Synthesis of two new arsenolipids and their identification in fish

Abstract

Arsenolipids (AsL) of the type arsenic‐containing fatty acids (AsFA) and hydrocarbons (AsHC) are natural organoarsenic compounds present in high abundance in seafood. Since little is known about their toxicity, there is a significant concern about their health risk. Here we report the synthesis of two new AsL and their identification in fish by liquid chromatography (LC) coupled simultaneously to inductively coupled plasma mass spectrometry (ICP‐MS) and to high resolution mass spectrometry (HR‐MS). The molecular structure was elucidated on the basis of their exact mass and their product ion mass spectra. One of the synthesized AsL has been already identified in fish samples, meanwhile, the other arsenolipid is reported here as a natural product in fish. Practical applications: The synthesized AsL can be used as analytical standards to confirm the identification of AsL in different biological samples and to optimize analytical methods for their determination by liquid chromatography coupled simultaneously to ICP‐MS and HR‐MS. The material can be further used for toxicity testing of AsL and to study their uptake, bioavailability, and biotransformation. We report the synthesis of two new arsenolipids and their identification in fish by liquid chromatography (LC) coupled simultaneously to inductively coupled plasma mass spectrometry (ICP‐MS) and to high resolution mass spectrometry (HR‐MS). One of the synthesized arsenolipid has been already identified in fish samples, meanwhile, the other arsenolipid is reported for the first time here as a natural product in fish.

Human exposure to organic arsenic species from seafood

“…Complete identification of As compounds requires synthesis and further characterization (NMR). This has been achieved for two of the AsSugar compounds (Traar et al 2009) and the metabolites DMAE (Edmonds et al 1982) and DMAA (Francesconi et al 1989), and, recently, nine of the AsLipid compounds (4 AsHC and 5 AsFA) (Taleshi et al 2014, Arroyo-Abad et al 2016). …”

Organoarsenicals in Seafood: Occurrence, Dietary Exposure, Toxicity, and Risk Assessment Considerations – A Review

“…The identification and quantification of AsLipids has been made possible by concurrent analysis using LC-ICP-MS for element specific detection and ESI-MS for structural determination. − Several AsHCs and AsFAs have been synthesized for confirmation of identity. ,− However, there are still no standards or reference materials accessible for AsLipids and AsSugar phospholipids (AsSugar-PLs). For example, standards for unsaturated AsLipids are not available, which incidentally are difficult to synthesize and therefore must be isolated from fish muscle …”

Analytical Methodologies for the Determination of Organoarsenicals in Edible Marine Species: A Review

“…RP-LC is based primarily on partitioning and is used mostly for analysis of intact arsenolipids. RP chromatography coupled to ICP–MS has been employed to identify different arsenolipids in cod liver oil, , capelin oil, fish, ,,,, macroalgae, fish meal from capelin, , and cod liver. ,, In contrast to ion-exchange chromatography, RP chromatography is more prone to matrix and pH effects. ,, …”

“…Some of the applications of Q-TOF–MS in elucidation of the structure for organoarsenicals include work by McSheehy et al in the characterization of arsenic species in the kidney of a clam, Sele et al in the identification of arsenicals in marine oils, and Arroyo-Abad et al in the identification and determination of arsenolipids in fresh cod liver oil . fish, , and canned cod liver …”