Sandra Gonçalves

By Sandra Gonçalves and Anabela Romano

Some drugs currently used are inhibitors of enzymes involved in mediating many disease processes. Concerns over the toxicity and side effects of synthetic enzyme inhibitors have led to a search for new safe and effective inhibitors particularly from natural sources. Owing to their wide range of biological effects, plant phenolic compounds are one of the most studied families of natural products. This chapter aims to provide an overview of the potential of phenolic compounds as enzyme inhibitors. Extensive research has been conducted to study the enzyme inhibitory capacity of many phenolic compounds against several enzymes linked with important human conditions. Investigations conducted are mainly focused on the inhibition of angiotensin I-converting enzyme, α-amylase and α-glucosidase, lipase, cholinesterases, proinflammatory enzymes (cyclooxygenases and 5-lipoxygenase) and tyrosinase, which are related with hypertension, type II diabetes, obesity, Alzheimer’s diseases, inflammation and skin hyperpigmentation, respectively. Overall, among phenolics, flavonoids are probably those with great capacity to inhibit the activity of the enzymes revised. Several studies demonstrated the potent antioxidant and anti-inflammatory properties of flavonoids, which highlight the therapeutic potential of these compounds. Although our literature survey showed that a huge number of phenolic compounds have been studied and there are some promising compounds depending on the enzyme, more in vivo tests and subsequent steps to be a drug candidate are required before therapeutic application.

Part of the book: Phenolic Compounds

By Bruno Filipe Figueiras Medronho, Sandra Gonçalves, Raquel Rodríguez-Solana, Artur J.M. Valente and Anabela Romano

Bio-based compounds, such as “green” surfactants and phytochemicals, are regarded as future sustainable resources for a vast range of applications in a modern society increasingly demanding economical, social, and environmental awareness. Natural compounds from plants (phytochemicals) are very sought by the pharmaceutical, cosmetic, and food industries. On the other hand, the growing interest in “green” surfactants (e.g., carbohydrate-based) is due to, inter alia, their preparation from renewable raw materials, ready biodegradability, and biocompatibility, among other reasons of fundamental, practical, economical, and environmental orders. Despite the wide range of potential applications of these bio-based compounds, their practical use is still limited due to many reasons such as poor aqueous solubility, volatility, reactivity, etc. Generally, when complexed with cyclodextrins, these bio-based compounds enhance considerably their performance and potential applications. Thus, this chapter aims at recalling some general fundamental aspects of phytochemicals and “green” surfactants, such as structure, function, and applications. In addition, their interactions with cyclodextrins are discussed from a physicochemical point of view with special focus on the techniques, mathematic modeling, and thermodynamic parameters (e.g., interactions, stoichiometries, association constants, etc.).

Part of the book: Cyclodextrin

By Sandra Gonçalves and Anabela Romano

Plants are a remarkable source of high-value secondary metabolites with applications in various domains. Plant cell and tissue culture techniques appear as environmentally friendly alternatives for the production of secondary metabolites when natural supply is limited or chemical synthesis is unviable. In this chapter, the main advantages of using plant cell and tissue culture techniques for the production of plant secondary metabolites are presented as well as the different biotechnological approaches available to improve their production. In addition, the production of anticancer compounds (camptothecin, podophyllotoxin, taxol, vinblastibe, and vincristine) and metabolites from Lamiaceae spp. (phenolics as rosmarinic acid) were selected as examples to be highlighted. The study reviewed shows that undifferentiated cells are the preferred culture system used for the production of high-value secondary metabolites in vitro although there are many examples reporting the production in differentiated tissues particularly in hairy roots. Efforts have been made to scale up the production, and several strategies have been successfully applied to increase the production yields at the laboratorial scale. Nevertheless, there are only few examples of plant secondary metabolites production at commercial level, and further in-depth studies are still required.

Part of the book: Secondary Metabolites