Thymus pannonicus
Encyclopedia
Thymus pannonicus, known by its common name Hungarian thyme or Eurasian thyme is a perennial herbaceous
plant, distributed in central and eastern Europe and Russia. It grows over open dry meadows, grasslands and rocks.
In Serbia, this plant species contributes to several xerothermous grass formations which develop on warm, dry silicate
terrains at altitude above 160 meters, mostly over plains or mild slopes, on acidic soils derived from crystalline albite
-muscovite
schist
and gneiss
-like granite
. In southern Banat (Serbia
), the dried herb is used to make tasty and refreshing herbal tea drinks, owing to its peculiar and pleasant lemon-like scent. Fresh leaves are used for aromatisation of homemade jams, candies and similar confections. Traditionally, it is used also for coughs and other respiratory complaints, as well as certain gastrointestinal disorders.
On the other hand, a T. pannonicus population, which is located over the southern slopes of Vršac Mountains
in southern Banat (Vojvodina province, Serbia) was characterised by exceptionally high percentage of oxygenated monoterpenes (91.75%). The most abundant components of its essential oil
were identified as geranial (41.42%, w/w) and neral
(29.61%, w/w), the mixture of which is frequently referred to as citral.
, Enterococcus faecalis
, Pseudomonas aeruginosa
, Escherichia coli
, two strains of Klebsiella pneumoniae
and two strains of Candida albicans
. The essential oil exhibited antimicrobial activity to varying degrees against all tested strains. The maximum activity of T. pannonicus oil was observed against E. coli, S. aureus and both tested strains of C. albicans (MIC
= 50 μl/ml, each). Moderate activity was observed against P. aeruginosa and one of the tested strains of K. pneumoniae (MIC = 200 μl/ml), while E. faecalis and the other strain of K. pneumoniae expressed a higher degree of resistance (MIC > 200 μl/ml))
Herbaceous
A herbaceous plant is a plant that has leaves and stems that die down at the end of the growing season to the soil level. They have no persistent woody stem above ground...
plant, distributed in central and eastern Europe and Russia. It grows over open dry meadows, grasslands and rocks.
In Serbia, this plant species contributes to several xerothermous grass formations which develop on warm, dry silicate
Silicate minerals
The silicate minerals make up the largest and most important class of rock-forming minerals, constituting approximately 90 percent of the crust of the Earth. They are classified based on the structure of their silicate group...
terrains at altitude above 160 meters, mostly over plains or mild slopes, on acidic soils derived from crystalline albite
Albite
Albite is a plagioclase feldspar mineral. It is the sodium endmember of the plagioclase solid solution series. As such it represents a plagioclase with less than 10% anorthite content. The pure albite endmember has the formula NaAlSi3O8. It is a tectosilicate. Its color is usually pure white, hence...
-muscovite
Muscovite
Muscovite is a phyllosilicate mineral of aluminium and potassium with formula KAl22, or 236. It has a highly-perfect basal cleavage yielding remarkably-thin laminæ which are often highly elastic...
schist
Schist
The schists constitute a group of medium-grade metamorphic rocks, chiefly notable for the preponderance of lamellar minerals such as micas, chlorite, talc, hornblende, graphite, and others. Quartz often occurs in drawn-out grains to such an extent that a particular form called quartz schist is...
and gneiss
Gneiss
Gneiss is a common and widely distributed type of rock formed by high-grade regional metamorphic processes from pre-existing formations that were originally either igneous or sedimentary rocks.-Etymology:...
-like granite
Granite
Granite is a common and widely occurring type of intrusive, felsic, igneous rock. Granite usually has a medium- to coarse-grained texture. Occasionally some individual crystals are larger than the groundmass, in which case the texture is known as porphyritic. A granitic rock with a porphyritic...
. In southern Banat (Serbia
Serbia
Serbia , officially the Republic of Serbia , is a landlocked country located at the crossroads of Central and Southeast Europe, covering the southern part of the Carpathian basin and the central part of the Balkans...
), the dried herb is used to make tasty and refreshing herbal tea drinks, owing to its peculiar and pleasant lemon-like scent. Fresh leaves are used for aromatisation of homemade jams, candies and similar confections. Traditionally, it is used also for coughs and other respiratory complaints, as well as certain gastrointestinal disorders.
Chemical composition
In a survey of available literature, only a few publications relevant to the chemical composition of Thymus pannonicus were found, suggesting that a substantial dearth of information in this field still exists. According to Karuza-Stojaković et al., the principal constituents of T. pannonicus essential oil from southern parts of Vojvodina province (northern Serbia) were terpinyl acetate, terpinen-4-ol, thymol, carvacrol and geranyl acetate (listed in order of descending quantity). Recent comprehensive studies of chemical variability in hydrodistilled essential oils of different wild growing and cultivated populations of T. pannonicus from Hungary, as well as supercritical fluid extracts of various Lamiaceae species, confirmed that high concentrations of both thymol and p-cymene are the main chemosystematic attributes of T. pannonicus essential oil,. Further research efforts of Pluhár Zs. et al. on the volatile oil composition of T. pannonicus from nineteen different localities of Hungary, confirmed a significant essential oil polymorphism in this plant species, as twelve different chemovarieties were determined, namely: thymol, thymol/p-cymene, thymol/p-cymene/γ-terpinene, thymol/p-cymene/neral, thymol/p-cymene/γ-terpinene/β-bisabolene, thymol/p-cymene/isoborneol/γ-terpinene, thymol/linalyl acetate/γ-terpinene/α-cubebene, p-cymene/geraniol/linalyl acetate, linalyl acetate/geranyl acetate, germacrene-D/β-caryophyllene, caryophyllene oxide/α-cubebene/linalool, and germacrene-D/β-caryophyllene/farnesol.On the other hand, a T. pannonicus population, which is located over the southern slopes of Vršac Mountains
Vršac Mountains
The Vršac Mountains , also known as Vršac Hill , are mountains located near Vršac , in the Serbian province of Vojvodina and partially also in Romania. They represent an independent and distinct massif, 19 kilometers long and spreading on an area of 170 square kilometers, of which 122 belong to...
in southern Banat (Vojvodina province, Serbia) was characterised by exceptionally high percentage of oxygenated monoterpenes (91.75%). The most abundant components of its essential oil
Essential oil
An essential oil is a concentrated hydrophobic liquid containing volatile aroma compounds from plants. Essential oils are also known as volatile oils, ethereal oils or aetherolea, or simply as the "oil of" the plant from which they were extracted, such as oil of clove...
were identified as geranial (41.42%, w/w) and neral
Neral
Neral may refer to:* An isomer of Citral* Neral, Raigad – A railway junction in Maharashtra en route to Matheran* A Romulan from Star Trek...
(29.61%, w/w), the mixture of which is frequently referred to as citral.
Biological activity
The antimicrobial activity of essential oil was evaluated using the agar disc diffusion and broth microdilution methods against Staphylococcus aureusStaphylococcus aureus
Staphylococcus aureus is a facultative anaerobic Gram-positive coccal bacterium. It is frequently found as part of the normal skin flora on the skin and nasal passages. It is estimated that 20% of the human population are long-term carriers of S. aureus. S. aureus is the most common species of...
, Enterococcus faecalis
Enterococcus faecalis
Enterococcus faecalis – formerly classified as part of the Group D Streptococcus system – is a Gram-positive, commensal bacterium inhabiting the gastrointestinal tracts of humans and other mammals. It is among the main constituents of some probiotic food supplements. Like other species in the genus...
, Pseudomonas aeruginosa
Pseudomonas aeruginosa
Pseudomonas aeruginosa is a common bacterium that can cause disease in animals, including humans. It is found in soil, water, skin flora, and most man-made environments throughout the world. It thrives not only in normal atmospheres, but also in hypoxic atmospheres, and has, thus, colonized many...
, Escherichia coli
Escherichia coli
Escherichia coli is a Gram-negative, rod-shaped bacterium that is commonly found in the lower intestine of warm-blooded organisms . Most E. coli strains are harmless, but some serotypes can cause serious food poisoning in humans, and are occasionally responsible for product recalls...
, two strains of Klebsiella pneumoniae
Klebsiella pneumoniae
Klebsiella pneumoniae is a Gram-negative, non-motile, encapsulated, lactose fermenting, facultative anaerobic, rod shaped bacterium found in the normal flora of the mouth, skin, and intestines....
and two strains of Candida albicans
Candida albicans
Candida albicans is a diploid fungus that grows both as yeast and filamentous cells and a causal agent of opportunistic oral and genital infections in humans. Systemic fungal infections including those by C...
. The essential oil exhibited antimicrobial activity to varying degrees against all tested strains. The maximum activity of T. pannonicus oil was observed against E. coli, S. aureus and both tested strains of C. albicans (MIC
MIC
- Business and industry :* Military-industrial complex, the relationship between a nation's military forces and its arms industry* Miami Intermodal Center, a mega-transportation hub in Miami, Florida...
= 50 μl/ml, each). Moderate activity was observed against P. aeruginosa and one of the tested strains of K. pneumoniae (MIC = 200 μl/ml), while E. faecalis and the other strain of K. pneumoniae expressed a higher degree of resistance (MIC > 200 μl/ml))