The ethanolic extract of the leaves of Catalpa speciosa with feeding deterrent activity against the gypsy moth larvae was fractionated by solvent partitioning and column chromatography. Two weakly active compounds were isolated and identified by spectral and chemical methods to be catalposide (1) and a new iridoid, specioside (2).A search for naturally occurring antifeeding substances active against the gypsy moth larvae, Lymantria dispar L., revealed that the ethanolic extract of catalpa leaves, Catalpa speciosa Warder (Bignoniaceae), possessed feeding de-terrent properties (1). Systematic fractionation of the extract showed that the activity was due to synergistic and cooperative interaction of many components, which when separated were inactive or only very weakly active (2). Two such constituents were identified as iridoid glycosides; one was the well-known catalposide (1) (3, 4), the other a new substance named specioside (2).
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