Cl. Cespedes et al., Insect growth regulator and insecticidal activity of beta-dihydroagarofurans from Maytenus spp. (Celastraceae), Z NATURFO C, 56(7-8), 2001, pp. 603-613
Citations number
40
Categorie Soggetti
Biochemistry & Biophysics
Journal title
ZEITSCHRIFT FUR NATURFORSCHUNG C-A JOURNAL OF BIOSCIENCES
From the aerial parts of Maytenus disticha, we have isolated 9 beta -benzoy
loxy-1 alpha ,2 alpha ,6 beta ,8 alpha ,15-penta-acetoxy-dihydro-beta -agar
ofuran (1) and from seeds of Maytenus boaria 9 beta -furoyloxyl-1 alpha ,6
beta ,8 alpha -triacetoxy-dihydro-beta -agarofuran (2). These compounds and
their MeOH and hexane/ethyl acetate (1:1 v/v) extracts were evaluated for
their effects on the fall armyworm (Spodoptera frugiperda). Toosendanin, a
commercial insecticide derived from Melia azedarach was used as a positive
control. When tested for activity using neonate larvae in a no-choice artif
icial diet bioassays, the agarofurans 1, 2 and toosendanin as well as the M
eOH and hexane/EtOAc extracts caused significant growth inhibitory effects
with GC(50) of 7.55; 3.84; 1.75; 14.0 and 7.3 ppm at 7 days, respectively.
Compounds I and 2 caused 100% larval mortality at 25 and 15 ppm, respective
ly. MeOH and hexane/EtOAc extracts caused 100% larval mortality at 25.0 ppm
, respectively, they also increased the development time of surviving larva
e and a significant delay for the time of pupation and adult emergence. The
se compounds showed comparable potency of activity with toosendanin. Acute
toxicity against adults of S. frugiperda was also found, for hexane/EtOAc e
xtract and 2 had the most potent activity with LD50 value of 4.7 and 1.9 pp
m, respectively. MeOH extract, hexane/EtOAc extract, 1 and 2 caused acetylc
holinesterase inhibition with 78.0, 89.2, 79.3 and 100% inhibition at 15.0
ppm, respectively. Therefore, the furoyloxy agarofuran may be responsible f
or the insecticidal activity of these plants.