Pharmacognostic,Pharmacognostic, Phytochemical and Antioxidant Studies of Hydnophytum formicarum L

摘要

The leaves of Hydnophytum formicarum Jack belonging to the family Rubiaceae, a tropical tree commonly found in eastern and southern Thailand, South Asia, Papua New Guinea and the Pacific Islands, were studied for these antioxidant compounds. Sterols, flavonoids and phenolic compounds appear to be good markers for this species. Chromatographic and histochemical techniques were used to analyze its secondary metabolites and to localize these molecules in the leaves of H. formicarum and its petiole. With histochemistry, we can locate the phenols in situ by an iron chloride reagent, which gives a black color, especially in fibers, hypodermis and xylem. Flavonoids are detected histochemically using a potassium hydroxide reagent to obtain a yellow coloration under visible light. Histochemical studies of H. formicarum showed a high concentration of natural antioxidants in the central cylinder, particularly in the vascular bundle, whereas condensed catechic tannins were mainly detected in collenchyma, fibers and also in xylem. The high levels of phenolic compounds and their localization in the conductive tissues allow us to explain the traditional medicinal use carried out in Thailand with this tree because, very often, compounds with antioxidant properties prove to be good anti-cancer agents.