CHEMICAL INVESTIGATION OF BROWN SEAWEED - Padina pavonica

Abstract

In recent years research on the chemistry o f seaweeds (or more generally marine algae)has experienced a tremendous increase due to the need for compounds possessing bioactivities o f possible pharmaceutical applications or other potential economic properties. Marine algae (Seaweeds) are known to produce an incredible diversity of secondary metabolites some o f which show potent anticancer, antibiotics, antiviral antimicrobial, anti-inflammatory, anthelmintic, antinmgal, antitumor and insecticidal activities. Considerable amount o f work have been done on seaweeds around the world. However, the biomedical potential o f the rich Sri Lankan seaweeds remains largely unexplored. Due to this reason Natural product program o f the Institute o f Fundamental studies initiated a project on chemistry and biological activity studies o f Sri Lankan seaweeds. Padina pavonica, brown algae was collected from the coastline o f Arugambay at Ampara District in the Eastem Province in Sri Lanka. Plant material was cleaned, washed with fresh water, air dried, powdered and extracted with MeOH using a sonicator. Dried MeOH extract was successively fractionated with Hexane, Chloroform and Ethyl acetate. After that the dried Hexane fraction was subjected to column chromatography with normal Silica and C-18, followed by Preparative Thin Layer Chromatography (PTLC) to gave three pure compovmds but the amount o f these compounds were small and needed high sensitive instruments to analyze them. As I was not in a position obtain the H NMR o f isolated compounds, for familiarization o f spectroscopic techniques, spectral data o f a compound isolated fiom green seaweed, Ulva lactuca was analyzed ('H and 13C NMR, HMQC and HMBC Spectrums) and its’ structure was proposed as 9-octadecenoic acid (Oleic Acid).