3-(2-((3-(Carboxymethyl)-4-methyl-5-((3-methyl-5-oxo-4-vinyl-1,5-dihydro-2H-pyrrol-2-ylidene)methyl)-2H-pyrrol-2-ylidene)methyl)-5-((3-ethylidene-4-methyl-5-oxo-2-pyrrolidinyl)methyl)-4-methyl-1H-pyrr ol-3-yl)propanoic acid AIDS-136009 AIDS136009 NSC636875 Phytochrom chromophore