Two new bromoindoles from red alga Laurencia similis

Two new bromoindole alkaloids have been isolated from the ethanolic extract of the red alga Laurencia similis.On the basis of chemical and spectroscopic methods(including 1D and 2D NMR technique),their structures have been elucidated as 2,2′,5,5′,6,6′-sixibromo -3,3′-bi-1H-indole and 3,5-dibromo-1-methylindole,respectively.     

Total synthesis of marine bisindole alkaloids, (+)-hamacanthins A, B and (−)-antipode of cis-dihydrohamacanthin B

The total synthesis of the marine bisindole alkaloids, (+)-hamacanthins A (2a) and B (2b), and (−)-antipode of cis-dihydrohamacanthin B (2e) was achieved by transamidation-cyclization of N-(2-aminoethyl)-2-oxoethanamide 18 derived from (S)-indolylglycinol 10.     

Aplicyanins A-F, new cytotoxic bromoindole derivatives from the marine tunicate Aplidium cyaneum

Six new bromoindole derivatives, aplicyanins A-F (1-6), have been isolated from the CH₂Cl₂/MeOH extract of the tunicate Aplidium cyaneum collected in Antarctica. Their structures were determined by extensive analysis of their spectroscopic features, particularly 1D and 2D NMR spectra, and comparison with related compounds. Cytotoxic and antimitotic activities were found for compounds 2 and 4-6.