Chemical Variability of the Leaf Essential Oil of Two Subspecies of <i>Juniperus oxycedrus</i> L. From Northwestern Algeria

Thirty-seven essential oil samples have been isolated from leaves of individual plants of Juniperus oxycedrus (subspecies oxycedrus and macrocarpa) growing wild in Tlemcen and Aïn Témouchent provinces (Northwestern Algeria). Analysis of eight selected oil samples by GC(RI), GC/MS and ¹³C NMR, allowed the identification of 88 components that accounted for 84.4-99.5 % of the whole compositions. The 37 compositions were subjected to statistical analysis which suggested the existence of groups and sub-groups I, IIA and IIB. Group I, the most important group with 24 oil samples out of 37, differed from sub-groups IIA and IIB, essentially by the high content of α-pinene (mean value, 69.2 %; SD 6.24). Sub-groups IIA and IIB were differentiated by their content of α-pinene (Mean values, 49.7 % and 27.3 %, respectively) as well as δ-3-carene (10.3 %, sub-group IIA), sabinene and (Z)-6-pentadecen-2-one (8.7 % and 4.9 %, respectively, sub-group IIB).