Two new pyrrolidine alkaloids from the red alga Acanthophora spicifera .

Two new pyrrolidine alkaloids, acanthophoraines B ( 1 ) and C ( 2 ), together with five known ones ( 3 - 7 ) were isolated from the red alga Acanthophora spicifera . Their structures were elucidated by extensive spectroscopic methods and single-crystal X-ray diffraction analysis. The absolute configuration of 2 was established by ECD calculation. The antibacterial activities of 1-7 were also evaluated.