Behaviour of the Phenolic Compounds on Capsicum annuum Leaves Infected with Phytophthora capsici

In Capsicum annuum leaves, some phenolic compounds, such as chlorogenic acid and various apigenin or luteolin glycosides, can be separated by HPLC technique. During infection with Phytophthora capsici (the agent of pepper mildew), the concentrations of these compounds decreased. A fungal glucosidasic activity may be implicated, producing apigenin aglycon in the necrotic areas. Some of the phenolic compounds were only present in intercellular spaces, where their concentration increasedduring fungal infection, mostly in the resistant pepper cultivar. The involvement of phenolics in C. annuum resistance is discussed in relation to oxidative metabolism.