Guava flavonoids and the effects of industrial air pollutants

Saplings of Psidium guajava (guava, Myrtaceae), a tropical tree species, were exposed to industrial air pollutants at Cubatâo, the largest industrial complex of Latin America, along two periods, each one comprising one-year: period I, July/2000 – June/2001; period II, December/2000 – November/2001. Saplings were exposed in two experimental sites: Pilões River Valley (PV), reference site, with low contamination by air pollutants; and Mogi River Valley (MV), a site severely affected by pollutants from chemical, fertilizer, ceramic, iron and steel industries. At both sites, the main flavonoids found were guaijaverin, quercitrin and two quercetin diglycosides. No interactions among factors were found as well as no significant differences were found among periods and among sites. However, total foliar flavonoid amounts showed the tendency of decrease after 12 months of experimentation. Cubatão industrial air pollution, with high concentrations of NO2, SO2 and particulate matter, plus climatic conditions of the initial months of exposure seem that does not influence flavonoid composition and quantities.