Direct Identification and Quantitative Determination of Acidic and Neutral Diterpenes Using ¹³C-NMR Spectroscopy. Application to the Analysis of Oleoresin of <i>Pinus nigra</i>

Abstract

We report a methodology that allows identification and quantitative detrmination of individual acidic and neutral diterpenes in natural mixtures, using the computer-aided analysis of their 13 C-NMR spectra. The analytical procedure was validated on artificial mixtures and then applied to authentic oleoresins of Pinus nigra. Up to eleven diterpenes, which represented 63% of the total composition of the oleoresin, were identified and quantified without previous separation or derivatization.