Dissertation committee:
Όλγα Τζάκου Καθηγήτρια (Επιβλέπουσα), Βασίλειος Ρούσσης Καθηγητής, Μαρία Κουλάδη Αναπληρώτρια Kαθηγήτρια
Original Title:
Συγκριτική μελέτη αιθερίων ελαίων φυλλώματος από 54 taxa του γένους Pinus L. - Απομόνωση και ταυτοποίηση δευτερογενών μεταβολιτών από τα είδη Pinus heldreichii Christ., Pinus pinea L. και Pinus nigra subsp. nigra Arn.
Translated title:
Comparative study of the essential oil composition of the foliage of 54 Pinus taxa - Isolation and structure elucidation of secondary metabolites from the species Pinus heldreichii Christ., Pinus pinea L. and Pinus nigra subsp. nigra Arn.
Summary:
In the framework of this study, the chemical composition of the organic
extracts of three Pinus species, as well as the needle essential oils of 54
Pinus taxa were investigated. Specifically, cones of Pinus heldreichii, fresh
needles of Pinus nigra subsp. nigra and bark of Pinus pinea were exhaustively
extracted and the crude extracts were subjected to a series of chromatographic
separations. The cones of P. heldreichii yielded 38 metabolites in total.
Specifically, twenty abietane diterpenes, eight diterpenes featuring the
pimarane skeleton, four labdane diterpenes, two macrocyclic cembrane
diterpenes, two podocarpene derivatives, one oxygenated sesquiterpene and one
steroid. Among these, three metabolites were new natural products (one abietane
and two pimarane diterpenes), one abietane diterpene was isolated for the first
time from Gymnospermae, four metabolites were isolated for the first time from
the genus Pinus and twenty-seven diterpenes were reported for the first time
from P. heldreichii. In addition, the spectroscopic data of 20 metabolites were
fully assigned for the first time. In total, 12 metabolites were isolated from
the fresh needles of P. nigra subsp. nigra, five of which were identified as
abietane diterpenes, four diterpenes possessed a labdane skeleton, one was a
steroid and two were phenolic compounds. Among these metabolites, one abietane
diterpene and one phenolic compound were new natural products, five metabolites
were reported for the first time from this species, while full assignment of
the spectroscopic data for six diterpenes was reported. Furthermore, the
chromatographic separation of P. pinea bark extract resulted in the isolation
of a flavonoid derivative and a mixture of ferulic acid esters. The fresh
needles of 46 pine species, including 37 and 17 taxa of the subgenera Pinus and
Strobus, respectively, were subjected to hydrodistillation and the essential
oils obtained were analyzed by means of GC–FID and GC–MS. Among the analyzed
taxa, significant quantitative and qualitative differences were observed.
Monoterpenes, sesquiterpenes and diterpenes dominated the pine foliage oils,
with most of the oils characterized by the presence of the monoterpene
hydrocarbons α- and β-pinene and the sesquiterpene hydrocarbon germacrene D.
This is the first report on the chemical composition of the essential oils of
21 pine taxa, including 15 taxa of the subgenus Pinus and six taxa of the
subgenus Strobus.
Keywords:
Pinus, Secondary metabolites, Diterpenes, Essential oil, Structure elucidation
