Identification and Quantitative Determination of Resin Acids from Corsican Pinus pinaster Aiton Oleoresin Using 13 C-NMR Spectroscopy.

Twenty-three resin samples have been obtained by tapping from individual Pinus pinaster adult trees grown in Corsica and submitted to acido-basic partition. Identification and quantitative determination of resin acids has been carried out using 13 C-NMR spectroscopy following a method developed by our group. The main components were dehydroabietic acid (up to 37.6 %), levopimaric acid (up to 35.5 %) and abietic acid (up to 24.7 %). A lignan, pinoresinol, has been identified in some samples. Within the 23 compositions, submitted to k-means analysis and Principal Component Analysis, two clusters have been perfectly differentiated, whose compositions were dominated by dehydroabietic acid (Group I, M=23.5 %, SD=6.3) and levopimaric acid (Group II, M=21.2 %; SD=6.2), respectively. Both compositions have been observed in the three locations of harvest.

Composition and chemical variability of the leaf oil from Corsican Juniperus thurifera. Integrated analysis by GC(RI), GC-MS and 13C NMR.

The composition of 16 samples of leaf oil from Corsican Juniperus thurifera was investigated by integrated techniques, GC, GC-MS and 13C NMR. K-means partitioning and PCA analysis of the data allowed the definition of a main group (14 samples) dominated by limonene (mean = 52.2%, SD = 6.4) and alpha-pinene (mean = 7.2%, SD = 3.8). Limonene and beta-elemol (up to 19.7%) were identified as the major components of two atypic samples.

Chemical variability of the needle oil of Juniperus communis ssp. alpina from Corsica.

The composition of 109 samples of essential oil isolated from the needles of Juniperus communis ssp. alpina growing wild in Corsica was investigated by GC (in combination with retention indices), GC/MS, and 13C-NMR. Forty-four compounds accounting for 86.7-96.7% of the oil were identified. The oils consisted mainly of monoterpene hydrocarbons, in particular, limonene (9.2-53.9%), beta-phellandrene (3.7-25.2%), alpha-pinene (1.4-33.7%), and sabinene (0.1-33.6%). The 109 oil compositions were submitted to k-means partitioning and principal component analysis, which allowed the distinction of two groups within the oil samples. The composition of the major group (92% of the samples) was dominated by limonene and beta-phellandrene, while the second group contained mainly sabinene beside limonene and beta-phellandrene.