Chemical composition and in vitro anti-algal activity of Potamogeton crispus and Myriophyllum spicatum extracts

The aim of this work was to investigate and compare the phytochemical constituents and anti-algal activities of crude extracts from dry macrophytes species, Potamogeton crispus and Myriophyllum spicatum. Organic solvents differed in polarity including petroleum ether, methylene chloride, chloroform, acetone and methanol were used to extract the phytochemical compounds and gas chromatograph-mass spectrometry (GC-MS) analyzer was used for the detection of these compounds. Generally, the results indicated that the composition and mass fraction of phytochemical constituents varied with plant species and extraction solvents. The growth inhibition effects of separate and mixed plants extracts on Pseudokirchneriella subcapitata were studied. In addition, the effects of mixed extracts on ten taxonomically different freshwater microalgae species, using the single-species and mixed culture species tests were also studied. Among the five different extracts tested chloroform extract and mixed extracts of the two plant species showed the highest anti-algal potential with P. subcapitata. The sensitivity of microalgae species tested in single-species cultures to P. crispus and M. spicatum extracts found to be group-specific, in which cyanophyte Anabaena flos-aquae var. treleasei and the diatoms Gomphoneis eriense var. apiculate and Tryblionella hungarica were more sensitive compared to the tested green microalgae species. In addition, the inhibitory effects of macrophyte extracts decreased for the mixed microalgae cultures. The extracts of P. crispus and M. spicatum showed the presence of some bioactive compounds that could contribute toward the phyto-algicidal properties of these plants.