Chemical Composition of Hypericum rumeliacumBoiss. Essential Oil. A New Chemotype of This Pharmacologically Valuable Species?

Abstract

Analysis by GC and GC/MS of the essential-oil samples obtained from dry above-ground parts of Hypericum rumeliacum Boiss. (collected in the flowering and fruit-forming vegetative stages) allowed the identification of 212 components in total, comprising ≥97.8% of the total oil composition. In the flowering phase, the major identified volatile compounds were undecane (6.6%), dodecanal (10.8%), and germacrene D (14.1%), whereas α-pinene (7.3%), β-pinene (26.1%), (Z)-β-ocimene (8.5%), (E)-β-ocimene (10.2%), bicyclogermacrene (7.7%), and germacrene D (15.1%) were dominant in the fruit-forming phase. Some of the minor constituents found in the studied oil samples (e.g., a homologous series of four 6-alkyl-5,6-dihydro-2H-pyran-2-ones, i.e., massoia dodeca-, trideca-, tetradeca-, and hexadecalactones) have a restricted occurrence in the Plant Kingdom, and their presence in Hypericum L. spp. has not been previously reported. The chemical compositions of the herein studied additional 34 oils obtained from selected Hypericum taxa were compared using multivariate statistical analysis (agglomerative hierarchical cluster analysis and principal component analysis). The results of these statistical analyses could not be used to either confirm or discard the existence of different H. rumeliacum chemotypes. However, they have implied that the volatile profile of this plant species is determined by the stage of its phenological development.

Essential Oil Composition of Seven Bulgarian Hypericum Species and Its Potential as a Biopesticide

“…In this study, monoterpenes (72.06%) were found to be the main class of compounds with α -pinene (9.89%), β -pinene (16.43%), β -myrcene (5.95%), and trans - β -ocimene (12.88%) being the most abundant compounds in this group ( Supplementary Table S6 ). When comparing the results of H. rumeliacum EO in this study with results obtained for the same species in previous reports [ 7 , 17 , 35 , 49 , 54 ], it appears that each of these studies found different dominant compounds. For example, 2-methyloctane (20.5%), α -pinene (13.7%), and spathulenol (9.8%) were the main EO compounds of samples from Serbia [ 17 ].…”

“…Secondary metabolites in plants have been successfully used as biomarkers in taxons [ 14 , 48 ]. There have been several published reports in which the authors looked for relationships between EO components as chemotaxonomic markers in the genus Hypericum [ 17 , 37 , 45 , 49 ]. However, because genetic and environmental conditions were the main factors that determined the composition of Hypericum EO, its components were deemed insufficient chemotaxonomical markers [ 17 , 48 ].…”

“…Hypericum rumeliacum , section Drosocarpium, is a Balkan endemic species, found in Albania, Serbia, Greece, and Bulgaria. The EO of H. rumeliacum from different regions of Serbia and Greece has been extensively studied [ 7 , 17 , 35 , 49 , 54 ]. Bulgarian samples of this species have not been analyzed and reported previously.…”

Chemical Composition of Hypericum laricifolium Juss. Essential Oil Collected from merida-Venezuela

“…Hydrocarbons, such as 3-mehtyl-nonane (12.3%), 2-methyl-octane (9.6%) and nonane (7.6%) were also present among main components of H. laricifolium essential oil in the current investigation; related components have also been reported, previously, in high concentrations for other Hypericum species [12,13,[15][16][17][18].…”

“…H. elongatum also showed a large amount of α-pinene (80.43%) and determined β-pinene (2.59%) between the minor compounds [14]. However, H. rumeliacum showed higher concentrations of β-pinene (26.1%) comparing to α-pinene (7.3%) [15]. On the other hand, H. perforatum, known as the most commercially important species within the genus Hypericum, showed the presence of α-pinene (8.6%) and β-pinene (3.8%), along with germacrene-D (22.1%), β-caryophyllene (11.3%), α-cadinol (4.4%), 2-methyl-octane (3.7%), terpinen-4-ol (3.3%), caryophyllene oxide (3.3%), α-muurolol (2.9%) and spathulenol (2.8%) [16].…”