2.1. Reagents. All the reagents, standards (capsaicin >95%; dihydrocapsaicin about 90% from Capsicum sp.), and solvents used were of high degree of purity or HPLC grade and were purchased from Sigma-Aldrich (St. Louis, MO, USA).
2.1. Reagents. All the reagents, standards (capsaicin >95%; dihydrocapsaicinabout 90% from Capsicum sp.), and solventsused were of high degree of purity or HPLC grade and werepurchased from Sigma-Aldrich (St. Louis, MO, USA).