Stable isotope characterization of raspberry ketone extracted from Taxus baccata and obtained by oxidation of the accompanying alcohol (betuligenol)

The natural abundance H-2 NMR characterization of raspberry ketone 1 extrac ted from himalayan Taxus baccata and of the accompanying (R) carbinol 2 is performed and compared with that of samples of I obtained from 2 by oxidati on with Candida boidinii and CrO3, respectively. The determination of the d elta(C-13) and/or delta(O-18) values of the above extractive products and o f benzoic acid (6) and 4-butylphenol (10), obtained from natural of synthet ic 1, and of 4-phenylbutan-2-ol (8), prepared from extractive 2, allows a d escription of the labeling pattern of this set of products. A graph of(D/H) (3)/(D/H)(2) vs (D/H)(5)/(D/H)(4) (Figure 3) of the presently examined samp les and of those previously characterized in the laboratory, including thre e commercial samples sold as natural, defines three areas, containing (a) t he material of botanical origin and that produced from extractive 2 by bioo xidation, (b) those produced by bioreduction of the unsaturated ketone 3, a nd (c) the synthetic samples.