Phenolic compounds are structures found in plant-based foods that play an important role in regulating health and disease. Accordingly, this book presents seven chapters that explore phenolic compounds from a variety of perspectives. Chapter One addresses the current knowledge about the presence of phenolic compounds in plants, their bioavailability and protective effects of interest for diabetes mellitus. Chapter Two describes the Bignoniaceae family and Handroanthus impetiginosus, as well as the main groups of phenolic compounds reported for this species and their main biological activities. Chapter Three highlights some scientific evidence corroborating the role of polyphenols in the prevention and treatment of cancer. Chapter Four presents the results of a study that indicate that L. leucocephala calli are promising biotechnological products for obtaining phenolic compounds in vitro. Chapter Five details a study that assessed the phenolic compound content and antioxidant and antibacterial activities of extracts and fractions of Bauhinia holophylla. Chapter Six evaluates the production of phenolic compounds in cell suspensions of B. variegate. Finally, Chapter Seven provides an insight on the anti-inflammatory activities of galangin through attenuation of allergic inflammation, regulation of PPARγ pathway, inhibition of ERK, NF-kappaB, PI3K/AKT and NLRP3 signaling, interplaying of MAPK signaling cascade, and through activation of Nrf2 signaling in animal models.