Anatomía del desarrollo de la semilla de Hippocratea celastroides

Embryological studies of Hippocratea are restricted to few species, and they show similarity between Hippocratea and Celastraceae. Nevertheless, differences based on H. grahamii have originate controversy on the taxonomic position of the genus. We have examined the seed development of H. celastroides H.B.K, by ligth microscopy. This specie has anatropous and bitegmic ovules. At anthesis, the micropyle is formed only by the inner integument. In the endotegmen and exotesta there are tannin deposits beginning in early stages. After fertilization, the outer integument increases abundantly, it alone forms the wing. The endosperm development is of the nuclear type. After syngamy the zygote rests for 3 months before dividing. The mesoteste develops aerenquima, which differentiates gradually into tracheoidal cells. One layer of endosperm remains at madurity. The cotyledons are connate and rotate 90°. On the basis of these results, we consider that Hippocratea belongs the Celastraceae.

Two novel Diels-Alder adducts from Hippocratea celastroides roots and their insecticidal activity

Two novel compounds, celastroidine A (1) and B (2), were isolated from the roots of Hippocratea celastroides K. Their structures were elucidated by spectroscopical and X-ray diffraction studies. Celastroidine A (1) (C50H74O5) was identified as a Diels-Alder adduct of a triterpene plus a diterpene and celastroidine B (2) as a beyerane, a type of dimer of two diterpene (C40H60O4). Both compounds could be formed in vivo by a Diels-Alder reaction. Celastroidine A showed some antifeeding activity against the stored grain insect Sitophyllus zeamays.Key words: Hippocratea celastroides, Hippocrataceae, roots, Diels-Alder adducts, diterpenoids, triterpenoids, x-ray diffraction, insect antifeedants, stored grain insects, Sitophyllus zeamays, insecticidal plants, Diels-Alderase.