γ-Lactones from the soft corals Sarcophyton trocheliophorum and Lithophyton arboreum

Six novel fatty acid derivatives containing one γ-lactone ring and unusual unsaturated chains were isolated from two soft corals, Sarcophyton trocheliophorum and Lithophyton arboreum, collected in the Red Sea. They were characterized by spectroscopic methods, predominantly 1H NMR, 13C NMR, MS, IR, CD and UV. The compounds gave positive results in a brine shrimp toxicity assay.