Brassicasterol

Pure standards of phenolic acids, tocopherols, ergosterol, stigmasterol, campesterol, β-sitosterol and squalene, were purchased from Sigma-Aldrich Inc. (St. Louis, MO, USA). Brassicasterol and sitostanol were from AVANTI Polar Lipids Inc. (Alabaster, AL, USA). Tocotrienols were purchased from Cayman Chemical Company (Ann Arbor, MI, USA).
All solvents were of analytical or high-performance liquid chromatography (HPLC) grade as required. Potassium hydroxide and trichloroacetic acid were from Carlo Erba. Tert-butyl-hydroquinone (TBHQ) was from Fluka Chemie AG (Buchs, Switzerland). Boron trifluoride in methanol (BF₃) was from Merck (Darmstadt, Germany).
Deionized water was provided by an Arium^® pro UV Water Purification System (Sartorius Stedim Biotech GmbH, Goettingen, Germany).
The reagents used for antioxidant activity determinations were purchased from Sigma-Aldrich (Merck Group, Darmstadt, Germany). The optical density was determined by a multi-mode plate reader (CLARIOstar Plus, BMG Labtech, Ortenberg, Germany).

Pure standards of tocopherols, ergosterol, stigmasterol, campesterol, β-sitosterol, squalene, β–carotene, lutein, zeaxanthin, and β–cryptoxanthin were purchased from Sigma-Aldrich Inc. (St. Louis, MO, USA). Brassicasterol and sitostanol were from AVANTI Polar Lipids Inc. (Alabaster, AL, USA). Tocotrienols were purchased from Cayman Chemical Company (Ann Arbor, MI, USA). All solvents were of analytical or high performance liquid chromatography (HPLC) grade as required. Potassium hydroxide, and butylated hydroxytoluene (BHT) were from Carlo Erba. Tert-butyl-hydroquinone (TBHQ) was from Fluka Chemie AG (Buchs, Switzerland). Deionized water was provided by an Arium^® pro UV Water Purification System (Sartorius Stedim Biotech GmbH, Goettingen, Germany).