UHPLC-MS-based metabolomics and chemoinformatics study reveals the neuroprotective effect and chemical characteristic in Parkinson's disease mice after oral administration of Wen-Shen-Yang-Gan decoction

Parkinson's disease (PD), the typical neurodegenerative disease, is characterized by the progressive loss of dopaminergic neurons in the substantia nigra (SN). However, no therapeutic agent used currently could slow down neuronal cell loss so as to decelerate or halt the progression of PD. Traditional Chinese medicine (TCM) has been utilized to treat the dysfunction of the autonomic nervous system. Wen-Shen-Yang-Gan decoction (WSYGD) has a good effect on the clinical treatment of PD with constipation. However, it is not clear which ingredients and what mechanism are responsible for the therapeutic effect. In this study, the pharmacodynamic study of WSYGD in PD mice was applied. Concurrently, a novel method for the identification of metabolic profiles of WSYGD has been developed. Finally, we found that WSYGD could protect the PD mice induced by rotenone. The underlying mechanism of the protective effect may be related to the reduction of the DA neurons apoptosis via reducing inflammatory reaction. By virtue of UPLC-MS and chemoinformatics method, 35 prototype compounds and 27 metabolites were filtered out and tentatively characterized. In conclusion, this study provides an insight into the metabolism of WSYGD in vivo to enable understanding of the metabolic process and therapeutic mechanism of PD.

Effect of M. chamomilla L. tea on chlorpromazine induced catalepsy: A neuroprotective study

We determined anti-Parkinson's activity of M. chamomilla L. tea in chlorpromazine (CPZ) developed investigational animal model. In this research, effects of M. chamomilla L. tea 2.14ml/ kg P.O were studied on cataleptic behavior and its effect on brain histopathological changes and immunohistochemistry (IHC) in rats. The experimental design was developed by administering CPZ (3mg/kg, I/P) for twenty-one days to produce Parkinson's disease-like symptoms to 4 animal groups. We observed that chlorpromazine significantly produced motor dysfunctions (catalepsy) in a time period of twenty-one days. The M. chamomilla L. significantly (P<0.005) minimized/shorten/taper down catalepsy in rats just like standard group (Levodopa/carbidopa treated group). The maximum reduction was observed from both treated and standard groups on the 21st day. M. chamomilla L. treated rats mid brain sections showed presence of proliferative blood vessels, increase cellularity with reactive glial cells as compared to CPZ group. Furthermore, immunostaining CD68 & CD21 of M. chamomilla L. treated rats mid brain region showed few CD68 cells & no polymorphs neutrophils after CD21 staining. Thus, this research work disclosed the neuroprotective effect of M. chamomilla L. tea against Parkinson's disease-like symptoms or anti-Parkinson's activity induced by CPZ.

Neuroprotective potential of Ayahuasca and untargeted metabolomics analyses: applicability to Parkinson's disease

ETHNOPHARMACOLOGY RELEVANCE

Ayahuasca is a tea produced through decoction of Amazonian plants. It has been used for centuries by indigenous people of South America. The beverage is considered to be an ethnomedicine, and it is traditionally used for the treatment of a wide range of diseases, including neurological illness. Besides, some scientific evidence suggests it may be applicable to Parkinson's disease (PD) treatment. Thus, Ayahuasca deserves in depth studies to clarify its potential role in this disease.

AIM OF THE STUDY

This study aimed to use an untargeted metabolomics approach to evaluate the neuroprotective potential of the Ayahuasca beverage, the extracts from its matrix plants (Banisteriopsis caapi and Psychotria viridis), its fractions and its main alkaloids on the viability of SH-SY5Y neuroblastoma cells in an in vitro PD model.

MATERIAL AND METHODS

The cytotoxicity of Ayahuasca, crude extracts, and fractions of B. caapi and P. viridis, as well as neuroprotection promoted by these samples in a 6-hydroxydopamine (6-OHDA)-induced neurodegeneration model, were evaluated by the MTT assay at two time-points: 48 h (T1) and 72 h (T2). The main alkaloids from Ayahuasca matrix plants, harmine (HRE) and N,N-dimethyltryptamine (DMT), were also isolated and evaluated. An untargeted metabolomics approach was developed to explore the chemical composition of samples with neuroprotective activity. Ultra-Performance Liquid Chromatography coupled to Electrospray Ionisation and Time-of-Flight (UPLC-ESI-TOF) metabolome data was treated and further analysed using multivariate statistical analyses (MSA): principal component analysis (PCA) and orthogonal partial least squares discriminant analysis (OPLS-DA). The metabolites were dereplicated using the Dictionary of Natural Products and an in house database. The main alkaloids were also quantified by UPLC-MS/MS.

RESULTS

The samples did not cause cytotoxicity in vitro and three of samples intensely increased cell viability at T1. The crude extracts, alkaloid fractions and HRE demonstrated remarkable neuroprotective effect at T2 while the hydroalcoholic fractions demonstrated this neuroprotective effect at T1 and T2. Several compounds from different classes, such as β-carbolines and monoterpene indole alkaloids (MIAs) were revealed correlated with this property by MSA. Additionally, a total of 2419 compounds were detected in both ionisation modes. HRE showed potent neuroprotective action at 72 h, but it was not among the metabolites positively correlated with the most efficacious neuroprotective profile at either time (T1 and T2). Furthermore, DMT was statistically important to differentiate the dataset (VIP value > 1), although it did not exhibit sufficient neuroprotective activity by in vitro assay, neither a positive correlation with T1 and T2 neuroprotective profile, which corroborated the MSA results.

CONCLUSION

The lower doses of the active samples stimulated neuronal cell proliferation and/or displayed the most efficacious neuroprotection profile, namely by preventing neuronal damage and improving cell viability against 6-OHDA-induced toxicity. Intriguingly, the hydroalcoholic fractions exhibited enhanced neuroprotective effects when compared to other samples and isolated alkaloids. This finding corroborates the significance of a holistic approach. The results demonstrate that Ayahuasca and its base plants have potential applicability for PD treatment and to prevent its progression differently from current drugs to treat PD.

Neuroprotective Activity of Some Marine Fungal Metabolites in the 6-Hydroxydopamin- and Paraquat-Induced Parkinson's Disease Models

A new melatonin analogue 6-hydroxy-N-acetyl-β-oxotryptamine (1) was isolated from the marine-derived fungus Penicillium sp. KMM 4672. It is the second case of melatonin-related compounds isolation from microfilamentous fungi. The neuroprotective activities of this metabolite, as well as 3-methylorsellinic acid (2) and 8-methoxy-3,5-dimethylisochroman-6-ol (3) from Penicillium sp. KMM 4672, candidusin A (4) and 4″-dehydroxycandidusin A (5) from Aspergillus sp. KMM 4676, and diketopiperazine mactanamide (6) from Aspergillus flocculosus, were investigated in the 6-hydroxydopamine (6-OHDA)- and paraquat (PQ)-induced Parkinson's disease (PD) cell models. All of them protected Neuro2a cells against the damaging influence of 6-OHDA to varying degrees. This effect may be realized via a reactive oxygen species (ROS) scavenging pathway. The new melatonin analogue more effectively protected Neuro2A cells against the 6-OHDA-induced neuronal death, in comparison with melatonin, as well as against the PQ-induced neurotoxicity. Dehydroxylation at C-3″ and C-4″ significantly increased free radical scavenging and neuroprotective activity of candidusin-related p-terphenyl polyketides in both the 6-OHDA- and PQ-induced PD models.

Oxysterols from a Marine Sponge Inflatella sp. and Their Action in 6-Hydroxydopamine-Induced Cell Model of Parkinson's Disease

Four new oxysterols 1⁻4 along with previously known oxygenated sterols 5⁻14 were isolated from the sponge Inflatella sp., collected from the Sea of Okhotsk. Structures of 1⁻4 were elucidated by the detailed NMR spectroscopic and mass-spectrometric analyses as well as by comparison of the corresponding experimental data with those reported in literature. The influence of compounds 1⁻14 on the viability of neuronal Neuro2a cells treated by 6-hydroxydopamine and reactive oxygen species (ROS) formation in these cells was investigated.

ANNIVERSARY REVIEW: 50 years since the discovery of bromocriptine

Ergotism is the long-term ergot poisoning by ingestion of rye or other grains infected with the fungus Claviceps purpurea and more recently by excessive intake of ergot drugs. It has either neuropsychiatric or vascular manifestations. In the Middle Ages, the gangrenous poisoning was known as St. Anthony's fire, after the order of the Monks of St. Anthony who were particularly skilled at treating the condition. In 1917, Prof. Arthur Stoll returned home to Switzerland from Germany, to lead the development of a new pharmaceutical department at Sandoz Chemical Company. Stoll, using the special methods of extraction learned from his work with his mentor Willstetter, started his industrial research work with ergot. He succeeded in isolating, from the ergot of rye, ergotamine as an active principle of an old popular remedy for excessive post-partum bleeding. The success of this discovery occurred in 1918 and was translated into a pharmaceutical product in 1921 under the trade name Gynergen. In subsequent work, Stoll and his team were leaders in identifying the structure of the many other alkaloids and amines produced by Claviceps purpurea This was the cultural background and scientific foundation on which bromocriptine was discovered.

Supplementation of Blackcurrant Anthocyanins Increased Cyclic Glycine-Proline in the Cerebrospinal Fluid of Parkinson Patients: Potential Treatment to Improve Insulin-Like Growth Factor-1 Function

Background: Insulin-like growth factor-1 (IGF-1) function is impaired in Parkinson disease. Cyclic glycine-proline (cGP), a metabolite of IGF-1, is neuroprotective through improving IGF-1 function. Parkinson disease patients score lower on Hospital-associated Anxiety and Depression Scale after supplementing blackcurrant anthocyanins (BCA), which may be associated with IGF-1 function. We evaluated the changes of cGP and IGF-1 before and after the supplementation. Methods: Plasma and cerebrospinal fluid (CSF) were collected from 11 male patients before and after 28 day supplementation of BCA. The concentrations of IGF-1, IGF binding protein (IGFBP)-3, and cGP were measured using ELISA and HPLC-MS assays. The presence of cGP in the BCA was evaluated. Results: cGP presented in the BCA. BCA supplementation increased the concentration of cGP (p < 0.01), but not IGF-1 and IGFBP-3 in the CSF. CSF concentration of cGP was correlated with plasma concentration of cGP (R = 0.68, p = 0.01) and cGP/IGF-1 molar ratio (R = 0.66, p = 0.01). The CSF/plasma ratio was high in cGP and low in IGF-1 and IGFBP-3. Conclusion: cGP is a natural nutrient to the BCA. The increased CSF cGP in Parkinson disease patients may result from the central uptake of plasma cGP. Given neurotrophic function, oral availability, and effective central uptake of cGP, the BCA has the potential to be developed to treat neurological conditions with IGF-1 deficiency.

Functional and Morphological Correlates in the Drosophila LRRK2 loss-of-function Model of Parkinson's Disease: Drug Effects of Withania somnifera (Dunal) Administration

The common fruit fly Drosophila melanogaster (Dm) is a simple animal species that contributed significantly to the development of neurobiology whose leucine-rich repeat kinase 2 mutants (LRRK2) loss-of-function in the WD40 domain represent a very interesting tool to look into physiopathology of Parkinson's disease (PD). Accordingly, LRRK2 Dm have also the potential to contribute to reveal innovative therapeutic approaches to its treatment. Withania somnifera Dunal, a plant that grows spontaneously also in Mediterranean regions, is known in folk medicine for its anti-inflammatory and protective properties against neurodegeneration. The aim of this study was to evaluate the neuroprotective effects of its standardized root methanolic extract (Wse) on the LRRK2 loss-of-function Dm model of PD. To this end mutant and wild type (WT) flies were administered Wse, through diet, at different concentrations as larvae and adults (L+/A+) or as adults (L-/A+) only. LRRK2 mutants have a significantly reduced lifespan and compromised motor function and mitochondrial morphology compared to WT flies 1% Wse-enriched diet, administered to Dm LRRK2 as L-/A+and improved a) locomotor activity b) muscle electrophysiological response to stimuli and also c) protected against mitochondria degeneration. In contrast, the administration of Wse to Dm LRRK2 as L+/A+, no matter at which concentration, worsened lifespan and determined the appearance of increased endosomal activity in the thoracic ganglia. These results, while confirming that the LRRK2 loss-of-function in the WD40 domain represents a valid model of PD, reveal that under appropriate concentrations Wse can be usefully employed to counteract some deficits associated with the disease. However, a careful assessment of the risks, likely related to the impaired endosomal activity, is required.

Schisantherin A protects against 6-OHDA-induced dopaminergic neuron damage in zebrafish and cytotoxicity in SH-SY5Y cells through the ROS/NO and AKT/GSK3β pathways

ETHNOPHARMACOLOGICAL RELEVANCE

The fruit of Schisandra chinensis (Turcz.) Baill, has been traditionally used in management of liver diseases and ageing associated neurodegeneration. The bioactive compound from this medicinal plant would be valuable for its potential use in prevention and treatment of Parkinson׳s disease.

AIM OF THE STUDY

The overall objective of the present study was to understand the neuroprotective effect of schisantherin A, a dibenzocyclooctadiene lignan from the fruit of S. chinensis (Turcz.) Baill, and to elucidate its underlying mechanism of action.

MATERIAL AND METHODS

This study investigated the protective effect of schisantherin A against selective dopaminergic neurotoxin 6-hydroxydopamine (6-OHDA)-induced neural damage in human neuroblastoma SH-SY5Y cells and zebrafish models. Oxidative stress and related signaling pathways underlying the neuroprotective effect were determined by multiple biochemical assays and Western blot.

RESULTS

Pretreatment with schisantherin A offered neuroprotection against 6-OHDA-induced SH-SY5Y cytotoxicity. Moreover, schisantherin A could prevent 6-OHDA-stimulated dopaminergic neuron loss in zebrafish. Our mechanistic study showed that schisantherin A can regulate intracellular ROS accumulation, and inhibit NO overproduction by down-regulating the over-expression of iNOS in 6-OHDA treated SH-SY5Y cells. Schisantherin A also protects against 6-OHDA-mediated activation of MAPKs, PI3K/Akt and GSK3β.

CONCLUSION

These findings demonstrate that schisantherin A may have potential therapeutic value for neurodegenerative diseases associated with abnormal oxidative stress such as Parkinson׳s disease.

Neurobehavioral assessment of hydroalcoholic extract of Trigonella foenum-graecum seeds in rodent models of Parkinson's disease

CONTEXT

Neuroprotective therapy to rescue dopaminergic neurons is an important trait in the management of Parkinson's disease (PD).

OBJECTIVE

The present study identified and evaluated SFSE-T, a standardized hydroalcoholic extract of Trigonella foenum-graecum L. seeds (Fabaceae), in animal models of PD.

MATERIALS AND METHODS

The identification of SFSE-T was carried out by high-performance liquid chromatography for the marker compound trigonelline (TGN). The effects of single dose oral treatment of SFSE-T (10, 30 or 100 mg/kg) were studied using animal models of PD, namely, 6-hydroxydopamine (6-OHDA)-induced unilateral lesions in rats, and 4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced neurodegeneration in C57BL/6 mice. The effects of SFSE-T on monoamino oxidase (MAO) enzyme in vitro as well as possible side effects of SFSE-T in vivo were also evaluated.

RESULTS

The concentration of TGN in a test sample of SFSE-T was found to be 82%. SFSE-T (30 mg/kg, oral) showed a significant increase in the number of ipsilateral rotations (45.67 rotations in 30-min period) as compared with vehicle control group (no rotations) when tested in 6-OHDA-induced unilateral lesioned rats. SFSE-T (30 mg/kg, oral) showed significant reversal of motor dysfunction (spontaneous motor activity scores, speed, distance traveled and number of square crossed) caused by MPTP induced lesions in C57BL/6 mice in pretreatment (1 h) schedule but not in post-treatment (1 h) schedule. SFSE-T neither showed anticholinergic effects nor showed selective MAO-B enzyme inhibition in vitro.

DISCUSSION AND CONCLUSION

SFSE-T showed reversal of motor symptoms in an animal model of PD probably through neuroprotective properties.

Quantitative determination of L-DOPA in tablets by high performance thin layer chromatography

A densitometric high performance thin-layer chromatographic (HPTLC) method was developed and validated for quantitative analysis of L-DOPA in tablets. Chromatographic separation was achieved on precoated silica gel F 254 HPTLC plates using a mixture of acetone-chloroform-n-butanol-acetic acid glacial-water (60:40:40:40:35 v/v/v/v/v) as mobile phase. Quantitative analysis was carried out at a wavelength of 497 nm. The method was linear between 100 and 500 ng/microL, with a correlation coefficient of 0.999. The intra-assay variation was between 0.26 and 0.65% and the interassay was between 0.52 and 2.04%. The detection limit was 1.12 ng/microL, and the quantification limit was 3.29 ng/microL. The accuracy ranged from 100.40 to 101.09%, with a CV not higher than 1.40%. The method was successfully applied to quantify L-DOPA in real pharmaceutical samples, including the comparison with HPLC measurements. The method was fast, specific, with a good precision, and accurate for the quantitative determination of L-DOPA in tablets.

Simultaneous enantioseparation of antiparkinsonian medication Rotigotine and related chiral impurities by capillary zone electrophoresis using dual cyclodextrin system

A dual cyclodextrin (CD) system consisting of sulfated beta-CD (S-beta-CD) and methyl-beta-CD (M-beta-CD) modified capillary zone electrophoresis (CZE) method was proposed to separate the antiparkinsonian drug Rotigotine ((-)-(S)-2-(N-propyl-N-2-thienylethylamino)-5-hydroxytetralin) and related chiral impurities (2-(N-propylamino)-5-hydroxytetralin, 2-(N-propylamino)-5-methoxytetralin). The method was optimized by varying the CD type, the buffer pH, individual CD concentration of the dual system and the ionic strength of background electrolyte. Under the optimum conditions, i.e. 2% (w/v) S-beta-CD and 2% (w/v) M-beta-CD in 100mM sodium phosphate (pH 2.5) as the running buffer, separation voltage -20 kV, detected at 200 nm and temperature controlled at 20 degrees C, a satisfactory separation of the six analytes was accomplished. The optimized method was validated for specificity, precision, linearity, accuracy and stability using sodium benzenesulfonate as the internal standard. The relative standard deviation for migration time was less than 0.58%, and 3.78% for peak area ratio. The linearity ranged from 0.005 to 0.25 mM. The recovery ranged from 95.9% to 108.3%. The limits of detection and limits of quantification for each enantiomer were 0.003 and 0.01 mM, respectively. This method was utilized for evaluating the chiral purity of five batches of Rotigotine.

3-Normeridamycin: A Potent Non-Immunosuppressive Immunophilin Ligand is Neuroprotective in Dopaminergic Neurons

3-Normeridamycin (1), isolated from fermentation extracts of the soil actinomycete Streptomyces sp. LL-C31037, demonstrated potent neuroprotective activity. When challenged with the neurotoxin 1-methyl-4-phenylpyridinium (MPP+), known to induce parkinsonism, 1 restored functional dopamine uptake in a concentration-dependent manner, with an EC50 of 110 nM in dopaminergic neurons. The structure of 1 was determined via spectroscopic methods, and the immunosuppressive and immunophilin binding properties of the compound were also measured.

Evaluation of Solid-Phase Sorbents for the Analysis of Ropinirole in Whole Blood

In this paper, the extraction and analysis of ropinirole from whole blood using solid-phase cartridges is presented. Previously published methods for the analysis of this drug have employed plasma samples using C(18) cartridges. Liquid-liquid extraction has been employed for analysis of postmortem samples. In the method, drug free blood was spiked with ropinirole (0 to 10 ng) and an internal standard (quinidine). The samples were buffered with distilled water and centrifuged. The supernatant liquid was applied to previously conditioned endcapped C(6), C(18), and C(8)/SCX solid-phase extraction columns. The columns were washed, dried, and eluted with various solvents systems. The eluants were collected and evaporated. The residue was dissolved in 100 microL of aqueous 0.1% trifluoroacetic acid and analyzed by liquid chromatography using a C(18) (4.6 x 150 mm, 5-microm particle size) column and monitored at 250 nm, using diode-array detection. A mobile phase consisting of methanol/0.1% TFA in distilled water (22:78 v/v) was employed. The data was collected and appraised. It was found that 3-mL 200-mg CEC06 C6 (Hexyl endcapped) solid-phase columns that had been washed with 3 x 3 mL water and 3 x 3 mL acetonitrile and eluted with a solvent system consisting of 95:5 v/v acetonitrile/ammonia performed best. The linear range for this analysis was found to be from 0 to 10 ng/mL. The limit of detection was determined to be 1 ng/mL with a limit of quantification of 2.5 ng/mL.

Antiparkinsonian-like effects of Plumbago scandens on tremorine-induced tremors methodology

Tremorine-induced tremors model is used to evaluate antiparkinsonian drugs because rest tremor is a sign that distinguishes Parkinson's disease (PD) from other diseases. The effects of crude ethanolic extract (CEE) and total acetate fraction (TAF) of Plumbago scandens were investigated at several doses. These extracts at doses of 125 and 250 mg/kg i.p. failed to reduce tremors in tremorine-treated mice. TAF showed significant effects only at a dose of 500 mg/kg. Both CEE and TAF at doses of 1000 and 2000 mg/kg i.p. suppressed the tremors in a dose-dependent fashion for 60 min. Biperiden, an anticholinergic drug, was used as standard at a dose of 3 mg/kg i.p. This study suggests that P. scandens is a plant with possible therapeutic value for PD.

HPLC resolution of the enantiomers of dihydroxyphenylalanine and selected salsolinol derivatives using sulfated beta-cyclodextrin

D- and L-dihydroxyphenylalanine (D- and L-DOPA) and enantiomers of the tetrahydroisoquinoline alkaloids salsolinol (SAL), 1-carboxysalsolinol (1-CSAL), and cis-3-carboxysalsolinol (3-CSAL) were chromatographed using sulfated beta-cyclodextrin (S-beta-CD) as a chiral selector in mobile phases with conventional reversed-phase ODS columns. S-beta-CD is a very effective chiral selector for SAL and 3-CSAL, less effective although still useful for resolving D- and L-DOPA, and gives only meager separation of the optical isomers of 1-CSAL. Stoichiometries of the complexes which form between S-beta-CD and SAL enantiomers are 1:1. Interactions between carboxylated substances and S-beta-CD appears to be more complex. Retention of the solutes studied is characterized by favorable negative enthalpy and unfavorable negative entropy changes. Enthalpy changes outweigh entropy values.

Separation and quantification of ropinirole and some impurities using capillary liquid chromatography

Ropinirole, 4-[2-(dipropylamino)ethyl]-1,3-dihydro-2H-indol-2-one, is a potent anti-Parkinson's disease drug developed by SmithKline Beecham Pharmaceuticals. Capillary liquid chromatography (CLC) was used for the separation and quantification of ropinirole and its five related impurities, potentially formed during its synthesis. A simultaneous optimization of three mobile phase parameters, i.e., pH, buffer concentration and acetonitrile content was performed employing an experimental design approach which proved a powerful tool in method development. The retention factors of the investigated substances in different mobile phases were determined. Baseline resolution of the six substances on a C18 reversed stationary phase was attained using a mobile phase with an optimized composition [acetonitrile-8.7 mM 2-(N-morpholino)ethanesulfonic acid adjusted to pH 6.0 (55:45, v/v)]. It was shown that CLC, operated in the isocratic mode under the mobile phase flow-rate of 4 microl/min, can determine the level of these impurities, down to a level of 0.06% of the main component within 25 min.

Determination of the dissociation constants of ropinirole and some impurities and their quantification using capillary zone electrophoresis

Ropinirole, 4-[2-(dipropylamino)ethyl]-1,3-dihydro-2H-indol-2-one, is a potent anti-Parkinson's disease drug developed by SmithKline Beecham Pharmaceuticals. Capillary zone electrophoresis (CZE) was used for the determination of the dissociation constants of ropinirole and five structurally related impurities, potentially formed during its synthesis and for separation and quantification of these substances. The dissociation constants obtained from the CZE measurements were confirmed by UV spectrophotometry for some of the test compounds, obtaining a good agreement between the values. Careful optimization of the running buffer composition permitted base-line resolution of the six compounds in a borate buffer containing acetonitrile and magnesium sulfate (a 100 mM borate buffer containing 30 mM MgSO4 and 20 vol.% of acetonitrile). It was shown that CZE can determine the level of these impurities, down to a level of 0.05% of the main component within 15 min.

[An evaluation of methods for isolating antiparkinson preparations from cadaveric material]

Methods of amedine, amyzyl, and tropacine isolation from cadaveric material, blood and urine were developed. They ensure higher output of the given substances as compared with conventional methods of isolation of toxicologically significant substances. An extraction-photometric method was developed for estimation of amedine, amyzyl, and tropacine in the cadaveric material.

[The detection and separation of antiparkinson preparations in cadaveric material by gas-liquid chromatography]

Method of gas-chromatographic detection of anti-parkinsonism substances (amedine, amysile, dinesine, midantane, tropazine and cyclodole) isolated from the cadaveric material is suggested. Conditions for separation of anti-parkinsonism substances when they are all present in the cadaveric material are developed.

[Triperidin (Norakin): separation, stability and structure of stereoisomers]

The antiparkinsonian triperiden (1; as hydrochloride Norakin) is a mixture of the stereoisomers 1a and 1b. Their identification and separation by chromatographic methods or fractional crystallisation of the tartrates is described. By means of IR- und 13C-NMR spectral data structures of 1a and 1b are proposed. Under proton catalysis 1b racemizes to 1a. In acidic solution (heating in 0.1 mol.1-1 HCl or storage in gastric juice at 37 degrees C) hydrolysis of 1 takes place and four isomeric products were observed (Z1-Z4), which arise by cleavage of the cyclopropyl moiety. The main product Z2 was identified as the 2"-hydroxy derivative. The solid drug is stable at least for 5 years.

Simultaneous determination of haloperidol and its reduced metabolite in serum and plasma by isocratic liquid chromatography with electrochemical detection

We describe a liquid-chromatographic method for simultaneous quantification of haloperidol and its reduced metabolite in plasma and serum. Haloperidol and reduced haloperidol are concentrated from blood samples by liquid/liquid extraction into a hexane/isoamyl alcohol mixture, with chlorohaloperidol as the internal standard. For chromatographic separation we used a reversed-phase cyano-bonded column and a mobile phase of pH 6.8 phosphate buffer/acetonitrile (55/45 by vol). Haloperidol and its reduced metabolite are detected electrochemically at +0.90 V potential between the working and reference electrodes. As little as 0.5 ng per injection is detectable. Within- and between-day CVs for determinations of haloperidol and reduced haloperidol ranged from 4 to 7% each at a concentration of 10 micrograms/L. Haloperidol concentrations measured by this method correlated well with those by gas-chromatography with nitrogen-sensitive detector and by radioimmunoassay. The present method can be used to study the effects of haloperidol on the central nervous system. It is simple enough for use in clinical laboratories that are monitoring haloperidol concentrations in the blood of psychiatric patients.