Phycochemistry and bioactivity of certain freshwater green algae of Sindh[Pakistan]

Methanol extracts of five species of freshwater green algae, Chara cotrariaA. Braun ex Kutzing, Chlorococcum humicolum (Nageli) Rabenhorst,Hydrodictyon indicum lyengar, Rhizoclonium hieroglyphicum (C. A. Agardh)Kutzing and Zygnenaa stellinum (Vaucher) C. A. Agardh, collected duringSeptember and December 1995 from water channels at Bhitshah, Tandoadam,Hyderabad and Jamshoro in the province of Sindh (Pakistan), werephysiochemical studied by GC-MS and NMR spectroscopy and investigated againstseven different tests of bioactivity. Thirty-three different fatty acids rangingfrom C10 to C29 were detected, 13 being saturated and 20 unsaturated ones.Among them 13 were monounsaturated, 4 diunsaturated and 3 triunsaturatedacids, polyunsaturated acids could not be detected. Palmitic acid was found tooccur in highest amount (on the average 9.5 %), but oleic acid was present inthe small proportion (0.79 - 5.83 %). A sterol (beta-sitosterol) and an acyclicditerpenoids (trans-phytol) have also been isolated and chemically elucidated.Strong bioactivities were observed regarding bactericidal and antifungalactivities by all the investigated species, H. indicum and Z. stellinum exhibitedpositive activity against six different tests of bioactivity, C. contrariaappeared to be the least active.