CHARACTERIZATION OF TETRACYCLIC TRITERPEN IC ALCOHOLS BY MASS-SPECTROMETRY AND PROTON NMR

Triterpenic alcohols are minor components of oils. Their identificatio n is useful to precise the origin of a lipid. This work is devoted to the spectral study of tetracyclic triterpenic alcohols. The mass spect ra analyze of these compounds permit to determine without ambiguity th e carbon backbone, the insaturation level of the molecule studied; on the other hand, these insaturations can't be localyzed, except in part icular cases. In proton NMR on the contrary, the signals of all import ant protons, particularly those of methyl groups, can be observed with out difficulty, giving the structure of the carbon backbone; the proto n chemical shifts permit to precise the localisation of insaturations. The NMR spectroscopy requires the obtention of compounds with a purit y of 80% which limits the use of this technic.