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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.

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.

Epiphorellic acids 1 and 2, two diaryl ethers from the lichen Cornicularia epiphorella

Abstract From the lichen Cornicularia epiphorella two new diaryl ethers, epiphorellic acids 1 and 2, were isolated besides the known compound atranorin. The structures of the new compounds were established by spectroscopic evidence and chemical transformations. The structure of epiphorellic acid 1 was also confirmed by correlation with a known compound.

Two triterpenoids from Boehmeria excelsa

Abstract Two new triterpenoids, boehmerone and boehmerol, and the known compounds ursolic acid and betulinic acid were isolated from the bark of Boehmeria excelsa. The structures of the new compounds were established by spectroscopic methods and X-ray analysis.

Stemodane diterpenoids from Stemodia chilensis

Abstract From the aerial parts of Stemodia chilensis a previously known diterpenoid, 2-deoxy stemodinone, and four new natural substances, 19-acetyloxy-stemodan-13α-ol, 17-acetyloxy-stemodan-13α-ol, stemodan-13α,14α-diol and stemodan-13α-17-diol, have been isolated. The structures of the compounds were elucidated by spectroscopic methods.

Labdane diterpenoids from nolana rostrata

Abstract Six new labdane diterpenes, methyl 3-oxo-18-hydroxylabda-8(17),13E-dien-15-oate, methyl 2β,3β- dihydroxylabda-8(17),13E-dien-15-oate, 2-oxo-labda-8(17),13Z-dien-15-oic acid, 3-oxo-18-acetoxylabda-8(17),13Z- dien-15-oic acid, 3-oxo-18-hydroxylabda-8(17),13Z-dien-15-oic acid, 2β,3β-dihydroxylabda-8(17),13Z-dien-15-oic acid, and the known compound kaempferol-3,7,4′-trimethyl ether were isolated from the aerial parts of Nolana rostrata. The structures of the new compounds were elucidated by spectroscopic methods.

Eudesmane derivatives from cyperus corymbosus

Abstract From the rhizomes of Cyperus corymbosus a new eudesmane sesquiterpenoid, isocorymbolone, was isolated besides the known compounds corymbolone and (+)-α-cyperone. The structure of the new compound was established by means of spectroscopic methods.