title: Rapid identification of bile acids in snake bile using ultrahigh-performance liquid chromatography with electrospray ionization quadrupole time-of-flight tandem mass spectrometry.
abstract: Snake bile, a precious traditional Chinese medicine (TCM), was used as the major ingredient of some Chinese patent drugs, such as Shedan Chuanbei powder and Shedan Chenpi powder for hundred years. However, there is still requirement for the comprehensive and definite composition of bile acids in snake bile. In order to rapidly identify the bile acids constituents in snake bile to avoid the adulteration, ultrahigh-performance liquid chromatography with electrospray ionization quadrupole time-of-flight tandem mass spectrometry (UPLC/ESI-QTOF-MS/MS) has been applied to conduct a qualitative analysis on snake bile acids. ESI ion source was used for mass spectra, and data were collected in both positive and negative ion mode. 16 kinds of reference standards, attributed to free bile acids, taurine- and glycine- conjugated bile acids, were detected and their MS behaviors were summarized. In negative ion mode, the diagnostic ions of free bile acids were obtained via the neutral losses of H2O and CO2molecules; the diagnostic ions of taurine-conjugated bile acids were at m/z 124.0068 ([C2H6NO3S]-), m/z 106.9803 ([C2H3O3S]-) and m/z 79.9568 ([SO3]-); the diagnostic ion of glycine-conjugated bile acids was at m/z 74.0242 ([C2H4NO2]-). In positive ion mode, dehydration ions, amide bond cleavage ions, and reversed Diels-Alder at A-ring ions were detected in every kind of reference. These reference MS behaviors were used for identifying bile acids without reference standards in snake bile. As a result, totally 15 compounds, including 4 pairs of isomers, were identified by comparing the retention time, exact molecular mass and fragmentation behaviors with reference standards, respectively. Tauro-3β,7α,12α-trihydroxy-5β-cholenoic acid, Tauro-△8-3β,7α,12α- trihydroxy-5β-cholenoic acid, Tauro-3α,7α,12α,23R-tetrahydroxy-5β-cholenoic acid, and Tauro-3α,7α-dihydroxy-12-oxo-5β-cholenoic acid, Taurocholic acid, Glycocholic acid, Taurochenodeoxycholic acid, Taurodeoxycholic acid and Cholic acid were detected as the common bile acids in snake bile. Tauro-△8-3β,7α,12α-trihydroxy-5β-cholenoic acid, Tauro-3α,7α,9α,16α-tetrahydroxy-5β-cholenoic acid, Tauro-3α,12α,17R,22R-tetrahydroxy-5β-cholenoic acid, and Tauro-△1,8-3β,7β,12α-trihydroxy-5β-cholenoic acid were firstly reported in this study.
authors.affiliation: Tongji School of Pharmacy, Huazhong University of Science and Technology, Wuhan 430030, China.
authors.forename: Jie
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Hubei Institute for Food and Drug Control, Wuhan 430064, China.
authors.forename: Jiao
authors.initials: J
authors.lastname: Peng
authors.affiliation: Hubei Institute for Food and Drug Control, Wuhan 430064, China.
authors.forename: Xiaoyong
authors.initials: X
authors.lastname: Chen
authors.affiliation: Tongji School of Pharmacy, Huazhong University of Science and Technology, Wuhan 430030, China.
authors.forename: Yajun
authors.initials: Y
authors.lastname: Gong
authors.affiliation: Tongji School of Pharmacy, Huazhong University of Science and Technology, Wuhan 430030, China.
authors.forename: Lesheng
authors.initials: L
authors.lastname: Wan
authors.affiliation: Tongji School of Pharmacy, Huazhong University of Science and Technology, Wuhan 430030, China.
authors.forename: Fei
authors.initials: F
authors.lastname: Gao
authors.affiliation: Tongji School of Pharmacy, Huazhong University of Science and Technology, Wuhan 430030, China.
authors.forename: Suran
authors.initials: S
authors.lastname: Gan
authors.affiliation: National Institutes for Food and Drug Control, Beijing 100050, China.
authors.forename: Feng
authors.initials: F
authors.lastname: Wei
authors.affiliation: National Institutes for Food and Drug Control, Beijing 100050, China.
authors.forename: Shuangcheng
authors.initials: S
authors.lastname: Ma
authors.affiliation: Tongji School of Pharmacy, Huazhong University of Science and Technology, Wuhan 430030, China. Electronic address: homespringchen@126.com.
authors.forename: Jiachun
authors.initials: J
authors.lastname: Chen
authors.affiliation: Hubei Institute for Food and Drug Control, Wuhan 430064, China. Electronic address: niejingwh@sina.com.
authors.forename: Jing
authors.initials: J
authors.lastname: Nie
mesh_terms: D001647:Bile Acids and Salts / Q000032:analysis*; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D004365:Drugs, Chinese Herbal / Q000737:chemistry*; D005998:Glycine / Q000031:analogs & derivatives / Q000032:analysis; D007536:Isomerism; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D053719:Tandem Mass Spectrometry / Q000379:methods; D013654:Taurine / Q000031:analogs & derivatives / Q000032:analysis
chemical_list: D001647:Bile Acids and Salts; D004365:Drugs, Chinese Herbal; D013654:Taurine; D005998:Glycine
keywords: Bile acids; Rapid identification; Snake bile; UPLC/ESI-QTOF-MS/MS