Fructose

Urea (≥99.0%), N, N-dimethyl formamide (DMF, 99.9%), Copper (II) chloride dihydrate (CuCl₂·2H₂O, 99.0%), Nickel (II) chloride hexahydrate (NiCl₂·6H₂O, ≥98.0%), NaOH (96.0%), AA (≥99.7%), sucrose, glucose and NaCl (≥99.5%) were purchased from XiLong Scientific. Citric acid (99.5%) and DA (98%) were purchased from Aladdin. 5wt% of Nafion was purchased from Sigma Aldrich. Ethylene glycol (EG, 99.0%), maltose, fructose, D-galactose and UA (99%) were purchased from Sinopharm Chemical Reagent Co., Ltd. Ultrapure water (ELGA, Veolia, 18.2 MΩ) was used throughout the experiments, and all reagents which were not mentioned above were of analytical grade.
The samples were characterized by X-ray photoelectron spectra (XPS, Thermo ESCALAB 250XI), transmission electron microscopy (TEM) and high resolution transmission electron microscope (HRTEM, FEI Tecnai G² 20), ultraviolet-visible spectra (UV-Vis, PerkinElmer Lambda 365), Fourier transform infrared spectra (FTIR, Bruker) and X-ray diffraction measurement (XRD, Bruker D8 Advance). All electrochemical experiments were performed on the electrochemical workstation (Shanghai, CHI 660C). The working electrodes were modified glassy carbon electrode (GCE, 3 mm in diameter), the reference electrode was saturated calomel electrode (SCE), and a platinum wire electrode was usedas the auxiliary electrode.

The salted jellyfish, Nemopilema nomurai, has been allowed to use by ethical code, was procured from the Tuandao Market (Qingdao, China), and subsequently subjected to a soaking process with constant water changes every 4 h for four days to eliminate excess salt. Following this, it was transformed into a lyophilized powder to enable enzymatic processing. The 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT), Flavourzyme, Protamex, and Alcalase were acquired from Solarbio Science & Technology Co., Ltd. (Beijing, China). Chemicals such as reduced L-glutathione (GSH), ninhydrin, fructose, potassium ferricyanide, trichloroacetic acid, and ferric chloride were procured from Sinopharm Chemical Reagent Co., Ltd. (Shanghai, China). Other reagents, including 2,2-Diphenyl-1-picrylhydrazyl (DPPH), Nitrotetrazolium Blue chloride (NBT), phenazine methosulfate (PMS), and nicotinamide adenine dinucleotide reduced disodium salt (β-NADH), were purchased from Macklin Biochemical Co., Ltd. (Shanghai, China). HaCaT cells were obtained from China Infrastructure of Cell Line Resource (Beijing, China). Fetal bovine serum (FBS) and MEM culture medium were procured from Hyclone (Logan, UT, USA). Sephadex G-25 was obtained from GE Healthcare (Fairfield, CT, USA). All chemicals utilized in the experiment were of analytical grade.

All reagents are analytical reagents, and they were used without further purification. Specifically, CuSO₄·5H₂O, Na₂SO₄, NiSO₄·6H₂O, aqueous ammonia (25–28%), NiCl₂·6H₂O, C₈H₆O₄, N, N-dimethylacetamide (DMF), D-(+)-Glucose, dopamine (DA), L-ascorbic acid (AA), acetaminophen, fructose, sucrose, folic acid, and l-cysteine were purchased from Sinopharm Chemical Reagent Co., Ltd (China). Additionally, K₂S₂O₈ was purchased from Tianjin Kaitong Chemical Reagent Co., Ltd. (Tianjin, China). Uric acid (UA) was purchased from Alfa Aesar.

Nickel disk electrode (diameter of 2 mm and length of 20 mm) was acquired from Tianjin Aida Hengsheng Technology Co., Ltd. (Tianjin, China). Potassium ferricyanide, potassium chloride, sodium hydroxide, glucose, sucrose, fructose, lactose, maltose, xylitol, sorbitol, and erythritol were purchased from Sinopharm Chemical Reagent Co., Ltd. (Shanghai, China). All the chemical reagents were used as received. All solutions were prepared using Milli-Q water, with resistivity of 18.2 MΩ·cm using a Millipore system.

Fruiting bodies of Ganoderma lucidum grown in north-eastern China were purchased from Leiyunshang Pharmaceutical Co. Ltd. (Shanghai, China). FYGL was obtained from Ganoderma lucidum as previously described [20 (link)], and Figure S1 shows its NMR spectrum. Yeast α-glucosidase (EC 3.2.1.20), purchased from Sigma-Aldrich Co. (St. Louis, MO, USA), was prepared in sodium phosphate buffer (0.1 M, pH 6.8). Metformin, acarbose, aminoguanidine (AG), p-nitrophenyl-α-D-glucopyranoside (pNPG), nitrotetrazolium blue chloride (NBT), Girard-T reagent, thioflavin T (ThT), and methylglyoxal (MGO) were purchased from Aladdin Chemical Co. (Shanghai, China). Fructose, sucrose, and trichloroacetic acid (TCA) were purchased from Sinopharm Chemical Reagent Co., Ltd. (Shanghai, China). The antibody of AGEs was purchased from Abcam (Cambridge, MA, USA). Bovine serum albumin (BSA) was obtained from Yeasen biotechnology Co., Ltd. (Wuhan, China). All other chemicals and solvents were of analytical quality, and fresh ultrapure water was used in all of the experiments.