DNA barcode reference data for the Korean herpetofauna and their applications.

Recently, amphibians and reptiles have drawn attention because of declines in species and populations caused mainly by habitat loss, overexploitation and climate change. This study constructed a DNA barcode database for the Korean herpetofauna, including all the recorded amphibians and 68% of the recorded reptiles, to provide a useful, standardized tool for species identification in monitoring and management. A total of 103 individuals from 18 amphibian and 17 reptile species were used to generate barcode sequences using partial sequences of the mitochondrial cytochrome c oxidase subunit I (COI) gene and to compare it with other suggested barcode loci. Comparing 16S rRNA, cytochrome b (Cytb) and COI for amphibians and 12S rRNA, Cytb and COI for reptiles, our results revealed that COI is better than the other markers in terms of a high level of sequence variation without length variation and moderate amplification success. Although the COI marker had no clear barcoding gap because of the high level of intraspecific variation, all of the analysed individuals from the same species clustered together in a neighbour-joining tree. High intraspecific variation suggests the possibility of cryptic species. Finally, using this database, confiscated snakes were identified as Elaphe schrenckii, designated as endangered in Korea and a food contaminant was identified as the lizard Takydromus amurensis.

Simultaneous determination of triflusal and its major active metabolite, 2-hydroxy-4-trifluoromethyl benzoic acid, in rat and human plasma by high-performance liquid chromatography.

A rapid, selective and sensitive high-performance liquid chromatography (HPLC) method was developed and validated for the simultaneous determination of triflusal and its major active metabolite, 2-hydroxy-4-trifluoromethyl benzoic acid (HTB), in rat and human plasma. HPLC analysis was carried out using a 5-microm particle size, C18-bonded silica column and acetonitrile-methanol-water (25:10:65, v/v/v) as the mobile phase and UV detection at 234 nm. Furosemide was used as the internal standard. The method involved extraction with an acetonitrile-chloroform mixture (60:40, v/v) and evaporation to dryness with nitrogen stream. The chromatograms showed good resolution and sensitivity and no interferences by plasma constituents. The mean absolute recovery for human plasma was 93.5 +/- 4.2% for triflusal and 98.5 +/- 3.1% for HTB. The lower limits of quantification of triflusal and HTB in human plasma were 20 and 100 ng/ml, respectively. The calibration curves in human plasma were linear over the concentration range 0.02-5.0 microg/ml for triflusal and 0.1-200.0 microg/ml for HTB with correlation coefficients greater than 0.999 and with inter- or intra-day coefficients of variation (CV) not exceeding 10.0%. This assay procedure was applied to the study of metabolite pharmacokinetics of triflusal and HTB in rat and human.