2,6-Disubstituted Piperidine Alkaloids with Neuroprotective Activity from Hippobroma longiflora.

Three new alkaloids, hipporidine A (1: ), hipporidine B (2: ), and (-)-lobeline N-oxide (3: ), were discovered from the whole plant of Hippobroma longiflora together with five known compounds (4: -8: ). Their 2,6-disubstituted piperidine structures were established based on the HRESIMS, NMR (COSY, HMBC, HSQC, NOESY), and UV spectroscopic data. Hipporidines A (1: ) and B (2: ) possess a rare 1,3-oxazinane moiety. Compound 3: is the N-oxide derivative of (-)-lobeline (6: ). Moreover, the absolute configuration of norlobeline (5: ) was established by single-crystal X-ray diffraction analysis. Three major secondary metabolites (6: -8: ) were evaluated for their neuroprotective effect against paclitaxel-induced neurotoxicity. Consequently, pretreatment with compound 8: at a concentration of 1.0 µM displayed significant attenuation on paclitaxel-damaged neurite outgrowth of dorsal root ganglion neurons without interfering with the cytotoxicity of paclitaxel on cervical cancer SiHa cells.

New smokeless moxibustion for knee osteoarthritis: A study protocol for a multicenter, single-blind, randomized controlled trial.

INTRODUCTION: Knee osteoarthritis (KOA) is a chronic inflammatory disease with high morbidity and disability. As the aging and obese population increase, so will the medical services for this disease. The purpose of this study is to compare the clinical efficacy of herbal activated carbon smokeless moxibustion and traditional moxibustion in the treatment of KOA and to determine the clinical efficacy of herbal activated carbon smokeless moxibustion in the treatment of KOA. METHODS/DESIGN: This is a multicenter, two parallel-group, single-blind, randomized controlled trial. Eighty-eight subjects with KOA (Kellgren Lawrence grade II or III) will be recruited and randomly treated with smokeless moxibustion or traditional moxibustion in the ratio of 1:1. The smokeless moxibustion group will use plant herbal activated carbon smokeless moxa cone. The traditional moxibustion group will be treated with pure moxa cone. Subjects in both groups will receive treatment at the affected knee(s) at the acupuncture point ST35, EX-LE2, and EX-LE4. Subjects in both groups will receive 3 sessions per week of moxibustion for 4 weeks. The primary outcome are changes in the Western Ontario and McMaster Universities Osteoarthritis Index pain scores from baseline to week 24. Secondary outcomes include visual analog scale, 50 yards fast walking time, short-form heath survey 36, overall clinical efficacy evaluation, self-assessment of safety, treatment credibility and expectancy, and cytokines related to osteoarthritis in serum. DISCUSSION: This randomized single-blind controlled trial takes traditional moxibustion as the control group to provide strict evidence for the clinical efficacy and safety of herbal activated carbon smokeless moxibustion in the treatment of KOA.

[Acupuncture combined with smokeless or smoky moxibustion for regulating immune function of experimental chronic rhinosinusitis mice].

OBJECTIVE: To observe the therapeutic effect of moxa fume in the treatment of chronic rhinosinusitis（CRS） and the effect of acupuncture plus smokeless moxibustion or smoky moxibustion on the expression of thymic stromal lymphopoietin (TSLP) and pituitary adenylate cyclase activating polypeptide (PACAP) proteins in the sinus mucosal tissue in CRS mice. METHODS: Sixty male C57BL/6J mice were randomly divided into 6 groups, namely normal control, sham operation, CRS model, medication, acupuncture plus smokeless moxibustion (Acu+smokeless Moxi) and acupuncture plus smoky moxibustion (Acu+smoky Moxi) groups, with 20 mice in each group. The CRS model was established by inserting a piece of polyporous sponge filled with streptococcus pneumoniae into the maxillary sinus after operation. The mice in the sham operation group received skin incision after opening the maxillary sinus. Mice of the medication group received gavage of clarithromycin 0.103 g·kg-1·d-1 for 21 days. For mice of the Acu+smokeless Moxi and Acu +smoky Moxi groups, manual acupuncture stimulation was applied to bilateral "Zusanli" (ST36), "Shenshu" (BL23) and "Hegu" (LI4) with the needles retained for 30 min, once every other day, and on the following day, moxibustion was applied to "Guanyuan" (CV4) and "Shenque" (BL23) for 20 min, once every other day. The treatment was given for 21 days. Mice of the normal, sham operation and model groups received gavage of normal saline (200 µL/d) for 21 days. Histopathological changes of the nasal mucosa were observed after H.E. staining, the TSLP and PACAP contents and expression were determined by enzyme-linked immunosorbent assay (ELISA) and immunohistochemistry, separately. RESULTS: At the end of the treatment, mice of the model group still had symptoms of nasal obstruction and runny nose, but those of the 3 treatment groups were obviously relieved in the nasal symptoms. H.E. staining showed an obvious chronic inflammatory reaction in the sinus mucosa, uneven distribution of the mucosal epithelium and necrotic and exfoliated epithelial cells, hyperplasia of fibrous tissue in the submucosa, etc. in the model group, which were relatively milder in the medication, Acu+smokeless Moxi and Acu+smoky Moxi groups, while no obvious inflammation was found in the normal group and sham operation group. In comparison with the normal group, no significant changes were found in the expression levels of PACAP and TSLP in the sham operation group (P>0.05). The expression level of PACAP was significantly lower (P<0.05) and that of TSLP significantly higher in the model group than in the normal and sham operatin groups (P<0.05). Compared with the model group, no significant changes were found in the expression of PACAP in the medication, Acu+smokeless Moxi and Acu+smoky Moxi groups (P>0.05), and the expression of TSLP was further obviously increased in the Acu+smokeless Moxi group (P<0.01), but obviously decreased in the Acu+smoky Moxi group (P<0.01). CONCLUSION: Acupuncture combined with smoky moxibustion can down-regulate the expression of TSLP protein in the nasal sinus mucosa in CRS mice, which maybe contribute to its effect in reducing the inflammatory reaction and nasal symptoms.

Smoke or smokeless moxibustion treatment for breech presentation: A three-arm pilot trial.

AIMS: We conducted a pilot trial to compare the effects of smoke and smokeless moxibustion with a control as a possible supplement to external cephalic version (ECV) for converting breech to cephalic presentation and increasing adherence to cephalic position, and to assess their effects on the well-being of the mother and child. METHODS: We used a quasi-experimental design with 3 arms: a smoke moxibustion (SM) (n = 20) and smokeless moxibustion (SLM) (n = 20) groups (20-min acupoint BL67 stimulation once or twice daily for 10-14 days), and a control group (n = 20). The participants had singleton breech presentations between 33 and 35 gestation weeks. The primary outcome was cephalic presentation at the conclusion of intervention. The secondary outcomes were cephalic presentation at birth and effects on mother and child well-being. RESULTS: At the conclusion of intervention, cephalic presentation was higher in the SLM (60.0%) than the control groups (25.0%), Relative Risk 2.40, 95% Confidence Interval [1.04-5.56]; there was no significant difference for SM. At birth, there were no significant differences in cephalic presentation or well-being. CONCLUSION: SLM treatment showed an increasing trend towards cephalic presentation at the conclusion of intervention. Although significant differences were not observed at birth possibly due to the small samples and non-randomization, moxibustion was safe, and not associated with perinatal morbidity and mortality. A randomized controlled trial with a larger sample is warranted to ascertain SLM treatment as a possible ECV supplement for converting and increasing adherence to cephalic position.

Chemical Profiling of Lobelia chinensis with High-Performance Liquid Chromatography/Quadrupole Time-of-Flight Mass Spectrometry (HPLC/Q-TOF MS) Reveals Absence of Lobeline in the Herb.

Lobelia chinensis is a kind of herbal medicine widely distributed and used in Asia. The chemical components of this herb, however, have not been well studied until now. Lobeline, as an essential and famous bioactive compound in Lobelia genus, has been assumed to be present in L. chinensis. In order to ascertain its presence and, more importantly, proper use of this herb, chemical profiling this herb with highly sensitive and high-resolution analytical mass spectrometry was applied. In this study, high-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (HPLC/Q-TOF MS) method was employed to systematically profile the chemical constituents of L. chinensis for the first time. Comparative chemical profiling study of L. chinensis and Lobelia inflata was also conducted to provide evidence whether lobeline is present or not. Piperidine alkaloids except for lobeline, alkaloid-lignan hybrids, flavonoids, polyacetylenes, nonanedioic acid, and some new phytochemicals were successfully identified in L. chinensis simultaneously. Comparing to the chemical profiles of L. inflata, lobeline was found to be absent in L. chinensis. All of the secondary metabolites in L. chinensis were determined with the HPLC/Q-TOF MS method. The absence of lobeline in L. chinensis was confirmed after this extensive study.

Lobelane analogues containing 4-hydroxy and 4-(2-fluoroethoxy) aromatic substituents: Potent and selective inhibitors of [(3)H]dopamine uptake at the vesicular monoamine transporter-2.

A series of lobelane and GZ-793A analogues that incorporate aromatic 4-hydroxy and 4-(2-fluoroethoxy) substituents were synthesized and evaluated for inhibition of [(3)H]dopamine (DA) uptake at the vesicular monoamine transporter-2 (VMAT2) and the dopamine transporter (DAT), and [(3)H]serotonin uptake at the serotonin transporter (SERT). Most of these compounds exhibited potent inhibition of DA uptake at VMAT2 in the nanomolar range (Ki=30-70nM). The two most potent analogues, 7 and 14, both exhibited a Ki value of 31nM for inhibition of VMAT2. The lobelane analogue 14, incorporating 4-(2-fluoroethoxy) and 4-hydroxy aromatic substituents, exhibited 96- and 335-fold greater selectivity for VMAT2 versus DAT and SERT, respectively, in comparison to lobelane. Thus, lobelane analogues bearing hydroxyl and fluoroethoxy moieties retain the high affinity for VMAT2 of the parent compound, while enhancing selectivity for VMAT2 versus the plasmalemma transporters.

HPLC-ESI-MS/MS of brain neurotransmitter modulator lobeline and related piperidine alkaloids in Lobelia inflata L.

There is a renewed interest in lobelia alkaloids because of their activity on the central nervous system. Lobeline, the most active of them, a nicotinic receptor ligand and neurotransmitter transporter inhibitor, is a candidate pharmacotherapy for metamphetamine abuse. In the present work, high-performance liquid chromatography coupled with electrospray ionization tandem mass spectrometry in positive ion mode was used for investigating the alkaloid profile in Lobelia inflata L. Chromatographic separations were achieved on a Gemini C6-phenyl reversed-phase column providing good peak shape and improved selectivity. Being mostly 2,6-disubstituted piperidines, lobelia alkaloids presented abundant [M + H](+) ions with typical fragmentation. Identification was possible from a few specific ions, especially those resulting from excision of one of the substituents. Based on fragmentation pattern of lobeline as reference compound, 52 alkaloids were identified in the aqueous methanolic extract of L. inflata in contrast to the previously known some 20. Structural variability of these alkaloids identified arises basically from their substituents which can be phenyl-2-ketoethyl- or phenyl-2-hydroxyethyl units as well as their methyl-, ethyl- or propyl- homologues attached in different combinations. Several propyl homologue lobelia alkaloids and five hydroxypiperidine derivatives were found in the plant at the first time. In addition to 8-O-esters of 2-monosubstituted piperidine alkaloids previously reported by us in L. inflata, a 3-hydroxy-3-phenylpropanoic acid ester of hydroxyallosedamine ring-substituted was also identified as a new natural product. High-performance liquid chromatography-electrospray ionization tandem mass spectrometry can be successfully applied to Lobeliacae plant samples in the routine screening for new and known bioactive constituents, quality control of the crude drug, lobelia herba, alkaloid production studies, breeding and chemotaxonomy.

Evaluation of mutagenic and genotoxic activities of lobeline and its modulation on genomic instability induced by ethanol.

AIM: Lobeline is a natural alkaloid derived from Lobelia inflata that has been investigated as a clinical candidate for the treatment of alcoholism. In a pre-clinical trial, lobeline decreased the preference for and consumption of ethanol, due to the modulation of the nicotinic acetylcholine receptor. However, the interaction between lobeline and ethanol is poorly known and thus there are safety concerns. The present study was conducted to evaluate the mutagenic and genotoxic effects of lobeline and assess its modulation of ethanol-induced toxicological effects. MAIN METHODS: CF-1 male mice were divided into five groups. Groups received an intraperitoneal injection of saline solution, lobeline (5 or 10mg/kg), ethanol (2.5 g/kg), or lobeline plus ethanol, once a day for three consecutive days. Genotoxicity was evaluated in peripheral blood using the alkaline comet assay. The mutagenicity was evaluated using both Salmonella/microsome assay in TA1535, TA97a, TA98, TA100, and TA102 Salmonella typhimurium strains and the micronucleus test in bone marrow. Possible liver and kidney injuries were evaluated using biochemical analysis. KEY FINDINGS: Lobeline did not show genotoxic or mutagenic effects and did not increase the ethanol-induced genotoxic effects in blood. Lobeline also protected blood cells against oxidative damage induced by hydrogen peroxide. Biochemical parameters were not altered, indicating no liver or kidney injuries or alterations in lipid and carbohydrate metabolisms. SIGNIFICANCE: These findings suggest that lobeline does not induce gene or chromosomal mutations, and that this lack of genetic toxicity is maintained in the presence of ethanol, providing further evidence of the safety of this drug to treat alcohol dependence.

Antiepileptic activity of lobeline isolated from the leaf of Lobelia nicotianaefolia and its effect on brain GABA level in mice.

OBJECTIVE: To investigate the anticonvulsant activity of the lobeline isolated from the Lobelia nicotianaefolia in chemoconvulsant-induced seizures and its biochemical mechanism by investigating relationship between seizure activities and altered gamma amino butyric acid (GABA) in brain of mice in Pentylenetetrazol (PTZ) seizure models. METHODS: The anticonvulsant activity of the isolated lobeline (5, 10, 20 and 30 mg/kg, i.p.) was investigated in PTZ and strychnine induced seizures in mice and the effect of isolated lobeline on brain GABA level in seizures induced by PTZ. Diazepam was used as reference anticonvulsant drugs for comparison. RESULTS: Isolated lobeline (10, 20 and 30 mg/kg, i.p.) significantly delayed and antagonized (P < 0.050-0.001) the onset of PTZ-induced seizures. It also antagonized strychnine induced seizures. The mortality was also prevented in the test group of animals. In biochemical evaluation, isolated lobeline (5, 10 and 20 mg/kg, i.p.) significantly increased the brain GABA level. And at dose of 30 mg/kg GABA level showed slight decrease in PTZ model. CONCLUSIONS: In our findings, isolated lobeline (20mg/kg) exhibited potent anticonvulsant activity against PTZ induced seizures. Also a biochemical evaluation suggested significant increase in barain GABA level at 20 mg/kg i.p. of isolated lobeline. Hence, we may propose that lobeline reduces epileptic seizures by enhancing the GABA release supporting the GABAergic mechanism.

Lobelane inhibits methamphetamine-evoked dopamine release via inhibition of the vesicular monoamine transporter-2.

Lobeline is currently being evaluated in clinical trials as a methamphetamine abuse treatment. Lobeline interacts with nicotinic receptor subtypes, dopamine transporters (DATs), and vesicular monoamine transporters (VMAT2s). Methamphetamine inhibits VMAT2 and promotes dopamine (DA) release from synaptic vesicles, resulting ultimately in increased extracellular DA. The present study generated structure-activity relationships by defunctionalizing the lobeline molecule and determining effects on [(3)H]dihydrotetrabenazine binding, inhibition of [(3)H]DA uptake into striatal synaptic vesicles and synaptosomes, the mechanism of VMAT2 inhibition, and inhibition of methamphetamine-evoked DA release. Compared with lobeline, the analogs exhibited greater potency inhibiting DA transporter (DAT) function. Saturated analogs, lobelane and nor-lobelane, exhibited high potency (K(i) = 45 nM) inhibiting vesicular [(3)H]DA uptake, and lobelane competitively inhibited VMAT2 function. Lobeline and lobelane exhibited 67- and 35-fold greater potency, respectively, in inhibiting VMAT2 function compared to DAT function. Lobelane potently decreased (IC(50) = 0.65 microM; I(max) = 73%) methamphetamine-evoked DA overflow, and with a greater maximal effect compared with lobeline (IC(50) = 0.42 microM, I(max) = 56.1%). These results provide support for VMAT2 as a target for inhibition of methamphetamine effects. Both trans-isomers and demethylated analogs of lobelane had reduced or unaltered potency inhibiting VMAT2 function and lower maximal inhibition of methamphetamine-evoked DA release compared with lobelane. Thus, defunctionalization, cis-stereochemistry of the side chains, and presence of the piperidino N-methyl are structural features that afford greatest inhibition of methamphetamine-evoked DA release and enhancement of selectivity for VMAT2. The current results reveal that lobelane, a selective VMAT2 inhibitor, inhibits methamphetamine-evoked DA release and is a promising lead for the development of a pharmacotherapeutic for methamphetamine abuse.

Lobeline, a piperidine alkaloid from Lobelia can reverse P-gp dependent multidrug resistance in tumor cells.

Multidrug resistance (MDR) can limit efficacy of chemotherapy. The best studied mechanism involves P-gp (P-glycoprotein) mediated drug efflux. This study focuses on MDR reversal agents from medicinal plants, which can interfere with P-gp. Rhodamine 123 accumulation assay and flow cytometry analysis were employed to screen for P-gp dependant efflux inhibitors. Lobeline, a piperidine alkaloid from Lobelia inflata and several other Lobelia species, inhibited P-gp activity. MDR reversal potential of lobeline could be demonstrated in cells treated with doxorubicin in that lobeline can sensitize resistant tumor cells at non-toxic concentrations. However, lobeline cannot block BCRP (Breast Cancer Resistance Protein) dependent mitoxantrone efflux. Lobeline could be a good candidate for the development of new MDR reversal agents.

Short-Term Effect of High Dose of Vitamin C on Coronary Flow Velocity and Coronary Flow Reserve in Healthy Young Non-Smoker Men

BACKGROUND AND OBJECTIVES: Vitamin C, water-soluble antioxidant, has been reported to restore coronary microcirculatory responsiveness and impaired coronary flow reserve in smokers. However, the effect of high dose of vitamin C on coronary circulation is unclear in nonsmokers. METHODS: We used transthoracic echocardiography to measure the coronary flow reserve, an integrated measure of coronary flow in 20 male healthy nonsmokers (26+/-3 years) before and after administration of the high dose of vitamin C. RESULTS: The coronary peak diastolic velocity was increased by 14.8% after administration of antioxidant vitamin C, whereas the coronary flow reserve did not changed. CONCLUSION: High dose of vitamin C acutely increases the coronary flow velocity without restoration of coronary flow reserve in male healthy nonsmokers.

A highly stereoselective asymmetric synthesis of (--)-lobeline and (--)-sedamine.

A highly stereoselective asymmetric synthesis of (--)-sedamine and (--)-lobeline is described from benzaldehyde in 16 and 17 steps with an overall yield of 20% and 14%, respectively. The key intermediate syn-3,4-epoxyalcohol was prepared in a highly diastereomeric fashion (>99% ee, dr) and served as a common intermediate for both alkaloids.

Lobeline inhibits nicotine-evoked [(3)H]dopamine overflow from rat striatal slices and nicotine-evoked (86)Rb(+) efflux from thalamic synaptosomes.

The present study evaluated the interaction of lobeline with neuronal nicotinic acetylcholine receptors using two in vitro assays, [(3)H] overflow from [(3)H]dopamine ([(3)H]DA)-preloaded rat striatal slices and (86)Rb(+) efflux from rat thalamic synaptosomes. To assess agonist interactions, the effect of lobeline was determined and compared to S(-)-nicotine. To assess antagonist interactions, the ability of lobeline to inhibit the effect of S(-)-nicotine was determined. Both S(-)-nicotine (0.1-1 microM) and lobeline (>1.0 microM) evoked [(3)H] overflow from superfused [(3)H]DA-preloaded striatal slices. However, lobeline-evoked [(3)H] overflow is mecamylamine-insensitive, indicating that this response is not mediated by nicotinic receptors. Moreover, at concentrations (<1.0 microM) which did not evoke [(3)H] overflow, lobeline inhibited S(-)-nicotine (0.1-10 microM)-evoked [(3)H] overflow, shifting the S(-)-nicotine concentration-response curve to the right. S(-)-Nicotine (30 nM-300 microM) increased (EC(50) value=0.2 microM) (86)Rb(+) efflux from thalamic synaptosomes. In contrast, lobeline (1 nM-10 microM) did not evoke (86)Rb(+) efflux, and the lack of intrinsic activity indicates that lobeline is not an agonist at this nicotinic receptor subtype. Lobeline completely inhibited (IC(50) value=0.7 microM) (86)Rb(+) efflux evoked by 1 microM S(-)-nicotine, a concentration which maximally stimulated (86)Rb(+) efflux. Thus, the results of these in vitro experiments demonstrate that lobeline inhibits the effects of S(-)-nicotine, and suggest that lobeline acts as a nicotinic receptor antagonist.

Effect of nicotine, lobeline, and mecamylamine on sensory gating in the rat.

In normal subjects, if an acoustic startle stimulus is immediately preceded by a small brief change in background noise intensity, the magnitude of the subsequent startle response is decreased. This prepulse inhibition (PPI) of an acoustic startle response has been shown to be associated with sensorimotor gating. PPI is disrupted in schizophrenic patients and has been linked to attentional disorders characteristic of this disease. We tested the effects of (-)-nicotine, (0.19, 0.62, and 1.9 mumol/kg IP) (equivalent to 0.03, 0.1, and 0.3 mg/kg base) and the nicotinic cholinergic receptor (nAChR) channel blocker, mecamylamine (5.0 and 50 mumol/kg IP) (equivalent to 1.0 and 10.0 mg/kg) on PPI of the acoustic startle response in the rat. Nicotine increased the PPI at the lowest prepulse signal levels but not at the stronger levels. Mecamylamine was without effect at 5.0 mumol/kg, but the 50 mumol/kg dose decreased the inhibition at both weak and strong prepulse (PP) levels. Mecamylamine (5.0 mumol/kg) pretreatment did not block the (-)-nicotine-induced increase in PPI. Lobeline (0.19, 0.62, 1.9, and 6.2 mumol/kg IP) (equivalent to 0.071, 0.23, 0.71, and 2.3 mg/kg) was without effect. These results are consistent with a mecamylamine-insensitive effect of nicotine to improve gating in normal rats. The nAChR subtype involved in producing nicotine's increase of PPI needs further investigation.

[The biological and electrophysiological parameters in the rat chronically treated with Lobelia inflata L]. / Parametri biologici ed elettrofisiologici nel ratto trattato cronicamente con Lobelia inflata L.

In this paper we have studied the rat under chronic treatment with Lobeline sulphate ip. For a three week period we have recorded, once a week, weight, rectal temperature, tail-flick, motor coordination and general activity in a one-arm radial maze and in a Boissier-Simon table. At the end of the third week surface (SEEG) and deep (DEEG) EEG were recorded both from treated and control animals. The findings are: 1) no changes was observed in weight, rectal temperature, tail-flick and motor coordination; 2) the treated rats showed an increased general activity both in a one-arm radial maze and in the Boissier-Simon table; 3) the EEG effects were analyzed and quantified, by means of Fast Fourier transform, as total power and as power in preselected bands of frequency. The lobeline sulphate seems to produce both in SEEG and hippocampus a shift toward low frequencies and in amygdala a drift toward high frequencies.

[Methods of stopping smoking]. / Méthodes d'arrêt du tabagisme.

The majority of smokers who stop smoking do it alone. The methods of stopping are aimed at helping those who cannot achieve this. The different methods used include psycho-therapy (individual-group), medication, and in the first place is nicotine chewing-gum (but also clonidine which opens a new perspective), aversive behaviour and reinforcement methods, hypnosis and acupuncture. The inadequacy of validated controlled trials by biological measurements makes it difficult to compare different methods. The levels of cessation evaluated varies as a function of recruitment, the relationship between the patient and the therapist, and between the association of the different methods. An important factor in the success resides in the motivation of the subjects explaining that the bias of recruitment readily lead to differences in the results which are superior to the action of the therapy itself. Associated to psychotherapy is the use of nicotine chewing-gum in pharmacologically dependent smokers, and seems to give good enough results. Behavioural methods have an important early success level but these are somewhat deceiving in the long-term and are not totally without risk. Acupuncture, hypnosis and the progressive reduction in nicotine levels (nicotine fading) requires controlled studies to judge their own efficacy. The frequency of failure in the first year remains the major current problem in the methods of stopping. It is convenient not only to develop maintenance strategies but also at the sociological level to diminish the environmental pressures inciting people to smoke.

Studies on vomitory effect of some acridine compounds.

Vomitory effect of 16 chosen acridine derivatives was observed on pigeons. The expected effect of the preparations as well as their interaction with, causing vomiting lobeline were considered. Two groups were distinguished: 1) preparations which alone caused vomitory reaction (C-283, C-410, C-541, C-609, C-684, C-702, C-829, C-835, C-846, C-1006 and C-1020). 2) Preparations which caused this effect while combined with a subthreshold dose of lobeline (C-429, C-516, C-666, C-857 and C-1005). Dependence of the effects on chemical structure and pharmacological activity of the compounds is discussed.