momilactone-A synthase [NAD(P)H] activity
Catalysis of the reaction: 3beta-hydroxy-9beta-pimara-7,15-diene-19,6beta-olide + NAD(P) = momilactone A + H+ + NAD(P)H.
GO:0016616
oxidoreductase activity, acting on the CH-OH group of donors, NAD or NADP as acceptor
is_a