 antagonist was carried out by considering a three-dimensional model which correlates the chemical structures of series of antagonists with their biological affinities. A molecular design is described by analyzing the differences between two 3D serotonin pharmacophores. This successful structural modification demonstrates the efficiency of this approach to design new serotonin ligands.