Leopold Jirovetz’s research while affiliated with University of Vienna and other places

The essential oil of Matricaria chamomilla L., which is commonly used for medicinal and cosmetic purposes, can be differentiated between several chemotypes. In the current study, six essential chamomile oil samples of various origins (four of commercial sources, one of cultivation, one of wild collection) were examined regarding their composition and biological activities, i. e., antibacterial, antifungal, mosquito repellent, and larvicidal effects. GC-MS analyses revealed that the samples largely varied in composition and could be attributed to various chemotypes. In contrast to the other two samples, the four commercial samples were unusually high in trans-β-farnesene. The overall antimicrobial effects were only moderate, but it could be shown that a higher content in α-bisabolol and a smaller in α-bisabolol oxides A and B had a positive effect on overall activity. All samples had a biting deterrent effect comparable to DEET. Higher concentrations of (Z )- and (E )-spiroethers improved larvicidal activity, whereas trans-β-farnesene had the opposite effect. In conclusion, the importance of α-bisabolol for the biological activity of chamomile essential oil could be demonstrated.

The chemical composition of a sample of lemon eucalyptus essential oil ( Corymbia citriodora) from China was determined by GC/FID and GC/MS. Citronellal (76.3%), citronellol (5.7%) and neo-isopulegol (5.5%) were the major components. The odor of the sample was evaluated as fresh, citrus-like and mildly fruity, with a pleasant woody background note. Lemon eucalyptus oil was found to exhibit antiradical activity with respect to DPPH and hydroxyl (OH•) radicals. The effect exercised on OH• radicals significantly exceeded that observed for the DPPH radical – the respective concentrations for 50% inhibition of the radicals were 0.38 μg/mL for OH• and 344.0 μg/mL for DPPH. Furthermore, the essential oil revealed antioxidant activities in a model system comprised of a linoleic acid emulsion. At a concentration of 0.1%, inhibition of conjugated dienes-formation by 59.8% was observed and the formation of secondary oxidized products of linoleic acid by 84.7%.

The chemical composition of a sample of Jasminum grandiflorum L. absolute from India was analyzed by GC and GC/MS. The major compounds identified were benzyl acetate (23.7%), benzyl benzoate (20.7%), phytol (10.9%), linalool (8.2%), isophytol (5.5%), geranyl linalool (3.0%), methyl linoleate (2.8%) and eugenol (2.5%). The odor of this absolute sample was olfactorically evaluated as intense and heavy floral-flowery, with penetrant-animalic and fruity side-notes. Some main and minor compounds were found to be responsible for the aroma impression of this sample. The antimicrobial activities of the J. grandiflorum sample and of some of its main and minor compounds were tested against Gram-positive and Gram-negative bacteria, as well as against the yeast Candida albicans, using agar dilution and agar diffusion methods. The jasmine absolute showed medium to high activity (reference compounds: eugenol and three synthetic antibiotics) against the Gram-positive bacterium Enterococcus faecalis, against the Gram-negative bacteria Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae and Salmonella sp., as well as against the yeast Candida albicans. A comparison of these biological data with those of some constituents of the jasmine absolute is also given.

In this investigation we examined the essential oils of three aromatic plants, Zanthoxylum armatum , Juniperus communis , and Dysphania ambrosioides , which are used by the local population of the western Himalayan region for medicinal purposes. These plants were studied for their antifungal, larvicidal and biting deterrent activities. Additionally, chemical compositions of the oils were determined by GC-MS and their odor evaluated. The main compounds were 2-undecanone (47.7%) and 1,8-cineol (20.5%) from Z . armatum and α-pinene (43.2%) and limonene (34.7%) from J . communis . p-Cymene (36.3%) and ascardiole (31.2%) were found as the main components of D . ambrosioides essential oil. Antifungal activity was evaluated against three Colletotrichum species. Dyspania ambrosioides oil showed the best activity against these strawberry anthracnose causing fungi. It also demonstrated biting deterrent activity against Aedes aegypti similar to DEET as positive control, whereas Z . armatum and J . communis were less effective against Colletotrichum and mosquitoes.

The essential oils (EOs) obtained by steam distillation from the leaves and the berries of Juniperus phoenicea L., harvested in northwest of Algeria were analyzed and their antimicrobial and anti-inflammatory activities were assessed. 63, 46 and 78 volatile compounds were identified by GC-FID and GC-MS from fresh leaves, dried leaves and berries representing 98.1%, 98.3% and 96.4% of the total oil, respectively. The fresh and dried leaves oils were mainly composed of β-phellandrene (43.9% / 44.9%), α-pinene (25.1% / 20.3%), myrcene (8.5% / 8.2%), α-phellandrene (4.7% / 4.5%) p-cymene (2.7% - 3.0%) and limonene (2.3% - 2.5%) whereas, the berries oil was mainly composed of α-pinene (43.7%), p-cymene (5.8%), β-phellandrene (4.6%), α-terpineol (4.3%) and α-campholenal (4.0%). The study of the antimicrobial activity showed that the 3 EOs were effective only on B. cereus ATCC 10876 and C. albicans ATCC 10231. No signs of acute toxicity have been noted in mice even at the highest dose tested (5000 mg/kg p.o). The fresh leaves, dried leaves and berries oils reduced the carrageenan-induced paw edema in mice by 16.8%, 15.2% and 6.4%, respectively, after 6 hours at a dose of 400 mg/kg p.o.

The essential oil obtained from the aerial parts of Cladanthus arabicus (L.) Cass was studied for its chemical composition, antioxidant, antimicrobial and insecticidal activities. The essential oil (EO) was analyzed by GC-MS. Sixty seven compounds representing 94.2 % of the oil were identified. The major components of C. arabicus EO were sabinene (31.1 %), β-pinene (16.7 %), myrcene (12.3 %) and α-pinene (5.3 %). Moreover, the antioxidant and antimicrobial activities of the essential oil against six bacteria and four Candida strains were studied. The results showed the existence of a strong antioxidant activity with IC50 of 55.4 ± 0.12 μg/mL and 57.2 ± 0.21 μg/mL, respectively for DPPH and FRAP methods. The EO exhibited great antimicrobial activity especially against Micrococcus luteus (MIC = 0.187 mg/mL) and Candida albicans (MIC = 0.187 mg/mL). LD50 and LD90 values were 43.6 and 74.1 ppm against 1d-old larvae of Aedes aegypti, respectively.

This work aims to elucidate the chemical composition of two essential oil (EO) samples obtained from the leaves of Thymus vulgaris L. (Lamiaceae) collected in two regions of Northwestern Algeria (Tlemcen and Mostaganem) and to assess their in vivo acute toxicity and anti-inflammatory activity. Sixty-six compounds could be identified by means of simultaneous GC-FID and GC-MS, accounting for 99.3% of total thyme oil of Mostaganem (EO.TM) and 99.0% of Tlemcen (EO.TT). In both samples, thymol was the major component, amounting to 59.5% (EO.TM) and 67.3% (EO.TT) of the total oil. EO.TT proved to be acutely toxic to mice at a dose of 4500 mg/kg p.o., whereas EO.TM did not show signs of acute toxicity, even at the highest dose tested (5000 mg/kg p.o.). Both EO samples were proven to possess anti-inflammatory activities, significantly reducing carrageenan-induced paw edema in mice (after 6 hours at a dose of 400 mg/kg p.o) at 58.4% for EO.TT and 50.4% for EO.TM, respectively. In conclusion, it could be demonstrated that EOs of T. vulgaris exhibit a considerable in vivo anti-inflammatory activity at non-toxic doses.

The essential oil of Bunium persicum collected from cultivated sources in the cold desert area of Lahaul-Spiti is described for its antimicrobial, larvicidal, and biting deterrent activities. Additionally, odor characterization is given. The chemical composition of the essential oil was analyzed by simultaneous GC-MS and GC-FID. γ-Terpinene and p-cymene were found to be the major compounds. Antibacterial testing by an agar dilution assay revealed low activity of the oil against all tested bacteria. Antifungal activity was evaluated against Candida albicans as well as three species of the strawberry anthracnose causing plant pathogen Colletotrichum. Bunium persicum essential oil demonstrated antifungal activity against all four pathogens. Biting deterrent activity against Aedes aegypti was greater than the solvent control, but significantly lower than DEET. The essential oil of B. persicum exhibited larvicidal activity with an LC50 value of 58.6 ppm against Ae. aegypti larvae.

The seed oils of twenty-six species of Apiaceae belonging to the genera Bunium, Cnidium, Ferula, Ferulago, Heracleum, Hippomarathrum, Malabaila, Myrrhoides, Olymposciadium, Pimpinella, Prangos, Szovitsia, Trigonasciadium, Trinia and Zosima, collected in Turkey, were investigated for their oil content, and amount of petroselinic acid (PA), as well as for the composition of their fatty acid methyl esters (FAMEs) by GC-MS. Seed oil content ranged from 7.1% in Szovitsia callicarpa to 29.3% in Ferda haussknechtii. The results showed that the seed oils of the studied species contained high amounts of PA (1.2-72.2%), followed by significant amounts of linoleic (LA, 13.8-50.8%) and oleic (OA, 4.2-61.6%) acids. PA was found in all the analyzed species, except for Olymposciadium caespitosum, which belongs to a monotypic endemic genus of the family. According to data from our study, PA was found to be predominantly in the seed oils of Hippomarathrum cristatum (72.2%), Trinia glauca (64.9%) and Bunium microcarpum (59.7%) and, therefore these species might be considered as new sources of PA, and represent a potential oleochemical raw material. This is the first extensive study of the composition ofTurkish Apiaceae species. The high amounts of PA may also have chemotaxonomic significance.

The chemical composition, antioxidant, antimicrobial and insecticidal properties of essential oil obtained by hydro-distillation from Bubonium imbricatum Cav. have been investigated. The essential oil of aerial parts was analyzed by GC-FID and GC-MS. A total of 63 compounds were identified representing more than 82% of the oil. The major components were cis-chrysanthenyl acetate (31.2%) and thymol isobutyrate (3.4%). The antioxidant activity was evaluated by the DPPH and reducing power test. The data showed moderate activity compared with the reference compounds. Our results showed strong activity of the investigated oil against all tested microorganisms. The highest antibacterial activity was observed against Bacillus subtilis (inhibition zone= 18 ± 0.21, MIC= 0.18 mg/mL). In general, Gram-positive bacteria were more susceptible than Gram-negative ones. Candida parapsilosis was the most sensitive among the Candida strains tested. LD50 and LD90 values were 33.1 and 53.1 ppm against 1-d-old larvae of Aedes aegypti L.