title: A novel electron paramagnetic resonance signal associated with the 'primary' electron acceptor in isolated photochemical reaction centers of Rhodospirillum rubrum.
mesh_terms: D004578:Electron Spin Resonance Spectroscopy; D004579:Electron Transport; D010674:Pheophytins; D010777:Photochemistry; D012247:Rhodospirillum rubrum / Q000502:physiology*; D013053:Spectrophotometry
chemical_list: D010674:Pheophytins