[Metabolites of tanshinone â and tanshinone â ¡A in vivo in rats].

An efficient method of ultra-high performance liquid chromatography coupled with linear ion trap-Orbitrap (UHPLC-LTQ-Orbitrap) mass spectrometer was established to elucidate the in vivo metabolites of tanshinone Ⅰ and tanshinone ⅡA in rats. Urine and plasma samples were collected after oral gavage. After processing biological sample by solid phase extraction, Waters ACQUITY HPLC BEH C18 column (2.1 mm×100 mm, 1.7 µm) was used with 0.1% formic acid (A) - acetonitrile (B) solution as the mobile phase for gradient elution. The plasma, urine and the blank samples were then analyzed by ESI-LTQ-Orbitrap equipped with an ESI ion source under positive ion mode. On the basis of the accurate mass measurements, multiple mass spectra and comparison of data with published literature, a total of 26 metabolites were tentatively identified and characterized in the rat samples. Among them, 7 metabolites were derived from tanshinone Ⅰ through metabolic pathways of glucuronide conjugation, hydroxylation, reduction reaction, demethylation reaction, methylation, sulfate conjugation and their composite reactions. Nineteen metabolites were derived from tanshinone ⅡA through metabolic pathways of hydroxylation, reduction reaction, methylation, sulfate conjugation, glucuronidation, glucosylation and their complicated reactions. The results showed that the metabolism of tanshinone Ⅰ and tanshinone ⅡA in rats could be comprehensively clarified by using UHPLC-LTQ-Orbitrap mass spectrometer, providing material basis for the further research in terms of pharmacodynamics, toxicology, and secondary development of Chinese medicine.

Dehydroabietic acid as a biomarker for exposure to colophony.

BACKGROUND: Colophony (rosin) is a natural product derived from the resin of coniferous trees with many industrial applications including soldering fluxes. Exposure to colophony fume through soldering is one of the leading causes of occupational asthma in the UK. AIMS: To assess occupational exposure to colophony from solder fume at selected workplaces in the UK and to investigate the use of dehydroabietic acid (DHA) as a biomarker of exposure. METHODS: Six companies in the UK electronics industry were visited and occupational hygiene assessments of extent and control of exposure to rosin-based solder flux fume were undertaken. Urine samples were analysed for one of the main constituents of rosin, DHA. RESULTS: There was a positive linear relationship between airborne exposure to solder fume and urinary DHA level. The levels of urinary DHA measured in UK workers were significantly lower than those previously measured in African workers because of the use of appropriate exposure control measures, for example, local exhaust ventilation with fixed ducting and flexible hose, tip extraction, etc. It is suggested that good occupational hygiene practice would result in urinary DHA levels of <3 micromol/mol creatinine in a post-shift urine sample. CONCLUSIONS: Urinary DHA is a valid biomarker of exposure to colophony in solder fume. Further work on the excretion kinetics of urinary DHA, the possibility of skin absorption and further occupational hygiene surveys would be beneficial.