oxidoreductase activity, acting on the CH-CH group of donors, with a flavin as acceptor 4,4'-diapophytoene desaturase (4,4'-diaponeurosporene-forming) activity https://github.com/geneontology/go-ontology/issues/23557 4,4'-diapo-zeta-carotene desaturase activity Catalysis of the reaction: 4 H+ + 15-cis-4,4'-diapophytoene + 4 FAD = 4,4'-diapolycopene + 4 FADH2. This reaction consists of four successive dehydrogenations that lead to the introduction of three double bonds into 4,4'-diapophytoene (dehydrosqualene), with 4,4'-diapophytofluene, 4,4'-diapo-zeta-carotene and 4,4'-diapolycopene as intermediates, and 4,4'-diapolycopene as the end product. molecular_function 4,4'-diaponeurosporene desaturase activity 4,4'-diapophytofluene desaturase activity EC:1.3.8.2 GO:0102223 MetaCyc:RXN-12224 MetaCyc:RXN-15614 GO:0102961 GO:0102225 GO:0102962 RHEA:31391 RHEA:42800 4,4'-diapophytoene desaturase activity