Gallic acid and its derivatives: Occurrence and identification in high altitude edible and medicinal plants

Phenolic compounds are molecules that have one or more hydroxyl groups bound to an aromatic ring. Together with vitamins, phenolic compounds are considered important dietary antioxidants. Thousands of phenolic compounds are found in plants, and they are classified into different types of functional groups. Phenolic compounds play a number of metabolic roles in plants, in growth and reproduction, and in protection against pathogens and external stress, UV radiation and predators for instance. Gallic acid is trihydroxybenzoic acid, a phenolic acid, also known as 3,4,5-trihydroxybenzoic acid. The presence of this phenolic compound and its derivatives is extensive in nature and it can be found in many plants and foods like fruits, vegetables and cereals. Bolivia is currently considered among few countries with a high bio-diversity in the world. This diversity is evident from many species of food plants found in so contrasting geographical regions like the Andean mountains or the Amazon flood plain. In particular, the Andean region has a variety of endemic and adapted foods like roots, fruits, cereals and pseudo-cereals all growing at high altitude (2000 to 4200 m.a.s.l.). The presence of ancient native populations such as the Aymara, Quechua and Guarani ethnic groups contributed through the centuries to present with their own and particular savoir-faire to the adaptation and use of these plants. As a sample, this part of the world has given to the world's kitchen two of the most celebrated foods in mankind's history -potato and corn- in their many varieties. Endemic Bolivian non-conventional crops have increased dramatically their importance during recent years due to the introduction of Andean foods onto the international market, never as widely open as nowadays. A typical example is quinoa -Chenopodium quinoa-, a protein-rich Andean grain currently available and a very common product in European markets. Bolivia offers a unique environment for researches on high solar UV radiation levels and related phenolics' contents in plants. The altiplano region particularly, is a sui generis site (because of its high altitude), where populations and food plants grow in an abundant variety and quantity with a non-negligible percentage in the per-year national statistics. This chapter presents the results of gallic acid and its derivatives found in food and high altitude plants. These results include an EIMS and NMR spectroscopic approach for gallic acid.