piperidines and benproperine

To investigate the enantioselective pharmacokinetic process of benproperine in healthy volunteers.. An enantiospecific HPLC method was developed and used to determine the plasma concentrations of each enantiomer. Six healthy Chinese male volunteers received an oral dose of 60 mg (+/-)-benproperine. The ratios of the enantiomers in plasma samples were measured on a chiral AGP column. The plasma concentration of each enantiomer was then calculated using the ratios of enantiomers and total concentration of the two enantiomers previously measured.. The plasma levels of (-)-(S)-benproperine were always significantly higher than those of its antipode in six volunteers. The mean AUC0-t and Cmax values for (-)-(S)-benproperine were 2.18 and 2.12 times higher than those of (+)-(R)-benproperine. There was no significant difference between the T1/2 for both enantiomers, tested by paired t test (P > 0.05). Half an hour after administration of benproperine, the S/R ratio in plasma samples was as high as 3.8, and in 2 hours it drastically decreased to about 2.2, then kept on till 24 hours.. Benproperine showed significant enantioselective pharmacokinetics in the human after an oral dose of the racemate.

Topics: Administration, Oral; Adult; Antitussive Agents; Area Under Curve; Benzhydryl Compounds; Humans; Male; Piperidines; Stereoisomerism

Pancreatic cancer (PC) is one of the most common human malignancies worldwide and remains a major clinical challenge. Here, we found that benproperine phosphate (BPP), a cough suppressant, showed a significant anticancer effect on PC both in vitro and in vivo via the induction of autophagy-mediated cell death. Mechanistic studies revealed that BPP triggered AMPK/mTOR-mediated autophagy initiation and disturbed Ras-related protein Rab-11A (RAB11A)-mediated autophagosome-lysosome fusion, resulting in excessive accumulation of autophagosomes. Inhibition of autophagy or overexpression of RAB11A partially reversed BPP-induced growth inhibition in PC cells, suggesting that BPP might induce lethal autophagy arrest in PC cells. In conclusion, our results identify BPP as a potent antitumor agent for PC via the induction of autophagy arrest, therefore providing a new potential therapeutic strategy for the treatment of PC.

Topics: Animals; Antitussive Agents; Autophagy; Benzhydryl Compounds; Cell Line, Tumor; Drug Repositioning; Humans; Male; Mice; Mice, Inbred BALB C; Mice, Nude; Pancreatic Neoplasms; Piperidines; Xenograft Model Antitumor Assays

Metastasis is the leading cause of cancer mortality and cancer cell migration is an essential stage of metastasis. We identified benproperine (Benp, a clinically used antitussive drug) as an inhibitor of cancer cell migration and an anti-metastatic agent. Benp selectively inhibited cancer cell migration and invasion, which also suppressed metastasis of cancer cells in animal models. Actin-related protein 2/3 complex subunit 2 (ARPC2) was identified as a molecular target of Benp by affinity column chromatography with Benp-tagged Sepharose beads. Benp bound directly to ARPC2 in cells, which was validated by pull-down assay using Benp-biotin and label-free biochemical methods such as the drug affinity responsive target stability (DARTS) and cellular thermal shift assay (CETSA). Benp inhibited Arp2/3 function, showing disruption of lamellipodial structure and inhibition of actin polymerization. Unlike Arp2/3 inhibitors, Benp selectively inhibited the migration of cancer cells but not normal cells. ARPC2-knockdown cancer cells showed defective cell migration and suppressed metastasis in an animal model. Therefore, ARPC2 is a potential target for anti-metastatic therapy, and Benp has the clinical potential to block metastasis. Furthermore, Benp is a useful agent for studying the functions of the Arp2/3 complex in cancer cell migration and metastasis.

Topics: Actin-Related Protein 2-3 Complex; Animals; Antineoplastic Agents; Benzhydryl Compounds; Cell Movement; Dose-Response Relationship, Drug; Female; HeLa Cells; Humans; Mice; Mice, Inbred BALB C; Mice, Nude; Neoplasm Metastasis; Piperidines; Protein Structure, Secondary; Protein Structure, Tertiary; Xenograft Model Antitumor Assays

The interaction between benproperine (BEN) and human serum albumin (HSA) has been simulatively and experimentally investigated based on docking, fluorometric, thermodynamic, and spectroscopic approach. The blind Autodock docking study first recognized the hydrophobic cavity of HSA at Domain IB as the probable binding site for BEN. BEN bound to HSA via a static quenching mechanism, resulting in the formation of BEN-HSA complex confirmed by fluorescence quenching and time-resolved fluorescence. Fluorescence titration and isothermal titration calorimetry (ITC) revealed that the binding mode between BEN and HSA owning moderate affinity (binding constant at 10

Topics: Benzhydryl Compounds; Binding Sites; Calorimetry; Fluorescence; Fluorometry; Humans; Molecular Docking Simulation; Piperidines; Serum Albumin; Thermodynamics

In the present paper, improved partial least squares (PLS) method was used to parse near infrared (NIR) reflectance spectrum of Cofrel medicine. The contents of benproperine phosphate, a availability pharmaceutical in Cofrel medicine, were accurately nondestructively quantitatively predicted. The best number of principal components (PC) was designed by scores plot of samples in PC. The effects of the wavelength range, conventional spectra, first-derivative spectra and second-derivative spectra on the results were discussed respectively. Comparing the results with those of HPLC, the relative errors(RE%) of benproperine phosphate were less than 0.42%. The analytical results were sufficient for practical manufacture of Cofrel medicine.

Topics: Algorithms; Antitussive Agents; Benzhydryl Compounds; Chromatography, High Pressure Liquid; Least-Squares Analysis; Piperidines; Principal Component Analysis; Reproducibility of Results; Spectroscopy, Near-Infrared; Technology, Pharmaceutical

Two novel metabolites of benproperine (BPP), 1-[1-methyl-2-[2-(phenylmethyl)phenoxy]ethyl]-3-piperidinol (3-OH-BPP) and 1-[1-methyl-2-[2-(phenylmethyl)phenoxy]ethyl]-4-piperidinol (4-OH-BPP), were confirmed by comparison of retention times and mass spectra with those of synthetic standards using liquid chromatography-tandem mass spectrometry. Selective and sensitive procedures were developed for the simultaneous determination of BPP, 3-OH-BPP and 4-OH-BPP in human plasma and urine. The analytes were extracted from plasma sample and enzymatically hydrolyzed urine samples by liquid-liquid extraction, separated through a Diamonsil C(18) column (150 mm x 4.6 mm i.d.) and determined by tandem mass spectrometry with an electrospray ionization interface in selected reaction monitoring mode. Dextromethorphan was used as internal standard. The mobile phase consisted of acetonitrile-water-formic acid (34:66:1, v/v/v), and flow-rate was 0.5 ml min(-1). This method has a lower limit of quantification (LLOQ) of 60, 4.0 and 4.0 nmol l(-1)for BPP, 3-OH-BPP and 4-OH-BPP in plasma, 4.9, 4.7 and 2.4 nmol l(-1) in urine, respectively. The intra- and inter-run precision were measured to be below 9.2%, and the accuracy was within +/-4.3% for the analytes. The method was successfully used to determine BPP, 3-OH-BPP and 4-OH-BPP in plasma and urine for pharmacokinetic investigation. The results indicated residue of 3-OH-BPP in the body at least 192 h after an oral dose of BPP.

Topics: Antitussive Agents; Benzhydryl Compounds; Calibration; Chromatography, Liquid; Humans; Piperidines; Reproducibility of Results; Sensitivity and Specificity; Spectrometry, Mass, Electrospray Ionization

To identify 4 unknown metabolites of benproperine (BPP, 1) in human urine after a po dose, and to investigate the antitussive effect of monohydroxylate metabolites.. The putative metabolite references were prepared using chemical synthesis. Their structures were identified using 1H and 13C nuclear magnetic resonance, and mass spectrometry. The metabolites in human urine were separated and assayed using liquid chromatography-ion trap mass spectrometry (LC/MS/MS), and further confirmed by comparison of their mass spectra and chromatographic retention times with those of synthesized reference substances. The antitussive effects of metabolites were evaluated on coughs induced by 7.5% citric acid in conscious guinea pigs.. 1-[1-Methyl-2-[2-(phenylmethyl)phenoxy]-ethyl]-4-piperidinol (2), 1-[1-methyl-2-[2-(phenylmethyl)phenoxy] ethyl]-3-piperidinol (3) and their glucuronides 4 and 5 were obtained from chemical synthesis. Four urinary metabolites in human urine showed peaks with the same chromatographic retention times and mass spectra in LC/MS/MS as synthetic substances 2, 3, 4 and 5. Phosphates of compounds 2 and 3 prolonged the latency of cough and reduced the number of coughs during the 3 min test using citric acid, but did not reduce the number of coughs during the 5 min immediately after the test in conscious guinea pigs.. Compounds 2, 3, 4, and 5 were identified as the metabolites of BPP in human urine. Among them, compounds 2 and 3 are inactive in the antitussive effect.

Topics: Adult; Animals; Antitussive Agents; Benzhydryl Compounds; Chromatography, Liquid; Citric Acid; Cough; Female; Guinea Pigs; Humans; Male; Piperidines; Spectrometry, Mass, Electrospray Ionization

The anti-tussive effect of the R-(+)- and S-(-)-enantiomers of benproperine was evaluated and compared with that of the racemate on cough induced by 7.5% citric acid in conscious guinea-pigs. All the three compounds, intraperitoneally administered 1.5 h before the test, significantly inhibited citric-acid-induced cough. The ID50 values (effective doses for 50% inhibition) (with 95% confidence intervals) were 16.1 (9.1-28.4), 23.3 (11.2-48.6), 25.4 (11.7-55.1) mg kg(-1) for the number of coughs in the 3 min of challenge, and 11.9 (5.3-26.6), 13.5 (5.6-32.4), 19.2 (12.8-28.9) mg kg(-1) for the number of coughs in the 5 min immediately after the challenge, for (+/-)-benproperine, R-(+)-benproperine and S-(-)-benproperine, respectively. These findings suggest that the use of either enantiomer does not show any advantage over the racemate with regard to their anti-tussive effect.

Topics: Animals; Antitussive Agents; Benzhydryl Compounds; Citric Acid; Cough; Disease Models, Animal; Dose-Response Relationship, Drug; Female; Guinea Pigs; Male; Piperidines; Stereoisomerism; Time Factors

To investigate the hydroxylation process of benproperine in humans.. After an oral administration of 60 mg benproperine to ten healthy male volunteers, urine samples collected within 0-24 h were extracted by solid phase extraction and analyzed by liquid chromatography-ion trap mass spectrometry. A microbial transformation of benproperine combined with semi-preparative HPLC was used to get two reference substances of the hydroxylated metabolites, and their structures were then elucidated by NMR. Furthermore, the structures of conjugated metabolites were speculated based on their characteristics in MS fragmentation.. Five hydroxylated metabolites of benproperine and some of their conjugates with endogenous glucuronic acid or sulfuric acid were found in urine of volunteers after the dose. The structures of two metabolites were identified as 4"-hydroxybenproperine and 4"'-hydroxybenproperine by comparison of HPLC retention times and mass spectra with those of authentics obtained from the microbial transformation.. Hydroxylation of benproperine occurs preferentially at para-position of the alkoxyl group in the aromatic ring. The hydroxylated metabolites of benproperine in human urine mainly exist as their glucuronic acid or sulfuric acid conjugates.

Topics: Adult; Antitussive Agents; Benzhydryl Compounds; Chromatography, High Pressure Liquid; Humans; Hydroxylation; Male; Molecular Structure; Piperidines; Spectrometry, Mass, Electrospray Ionization