The intramolecular self-assembly of bidesmosidic kalopanaxsaponins.

The phenomena of intramolecular self-assembly of bidesmosidic kalopanaxsaponins was identified for the first time in this paper. NMR (1H-NMR, NOESY), transmission electron microscopy (TEM), and molecular dynamics (MD) simulation techniques were used to compare the spatial structures of bidesmosidic kalopanaxsaponins and monodesmosidic kalopanaxsaponins. The results showed that the bidesmosidic kalopanaxsaponins formed a clustered and twisted structure in space, whereas the monodesmosidic kalopanaxsaponins were in an extended state. This discovery confirmed the presence of intramolecular self-assembly in bidesmosidic kalopanaxsaponins.

Development and validation of an UPLC-Q/TOF-MS assay for the quantitation of neopanaxadiol in beagle dog plasma: Application to a pharmacokinetic study.

Neopanaxadiol (NPD), the main panaxadiol constituent of Panax ginseng C. A. Meyer (Araliaceae), has been regarded as the active component for the treatment of Alzheimer's disease. However, few references are available about pharmacokinetic evaluation for NPD. Accordingly, a rapid and sensitive method for quantitative analysis of NPD in beagle dog plasma based on ultra-performance liquid chromatography quadrupole time-of-flight mass spectrometry was developed and validated. Analytes were extracted from plasma by liquid-liquid extraction and chromatographic separation was achieved on an Agilent Zorbax Stable Bond C18 column. Detection was performed in the positive ion mode using multiple reaction monitoring of the transitions both at m/z 461.4 → 425.4 for NPD and internal standard of panaxadiol. All validation parameters, such as lower limit of quantitation, linearity, specificity, precision, accuracy, extraction recovery, matrix effect and stability, were within acceptable ranges and the method was appropriate for multitude sample determination. After oral intake, NPD was slowly absorbed and eliminated from circulatory blood system and corresponding plasma exposure was low. Application of this quantitative method will yield the first pharmacokinetic profile after oral administration of NPD to beagle dog. The information obtained here will be useful to understand the pharmacological effects of NPD.

Tissue distribution and excretion study of neopanaxadiol in rats by ultra-performance liquid chromatography quadrupole time-of-flight mass spectrometry.

Neopanaxadiol (NPD), a major ginsenoside in Panax ginseng C. A. Meyer (Araliaceae), was reported to have neuroprotective effect. In this study, a method of ultra-performance liquid chromatography quadrupole time-of-flight mass spectrometry (UPLC/QTOF-MS) was developed and validated for quantitative analysis of NPD in tissues, urine and feces, using liquid-liquid extraction (LLE) to isolate NPD from different biological samples, and chromatographic separation was performed on an Agilent Zorbax Stable Bond C18 (2.1 × 50 mm, 1.8 µm) column with 0.1% formic acid in water and acetonitrile. All standard calibration curves were linear (all r(2) > 0.995) within the test range. After oral administration, NPD was extensively distributed to most of the tissues without long-term accumulation. The higher levels were observed in stomach and intestine, followed by kidney and liver. Approximately 64.56 ± 20.32% of administered dose in feces and 0.0233 ± 0.0356% in urine were found within 96 h, which indicated that the major elimination route was fecal excretion. This analytical method was applied to the study of NPD distribution and excretion in rats after oral intake for the first time. The results we found here are helpful for us to understand the pharmacological effects of NPD, as well as its toxicity.

[Preparation and Determination of Insulin-like Growth Factor I in Deer Antler, Heart and Blood].

OBJECTIVE: To optimize the method for preparation of the insulin-like growth factor I (IGF-I ) in deer antler, and to determine the IGF-I in deer antler, heart and blood. METHODS: Ultrasonic extraction was used to extract IGF-I from different tissues of deer with ammonia-ammonium acetate buffer, followed by ultrafiltration and solid phase extraction to concentrate and purify the samples. At the same time, ethanol precipitation method was carried out in the purification of IGF-I ultrafiltratein deer antler, a parallel test proceeded and radio immune assay (RIA) was set to determine the IGF-I in deer antler, heart and blood. RESULTS: The IGF-I (60.8 ng/g) in deer antler by solid phase extraction was only existed in 30% methanol aqueous solution which was much higher than that (46.1 ng/g) by ethanol precipitation method. The quantities of IGF-I in deer antler, heart and blood were significantly different, it was 61.9 ng/g in antler and 21.9 ng/mL in blood, while there was no IGF-I tested in deer heart. CONCLUSION: Solid phase extraction is superior to ethanol precipitation method in preparing IGF-I in deer antler and it is clear that the IGF-I contained in deer antler is significantly higher than that in deer heart and blood, so it is the best choice to take IGF-I from deer antler.

Rapid and sensitive detection of vinorelbine in the urine of tumor patients by capillary electrophoresis with tris(2,2'-bipyridyl)ruthenium(II)-based electrochemiluminescence assay.

A capillary electrophoresis method coupled with electrochemiluminescence detection for the analysis of vinorelbine (VNB) in the urine of tumor patients was established in this research. Complete determination of VNB was achieved in 8 min using a background electrolyte of 50 mmol/L phosphate buffer (pH 9.0) and a separation voltage of 15 kV. The calibration curves showed a linear range from 2.8 × 10(-10) to 1.6 × 10(-8) mol/L. The relative standard derivation for VNB was below 3.4%. The linear relationships were good and the correlation factor of VNB exceeded 0.985. The detection limits were 1.0 × 10(-11) mol/L under the optimal conditions. The developed method was applied to the sensitive determination of VNB in the urine of tumor patients.

[Progress in the study of heat shock protein 90 inhibitors].

Heat shock protein 90 is a new target of antitumor drug, the inhibitor of Hsp90 fight against tumor by destroy and degrade the structure of protein. In recent years, looking for Hsp90 inhibitor is not only via structure modifying of natural products, but also via high throughput screening and computer aided drug design to find and synthesize new kinds of Hsp90 inhibitor. Anyway, Hsp90 inhibitor has considered as an important biology target and to pay more and more attention. This review describes recent developments of small molecule Hsp90 inhibitors.