Sodium thiosulfate

The following chemicals were purchased from Sinopharm Chemical Reagent Co., Ltd. (Shanghai, China): ethanol, petroleum ether, sodium thiosulfate, anhydrous sodium carbonate, acetic acid, isooctane, n-hexane, trichloromethane, sodium sulfate, n-heptane, potassium iodide, phenol, phenolphthalein, potassium hydroxide, tetrahydrofuran, and alumina. All other reagents were of analytical grade and were commercially available.

Chicken wings and potato chips were purchased from a local supermarket. Fresh soybean oil (with no antioxidants added) was provided by Yi Hai Kerry Co., Ltd (Shanghai, China). Potassium hydroxide, phenolphthalein, potassium iodide, sodium thiosulfate, isopropyl alcohol, ethyl ether, ethanol, chloroform, and glacial acetic acid were purchased from Sinopharm Group Co., Ltd. (Beijing, China).

Fontana–Masson staining was carried out to visualize melanin content and distribution in irradiated dorsal skin as described previously [12 (link)]. Sections were deparaffinized and hydrated in water and placedinto a 2.5% silver nitrate solution (Sinopharm Chemical Reagent Co., Ltd, Beijing, China) for 4 h in a dark chamber. After rinsing in water, the slides were placed in 0.1% gold chloride (Sinopharm Chemical Reagent Co., Ltd, Beijing, China) for 1 min,rinsed again in water, and then in 5% sodium thiosulfate (Sinopharm Chemical Reagent Co., Ltd, Beijing, China) for an additional2 min. After a final rinse with water, the sections were counter-stained with eosin red.

The freshly collected tuna (Katsuwonus pelamis) livers were supplied by Ning Bo Today Food Co. (Zhejiang, China) from the same batch of canning processing. Endogenous enzymes were all inactivation prior to rapid freezing at −40 °C. Frozen samples were then transported at −18 °C vehicle, arrived the laboratory within same day. All samples were immediately transferred and stored in a − 30 °C freezer room. Samples were set in a 4 °C refrigerator overnight for thawing before all processing and analysis.
Boron trifluoride (BF₃) in methanol (13–15%) was provided by Adamas-Beta Co. (Shanghai, China). Standards of 37 individual fatty acid methyl esters were purchased from ANPEL Laboratory Technologies Co. (Shanghai, China). HPLC-grade hexane was acquired from Aladdin Reagent Co. (Shanghai, China). Analytical-grade chloroform, methanol, n-hexane, ether, isopropanol, isooctane, acetic acid, sodium hydroxide, sodium chloride, potassium iodide, sodium thiosulfate, and p-anisidine were provided from Sinopharm Chemical Reagent Co. Technical-grade DME gas (99.95% purity) was purchased from Jingong Special Gas Co. (Hangzhou, China).

Chloroform, petroleum ether, phenolphthalein, sodium thiosulfate, thiobarbituric acid (TBA), and triphenylphosphine were supplied by Sinopharm Chemical Reagent Co., Ltd. (Shanghai, China). P-anisidine, dithiothreitol (DTT), Ethylenediaminetetraacetic acid disodium salt (EDTA-2Na), trichloroacetic acid (TCA), p-nitrophenyl laurate (p-NPL), 4-methylumbelliferyl oleate, and tween 20 were obtained from Sigma-Aldrich Inc. (Beijing, China). Phosphate buffer, Tris-HCL buffer, citric acid buffer, ethylene glycol tetraacetic acid (EGTA), 2,4-dinitrophenylhydrazine, and Triton X-100 were produced by Thermo Technology Co., Ltd. (Beijing, China).

MCLR, MCLF, MCLA, MCLY, and MCLW were purchased from Sigma (Saint-Quentin Fallavier, France). PP2A was purchased from New England Biolabs Inc (Beverly, MA, USA). Bovine serum albumin, dithiothreitol, MnCl₂, P-nitrobenzene disodium orthophosphate, sodium thiosulfate, tris(hydroxymethyl) aminomethane, and other reagents were purchased from Sinopharm (Shanghai, China).