Effect of ent-labdane diterpenes from Potamogetonaceae on Selenastrum capricornutum and other aquatic organisms.

Twenty ent-labdane diterpenes, isolated from the aquatic plants Ruppia maritima and Potamogeton natans, were tested to detect their effects on aquatic organisms from different trophic levels. Toxicity tests were performed on aquatic producers (the alga Selenastrum capricornutum), and consumers including a rotifer (Brachionus calyciflorus), a cladoceran crustacean (Daphnia magna), and two anostracan crustaceans (Thamnocephalusplatyurus and Artemia salina). Furano-ent-labdanes exhibited high toxicity toward all of these organisms. 15,16-Epoxy-12(S)-hydroxy-8(17),13(16),14-ent-labdatrien-20.19-olide had a high toxicity only toward the algae and the rotifers. It was inactive for the crustaceans.