In enzymology, a secologanin synthase (EC 1.14.19.62, was wrongly classified as EC 1.3.3.9 in the past) is an enzyme that catalyzes the chemical reaction

loganin + NADPH + H⁺ + O₂ ${\displaystyle \rightleftharpoons }$ secologanin + NADP⁺ + 2 H₂O

The 4 substrates of this enzyme are loganin, NADPH, H⁺, and O₂, whereas its 3 products are secologanin, NADP⁺, and H₂O.

This enzyme belongs to the family of oxidoreductases, specifically those acting on the CH-CH group of donor with oxygen as acceptor. The systematic name of this enzyme class is loganin:oxygen oxidoreductase (ring-cleaving). This enzyme participates in indole and ipecac alkaloid biosynthesis.

References

• Yamamoto H, Katano N, Ooi A, Inoue K (2000). "Secologanin synthase which catalyzes the oxidative cleavage of loganin into secologanin is a cytochrome P450". Phytochemistry. 53 (1): 7–12. doi:10.1016/S0031-9422(99)00471-9. PMID 10656401.
• Strack D, Matern U, Schroder J (2000). "Indole alkaloid biosynthesis in Catharanthus roseus: new enzyme activities and identification of cytochrome P450 CYP72A1 as secologanin synthase". Plant J. 24 (6): 797–804. doi:10.1046/j.1365-313x.2000.00922.x. PMID 11135113.
• Yamamoto H, Katano N, Ooi Y, Inoue K (1999). "Transformation of loganin and 7-deoxyloganin into secologanin by Lonicera japonica cell suspension cultures". Phytochemistry. 50 (3): 417–422. doi:10.1016/S0031-9422(98)00613-X.