3 5 dihydroxybenzoic acid 3 5 dhba

Human GBM cell lines (U87-MG, A172, and U251) were purchased from ATCC Company (Milan, Italy). Cells were suspended in Dulbecco’s modified Eagle’s medium (DMEM) (cat. no. 11965092) containing 10% fetal bovine serum (FBS) (cat. no. 10082147), 100 U/ml penicillin, and 100 U/ml streptomycin (cat. no. 15070063; all from Gibco, Waltham, MA, USA). At 80% confluency, cells were passaged using trypsin–EDTA solution (0.05% trypsin and 0.02% EDTA; cat. no. 25300054, Gibco, Waltham, MA, USA).
Sodium lactate and 3,5-dihydroxybenzoic acid (3,5-DHBA) (both from Sigma-Aldrich, Milan, Italy) were added into the cell culture of all experiments at final concentrations of 20 mM and 150 μM, respectively, for 24, 48, and 72 h.

Human uveal melanoma cells (92.1) were purchased from ATCC Company (Milan, Italy). Briefly, cells were cultured in RPMI1640 medium with 10% fetal bovine serum (FBS) (cat. no. 10082147), 100 U/mL penicillin, and 100 U/mL streptomycin (cat. no. 15070063; all from Gibco, Waltham, MA, USA) and expanded once they reached 80% confluency using trypsin-EDTA solution (0.05% trypsin and 0.02% EDTA). Lactate (Sigma-Aldrich, Milan, Italy), AZD3965, 3,5-dihydroxybenzoic acid (3-5-DHBA) (Sigma-Aldrich, Milan, Italy), and 3-hydroxybutyric acid (3-OBA) (Sigma-Aldrich, Milan, Italy) were added to cell culture at final concentrations of 20 mM, 10 μM, 150 μM, and 3 mM, respectively, when needed.

Trans-cinnamic acid; 3,5 dihydroxybenzoicacid (3,5 DHBA); chlorogenic acid; catechin; 2-methoxycinnmaldehyde (2–MC); ellagic acid; (±) -naringenin; naringin; procyanidin B2; trans-sinapic acid; taxifolin were procured from Sigma Aldrich (St Louis, MO, USA). Rutin hydrate; syringic acid; kaempferol; isoquercetin; kaempferol-3-O-β rutinoside (K-3-O-βR); daidzein were obtained from Sigma (St Louis, MO, USA). Gallic acid; caffeine; vanillin; salicyclic acid; 3,4 dihyroxybenzoic acid (3,4 DHBA); trans-ferulic acid; trans–p-coumaric acid were procured from Fluka (St Louis, MO, USA). Catechol; hesperdin; apigenin; quercetin dihydrate were purchased from Alfa Acer, Thermo Fisher Scientific (USA). Stock solutions (2000 ppm) of individual compound were prepared in methanol. Two separate intermediate solutions of all the standards were prepared. One was used for the estimation of LOQ (limit of quantification) and LOD (limit of detection) while the other for recovery and linearity by diluting in methanol as depicted in Table 1. The working solution was further prepared by diluting in mobile phase A and B in the ratio 80:20.