Polycyclic xanthones are a family of structurally complex natural products with diverse and potent biological activity and thus attract much attention in organic and medicinal communties. The development of new drugs from polycyclic xanthones is rather slow because these natural products were isolated with minute quantity and are not commercially available. This thesis focuses on chemical synthesis of hexacyclic xanthones for biological evaluation of their potentials as antibiotic/anticancer drug leads.

Chapter one introduces the classification, biosynthesis, and previous research on the biogenetic synthesis of xanthone natural products. In addition, we outlined some synthetic work related to the polycyclic xanthone natural products and the application of copper(II)-catalyzed oxidative...[ Read more ]

Polycyclic xanthones are a family of structurally complex natural products with diverse and potent biological activity and thus attract much attention in organic and medicinal communties. The development of new drugs from polycyclic xanthones is rather slow because these natural products were isolated with minute quantity and are not commercially available. This thesis focuses on chemical synthesis of hexacyclic xanthones for biological evaluation of their potentials as antibiotic/anticancer drug leads.

Chapter one introduces the classification, biosynthesis, and previous research on the biogenetic synthesis of xanthone natural products. In addition, we outlined some synthetic work related to the polycyclic xanthone natural products and the application of copper(II)-catalyzed oxidative coupling reactions in the synthesis of natural products.

Chapter two presents our research on the chemical synthesis of polycyclic xanthone derivatives. Although many research groups have reported the total synthesis of polycyclic xanthone natural products, we developed a versatile and efficient synthetic route that could provide milligrams to more than 10 mg of analogues for our bioactivity tests. Installation of different functional groups through the use of various chiral ethanolamine in the synthesis allowed us to study the structure-activity relationship. The positive and encouraging results of anticancer activity (IC₅₀: 20nM-10μM) suggested the derivatives of polycyclic xanthones have a great medicinal potential.