Identification of bioactive natural products after screening Irish marine bio-resources

Abstract

According to the “Real Map of Ireland” published by Marine Institute, Ireland, the Nation marine territory has ten times more area than its land mass. Despite the well-studied and reported biodiversity present in Irish waters, the chemo-diversity of Irish marine invertebrates has been poorly investigated. The present thesis highlights the isolation of Marine Natural Products from different types of Irish marine organisms such as sponges, lichen, macroalgae, and marine fungi. The library of 864 extracts was prepared and subjected to antioxidant High Throughput Screening. Five most promising “hit” extracts were chemically investigated that led to the isolation of 8 novels and 16 known metabolites. Pygmaniline-A (I) and Pygmaniline-B (II), discovered from the most promising hit extract of lichen Lichina pygmaea are antioxidant and immunomodulatory in nature. The synthesis of I and II was carried out in a single step reaction with more than 85% yield. An additional integrated approach of Bioactivity-Chemical guided screening of 20 sponges was carried out that resulted in the isolation of two novel metabolites. Later, both the approaches are compared for in the interest of finding novel bioactive marine natural products.