- Dammarane triterpenes from Gardenia aubryi vieill.
-
Three new dammarane triterpenoids, gardaubryones A-C (1-3), were isolated from the gum collected on the aerial parts of Gardenia aubryi Vieill., together with the known compounds hydroxydammarenone II (4), ocotillone (5), cabraleone, and hollongdione. The structures of the novel compounds were established on the basis of mass spectrometry, NMR experiments, and chemical-correlation reactions. Copyright
- Grougnet, Raphael,Magiatis, Prokopios,Mitaku, Sofia,Skaltsounis, Alexios-Leandros,Cabalion, Pierre,Tillequin, Francois,Michel, Sylvie
-
-
Read Online
- Dammarane Triterpenes of Trevoa trinervis: Structure and Absolute Stereochemistry of Trevoagenins A, B, and C
-
Trevoagenins A, B, and C, extracted from Trevoa trinervis Miers, are shown, by chemical and spectral means, to be isomeric dammarane triterpenes posessing the general 3β,25,30-trihydroxy-(20,24)-epoxydammaran-16-one structure with stereoisomeric side-chains of the ocotillol type.Trevoagenin A (20R,24R)-(1),, whose stereochemistry has been esteblished by chemical methods and confirmed by X-ray analysis, was transformed into (20R,24ξ)-ocotillone (26) and the C-24 stereochemistry was assigned as R.As a consequence, the C-24 stereochemistry for ocotillol-related compounds of the (20R)-series, unestablished so far, has been determined.The stereochemistry of trevoagenin B, (20S,24R)-(13), was established by chemical correlation with trevoagenin A.Moreover, trevoagenin B was transformed into ocotillol (20S,24R)-(21) and its recently questioned C-24 stereochemistry has been reaffirmed.Trevoagenin C, (20S,24S)-(17), is the C-24 isomer of trevoagenin B as shown by degradation of both compounds to the lactone (16).
- Betancor, Carmen,Freire, Raimundo,Hernandez, Rosendo,Suarez, Ernesto,Cortes, Manuel,et al.
-
p. 1119 - 1126
(2007/10/02)
-
- TRITERPENOIDS FROM THE LEAVES OF Betula lanata
-
From the unsaponifiable fraction of an ethereal extract of the leaves of Betula lanata, in addition to 3-epiocotillol (I) we have isolated a new triterpene, 20(S),24(R)-epoxydammarane-3α,11α,25-triol (V) and also derivatives of it - the monoacetates at C-3 (II) and C-11 (III), and the monoketone at C-3 (IV).The structures of compounds (I-V) have been established on the basis of the results of physicochemical investigations.
- Pokhilo, N. D.,Malinovskaya, G. V.,Makhan'kov, V. V.,Anufriev, V. F.,Uvarova, N. I.
-
p. 368 - 372
(2007/10/02)
-