Precoated silica gel 60 f 254 aluminum sheets

UV spectra were recorded on a Shimadzu UV-1601PC spectrophotometer in spectroscopic grade MeOH. IR spectra were recorded on a Shimadzu IR-460 spectrometer in pressed KBr disks. NMR spectra were recorded on Bruker AMX 400, operating at 400 MHz for proton and 100 MHz for carbon in spectroscopic grade CDCl₃, DMSO-d6, and CD₃OD. EI-MS (70 eV) were recorded on Agilent 7890A/5975C. TLC was carried out on precoated silica gel 60 F 254 aluminum sheets (Merck, Rahway, NJ, USA). Whatman chromatography paper (Grade 1 CHR) was obtained from GE Healthcare Life Sciences (Shanghai, China) and used with further adjustment of size. All chromatographic solvents were of reagent grade (Sinopharm Chemical Reagent Co., Ltd., Shanghai, China). For column chromatography, normal phase silica gel 60 (70–230 mesh, Merck), Sephadex LH-20 (25–100 μm, Sigma-Aldrich, St. Louis, MO, USA), and polyamide (particle size 50–160 μm, Sigma-Aldrich) were used.

Crude fucoxanthin was separated on a 10 × 8 cm TLC column (Merck precoated silica gel 60 F254 aluminum sheets, layer thickness 0.2 mm). The mobile phase consisted of chloroform:methanol at a ratio of 98:2 (v/v). The bands on the chromatographic plate were detected by spraying with 10% H₂SO₄ solution and drying on an alcohol lamp.