Search Results

You are looking at 1 - 10 of 3,701 items for :

  • Refine by Access: All Content x
Clear All

Summary

High-performance liquid chromatography (HPLC) and ultraviolet (UV) spectrophotometric methods were developed for analysis of berberine, the principal bioactive constituent, in Coscinium fenestratum extracts. The HPLC and UV spectrophotometric determinations were performed at 226, 270, and 340 nm. The methods were validated by assessing linearity, sensitivity, precision, and accuracy. HPLC detection was found to be more effective than spectrophotometric determinations. The content of berberine determined by HPLC method at detection wavelengths of 270 and 340 nm was found to be higher as compared to the value obtained at wavelength of 226 nm. The content of berberine determined by HPLC ranged from 0.98 to 0.99 (%w/w) in the methanol extract, 0.85 to 0.88 (%w/w) in the methanol-water (1:1) extract, and 0.24 to 0.25 in the water extract.

Full access

Summary

Harmaline and harmine accounted for more than 70% in composition in extracts of P. harmala. More attention, however, should be paid to the other alkaloids which would be favorable or unfavorable to the efficacy and safety of the products. It was necessary to determine these trace alkaloids in the extracts; thereafter, most of them have been characterized. Diglycoside vasicine, vasicine, vasicinone, harmalol, harmol, tetrahydroharmine, 8-hydroxy-harmine, ruine, harmaline, and harmine were separated and identified with reference substances and characteristic MS spectra in extracts by liquid chromatography-electrospray ionization-mass spectrometry (LC-ESI-MS) and high-performance liquid chromatography (HPLC). Three trace alkaloids, vasicine, harmalol, and harmol were determined using the developed chromatographic separation method subsequently. The average contents of vasicine, harmalol, and harmol in extracts of ten batches were 2.53 ± 0.73, 0.54 ± 0.19, and 0.077 ± 0.03%, respectively. The total content of the three alkaloids was 3.23 ± 0.90% (from 1.81 to 4.48%). For rough estimation of all the relative alkaloids except of harmaline and harmine, the average total areas of all peaks in extracts varied from 4.35 to 26.64% detected at 220, 254, 265, 280, and 380 nm, respectively. The results indicated that area normalization method was powerless for the quality evaluation for traditional herb medicine consisting of numerous compounds with highly differential features. It might be concluded that LC-MS or HPLC could be utilized as a qualitative and quantitative analytical method for quality control of the extracts from seeds of P. harmala L.

Full access

The application of medicinal plant drugs for curing has become popular again. The favourable effects of most of them have been examined and proven. Nevertheless, the beneficial properties of plants and extracts may be due to inorganic mineral elements besides organic constituents. Investigation of microelement content in plant drugs may be relevant for the determination of environmental relations. In pharmacological aspect microelement content in teas is essential. For plants, all extracts (teas, alcoholic extracts, etc.) prepared by divers ways (traditional-, microwave extraction, etc.) contain elements in different quantity. The comparison of microelement content of definite amount of tea consumed with Recommended Dietary Allowances, Dietary Reference Intake may give information on possible nutritional value.

Restricted access

73 Pal, A., Pal, A. K. (2000) Studies on the genotoxicity of turmeric extracts in bacterial system. Int. J. Antimicrob. Agents. 16 , 415-417. Studies on the

Restricted access

-Pereira 2006 Catharanthus roseus flower extract has wound-healing activity in Sprague Dawley rats BMC Comp. Alter. Med. 21 41 . [7]. O. Rau M. Wurglics T. Dingermann M. Abdel-Tawab 2006 Screening of herbal extracts for activation

Restricted access
Journal of Thermal Analysis and Calorimetry
Authors: Ghalib Al-Saidi, Mohammad Shafiur Rahman, Ahmed Al-Alawi, and Nejib Guizani

on its structural properties, as well as its physico-chemical properties that are greatly influenced not only by the species or tissue from which it is extracted, but also by the method of pretreatment and extraction [ 2 ]. Collagen, the parental form

Restricted access

Miliauskas, G., Venskutonis, P.R. & Van Beek, T.A. (2004): Screening of radical scavenging activity of some medicinal and aromatic plant extracts. Fd Chem. , 85, 231-237. Screening of radical scavenging activity of some medicinal

Restricted access

key indicator of changes in their structure. DSC is able both to impose a thermal history and to measure the rate of melting as a function of temperature [ 22 ]. The aim of this article was to assess the oxidative stability of fats extracted

Restricted access

Abdallah, M. D., Kandil, M. A. and Farag, A. A. (1986): Bioactivity of plant extracts against Sitophilus granarius (L.) and Tribolium castaneum (Hbst.). Bull. Entomol. Soc. Egypt, Econ. Ser. 15, 199

Restricted access

isoquinoline alkaloids in extracts of Chelidonium majus . Chromatographia , DOI 10.1365s10337-006-0808-8. Pieroni, A., Dibra, B., Grishaj, G. & Macai, S.G. (2005): Traditional phytotherapy of the

Restricted access