María C. Chamy

Effects and mode of action of 1,4-naphthoquinones isolated from Calceolaria sessilis on tumoral cells and Trypanosoma parasites

The naphthoquinones 2-hydroxy-3-(1,1-dimethylallyl)-1,4-naphthoquinone (CS-1), (-)-2,3,3-trimethyl-2-3-dihydronaphtho[2,3-b]furan-4,9-quinone (CS-3), and 2-acetoxy-3-(1,1-dimethylallyl)-1,4-naphthoquinone (CS-5) isolated from Calceolaria sessilis were tested against Trypanosoma cruzi epimastigotes, the TA3 tumor cell line and the methotrexate-resistant subline TA3-MTX-R. Naphthoquinone CS-3 was the most active; the 50% culture growth inhibition (I50) on T. cruzi (Tulahuén and LQ strain and DM28c clone) was at concentrations ranging from 2.1 to 5.2 mumolar. Also CS-3 inhibited TA3 and TA3-MTX-R culture growth with an I50 of 2.1 and 3.8 mumolar, respectively. Naphthoquinone CS-3 inhibited the respiration of the tumor cells by interfering with the electron transport at some point between NADH and ubiquinone. The respiration of T. cruzi was not inhibited by naphthoquinone CS-3. Naphthoquinone CS-3 produced a temporary increase of oxygen consumption in T. cruzi and tumor cells, suggesting the generation and participation of free radicals.

Diterpenoids from Calceolaria thyrsiflora

Abstract Three novel diterpenes, thyrsiflorin A, thyrsiflorin B, thyrsiflorin C, and the dehidroabietane derivatives, abietatrien-3β-ol and 3β-acetoxy abietatrien were isolated from the aerial parts of Calceolaria thyrsiflora . The structures of the new compounds were elucidated by spectroscopic methods, chemical transformation and X-ray analysis.

Dehydroabietane diterpenoids from Calceolaria ascendens

Abstract Two new dehydroabietane diterpenes, dehydroabietinol and 19-malonyloxy-dehydroabietinol, and the known compound 4-epi-dehydroabietic acid were isolated from the aerial parts of Calceolaria ascendens. The structures of the new compounds were elucidated by spectroscopic methods.

18-Malonyloxy-9-epi-ent-isopimarol, a diterpene from Calceolaria glandulosa

Abstract A new pimarane diterpene, 18-malonyloxy-9- epi - ent -isopimarol, was isolated from the aerial parts of Calceolaria glandulosa . The structure of the new compound was established by spectroscopic evidence, chemical transformations and X-ray analysis.

Foliosate, a bis-diterpene and 9-epi-ent-7,15-isopimaradiene· derivatives from Calceolaria foliosa

Abstract In addition to four new 9- epi -pimarane diterpenes, the aerial part of Calceolaria foliosa yielded a new bis-diterpene, foliosate, derived from the esterification of malonic acid by two 17-hydroxy-9- ent -7,15-isopimaradiene units. The structures of the new compounds were elucidated by spectroscopic methods and chemical transformations.

Diterpenes from Calceolaria lepida

Abstract In addition to four new pimarane derivatives, the aerial parts of Calceolaria lepida yielded a new bisditerpene and two novel stemarane diterpenes. The structure of the compounds were elucidated by spectroscopic methods and chemical transformations.

The distribution of phenylpropanoid glycosides in Chilean calceolaria Spp.

Abstract The distribution of phenylpropanoid glycosides in Chilean species of Calceolaria belonging to Reiches section III was investigated by HPLC. Verbascoside, calceolariosides A-E, forsythoside A and isoarenarioside were detected. All species investigated contained verbascoside and/or calceolarioside A. The patterns of these phenolic constituents seem to be characteristic of species and groups of species rather than of higher infrageneric taxa.

9-epi-ent-7,15-isopimaradiene derivatives from Calceolaria glandulosa

Abstract In addition to two new 9- epi -pimarane diterpenes, the aerial parts of Calceolaria glandulosa yielded a new bis-diterpene, glandulosate, derived from the esterification of malonic acid by two 18-hydroxy- ent -9- epi -7,15-isopimaradiene units. The structures of the compounds were elucidated by spectroscopic evidence and chemical transformations.

Diterpenoids from calceolaria dentata

Five diterpenoids were isolated from the aerial parts of Calceolaria dentata. Their structures were elucidated by spectroscopic methods. Three of them are esterified with isovaleric acid.

Diterpenoids from Calceolaria purpurea

Abstract Four new diterpenes were isolated from the aerial parts of Calceolaria purpurea . The structures of these new compounds were established by spectroscopic evidence, and chemical transformations.