Search

Your search keyword '"Jirovetz, Leopold"' showing total 363 results
Start Over Author "Jirovetz, Leopold"
363 results on '"Jirovetz, Leopold"'

1. Antifungal and repellent activities of the essential oils from three aromatic herbs from western Himalaya

Author

Stappen Iris, Tabanca Nurhayat, Ali Abbas, Wanner Jürgen, Lal Brij, Jaitak Vikas, Wedge David E., Kaul Vijay K., Schmidt Erich, and Jirovetz Leopold

Subjects
terpenes, antifungal, larvicidal, biting deterrent, mosquitoes, ascaridole, Chemistry, QD1-999
Abstract

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.

Published
2018
Full Text
View/download PDF

2. Multistage and tandem mass spectrometry of glycosylated triterpenoid saponins isolated from Bacopa monnieri: comparison of the information content provided by different techniques

Author

Zehl, Martin, Pittenauer, Ernst, Jirovetz, Leopold, Bandhari, Pamita, Singh, Bikram, Kaul, Vijay K., Rizzi, Andreas, and Allmaler, Guenter

Subjects
Saponins -- Chemical properties, Time-of-flight mass spectrometry -- Methods, Scrophulariaceae -- Chemical properties, Chemistry
Abstract

Whereas all state-of-the-art techniques in mass spectrometry (MS) have been extensively applied to oligosaccharides derived from glycoproteins, less effort has been devoted to the analysis of smaller glycoconjugates. In the present study, the application of a variety of MS techniques for the analysis of two dammarane-type triterpenoid saponins isolated from B. monnieri is reported. The structural information provided by ESI-ion trap (IT)-, APMALDI-IT-, and MALDI-IT/reflectron time-of-flight (RTOF)MS, all utilizing low-energy collision-induced dissociation (CID), and MALDI-TOF/RTOF-MS, facilitating postsource decay and high-energy CID analysis, was compared. The applied desorption/ionization technique does not influence the fragmentation of identical precursor ions in low-energy CID. All three fragmentation techniques clearly yield the sequence and branching of the glycan moiety as well as the molecular mass of the intact aglycon. Crossring cleavage of the branching sugar, which gives some information about the sugar linkages, was mainly observed in low-energy CID. High-energy CID, on the other hand, yielded some additional diagnostic fragment ions from the aglycon moiety. Internal cleavage ions are formed by alternative mechanisms in high-energy CID and are assumed to be diagnostic for some linkages. However, none of the applied MS techniques facilitates the identification of those saponins that differ only by their agiycon moiety (i.e., jujubogenin or pseudojujubogenin).

Published
2007

11. Quantitation of dehydroascorbic acid by the kinetic measurement of a derivatization reaction

Author

Goldenberg, Hans, Jirovetz, Leopold, Krajnik, Paul, Mosgoller, Wilhelm, Moslinger, Thomas, and Schweinzer, Esther

Subjects
Vitamin C -- Research, Chemistry
Abstract

Micromolar concentrations of dehydroascorbic acid in aqueous solutions react with methanol-containing phosphate or citrate buffers to form a mixture of derivatives with an absorption maximum at 346 nm. The compounds, different methyl ketals, were analyzed using fast atom bombardment mass spectrometry. After calibration, kinetic analysis of the formation rates can be used for fast and simple determination of dehydroascorbic acid concentrations. In samples containing both forms of vitamin C, ascorbate and dehydroascorbic acid, autoxidation of ascorbate can be inhibited by addition of transition metal complexing agents; thus, only formation rates accounting for the amounts of dehydroascorbic acid are measured.

Published
1994

15. Cytotoxic Properties of Selected Sesquiterpene Alcohols on Human Cervix Carcinoma Cell Lines

Author

Buchbauer Gerhard, Tulupova Elena, Jäger Walter, Schmidt Erich, Ryabchenko Boris, and Jirovetz Leopold

Subjects
Patchoulol, Cell growth, Organic Chemistry, Biology, Sesquiterpene, biology.organism_classification, Biochemistry, Analytical Chemistry, Cedrol, HeLa, chemistry.chemical_compound, chemistry, Viability assay, Cytotoxicity, Salicylic acid
Abstract

The sesquiterpene alcohols cis-nerolidol, α-bisabolol, cedrol, patchoulol, and santalol were screened for cytotoxicity and cytoproliferative activity on HeLa cell using Cytotoxicity Detection Kit (LDH) and the Cell Proliferation Reagent WST-1, respectively. Actinomycin D and curcumin as well as the plant acids geranic and salicylic acid were used as reference samples, all known for their cytotoxic properties. Among the sesquiterpene alcohols studied, cis-nerolidol possessed the strongest cytotoxic properties (16.5 μM ± 6.7). Low cytotoxicity and influence on HeLa cell viability was demonstrated for geranic and especially salicylic acid.

Published
2011

16. Chemical Composition, in vitro Antioxidant, Antimicrobial and Insecticidal Activities of Essential Oil from Cladanthus arabicus

Author

Aghraz, Abdellah, primary, Wanner, Jürgen, additional, Schmidt, Erich, additional, Aitdra, Loubna, additional, Aitsidibrahim, Malika, additional, Tabanca, Nurhayat, additional, Ali, Abbas, additional, Nafis, Ahmed, additional, Hassani, Lahcen, additional, Markouk, Mohamed, additional, Jirovetz, Leopold, additional, and Larhsini, Mustapha, additional

Published
2017
Full Text
View/download PDF

19. Chemical composition and antibacterial activities of the essential oils of Plectranthus glandulosus and Cinnumomum zeylrrnicum from Cameroon

Author

B Ngassoum Martin, N Tatsadjieu Leopold, J Essia-Ngang Jean, Buchbauer Gerhard, Adjoudji Ousman, and Jirovetz Leopold

Subjects
biology, Plectranthus, Pharmaceutical Science, Cinnamomum zeylanicum, biology.organism_classification, Plectranthus glandulosus, law.invention, Eugenol, chemistry.chemical_compound, chemistry, law, Mic values, Botany, Food science, essential oils, Chemical composition, Bacteria, Essential oil, antibacterial activity, composition, Cinnamomum
Abstract

Two aromatic plants have been selected for chemical investigation on account of their antibacterial activities, Plectranthus glandulosus (fresh leaves) and Cinnamomum zeylunicum (dried leaves). P. glandulosus is used as a medicinal plant, while Cinnamomum zeylunicum is used as a common spice in many recipes in Cameroon. The essential oils of the plants have been obtained by hydrodistillation using a Clevenger type apparatus, the yields of oils are about 0.3% and 2.0% respectively.The essential oil of P. glandulosus contains mainly β-thujone (about 31%), p-cymen-8-01 (about 25%) and neral (about 10%) and the essential oil of C. zcylcinicum is characterised by a high percentage of eugenol (85%).These essential oils have been tested against three strains of bacteria, namely Pseudornonas fluorescens. Escherichiu coli and Staphylococcus aureus, qualitative tests (diffusion through solid medium) and quantitative tests (dilution method) have been carried out. P. fluorescens shows a higher resistance to the two oils (MIC values not less than 5000 ppm). E. coli is more sensitive to these oils, while against S uureus the essential oil of C. zcylcinicum still shows a high activity (3500 ppm).The antibacterial activities of the essential oils could be attributed to the components eugenol as the active component of C. zcylcinicum and β-thujone and p-cymen-4-01 of the essential oil of P. glandulosus.

Published
2002

21. Chemical Composition, Antioxidant, Antimicrobial and Insecticidal Activities of Essential Oil from a Moroccan Endemic Plant: Bubonium imbricatum

Author

Aghraz, Abdellah, primary, Wanner, Jürgen, additional, Schmidt, Erich, additional, Aitdra, Loubna, additional, Aitsidibrahim, Malika, additional, Tabanca, Nurhayat, additional, Abbas, Ali, additional, Hassani, Lahcen, additional, Markouk, Mohammed, additional, Jirovetz, Leopold, additional, and Larhsini, Mustapha, additional

Published
2016
Full Text
View/download PDF

36. Chemical Composition and Biological Activity of Essential Oils from Wild Growing Aromatic Plant Species of Skimmia laureola and Juniperus macropoda from Western Himalaya

Author

Stappen, Iris, primary, Tabanca, Nurhayat, additional, Ali, Abbas, additional, Wedge, David E., additional, Wanner, Jürgen, additional, Kaul, Vijay K., additional, Lal, Brij, additional, Jaitak, Vikas, additional, Gochev, Velizar K., additional, Schmidt, Erich, additional, and Jirovetz, Leopold, additional

Published
2015
Full Text
View/download PDF

39. Chemical Composition and Biological Activity of Essential Oils of Dracocephalum heterophyllum and Hyssopus officinalis from Western Himalaya

Author

Stappen, Iris, primary, Wanner, Jürgen, additional, Tabanca, Nurhayat, additional, Wedge, David E., additional, Ali, Abbas, additional, Kaul, Vijay K., additional, Lal, Brij, additional, Jaitak, Vikas, additional, Gochev, Velizar K., additional, Schmidt, Erich, additional, and Jirovetz, Leopold, additional

Published
2015
Full Text
View/download PDF

50. Chemical Composition and Biological Effects of Artemisia maritima and Artemisia nilagirica Essential Oils from Wild Plants of Western Himalaya

Author

Stappen, Iris, additional, Wanner, Jürgen, additional, Tabanca, Nurhayat, additional, Wedge, David, additional, Ali, Abbas, additional, Khan, Ikhlas, additional, Kaul, Vijay, additional, Lal, Brij, additional, Jaitak, Vikas, additional, Gochev, Velizar, additional, Girova, Tania, additional, Stoyanova, Albena, additional, Schmidt, Erich, additional, and Jirovetz, Leopold, additional

Published
2014
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results