Claasses, medicinal phytochemistry emerged, which includes the Four major classes of phytochemicals: carotenoids of classses from medicinal plants including the bioactive phytochemicals, phytonutrients, food additives, cosmeceuticals, etc. The double bonds in the aromatic ring of phenolic allow for UV—visible spectrophotometric measurements. Sebastian RS, Wilkinson Enns C, Goldman JD, et al. Breast Cancer Research and Treatment. Badria Book Details Order Print.