Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 37
Filter
1.
Article in Chinese | WPRIM | ID: wpr-991143

ABSTRACT

Drug adulteration and contamination are serious threats to human health therefore,their accurate monitoring is very important.Allopurinol(Alp)and theophylline(Thp)are commonly used drugs for the treatment of gout and bronchitis,while their isomers hypoxanthine(Hyt)and theobromine(Thm)have no effect and affect the efficacy of the drug.In this work,the drug isomers of Alp/Hyt and Thp/Thm are simply mixed with α-,β-,y-cyclodextrin(CD)and metal ions and separated using trapped ion mobility spectrometry-mass spectrometry(TIMS-MS).TIMS-MS results showed that Alp/Hyt and Thp/Thm iso-mers could interact with CD and metal ions and form corresponding binary or ternary complexes to achieve their TIMS separation.Different metal ions and CDs showed different separation effect for the isomers,among which Alp and Hyt could be successfully distinguished from the complexes of[Alp/Hyt+y-CD+Cu-H]+with separation resolution(Rp-p)of 1.51;whereas Thp and Thm could be baseline separated by[Thp/Thm+y-CD+Ca-H]+with Rp-p of 1.96.Besides,chemical calculations revealed that the complexes were in the inclusion forms,and microscopic interactions were somewhat different,making their mobility separation.Moreover,relative and absolute quantification was investigated with an internal standard to determine the precise isomers content,and good linearity(R2>0.99)was ob-tained.Finally,the method was applied for the adulteration detection where different drugs and urine were analyzed.In addition,due to the advantages of fast speed,simple operation,high sensitivity,and no chromatographic separation required,the proposed method provides an effective strategy for the drug adulteration detection of isomers.

2.
Article in Chinese | WPRIM | ID: wpr-991145

ABSTRACT

Sialylated N-glycan isomers with α2-3 or 42-6 linkage(s)have distinctive roles in glycoproteins,but are difficult to distinguish.Wild-type(WT)and glycoengineered(mutant)therapeutic glycoproteins,cyto-toxic T lymphocyte-associated antigen-4-immunoglobulin(CTLA4-Ig),were produced in Chinese ham-ster ovary cell lines:however,their linkage isomers have not been reported.In this study,N-glycans of CTLA4-Igs were released,labeled with procainamide,and analyzed by liquid chromatography-tandem mass spectrometry(MS/MS)to identify and quantify sialylated N-glycan linkage isomers.The linkage isomers were distinguished by comparison of 1)intensity of the N-acetylglucosamine ion to the sialic acid ion(Ln/Nn)using different fragmentation stability in MS/MS spectra and 2)retention time-shift for a selective m/z value in the extracted ion chromatogram.Each isomer was distinctively identified,and each quantity(>0.1%)was obtained relative to the total N-glycans(100%)for all observed ionization states.Twenty sialylated N-glycan isomers with only α2-3 linkage(s)in WT were identified,and each isomer's sum of quantities was 50.4%.Furthermore,39 sialylated N-glycan isomers(58.8%)in mono-(3 N-glycans;0.9%),bi-(18;48.3%),tri-(14;8.9%),and tetra-(4;0.7%)antennary structures of mutant were obtained,which comprised mono-(15 N-glycans;25.4%),di-(15;28.4%),tri-(8;4.8%),and tetra-(1;0.2%)sialy-lation,respectively,with only α2-3(10 N-glycans;4.8%),both α2-3 and α2-6(14;18.4%),and only α2-6(15;35.6%)linkage(s).These results are consistent with those for α2-3 neuraminidase-treated N-glycans.This study generated a novel plot of Ln/Nn versus retention time to distinguish sialylated N-glycan linkage isomers in glycoprotein.

3.
Article in Chinese | WPRIM | ID: wpr-998774

ABSTRACT

Background Previous research indicated that isomers and alternatives of per- and polyfluoroalkyl substances (PFAS) probably disturb glucose metabolism; however, current epidemiological evidence on the associations of PFAS with fasting blood glucose is inconsistent. Besides, studies on the joint association of multiple components of PFAS and fasting blood glucose as well as the key component are scarce. Objective To evaluate the associations of PFAS isomers and alternatives with fasting blood glucose and their joint effects, as well as identify the key component among population without glucose metabolism problems. Methods We selected 923 adults without glucose metabolism problems or missing data from the Isomers of C8 Health Project in China (2015—2016). Serum PFAS isomers and alternatives and fasting blood glucose were measured using ultra-performance liquid chromatography coupled with tandem mass spectrometry (UPLC-MS/MS) and automatic biochemical analyzer. We applied multiple linear regression to explore the associations of 16 pollutants which were detected among over 80% participants with fasting blood glucose. Meanwhile, we utilized qgcomp and Bayesian kernel machine regression (BKMR) models to explore the joint effects of PFAS isomers and alternatives mixture on target outcome indicators and identify the key component. Results The average age among the 923 participants in this study was (62.4±13.8) years old, including 472 men (51.1%) and 451 women (48.9%). Among selected PFAS isomers and alternatives, the highest serum concentration was ∑3+4+5m-PFOS (perfluoro-3/4/5-methylheptanesulfonate) with a median concentration of 10.20 ng·mL−1. The concentrations of linear perfluorooctane sulfonate (n-PFOS, 9.61 ng·mL−1), perfluorooctanoic acid (PFOA, 4.55 ng·mL−1), linear perfluorohexane sulfonic acid (n-PFHxS, 2.48 ng·mL−1), 6:2 chlorinated polyfluorinated ethersulfonic acid (6:2 Cl-PFESA, 1.90 ng·mL−1), perfluoro-6-methylheptanesulfonate (iso-PFOS, 1.85 ng·mL−1), perfluorobutanoic acid (PFBA, 1.81 ng·mL−1), perfluorinated n-nonanoic acid (PFNA, 1.39 ng·mL−1), and perfluoro-1-methylheptanesulfonate (1m-PFOS, 1.27 ng·mL−1) were higher than 1.00 ng·mL−1. After being adjusted for selected confounders, PFAS isomers and alternatives were positively associated with fasting blood glucose. With 1 ln unit concentration increment of 6:2 Cl-PFESA and PFNA, the estimated changes of fasting blood glucose were 0.18 (95%CI: 0.13, 0.23) mmol·L−1 and 0.24 (95%CI: 0.18, 0.30) mmol·L−1, respectively. The multi-pollutant models indicated a joint association of PFAS isomers and alternatives mixture with fasting blood glucose. The BKMR models reveals that as the quantiles of mixture elevated from the 50th to the 75th percentile, the values of fasting blood glucose increased 0.25 (95%CI: 0.21, 0.30) mmol·L−1, and the posterior inclusion probability of PFNA was 0.92, implying that PFNA was the key component. Conclusion PFAS isomers and alternatives are positively associated with fasting blood glucose. PFNA is the key component of the joint association.

4.
Acta Pharmaceutica Sinica ; (12): 2738-2742, 2022.
Article in Chinese | WPRIM | ID: wpr-941524

ABSTRACT

To compare the neuroprotective and anti-dementia pharmacological effects of chiral oxiracetam, glutamate and calcium ions were used to establish neuronal injury models in vitro, and the protective effects of chiral oxiracetam on primary neurons were assayed by MTT. Permanent bilateral common carotid artery occlusion (2-VO)-induced rats were randomly divided into sham group, model group, galantamine 3 mg‧kg-1 group, oxiracetam groups (30, 100 and 200 mg‧kg-1), S-oxiracetam groups (30, 100 and 200 mg‧kg-1) and R-oxiracetam 200 mg‧kg-1 group. The animal experiments in the present study were performed in accordance with the Ethical Guidelines of the Laboratory Animal Welfare Ethical Committee of Peking Union Medical College. Morris water maze and step-down test were applied to evaluate the cognitive dysfunction induced by cerebral hypoperfusion in rats. Oxiracetam, S-oxiracetam and R-oxiracetam exerted protective effects on primary neuronal damage caused by various stimuli, and oxiracetam and S-oxiracetam showed better neuro-protective effects. Morris water maze and step-down results showed that oxiracetam, S-oxiracetam and R-oxiracetam improved the cognition of 2-VO rats. In summary, S-oxiracetam exerted a better neuro-protective effect than oxiracetam and R-oxiracetam.

5.
Article in Chinese | WPRIM | ID: wpr-920748

ABSTRACT

Objective To compare the effects of levo-praziquantel (L-PZQ) and dextro-praziquantel (D-PZQ) on the proliferation and activation of the human hepatic stellate cell line LX-2 in vitro. Methods LX-2 cells were stimulated with transforming growth factor-β (TGF-β). LX-2 cell proliferation was measured using the CCK-8 assay after 24 h stimulation with 0 to 50 μg/mL concentrations of praziquantel, and the gene and protein expression of type Ⅰ collagen (collagen Ⅰ), type Ⅲ collagen (collagen Ⅲ) and α-smooth muscle actin (α-SMA) was quantified in LX-2 cells using quantitative real-time PCR (qPCR) and Western blotting assays 24 h and 48 h following stimulation with 15 μg/mL praziquantel to detect LX-2 cell activation. Results There were significant differences in the survival rate of LX-2 cells between L-PZQ and D-PZQ treatments at all concentrations (F = 6.119 and 79.180, both P values < 0.05). Either L-PZQ or D-PZQ at a concentration of < 30 μg/mL showed no remarkableeffectsonthe LX-2 cell proliferation (both P values > 0.05), and L-PZQ at a concentration of > 50 μg/mL and D-PZQ at a concentration of > 40 μg/mL inhibited the LX-2 cell proliferation (both P values < 0.05), while D-PZQ at concentrations of 40 μg/mL and 50 μg/mL showed greater inhibition on LX-2 cell proliferation than L-PZQ (t = 3.419 and 8.776, both P values < 0.05). There were significant differences in the collagen Ⅰ, collagen Ⅲ and α-SMA expression in LX-2 cells at both transcriptional (F = 21.55, 79.99 and 46.70, all P values < 0.05) and translational levels (F = 20.12, 30.29 and 32.93, all P values < 0.05) among the blank control group, TGF-β stimulation group, L-PZQ treatment group and D-PZQ treatment group. L-PZQ treatment resulted in remarkable inhibition on collagen Ⅲ and α-SMA gene expression in LX-2 cells (both P values < 0.05); however, the treatment showed no remarkable inhibition collagen Ⅰ gene expression or collagen Ⅰ, collagen Ⅲ or α-SMA protein expression in LX-2 cells (all P values > 0.05). In addition, D-PZQ treatment resulted in significant inhibition on collagen Ⅰ, collagen Ⅲ and α-SMA expression in LX-2 cells at both translational and transcriptional levels (all P values < 0.05), and D-PZQ showed higher inhibition on collagen Ⅰ, collagen Ⅲ and α-SMA gene expression in LX-2 cells than L-PZQ (all P values < 0.05). Conclusions Both L-PZQ and D-PZQ inhibit the proliferation and activation of LX-2 cells, and D-PZQ shows a higher inhibitory activity than L-PZQ.

6.
Article in Chinese | WPRIM | ID: wpr-993268

ABSTRACT

Objective:To systematically review the correlation between serum Mac-2-binding protein glycosylation isomer (M2BPGi) level and hepatocellular carcinoma (HCC).Methods:The PubMed, Embase, Ovid, CBM (China Biology Medicine), Wanfang Databases were searched for studies on the correlation between serum M2BPGi level and HCC. After the selection process, 16 papers were included in this systematic review. A total of 7 810 patients were enrolled in the study, including 629 patients with HCC. The RevMan 5.2 software and R 4.1.2 software were used for the meta-analysis.Results:The elevated level of M2BPGi was significant positively associated with the risk of HCC( HR=2.28, 95% CI: 1.82-2.86, P<0.01). In Japan and Chinese groups, the elevated level of M2BPGi was significantly associated with an increased risk of HCC, with HR of 4.77 (95% CI: 2.73-8.32, P<0.01) and 2.04 (95% CI: 1.38-3.03, P<0.01), respectively. The elevated level of M2BPGi in three subgroups of people with untreated hepatitis C virus (HCV) infection, during treatment of hepatitis B virus (HBV) infection, and after HCV virological cure predicted an increased risk of HCC, with HR of 3.14 (95% CI: 2.19-4.50, P<0.01), 2.09 (95% CI: 1.36-3.22, P<0.01) and 5.07 (95% CI: 1.57-16.42, P<0.01), respectively. Conclusion:The elevated level of M2BPGi can indicate the increased risk of HCC, which can be used as one of the early warning indicators of HCC.

7.
Article | IMSEAR | ID: sea-210742

ABSTRACT

Methocarbamol is a central nervous system depressant with skeletal muscle relaxant properties indicated to treatspasms. During the synthesis of methocarbamol from guaifenesin, both potential known and an unknown impurity(0.05%–0.1%), high performance liquid chromatography) were observed. The later was separated using preparativeliquid chromatography. Upon the findings of the 1H nuclear magnetic resonance, Mass, and IR spectral analysis, theunknown impurity was designated as a β-isomer of methocarbamol [1-hydroxy-3-(2-methoxy phenoxy) propan-2-ylcarbamate]. The impurity isolation, its structure elucidation, and the potential formation mechanism are discussed.

8.
Int J Pharm Pharm Sci ; 2019 Feb; 11(2): 94-99
Article | IMSEAR | ID: sea-205841

ABSTRACT

Objective: Separation and identification of the process impurities in the manufacture of temsirolimus drug viz., rapamycin, temsirolimus regioisomer (monoester) (TS monoester), and temsirolimus diester (TS diester). Methods: During the process development of temsirolimus (TS), three process impurities-rapamycin, temsirolimus regioisomer (monoester) and temsirolimus diester-were detected by high-performance liquid chromatography (HPLC). Impurities were isolated by medium pressure liquid Chromatography (MPLC) and characterized by ESI-MS/MS, 1H NMR, FT-IR spectral data. Results: These impurities are characterised with the help of ESI MS/MS, 1H NMR, and FT-IR data. The impurities are identified and characterised as the process impurities. One of them is the starting material i.e. rapamycin and the other two are formed during the manufacture of the drug. This method offers advantages over using photodiode-array UV detection (LC-PDA) for the determination of peak purity, viz. components with similar UV spectra can be distinguished. Conclusion: The structures of these impurities were characterized as rapamycin, TS Monoester, and TS Diester. Out of these process impurities, rapamycin has been previously identified while the other two are previously unreported.

9.
Article in Chinese | WPRIM | ID: wpr-753358

ABSTRACT

Related substances in pharmaceutical formulations are associated with their safety, efficacy and stability. However, there is no overall study already published on the assessment of related substances in the Compound Ketoconazole and Clobetasol Propionate Cream. In this work, a reliable HPLC-TOF-MS qua-litative method was developed for the analysis of related substances in this preparation with a quick and easy extraction procedure. Besides the active pharmaceutical ingredients, two compounds named ke-toconazole impurity B′ optical isomer and ketoconazole impurity E were identified. Furthermore, a new HPLC method for qualitative and quantitative assessment on related substances and degradation pro-ducts, which were found in the stability test, was established and validated. The single standard to determine multi-components method was applied in the quantitative analysis, which was an effective way for reducing cost and improving accuracy. This study can provide a creative idea for routine analysis of quality control of the Compound Ketoconazole and Clobetasol Propionate Cream.

10.
Article in Chinese | WPRIM | ID: wpr-851220

ABSTRACT

Objective To study the alkaloids constituents from Cephalotaxus hainanensis. Methods The column chromatography Sephadex LH-20 and ODS were used to isolate and purify the compounds of alkaloids part of C. hainanensis. The chemical structures were identified on basis of physicochemical properties and spectral data. Results Thirteen compounds were isolated and identified as cephalotaxine (1), isocephalotaxinone (2), cephalotaxinone (3), cephalezomine G (4), (2R,3S,4S,5S)-2,3-dihydroxycephalotaxane (5), acetylcephalotaxine (6), deoxyharringtonine (7), (R)-fortunine (8), (S)-fortunine (9), isomer of 3-epi-schellhammericine (10), 1,4 (PrINH)2-anthraquinone (11), 2-ethyl-n-hexyl benzoate (12), and β-sitosterol (13). Conclusion Compounds 3-6 and 10-13 are isolated from this plant for the first time.

11.
Article in Chinese | WPRIM | ID: wpr-664894

ABSTRACT

Oligosaccharide isomers were distinguished by electron capture dissociation Fourier transform ion cyclotron resonance mass spectrometry ( ECD-FT-ICR-MS ) in combination with utiliZing alkali, alkaline earth, and transition metals ( Na+, Ca2+, Ba2+, Mg2+, Mn2+ and Co2+) as charge carriers in electrospray.Maltoheptaose, mannohexaose and laminarihexaose were taken as examples to investigate influence of metal ions on the extent of oligosaccharide fragmentation.The same types of fragmentation ions ( 0,2 A and 2,4 A) were obtained for barium- and calcium-adducted maltoheptaose.Mg2+ and Mn2+ had the similar influence ( 0,2 A, 2,4 A and 2,5 A ).Three cross-ring cleavage ions ( 1,4 A, 2,4 A and 2,5 A ) were generated in the spectrum of cobalt-associated maltoheptaose.But in the case of doping Na+into maltoheptaose, only 0,2 A ion was detected.It was found that the signals in the spectra of mannohexaose and laminarihexaose were worse than that in the spectrum of maltoheptaose, probably resulting from different numbers of adducted metal ions.The isomers, mannohexaose and laminarihexaose could be distinguished by ECD-MS in conjunction with the addition of Ca2+, Mg2+ or Co2+.The addition of Ca2+ was the best choice for analysis of oligosaccharides.

12.
Acta Pharmaceutica Sinica B ; (6): 825-832, 2018.
Article in English | WPRIM | ID: wpr-690860

ABSTRACT

The dense extracellular matrix and high interstitial fluid pressure of tumor tissues prevent the ability of anti-tumor agents to penetrate deep into the tumor parenchyma for treatment effects. C-end rule (CendR) peptides can enhance the permeability of tumor blood vessels and tumor tissues binding to neuropilin-1 (NRP-1), thus aiding in drug delivery. In this study, we selected one of the CendR peptides (sequence RGERPPR) as the parent l-peptide and substituted d-amino acids for the l-amino acids to synthesize its inverso peptide (RGERPPR). We investigated the NRP-1 binding activity and tumor-penetrating ability of (RGERPPR). We found that the binding affinity of (RGERPPR) with NRP-1 and the cellular uptake was significantly higher than that of RGERPPR. Evans Blue tests revealed that (RGERPPR) exhibited improved tumor-penetrating ability in C6, U87 and A549 tumor-bearing nude mice. Using nude mice bearing A549 xenograft tumors as a model, we found that the rate of tumor growth in the group co-administered with (RGERPPR) and gemcitabine (Gem) was significantly lower than the gemcitabine-treated group with a tumor suppression rate (TSR%) of 55.4%. Together, our results demonstrate that (RGERPPR) is a potential tumor-penetrating peptide.

13.
Article in Chinese | WPRIM | ID: wpr-790852

ABSTRACT

Objective To explore the licorice herbs principal component isomer content and percentage change in differ-ent processing and extracting conditions.Methods RP-HPLC method were used with 18 beta glycyrrhizic acid(18β-Gly)and 18 alpha glycyrrhizic acid(18α-Gly)as the basis of evaluation,determination of main components and impurities of licorice pieces,effects of processing temperature and processing time on licorice pieces and standard mixture of principal components andimpuritiesthecontentof18-Glyand18α-Glyand18β-Glyratiochange.Results Duringtheprocessof Glycyrrhizauralen-sis Fisch,increasing the processing temperature and prolonging the processing time caused the decomposition of 18β-Gly and 18α-Gly,which was the main component isomer of licorice root,and the total content of licorice root was slightly decreased. During the processing,the main components did not change the conformation,and had no effect on the proportion of the two. The content of 18β-Gly and 18α-Gly content of glycyrrhizic acid in Glycyrrhiza uralensis Fisch after processing were lower than those before processing in 18β-Gly and 18α-Gly.Conclusion The processing time of licorice pieces could not be too long,the temperature could not be too high,so as to avoid excessive loss of active ingredients.Baking conditions suitable for baking tem-perature was 65 ℃,time was 1-2 h.The processing condition was convenient,the time and the temperature were controllable, and the sample quality was stable.

14.
Chinese Pharmaceutical Journal ; (24): 1269-1272, 2017.
Article in Chinese | WPRIM | ID: wpr-858647

ABSTRACT

OBJECTIVE: To establish a method for isomer analysis of bepotastine besilate eye drops and test the stability of isomer in the preparation. METHODS: The analysis was performed on an ULTRON ES-CD chiral column (6.0 mm×150 mm, 5 μm). The mobile phase was 0.02 mol·L-1 potassium phosphate monobasic-acetonitrile(75∶25) at the flow of 0.8 mL·min-1. The column temperature was maintained at 35℃ and the detection wavelength was set at 225 nm. The injection volume was 10 μL. RESULTS: The limit of detection and limit of quantification of bepotastine besilate R-isomer were 12 and 48 ng, respectively. The linear range of bepotastine besilate R-isomer was 0.01-0.1 mg·mL-1 and the repeatability was good at high, medium and low concentrations. CONCLUSION: The method is simple and accurate, which can be used for isomer separation of bepotastine besilate and testing the stability of isomer in bepotastine besilate eye drops.

15.
Herald of Medicine ; (12): 1179-1182, 2017.
Article in Chinese | WPRIM | ID: wpr-658929

ABSTRACT

Objective To establish a HPLC method for determination of 18β-isomer in magnesium isoglycyrrhizinate. Methods The determination was performed by Agilent Extend-C18 column ( 4. 6 mm × 250 mm, 5 μm ) . Mobile phase consisted of 0. 1 mol·L-1 potassium dihydrogen phosphate buffer solution ( adjusted to pH 7. 0 with potassium hydroxide )-acetonitrile (80︰20) at the flow rate of 1.0 mL·min-1. The column temperature was 30 ℃, and the detection wavelength was set at 250 nm. Results The resolution of magnesium isoglycyrrhizinate and 18β-isomer was greater than 2.0. The linear range of them was 0.41-2.46μg·mL-1( r=0.9998) , the detection limit was 0.21 ng, and the average recovery were 100.2%,99.1%, 110.2%,RSD were 0.9%,0.1%,0.2%(n=3). Conclusion The method is simple and accurate, and can be used for determination of 18β-isomer in magnesium isoglycyrrhizinate.

16.
Herald of Medicine ; (12): 1179-1182, 2017.
Article in Chinese | WPRIM | ID: wpr-661848

ABSTRACT

Objective To establish a HPLC method for determination of 18β-isomer in magnesium isoglycyrrhizinate. Methods The determination was performed by Agilent Extend-C18 column ( 4. 6 mm × 250 mm, 5 μm ) . Mobile phase consisted of 0. 1 mol·L-1 potassium dihydrogen phosphate buffer solution ( adjusted to pH 7. 0 with potassium hydroxide )-acetonitrile (80︰20) at the flow rate of 1.0 mL·min-1. The column temperature was 30 ℃, and the detection wavelength was set at 250 nm. Results The resolution of magnesium isoglycyrrhizinate and 18β-isomer was greater than 2.0. The linear range of them was 0.41-2.46μg·mL-1( r=0.9998) , the detection limit was 0.21 ng, and the average recovery were 100.2%,99.1%, 110.2%,RSD were 0.9%,0.1%,0.2%(n=3). Conclusion The method is simple and accurate, and can be used for determination of 18β-isomer in magnesium isoglycyrrhizinate.

17.
Article in Chinese | WPRIM | ID: wpr-663466

ABSTRACT

A device to produce low temperature plasma ( LTP) was designed and constructed to serve as the ion source of a high resolution mass spectrometry, and was applied to qualitatively analyze the steroid samples. In comparison with conventional electrospray ionization mass spectrometry, low temperature plasma mass spectrometry ( LTP-MS) had some advantages such as simple sample pretreatment and less interference. Mass spectrometry and tandem mass spectrometry were used to characterize the steroid samples in this research, and it was found that the structural stability of each steroid sample was presented in its mass spectrum, while in the tandem mass spectra there were more fragments of H2 O lost. And then the fragmentation process of typical steroid samples in collision induced dissociation ( CID ) was discussed based on theoretical calculation. In addition, by comparing tandem mass spectrometry and the fragmentation process, a pair of isomers of testosterone and dehydroepiandrosterone could be distinguished successfully.

18.
China Pharmacy ; (12): 3506-3510, 2017.
Article in Chinese | WPRIM | ID: wpr-611016

ABSTRACT

OBJECTIVE:To study the affinity of penehyclidine optical isomers to muscarinic(M)receptor subtypes,and pro-vide reference for revealing the action targets and efficacy selectivity of penehyclidine. METHODS:Homology modeling,molecu-lar docking and other molecular simulation technologies were used to analyze and predict the binding energy of 4 optical isomers to M receptor subtypes and judge its affinity by comparing the binding energy of different optical isomers R1 (3R,2′R),R2 (3R, 2′S),S1(3S,2′R),S2(3S,2′S)with M receptor subtypes M1-M5. RESULTS:All the 4 optical isomers can dock into the ac-tive sites of M receptor subtypes,and different optical isomers showed great differences in the molecular docking with different M receptor subtypes. Penehyclidine isomers showed larger binding energy to M3,the binding energy of 4 optical isomers ranged in 5736.519-5907.143 kcal/mol. The binding energy of R1 to M1 was 1190.041 kcal/mol;while those of other optical isomers to each receptor subtype were lower or negative. CONCLUSIONS:R1 shows the affinity to M1 receptor. And all the 4 optical isomer show the affinity to M3.

19.
Drug Evaluation Research ; (6): 792-796, 2017.
Article in Chinese | WPRIM | ID: wpr-619695

ABSTRACT

Objective Chiral recognition for the glimepiride and glimepiride-cis-isomer by applying three amino acid (D-Lysine,L-Glutamine and L-Tyrosine) as chiral probes based on electrospray ionization mass spectrometry (ESI-MS) was achieved.Methods glimepiride/glimepiride-cis-isomer solutions were mixed with three amino acid solutions.The complex was extracted by ESI-MS and then the fragmentation abundance was investigated applying collision induced dissociation (CID) by MS/MS,which is the basis of chiral recognition for glimepiride and glimepiride-cis-isomer.Results Chiral recognition effect was achieved with the recognition rate (R) 1.61,2.92 and 2.17 for D-Lysine,L-Glutamine and L-Tyrosine respectively.Conclusion 3 kinds ofchiral amino acids were used as probes to distinguish between stereoisomers,and rapid identification of glimepiride and glimepiride cis isomer by mass spectrometry come true for the first time.

20.
Braz. j. pharm. sci ; 52(4): 595-601, Oct.-Dec. 2016. tab, graf
Article in English | LILACS | ID: biblio-951869

ABSTRACT

ABSTRACT A simple high performance thin layer chromatography (HPTLC) has been developed and validated for determination of sunitinib malate and possible impurities. The samples were applied in forms of bands on an aluminum TLC plate pre-coated with silica gel and were separated using dichloromethane: methanol: toluene: ammonia solution as the mobile phase. Sunitinib malate was thoroughly separated from impurities including E-isomer, sunitinib N-oxide and impurity B with a retention factor (RF) of 0.35±0.02. Quantitative analysis of sunitinib was carried out using a mobile phase consisting of dichloromethane:methanol:ammonia solution, RF value was 0.53±0.02 for Z isomer. Detection was performed densitometrically in absorbance mode at 430 nm. This method was found to produce sharp, symmetrical, and well resolved peaks. Linear relationship with the coefficients of determination > 0.99 was achieved over the concentration range of 27.34 to 437.5 ng/spot. This method provides robust, replicable and accurate results with acceptable sensitivity.


Subject(s)
Chromatography/classification , Anticarcinogenic Agents/analysis , Validation Study , Chromatography, High Pressure Liquid
SELECTION OF CITATIONS
SEARCH DETAIL