The Metabolism of Salidroside to Its Aglycone <i>p</i>-Tyrosol in Rats following the Administration of Salidroside

<div><p>Salidroside is one of the major phenolic glycosides in <i>Rhodiola</i>, which has been reported to possess various biological activities. In the present study the <i>in vivo</i> deglycosylation metabolism of salidroside was investigated and its aglycone <i>p</i>-tyrosol but not the original salidroside was identified as the main form in rat tissues following the administration of salidroside. After the i.v. administration of salidroside at a dose of 50 mg/kg in rats, salidroside was quantified only in the liver, kidney and heart tissues. The highest level of <i>p</i>-tyrosol was detected in the heart, followed by the spleen, kidney, liver and lungs, in order. Salidroside was detected only in the liver, in contrast, <i>p-</i>tyrosol was detectable in most tissues except the brain, and the kidney tissues contained a significant amount of <i>p-</i>tyrosol compared to the other tissues after the i.g. administration of 100 mg/kg salidroside. The excretion behaviour revealed that the administrated salidroside mainly eliminated in the form of salidroside but not its aglycone metabolite <i>p</i>-tyrosol through urine. After i.v. and i.g. administration in rats, 64.00% and 23.80% of the total dose was excreted through urine in the form of salidroside, respectively. In addition, 0.19% and 2.25% of the dose was excreted in the form of <i>p-</i>tyrosol through urine after i.v. and i.g. administration, respectively. The faecal salidroside and <i>p</i>-tyrosol concentrations were 0.3% and 1.48% of the total dose after i.v. administration, respectively. After the i.g. administration of salidroside, trace salidroside and <i>p</i>-tyrosol were quantified in faeces within 72 h. In addition, the biliary excretion levels of salidroside after i.v. and i.g. administration were 2.86% and 0.02% of the dose, respectively. The obtained results show that salidroside was extensively metabolised to its aglycone <i>p</i>-tyrosol and distributed to various organs and the orginal salidroside was cleared rapidly through urine following the administration of salidroside.</p></div

Accuracy, precision, recovery and matrix effects for the determination of salidroside in different matrixes (n = 6).

<p>Accuracy, precision, recovery and matrix effects for the determination of salidroside in different matrixes (n = 6).</p

Cumulative content of salidroside and <i>p</i>-tyrosol in biliary samples following i.v. and i.g. administration of salidroside (i.v. 50 mg/kg, i.g. 100 mg/kg) (n = 6).

<p>Cumulative content of salidroside and <i>p</i>-tyrosol in biliary samples following i.v. and i.g. administration of salidroside (i.v. 50 mg/kg, i.g. 100 mg/kg) (n = 6).</p

Cumulative content of salidroside and <i>p</i>-tyrosol in urinary samples following i.v. and i.g. administration of salidroside (i.v. 50 mg/kg, i.g. 100 mg/kg) (n = 6).

<p>Nd: not detectable.</p

Mean concentration-time profiles of (A) salidroside and (B) <i>p-</i>tyrosol in rat tissues (n = 6) obtained after i.v. administration of salidroside (i.v. 50 mg/kg).

<p>Mean concentration-time profiles of (A) salidroside and (B) <i>p-</i>tyrosol in rat tissues (n = 6) obtained after i.v. administration of salidroside (i.v. 50 mg/kg).</p

MRM chromatograms of salidroside, <i>p</i>-tyrosol and the IS in (A) a blank rat liver tissue homogenate sample, (B) a blank rat liver tissue sample spiked with salidroside (500 ng/mL), <i>p</i>-tyrosol (500 ng/mL) and the IS (200 ng/mL), (C) a rat liver tissue homogenate sample collected 0.17 h after i.v. administration of salidroside (50 mg/kg) with the IS (200 ng/mL), (D) a rat liver tissue homogenate sample collected 1 h after i.g. administration of salidroside (100 mg/kg) with the IS (200 ng/mL).

<p>MRM chromatograms of salidroside, <i>p</i>-tyrosol and the IS in (A) a blank rat liver tissue homogenate sample, (B) a blank rat liver tissue sample spiked with salidroside (500 ng/mL), <i>p</i>-tyrosol (500 ng/mL) and the IS (200 ng/mL), (C) a rat liver tissue homogenate sample collected 0.17 h after i.v. administration of salidroside (50 mg/kg) with the IS (200 ng/mL), (D) a rat liver tissue homogenate sample collected 1 h after i.g. administration of salidroside (100 mg/kg) with the IS (200 ng/mL).</p

Chemical structures of (A) salidroside, (B) <i>p-</i>tyrosol and (C) paracetamol (IS).

<p>Chemical structures of (A) salidroside, (B) <i>p-</i>tyrosol and (C) paracetamol (IS).</p

Mean concentration-time profiles of (A) salidroside and (B) <i>p-</i>tyrosol in rat tissues (n = 6) obtained after i.g. administration of salidroside (i.g. 100 mg/kg).

<p>Mean concentration-time profiles of (A) salidroside and (B) <i>p-</i>tyrosol in rat tissues (n = 6) obtained after i.g. administration of salidroside (i.g. 100 mg/kg).</p

Mass spectrometric settings.

a<p>Ion for quantification.</p

Cetyltrimethylammonium Bromide-Coated Fe₃O₄ Magnetic Nanoparticles for Analysis of 15 Trace Polycyclic Aromatic Hydrocarbons in Aquatic Environments by Ultraperformance, Liquid Chromatography With Fluorescence Detection

Accurate determination of polycyclic aromatic hydrocarbons (PAHs) in surface waters is necessary for protection of the environment from adverse effects that can occur at concentrations which require preconcentration to be detected. In this study, an effective solid phase extraction (SPE) method based on cetyltrimethylammonium bromide (CTAB)-coated Fe₃O₄ magnetic nanoparticles (MNPs) was developed for extraction of trace quantities of PAHs from natural waters. An enrichment factor of 800 was achieved within 5 min by use of 100 mg of Fe₃O₄ MNPs and 50 mg of CTAB. Compared with conventional liquid–liquid extraction (LLE), C18 SPE cartridge and some newly developed methods, the SPE to determine bioaccessible fraction was more convenient, efficient, time-saving, and cost-effective. To evaluate the performance of this novel sorbent, five natural samples including rainwater, river waters, wastewater, and tap water spiked with 15 PAHs were analyzed by use of ultraperformance, liquid chromatography (UPLC) with fluorescence detection (FLD). Limits of determination (LOD) of PAHs (log <i>K</i>_ow ≥ 4.46) ranged from 0.4 to 10.3 ng/L, with mean recoveries of 87.95 ± 16.16, 85.92 ± 10.19, 82.89 ± 5.25, 78.90 ± 9.90, and 59.23 ± 3.10% for rainwater, upstream and downstream river water, wastewater, and tap water, respectively. However, the effect of dissolved organic matter (DOM) on recovery of PAHs varied among matrixes. Because of electrostatic adsorption and hydrophobicity, DOM promoted adsorption of Fe₃O₄ MNPs to PAHs from samples of water from the field. This result was different than the effect of DOM under laboratory conditions. Because of competitive adsorption with the site of action on the surface of Fe₃O₄ MNPs for CTAB, recoveries of PAHs were inversely proportional to concentrations of Ca²⁺ and Mg²⁺. This novel sorbent based on nanomaterials was effective at removing PAHs at environmentally relevant concentrations from waters containing relevant concentrations of both naturally occurring organic matter and hardness metals