Diterpenes and other constituents from Croton draco (Euphorbiaceae)

Croton draco (Euphorbiaceae) from Guadalupe, San José, Costa Rica was collected in July 1992 and phytochemically studied (leaves, seeds, wood, bark, sap and flowers separately). Commonly known compounds such as 1-hydroxyjunenol, p-hydroxybenzaldehyde, p-methoxybenzoic acid, 3,4,5-trimethoxycinnamyl alcohol, the coumarin scopoletin, the nor-terpenoids 9-dehydrovomifoliol and 2,3-dihydrovomifoliol were obtained. Taspine, two aporphinic alkaloids, the diterpenes 9(11)-dehydrokaurenic acid, hardwikiic acid, the corresponding new 12-oxo derivative as well as five clerodanes and a phorbol ester were also isolated. Three clerodanes were not previously described and their NMR spectroscopical data and MS fragmentation patterns are reported.

Diterpenes and other constituents from Croton draco (Euphorbiaceae).

Croton draco (Euphorbiaceae) from Guadalupe, San José, Costa Rica was collected in July 1992 and phytochemically studied (leaves, seeds, wood, bark, sap and flowers separately). Commonly known compounds such as 1-hydroxyjunenol, p-hydroxybenzaldehyde, p-methoxybenzoic acid, 3,4,5-trimethoxycinnamyl alcohol, the coumarin scopoletin, the nor-terpenoids 9-dehydrovomifoliol and 2,3-dihydrovomifoliol were obtained. Taspine, two aporphinic alkaloids, the diterpenes 9(11)-dehydrokaurenic acid, hardwikiic acid, the corresponding new 12-oxo derivative as well as five clerodanes and a phorbol ester were also isolated. Three clerodanes were not previously described and their NMR spectroscopical data and MS fragmentation patterns are reported.

Biological activity of Ruta chalepensis (Rutaceae) and Sechium pittieri (Cucurbitaceae) extracts on Hypsipyla grandella (Lepidoptera: Pyralidae) larvae.

Biological activity of a plant extract (common rue, Ruta chalepensis) and a semi purified fraction (from "tacaco cimarrón", Sechium pittieri) on mahogany shootborer larvae (Hypsipyla grandella) was studied. A randomized complete block design, with four replications, was used. H. grandella third instar larvae were exposed for 24 h to Cedrela odorata leaf discs dipped in several treatment dissolutions of each extract (0.1, 0.32, 1.0, 3.20, and 10%); afterwards, each larva was transferred to a flask containing an artificial diet and was allowed to complete its development. Variables measured included food consumption (foliar area eaten in 24 h), mortality, and developmental effects (developmental time for each larval instar and the pupa, and pupal weight). The common rue extract showed a clear antifeedant activity at a concentration as low as 0.32%, whereas the "tacaco cimarrón" fraction caused toxicity, especially at the two highest concentrations (3.20 and 10%).

Structures and antiproliferative activity of saponins from Sechium pittieri and S. talamancense.

Six bisdesmosidic bayogenin saponins, named tacacosides A1, A2, B1, B2, B3 and C, were isolated from the fruit and aerial parts of Sechium pittieri (COGN.) C. Jeffrey and S. talamancense (WUNDERLIN) C. Jeffrey, Costa Rican cucurbitaceae plants. Their structures were elucidated on spectral and chemical evidence as follows. Tacacoside A1: 3-O[beta-D-glucopyranosyl-(1-->3)-beta-D-glucopyranosyl]bayogenin 28-O-(alpha-L-rhamnopyranosyl- (1-->3)-beta-D-xylopyranosyl-(1-->4)-beta-D-apiofuranosyl-(1-->3)] - alpha-L-rhamnopyranosyl-(1-->2)-alpha-L-arabinopyranosyl) ester, tacacoside A2: 3-O-[beta-D-glucopyranosyl-(1-->3)-beta-D-glucopyranosyl]bayogenin 28-O-(alpha-L-rhamnopyranosyl- (1-->3)-beta-D-xylopyranosyl-(1-->4)-[beta-D-xylopyranosyl-(1-->3)]-a lph a-L- rhamnopyranosyl-(1-->2)-alpha-L-arabinopyranosyl) ester, tacacoside B1: 3-O-[beta-D-glucopyranosyl]bayogenin 28-O-(alpha-L-rhamnopyranosyl-(1-->3)-beta-D-xylopyranosyl- (1-->4)-[beta-D-apiofuranosyl-(1-->3)]-alpha-L-rhamnopyranosyl-(1- ->2)-alpha- arabinopyranosyl) ester, tacacoside B2: 3-O-[beta-D-glucopyranosyl]bayogenin 28-O-(alpha-L-rhamnopyranosyl-(1-->3)- beta-D-xylpyranosyl-(1-->4)-[beta-D-xylopyranosyl- (1-->3)]-alpha-L-rhamnopyranosyl-(1-->2)-alpha-L-arabinopyranosyl) ester, tacacoside B3: 3-O-[beta-D-glucopyranosyl-(1-->3)-beta-D-glucopyranosyl] bayogenin 28-O-[alpha-L-rhamnopyranosyl-(1-->3)-beta-D-xylopyranosyl- (1-->4)-alpha-L-rhamnopyranosyl- (1-->2)-alpha-L-arabinopyranosyl] ester, and tacacoside C: 3-O-[beta-D-glucopyranosyl]bayogenin 28-O-[alpha-L-rhamnopyranosyl- (1-->3)-beta-D-xylopyranosyl-(1-->4)-alpha-L-rhamnopyranosyl-(1-->2)- alpha-L-arabinopyranosyl] ester. These saponins showed moderate antiproliferative activity (ED50:10-74 micrograms/ml) against MK-1, HeLa and B16F10 cells.