Singlet oxygen generation of a natural anthraquinone

COMINI LR .; MARIONI J; NÚÑEZ MONTOYA SC; FERNÁNDEZ I; RIVAROLA V; GARAGIOLA B; BORSARELLI C; CABRERA JL.

Córdoba

Encuentro; XI ENCUENTRO LATINOAMERICANO DE FOTOQUÍMICA Y FOTOBIOLOGÍA.; 2012

Universidad Nacional de Río Cuarto

Many photosensitizers molecules (PS) possess the ability to interact with triplet molecular oxygen and absorb visible light to produce reactive oxygen species (ROS), such as superoxide anion (O2?-) and singlet molecular oxygen (1O2) by means of different mechanisms: electrons transfer (Type I) and energy transfer (Type II), respectively. Because of this property to generate ROS by photoinduction, these compounds are classified as photodynamic PS [1]. It has been shown that several natural photodynamic PS were bioactive, exhibiting antibiotic, antifungal, antitumoral and antiviral properties, and thus could be used in photodynamic therapy (PDT) [2]. From the aerial parts of Heterophyllaea pustulata Hook f (Rubiáceas, ?cegadera?), ten anthraquinone derivatives were isolated [3,4]; and their Type I and/or Type II photosensitizing properties were demonstrated by our research group, as well as their photodynamic antibacterial and anticancer activity in vitro of some of them [5,6]. Continuing the phytochemical studies of this vegetal specie, a new anthraquinone was isolated and identified from its roots: lucidin ω-metil ether (LC), which has demonstrated its ability as PS Type I [7]. In the present work, we report its capability as PS Type II