Pyrimidines from the Philippine Marine Sponge Aaptos suberitoides

Abstract

Abstract— The pyrimidines thymine and uracil were isolated from the ethyl acetate extract of the marine sponge Aaptos suberitoides collected in Kalangahan, Luga-it, Misamis Oriental, Philippines. The extract showed to be toxic against brine shrimp nauplii at LC 50 of 954.99 ppm. It also displayed significant activities towards Staphylococcus aureus and Escherichia coli . The elucidation of the structures of thymine and uracil were aided by spectroscopic techniques such as Fourier Transform - Infrared Spectroscopy (FT-IR), Ultraviolet Spectroscopy (UV), ESITOF Mass Spectroscopy (ESITOF-MS), 1-D ( 1 H, 13 C) and 2-D (COSY, HMQC, HMBC) Nuclear Magnetic Resonance (NMR). Index Terms— Characterization, Crude extract, Secondary metabolites, Spectroscopy —————————— —————————— 1 INTRODUCTION ARINE organisms evolved differently from terrestrial organisms. Because of greater competition of existence in their habitat, marine organisms secrete antibacterial proteins and bioactive secondary metabolites for bacterial defense as part of their metabolism that help them survive [1]. Marine sponges, being sessile, are one of the marine organisms that attract the interest of many natural product chemists because of its unique characteristics in adapting to the harsh and diverse marine environment. The Philippines, as an archipelago, offers vast potentials from its marine resources, sponges in particular, waiting to be utilized as source of essential bioactive substances with pronounced pharmacological potentials. The challenge now lies in the effective exploration of the rich chemical diversity offered by marine life. This research study involved isolation and elucidation of one metabolite from the marine sponge,