1 1 3 3 tetramethoxypropan

The content of malondialdehyde (MDA) and the activities of the enzymes glutathione S-transferase (GST), catalase (CAT), and acetylcholinesterase (AChE), were assessed spectrophotometrically in samples of mussel digestive gland and/or gills preliminarily processed at the specific conditions reported in SM (Table S1). The MDA content was quantified in digestive glands according to Franzellitti et al. [32 (link)] by interpolating the data of absorbance at 570 nm on a standard curve obtained using the MDA precursor 1,1,3,3-Tetramethoxypropan (TMOP, Sigma-Aldrich ^®, Milan, Italy). GST and CAT activities were measured in both digestive glands and gills according to Capolupo et al. [33 (link)]. GST activity was evaluated at 340 nm by following the reaction kinetics between the enzyme and the substrate 1-chloro-2,4-dinitrobenzene (CDNB, Sigma-Aldrich ^®, Milan, Italy) for 10 min (at 1 min intervals). Similarly, CAT activity was measured by tracking the decrease in the absorbance of samples at 240 nm for 2 min (at 10 s intervals) in the presence of 55 mM H₂O₂. AChE activity was determined in gills at 405 nm as described by Valbonesi et al. [34 (link)]. Samples were read at 405 nm for 10 min in the presence of 0.5 mM acetylthiocholine iodide and 0.33 mM 5.5′-dithiobis-2-nitrobenzoic acid (DTNB, Sigma-Aldrich ^®, Milan, Italy).