Precocene II is a chromene that has been found inA. houstonianumand has anti-juvenile hormone activity.^1,2,3It inhibits juvenile hormone biosynthesis in isolated spontaneously active cockroach (P. americana) corpora allata when used at concentrations of 1 mM or higher.¹Precocene II (8 μg/cm²coating in Petri dish) inhibits development of the corpus allatum in newly eclosed female milkweed bugs and causes allatal regression when applied 120 hours post-eclosion in normally developing females.²It induces precocious metamorphosis in milkweed bug second-stage nymphs when applied as a coating to Petri dishes at concentrations of 0.4 and 0.7 μg/cm².³Precocene II inhibits ovarian development in various insects, including milkweed bugs, cotton stainers, apple maggots, and Mexican bean beetles. Precocene II also inhibits production of the trichothecene mycotoxin 3-acetyldeoxy nivalenol inF. graminearum(IC₅₀= 1.2 μM) without inhibiting fungal growth.⁴

1.Pratt, G.E., and Bowers, W.S.Precocene II inhibits juvenile hormone biosynthesis by cockroach corpora allata in vitroNature265(5594)548-550(1977) 2.Bowers, W.S., and Martinez-Pardo, R.Antiallatotropins: Inhibition of corpus allatum developmentScience197(4311)1369-1371(1977) 3.Bowers, W.S., Ohta, T., Cleere, J.S., et al.Discovery of insect anti-juvenile hormones in plantsScience193(4253)542-547(1976) 4.Sakuda, S.Mycotoxin production inhibitors from natural productsMycotoxins60(2)79-86(2010)