%0 Journal Article %A Khalid, M. N. %A Shameel, M. %D 2011 %I Begell House %K algae, Cyanophycota, Lyngbya, bioactivity, phycochemistry, fatty acids, sterols, terpenes %N 3 %P 234-249 %R 10.1615/InterJAlgae.v13.i3.30 %T Studies on the Bioactivity and Phycochemistry of Lyngbya Agardh (Cyanophycota) %U https://www.dl.begellhouse.com/journals/7dd4467e7de5b7ef,36a140ec7a8eb1a3,1c6caac6457b1af5.html %V 13 %X The crude methanol extracts of two toxic algae, Lyngbya majuscule (Dillwyn) Harv. and L. martensiana Menegh., collected during 1993−1994 from freshwater habitats of Sindh Province of Pakistan, showed a strong antimicrobial activity against 14 bacterial and 20 fungal species, including 7 human- and 5 plant-pathogens and 8 saprophytes, but their cytotoxic activity against brine shrimp larvae was non-significant. From methanol extracts 43 fatty acids were detected by GC-MS, including 15 saturated, 12 mono-, 6 di-, 8 tri- and 2 polyunsaturated acids. In L. majuscule the saturated acids were found in larger amount (54.19%) than unsaturated ones (45.77%), while in L. martensiana the unsaturated acids were present in greater proportion (58%) than saturated acids (41.87%). In the former alga palmitic acid occurred in the highest proportion (22.2%), which in the latter one oleic acid was present in the largest quantity (6.93%). Furthermore, three sterols (β-sitosterol, 24-isoprophyl-5-cholesten-3-ol and 22-dehydro-24-isopropyl-cholesterol), a triterpene (filican-3-one), an epoxy lipid (nonadeca-9,18-diene-6,7-diol), and two isoprenoid hydrocarbons (woljicene and isowoljicene) were isolated from the extract of L. majuscula, and three sterols (stigmasterol, dinosterol and cholesterol), a triterpene (naviotine-A) and a disaccharide (sucrose) were extracted from L. martensiana and chemically elucidated by a variety of spectroscopic techniques. Both the species indicated the presence of natural products which are different from one another. %8 2011-07-01