Valeria Tegolaa, Chiara Melchiorrea,b, Michela Varraa, Carmela Dell'Aversanoa,b

aUNINA DF, University of Naples Federico II, School of Medicine and Surgery, Department of Pharmacy, Napoli, Italy
bNBFC, National Biodiversity Future Center, Palermo, Italy c WHOI, Woods Hole Oceanographic Institution, Woods Hole, MA, USA

Ostreopsis cf. ovata, a marine dinoflagellate typically found in tropical and subtropical regions, has recently emerged as a growing concern due to its expanding global distribution, contributing to the increasing frequency of Benthic Harmful Algal Blooms (BHAB) [1]. The toxic effects of this species on humans and marine environment are attributed to ovatoxins (OVTXs), a class of marine neurotoxins structurally related to palytoxin (PLTX). Human exposure to contaminated seawater can result in skin and eye irritation, respiratory issues, and muscle pain [2]. Despite the recognized health risks associated with OVTXs, the lack of well-characterized reference materials (RMs) for these toxins remains a significant challenge for accurate detection and risk assessment. The isolation procedure consists of 4 steps: Extraction, Medium Pressure Liquid Chromatography (MPLC), Semi-preparatory High Pressure Liquid Chromatography (HPLC-step 1) and Preparatory HPLC (HPLC-step 2). 

This procedure has been recently optimized and led to separate OVTX-a from the other analogues (OVTX-d/e and isobaric PLTX) and from the other contaminants/metabolites contained in the cell pellet, obtaining mg amounts of OVTX-a at a high purity grade (>94%) [4]. In order to make this isolation procedure applicable in as many laboratories as possible, HPLC-Step1 and Step2 of the method were transferred on a HPLC-UV platform. This is a key objective for the preparation of OVTX-RM to be used for analytical and toxicological purposes, both necessary to facilitate the implementation of the most appropriate measures to protect public health.

Acknowledgements: Participation of CM was funded by a Project funded under the National Recovery and Resilience Plan (NRRP), Mission 4 Component 2 Investment 1.4 - Call for tender No. 3138 of 16 December 2021, rectified by Decree n.3175 of 18 December 2021 of Italian Ministry of University and Research funded by the European Union – NextGenerationEU; Award Number: Project code CN_00000033, Concession Decree No. 1034 of 17 June 2022 adopted by the Italian Ministry of University and Research, CUP Unina: E63C22000990007, Project title “National Biodiversity Future Center - NBFC”

References

1. Tester, P.A.; Litaker, et al., Harmful Algae, 91 (2020), 101655. DOI: 10.1016/j.hal.2019.101655 

2. Berdalet, E., Pavaux, et al., Harmful Algae, 119 (2022), 102320. DOI: 10.1016/j.hal.2022.102320 

3. Ciminiello, P., Dell’Aversano, et al., J. Am. Chem. Soc. 134 (2012), 1869–1875. DOI: 10.1021/ja210784u

4. Miele, V., Varriale, F., et al. Journal of Chromatography A, (2024), 465350. DOI: 10.1016/j.chroma.2024.465350