Search Results

You are looking at 101 - 110 of 359 items for :

  • "fingerprint" x
  • All content x
Clear All

Coffee, due to its common consumption, is one of the main sources of polyphenols in human diet. Coffee species and coffee-related products differ in composition and content of main components, such as chlorogenic acid and caffeine. Chemical and biological fingerprints of various Coffea arabica L. extracts were obtained in order to check and compare their antibacterial and antioxidant properties. The antibacterial activity of green and roasted coffee seeds and pomace was evaluated against Bacillus subtilis using thin-layer chromatography (TLC)-direct bioautography. TLC-2,2-diphenyl-1-picrylhydrazyl (DPPH) test was used to determine antioxidant properties of the afore-mentioned extracts. Furthermore, different solvents and several extraction methods such as simple maceration, maceration under stirring, and ultrasonic accelerated extraction were tested. The most efficient method of extraction of caffeine and chlorogenic acid was chosen based on quantitative TLC analysis. Additionally, these two main components of coffee were quantitatively determined in commercial products of green coffee.

Restricted access

Quantitative evaluation of phytochemical diversity in Adhatoda vasica Nees populations from five different ecogeographical regions was performed using a highly sensitive, robust and economic high performance thin layer chromatography (HPTLC) procedure. The method was validated for specificity, precision and accuracy as per the guidelines affirmed by International Conference on Harmonization of technical requirements for registration of pharmaceuticals for human use (ICH). The findings support the existence of distinct natural chemotypes within the species. Two out of the five regions had about three times higher mean vasicine content than the remaining three regions. The comparative phytochemical fingerprint profiles were quite similar except for the concentration variation seen for different alkaloids. As the quinazoline alkaloids are the biologically active compounds in A. vasica, the samples that accumulate high levels of alkaloids seem to be promising for further propagation.

Restricted access

Two-dimensional separations were performed on polar bonded stationary phase of type cyanopropyl-silica and diol-silica by use of non-aqueous eluents (polar modifier dissolved in n-heptane) as the first direction eluents and aqueous eluents (organic modifier — MeOH dissolved in water) as the second direction eluents. The chromatographic process was performed in micro scale using 5 × 5 cm plates, small volumes of eluents, and 10 μL of plant extracts to obtain satisfying separation. Plates developed in horizontal chambers were dried and observed in UV light (254 nm and 366 nm) photographed by digital camera and derivatized by 1,1-diphenyl-2-picrylhydrazyl (DPPH) to detect antioxidants (free radical scavengers) or derivatized by Naturstoff reagent to detect phenolic compounds (characteristic luminescence of some phenolic compounds). The above experiments give the possibility to construct fingerprints for investigated Mentha species and varieties and preparations containing the herb. It can be used in quality control of the plant material and its antioxidative activity.

Restricted access

This article presents the findings of an in-depth study on high-performance thin-layer chromatographic (HPTLC) profiling of Jarrah (Eucalyptus marginata) and Manuka (Leptospermum spp.) honeys following a simple one-step solvent extraction process. The study demonstrates that different HPTLC fingerprints are obtained from honeys from varying floral sources and that honeys of the same floral origin present a consistent reproducible HPTLC profile. In addition, the linearity and reproducibility of this technique as well as its ability to detect (accidental or deliberate) contaminations with honeys of different floral sources are demonstrated. The study thus illustrates the usefulness of HPTLC profiling as a potential quality control tool that might complement other analytical techniques used in the authentication of monofloral honeys.

Restricted access

The oleo-gum-resin known as ‘guggul’, obtained from the plant Commiphora mukul , Hook (family Burseraceae), is widely used, as a component of formulations containing other Ayurvedic drugs, for treatment of hypercholesterolemia, rheumatism, and arthritis. Chemically, guggul contains two active keto steroids, guggulsterones E and Z , which are reported to be responsible for its antihyperlipidemic activity. These cis and trans isomers have been isolated, purified by TLC and column chromatography, and characterized by determination of melting point and by acquisition of UV, IR, and NMR spectra. After confirmation of their identity, they were used as biomarkers in HPTLC fingerprinting analysis of five commercial Ayurvedic formulations, four tablets and a capsule, all of which contain guggul as a constituent. The analytical method was fully validated. Extrapolation was used to calculate probable amounts of guggul added to the formulations on the basis of E and Z isomer content.

Restricted access

Summary  

Sixteen pumice samples produced by the youngest eruption sequences of Mt. Pelato (Island of Lipari, Italy) were analyzed with instrumental neutron activation analysis (INAA) for their major and trace element contents, in particular Al, Ba, Ca, Ce, Co, Cr, Cs, Dy, Eu, Fe, Hf, K, La, Lu, Mn, Na, Nd, Rb, Sb, Sm, Ta, Tb, Th, Ti, U, V, Yb, Zn, and Zr. A pumice from the archaeological excavation in Tel Megadim, Israel, could be correlated to this volcanic source, using its chemical fingerprint. This result, together with the background information about the well dated eruption cycles of this volcano, lead to the assumption that trade connections existed between cultures in Palestine and the Tyrrhenian region during the Persian Period (approx. between the 6th and 3rd century B.C.), in spite of the long distance of over 2000 km.

Restricted access

Abstract  

A procedure is demonstrated, through a simulation study, for the determination of the origin of unknown spent nuclear fuel, an important and challenging task in nuclear forensics. The procedure is an isotopic fingerprinting method relying on the fission product content of the unknown. The ‘unknown’ nuclear material is represented by the spent nuclear fuel of known origin in order to demonstrate the method and verify its predictive capabilities. The method is based on the comparison of the fission product compositions of the ‘unknown’ material and simulated known spent fuels from a range of commercial nuclear power stations using the multivariate statistical technique of factor analysis. Then, the provenance of the ‘unknown’ spent fuel is the commercial fuel with which it exhibits the highest similarity with respect to the fission product content.

Restricted access

Summary  

We have developed cleanroom compatible techniques for processing bone samples for characterization of their uranium and plutonium content. The bone samples are dried and ashed in quartz crucibles placed inside cleanroom compatible thermal ashing furnaces. The bone ash is dissolved in ultra-pure acids prepared by sub-boiling distillation. The uranium and plutonium in the samples are isolated and purified by ion-exchange chromatography and measured by thermal ionization mass spectrometry. The technique is capable of detecting 74 picograms of 238U and 8 femtograms of 239Pu in 100 mg bone ash samples. If the ash contains larger amounts of uranium and plutonium, the technique can be used to isotopically fingerprint the material to identify potential origins.

Restricted access

Jayarao, B. M., Gillespie, B. E. and Oliver, S. P. (1998): Application of randomly amplified polymorphic DNA fingerprinting for species identification of bacteria isolated from bovine milk. Journal of Food

Restricted access
Acta Veterinaria Hungarica
Authors: László Makrai, Csaba Nemes, Anna Simon, Éva Ivanics, Zoltán Dudás, László Fodor, and Róbert Glávits

Enterococcus cecorum is the most frequently occurring enterococcal species in the intestine of chickens of over 12 weeks of age, and there are few reports on its isolation from the skeleton of broiler parent chicks. In the present study, observations on vertebral osteomyelitis and spondylolisthesis (‘kinky back syndrome’) showing high incidence in 8 broiler parent flocks in different parts of Hungary are summarised. Clinical signs were seen only in roosters between 5 and 13 weeks of age. Diseased birds were alert and remained sitting on their hocks with their feet slightly raised off the ground. Incidence of the disease among male birds ranged from 8% to 30% depending on flocks. Enlargement and distortion of the body of the 6th vertebra were seen as the main pathological lesions. The cavity of the spinal canal was constricted by the distorted vertebral bodies. Resorption of bone tissue and sequestrum formation, signs of increased osteoclast activity, proliferation of fibrotic tissues, infiltration with heterophils and formation of sclerotic layers were detected in the vertebral bodies. From all 24 samples collected from the vertebral lesions, Enterococcus cecorum was isolated and identified using metabolic fingerprinting as well as 16S rRNA gene sequencing. Demonstration of E. cecorum from the vertebral lesions in all examined broiler breeder roosters showing the same clinical and pathological findings in different flocks suggested the pathogenic role of this microorganism for the first time in Hungary.

Restricted access