Quantification of Glucuronide Metabolites in Biological Matrices by LC-MS/MS

In Vitro Metabolism of Montelukast by Cytochrome P450s and UDP-Glucuronosyltransferases

“…Our data broadly agree with a previous study showing much higher Cl int for the formation of acyl-glucuronide than any of the oxidative metabolites in HLMs , although their findings were not discussed in the context of the contribution of oxidation versus glucuronidation to montelukast metabolism. In contrast, relatively low yield of acyl-glucuronide was reported in human bile collected for a brief period of time (4-6 hours) , which could be attributable in part to low stability of acyl glucuronides, particularly at neutral or slightly alkaline conditions during sample preparation (Faed, 1984;Trontelj, 2012). Since UGT1A3 is expressed in the gut and liver (Ritter, 2007), it is also possible that montelukast is conjugated before it reaches the systemic circulation.…”

Simultaneous quantification of mycophenolic acid and its glucuronide metabolites in human plasma by an UPLC–MS/MS assay

“…Either a hydrolysis or an acyl migration can occur (de Loor et al, 2008;Horng et al, 2013;Shipkova et al, 2000;Trontelj et al, 2012). Hydrolysis leads to the regeneration of the pharmacologically active parent drug.…”

A rapid and sensitive UPLC–MS/MS method for the simultaneous quantification of serum androsterone glucuronide, etiocholanolone glucuronide, and androstan-3α, 17β diol 17-glucuronide in postmenopausal women

“…The previously reported quantitation methods of steroid glucuronides have been applied to the matrix urine at high steroid concentrations [8][9][10][11][12][13][14][15][16][17][18][19][20][21]. In the present work, we develop a fully validated liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the simultaneous direct quantitation of androsterone glucuronide (ADT-G), etiocholanolone glucuronide (Etio-G) and androstan-3a, 17b diol 17-glucuronide (3a-diol-17G) in human serum.…”

“…In most cases, the sample preparation procedures for LC-MS/MS are much simpler than for GC-MS/MS, among which are solid phase, liquid-liquid and protein precipitation extractions [8][9][10]. Therefore, LC-MS/MS appears well-suited for the quantification [11][12][13][14][15][16] and characterization [17][18][19][20][21] of steroid glucuronides in different biological matrices such as urine [8][9][10][11][12][13][14][15][16][17][18][19][20][21], serum [2,3] and tissue [22]. Using liquid-liquid extraction, a highly acidic buffer and polar extraction solvent such as ethyl acetate are required [11], resulting in the co-extraction of many other polar compounds which could potentially interfere with the investigated steroid glucuronides and affect the column life time.…”

“…If the sensitivity of the target glucuronides permits, the direct and simple protein precipitation can be a choice. On the other hand, solid phase extraction (SPE) is most suitable for sample preparation of steroidal glucuronides since this technique is less laborious and easy to automate resulting in cleaner samples [8][9][10].…”