Involved in the chlorophyll breakdown by its action in nonpolar primary fluorescent chlorophyll catabolite (pFCC) decarbonylation (Ref.6, PubMed:23723324). Involved in the formation of major chlorophyll breakdown products, including non-fluorescent dioxobilin-type chlorophyll catabolites (NDCCs), during leaf senescence (PubMed:23723324). O2 + primary fluorescent chlorophyll catabolite + reduced [NADPH--hemoprotein reductase] = formate + 2 H(+) + oxidized [NADPH--hemoprotein reductase] + primary fluorescent dioxobilin-type chlorophyll catabolite Porphyrin-containing compound metabolism; chlorophyll degradation. Impaired accumulation of non-fluorescent dioxobilin-type chlorophyll catabolites (NDCCs) compensated by higher amounts of non-fluorescent chlorophyll catabolites (NCCs) in senescing leaves. Belongs to the cytochrome P450 family.