A novel reductive amination method with isotopic formaldehydes for the preparation of internal standard and standards for determining organosulfur compounds in garlic

• Published in: Food chemistry Vol. 197; no. Pt A; pp. 692 - 698
• Main Authors: Tsai, De-Cheng, Liu, Meng-Chieh, Lin, Yi-Reng, Huang, Mei-Fang, Liang, Shih-Shin
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 15.04.2016
• Subjects: Amination; Cysteine - analogs & derivatives; Cysteine - analysis; Formaldehyde - chemistry; Garlic - chemistry; Organosulfur compounds (OSCs); Plant Extracts - analysis; Reductive amination; Reference Standards; S-allylcysteine (SAC); S-allylcysteinine sulfoxide (alliin); S-ethylcysteine (SEC); S-methylcysteine (SMC); Sulfoxides - analysis; Tandem Mass Spectrometry; Reductive amination; Organosulfur compounds (OSCs); S-allylcysteine (SAC); S-allylcysteinine sulfoxide (alliin); S-methylcysteine (SMC); S-ethylcysteine (SEC)
• ISSN: 0308-8146; 1873-7072
• DOI: 10.1016/j.foodchem.2015.11.022

•Cheap, simple, convenient and fast fabrications of standards and internal standards.•Standards and internal standards are fabricated by reductive amination with isotopic formaldehydes.•Absolute quantification of SAC, SMC, SEC and alliin to garlic extraction.•SEC and SMC are extracted by water better than by methanol. Garlic (Allium sativum) is a long-cultivated plant that is widely utilized in cooking and has been employed as a medicine for over 4000years. In this study, we fabricated standards and internal standards (ISs) for absolute quantification via reductive amination with isotopic formaldehydes. Garlic has four abundant organosulfur compounds (OSCs): S-allylcysteine, S-allylcysteinine sulfoxide, S-methylcysteine, and S-ethylcysteine are abundant in garlic. OSCs with primary amine groups were reacted with isotopic formaldehydes to synthesize ISs and standards. Cooked and uncooked garlic samples were compared, and we utilized tandem mass spectrometry equipped with a selective reaction monitoring technique to absolutely quantify the four organosulfur compounds.