A new isopimarane diterpenoid, 8(9),15-isopimaradien-7-one-20,12-carbolactone (1), was isolated from Vellozia pusilla Pohl. Its structure was established on the basis of UV, IR, MS, uni and bidimensional ¹H and 13C NMR and comparison of the data with model compounds.
From the hexane extract of leaves, stem and roots, of Vellozia aff. carunculares, fourteen cleistanthane diterpenoids were detected by HRGC-MS, through the analysis of their fragmentation patterns. Comparison of their MS spectra with those of authentic standards previously isolated Cram other species of the family Velloziaceae allowed the identification, with a high degree of confidence, of eigth known cleistanthane diterpenoids. Of these, four were isolated and identified from their MS, IR and H-1 and C-13 NMR spectra, as the known cleistantlia-8,11,13-trien-7-one, cleistantha-8,11,13-trien-3,7-dione, cleistantha-1,8,11,13-tetraen-3,7-dione and the first reported 6-alpha -hydroxy-cleistantha-8,11,13-trien-7-one, The triterpenoid beta -amyrin was also isolated.
Bioassay-directed fractionation of the bioactive alcoholic extracts of Vellozia candida yielded a new 6,7-seco-rosane diterpenoid, candidalactone (1), which showed moderate toxicity toward DNA repair-deficient mutants of Saccharomyces cerevisiae. Another new but inactive rosane diterpenoid, candidenodiol (3), was also obtained.
The new norcucurbitacin glycosides, andirobicin A gentiobioside [2], and andirobicin C gentiobioside [1], and the known fevicordin F gentiobioside [3], were isolated from the aqueous MeOH fraction of a liquid-liquid partition of the MeOH extract of the seeds of Fevillea trilobata. Their structures were determined by nmr and ms techniques.
From the MeOH extract of the seeds of Fevillea trilobata (Cucurbitaceae) were isolated fevicordin A glucoside [1], cayaponoside B [2], cayaponoside D [3], a new norcucurbitacin glucoside, and a new heptanorcucurbitacin glucoside. The structure of the new norcucurbitacin glucoside, andirobicin A glucoside, was established as 29-nor-1,2,3,4,5,10-dehydro-25-methoxy-2-O-beta-D-glucopyranosyl- 3,16 alpha,20R,22 xi-tetrahydroxy-11-oxocucurbit-23-ene [4], and that of the novel heptanorcucurbitacin glucoside, andirobicin B glucoside, as 22,23,24,25,26,27,29-heptanor-1,2,3,4,5,10-dehydro-2-O-beta-D-g luc opyranosyl-3,16 alpha-dihydroxycucurbita-11,20-dione [5].
Two new cleistanthane diterpenes have been isolated from Vellozia declinans, and their structures elucidated by spectroscopic methods and chemical interconversion.
Two new diterpenes, nanuzone and 11β-hydroxy-nanuzone, have been isolated from Vellozia nanuzae. Their structures were elucidated by spectroscopic methods and confirmed by partial synthesis.
New norditerpenoids and a series of known di-and triterpenoids were isolated from Vellozia pusilla and their structures were elucidated by spectroscopic methods and chemical transformations.