Biomedical subjects

Yuqing Sun

Publications and source records attributed to Yuqing Sun.

8 recordsLinked to original sources

PubMed2006

Single-based resolution for oligodeoxynucleotides and their phosphorothioate modifications by replaceable capillary gel electrophoresis.

A replaceable capillary gel electrophoretic (replaceable CGE) method was developed for the separation of two sets of model compounds of single-stranded oligodeoxynucleotide mixtures (18-20 mers), phosphodiester oligodeoxynucleotides (PO-ODNs) and their phosphorothioate modifications (PS-ODNs), with equal sequences differing in a single base. Polyethylene glycol (PEG) 35000 was chosen as the sieving matrix. It was confirmed that PEG polymer solution less influenced resolutions of the PS-ODNs compared with those of the PO-ODNs, while acetonitrile used as an additive in the system improved the separation significantly. It was also noticed that the effect of temperature on separation was much larger than that of denaturant urea.

Acetonitriles↗

PubMed2006

[Study on the fingerprints of Fructus Forsythiae by high performance capillary electrophoresis].

The capillary electrophoresis fingerprints (CEFP) of Fructus Forsythiae was established to control its quality. The background electrolyte (BGE) was a 75 mmol/L sodium borate solution adjusted to pH 9.7 with 0.1 mmol/L NaOH solution. The detection wavelength was 228 nm and a voltage of 14 kV was applied. The Forsythia suspensa (Thunb.) Vahl was extracted by water and a set of CEFP containing 29 peaks was obtained. The CEFP had acceptable precision and reproducibility with the relative standard deviation (RSD) of the relative migration time less than 5.0% and the RSD of the relative peak area from 2% to 15%. There were good similarities between the standard CEFP and each set of CEFP of Forsythia suspensa (Thunb.) Vahl from ten different places, and their similarity coefficients were not less than 0.94. The CEFP were also evaluated by the information index I and the relative information index Ir, of chromatographic fingerprint.

Borates↗

PubMed2004

[Discussion on the expression of retention factor in capillary electrochromatography].

On the assumption that the component electrophoresis factor does not have parametric interaction with its chromatographic behavior in capillary electrochromatography, two new retention factor expressions k*CEC = k' - microep/microeo + microep (I) and k**CEC = k'microep - micro(0)ep/microeo + microep (II) are deduced, and they are complementary to each other. Two expressions of component retention factor in the literature, kCEC = k' + k' (microep + microep/microeo + microeo (III) and kCEC = k' microep/microeo/1 + microep/microeo (IV), are discussed. Wrong citation of the component electrophoresis migration distance expression in the deduction of expression (III) is pointed out. But the expressions (I) and (IV) also can't reflect the influences of microep and k' on kCEC under some conditions. The expression (II) can make up the limitation of the above expressions, especially when microeo = 0. Expressions (I) and (II) can reflect the integrated effect of component chromatographic and electrophoretic behaviors.

Chromatography, High Pressure Liquid↗

PubMed2004

[Determination of four nucleosides in Banlangen injections using capillary zone electrophoresis].

The contents of cytidine, adenosine, guanosine and uridine in Banlangen Injections were determined by capillary zone electrophoresis. Shorter fused silica capillary (32.5 cm x 50 microm i. d. with effective length of 23.5 cm) was used. The samples were analyzed with 60 mmol/L borate-10% (v/v) 2-propanol-20% (v/v) acetonitrile running buffer at 20 kV voltage (25 degrees C capillary temperature). Pressure injection of 1 kPa x 10 s was employed, and the detection wavelength was 254 nm. Factors of the electrophoresis condition were investigated, such as the kinds and concentration of the electrolyte, buffer pH value, the type and concentration of organic modifier, separation voltage and temperature. The samples were filtered through 0.45 microm membrane, then direct injection was employed. External calibration of peak area versus concentration was used in the determination. Linear calibrations of four nucleosides were obtained within 12.5 - 250 mg/L (r > 0.999 1). The limits of detection (mg/L) were 6.2 of cytidine, 4.6 of adenosine, 6.7 of guanosine, and 9.0 of uridin. The average recoveries of the four nucleosides were between 95.1% - 102.3% with RSDs of 0.3% - 4.9%. The method is simple, rapid, reproducible and accurate. It can be used for the routine analysis of the four nucleosides in Banlangen Injections.

Adenosine↗

PubMed2004

[Study on the fingerprints of Belamcanda chinensis (L.) DC by capillary electrophoresis].

A capillary electrophoresis fingerprints (CEFP) method was established to evaluate the quality of Belamcanda chinensis (L.) DC. The background electrolyte (BGE) was a 80 mmol/L boric acid containing 15 mmol/L borate solution (adjusted pH 9.7 with KOH solution). The detection wavelength was 228 nm and 12.1 kV was applied. The Belamcanda chinensis (L.) DC was extracted by water to obtain a CEFP containing 21 peaks. The CEFP has good precision, reproducibility and stability with the relative standard deviations (RSDs) of the relative migration time less than 3.5% and the RSDs of the relative peak area about 5.0%. There were good similarities between the standard CEFP and each CEFP of samples collected from ten different places. The coefficients were from 0.913 to 0.993. Meanwhile, fundamental studies related to the methods in peak identification of fingerprints and content evaluation of different sample constituents were carried out.

Boric Acids↗

PubMed2003

Analysis of Paeoniae Radix by high-performance liquid chromatography-electrospray ionization-mass spectrometry.

A method has been developed for the qualitative analysis of paeonol, paeoniflorin and their derivatives in Paeoniae Radix by high-performance liquid chromatography-electrospray ionization-mass spectrometry (HPLC-ESI-MS). Gradient elution with acetonitrile-water solvent system was employed in an HPLC-ESI-MS study. The negative-ion ESI mode was suitable for these compounds. The peaks were identified by their mass spectra, UV spectra and fragments of their MS2 spectra. The structures of three unknown compounds are inferred in this paper.

Journal Article↗

PubMed2003

The quality assessment of compound liquorice tablets by capillary electrophoresis fingerprints.

Capillary electrophoresis (CE) is a powerful separation technique that is peculiarly able to determine the fingerprints of traditional Chinese medicine. The Capillary Electrophoresis Fingerprints (CEFP) of compound liquorice tablets (CLTs) was established to evaluate the quality of CLTs. The background electrolyte was a 50 mM sodium borate solution. The detection wavelength was 228 nm and a 14 kV voltage was applied. Hydrochlorothiazide served as an internal standard and temperature was 24-25 degrees C. The CLTs were extracted by a 50 mM borate solution containing 10% (v/v) methanol. The results showed that CE was a powerful tool for detecting of the fingerprints of traditional Chinese medicine and their constituents. The quality assessments were performed to compare the correlation coefficients (R) and cos theta (C) between each batch vector of CLTs and the total standard profile vector (TSPV), which was the mean vector of all the batch vectors of CLTs with 1.0. The nearer to 1.0 was the R or C, the higher was the similarity. The values of R and C between the TSPV and each batch vector of CLTs produced at different factories were all above 0.9150. The values of R and C between every two standard profile vectors (SPV) from different factories were all above 0.9420. A good stability and reproducibility of the CEFP of CLTs were obtained in the study. Further, we first put forward a new parameter Q to evaluate both the quantification accuracy and the qualitative accuracy for a CEFP, which was verified by determinations of GHIA, GHEA, MP and SB in CLTs. The CEFP was successfully employed to assess the quality of CLTs produced at Kunming Pharmaceutical Factory to be good.

Electrophoresis, Capillary↗

PubMedDate not supplied

Semipreparative separation and determination of eleutheroside E in Acanthopanax giraldii Harms by high-performance liquid chromatography.

A method for the isolation, purification, and determination of eleutheroside E in Acanthopanax giraldii Harms, collected in the Sichuan province (China), is established. The water extraction of A. giraldii Harms is pre-isolated using macroporous adsorption resin (D-101) and a C18 solid-phase extraction cartridge, and the enriched extract is purified to give eleutheroside E (syringaresinol-di-O-beta-D-glucoside; liriodendrin) by semipreparative reversed-phase high-performance liquid chromatography. Structure identification is performed by a comparison of IR, 1H-NMR, 13C-NMR, and electrospray ionization-mass spectrometric data with the literature. The final purity of the compound is 97%. Quantitative determination of eleutheroside E in A. giraldii Harms is performed on a Zorbax SB C18 (150- x 4.6-mm i.d., 5 microm) column. The linear range of eleutheroside E is 4.85-194 mg/L (r = 0.9998), and the average recovery is 99.6-101%. The developed method is simple, reproducible, and easy to operate. It is useful for the evaluation of Acanthopanax giraldii Harms.

Chromatography, High Pressure Liquid↗