Chemical composition and bioactivity of some benthic algae from Karachi Coast of Pakistan

• DOI: 10.1615/interjalgae.v11.i4.70
• Publication Date: 2009-11-19T00:36:32Z
• Authors: Mustufa Shameel; Laila Shahnaz
• Keywords: Stigmasterol; Stearic acid; Gram; Sargassum

Fourteen commonly occurring species of marine benthic algae were collected from the coastal area near Karachi (Pakistan) during March 1996 to September 1997 and extracted in methanol. A variety saturated unsaturated fatty acids (FAs) detected extracts analyzed as methyl esters qualitatively well quantitatively by gas chromatographic (GLC & GC-MS) techniques. Some sterols have also been detected, isolated purified, their structure elucidated chemically through standard spectroscopic methods (EIMS 1H- C13 NMR). Altogether 57 different FA including 21 (SFAs) 36 (UFAs) containing 19 monounsaturated (MUFA), 8 diunsaturated (DUFA), 6 triunsaturated (TUFA) 3 polyunsaturated (PUFA) 2 i.e. β-Sitosterol cholesterol found. The SFAs found larger amount (53-84%) than UFAs (16-47%). Only Chaetomorpha antennina Acanthophora spicifera present quantity (74-84%) (16-26%). Palmitic acid (C16:0) was most followed oleic (C18:1); myristoleic (C14:1), pentadecylic (C15:0), pentadecatrienoic (C15:3), margaric (C17:0), stearic (C18:0) nonadecylic (C19:0) detected. Algal investigated for a antibacterial tests. A. appeared be active seaweed against tested Gram-positive Gram-negative bacteria. Staphylococcus aureus affected extracts, 11 displayed positive activity it only two did not. Among sensitive bacterium Shigella flexnariae. exhibited antifungal nine out 13 fungal this aspect. Microsporum canis species, its growth eleven seaweeds. Oscillatoria sancta, Caulerpa scalpelliformis Dictyopteris australis significant phytotoxicity showed cytotoxicity.