Search results for "composition"
showing 10 items of 2675 documents
Determination of Sulfur in Fertilizers by Inductively Coupled Plasma-Atomic Emission Spectrometry: Spectral and Interelement Effects at Various Wavel…
1996
Abstract Three analytical wavelengths (180.731,182.037, and 182.625 nm) were tested for determination of sulfur in 2 fertilizers by inductively coupled plasmaatomic emission spectrometry (ICP-AES). Variable S results at 182.037 nm were caused by a downward sloping background shift (Fe line at 181.851 nm) during measurement of the sample solutions. At 182.625 nm an emission peak doublet, 182.619/182.635 nm, was observed from which the instrument selected the measurement peak. A shift from calibrated peak 182.619 nm to noncalibrated peak 182.635 nm occurred when the S/B ratios were ≤22-31 in the fertilizer samples examined. For the 3 wavelengths of S investigated, the pattern of spectral and …
The Cytotoxic Properties of Natural Coumarins Isolated from Roots ofFerulago campestris(Apiaceae) and of Synthetic Ester Derivatives of Aegelinol
2009
Grandivittin (1), agasyllin (2), aegelinol benzoate (3) and felamidin (20), four natural coumarins isolated from Ferulago campestris, and several synthetic ester derivatives of aegelinol (4) were tested against four tumor cell lines. Some of them were shown to be marginally cytotoxic against the A549 lung cancer cell line.
Die Umsetzung von L-Äpfelsäure durchSaccharomyces cerevisiae bei der Gärung
1970
Yeasts of the genusSaccharomyces are able to decompose L-malic acid partially, during and after fermentation, whereby ethanol and carbon dioxide are the end products. The decarboxylation of malic acid by yeast can be achieved with resting cells and cell free extracts.
The Antibody Response to the BNT162b2 mRNA COVID-19 Booster in Healthcare Workers: Association between the IgG Antibody Titers and Anthropometric and…
2022
Background: Research shows that in most people, two-dose vaccination helps to shape the humoral response to Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2). Further studies are required to learn about the vaccine’s effectiveness after boosting. Methods: We conducted a prospective study among 103 healthcare workers (HCWs) from a regional multi-specialty hospital vaccinated with three doses of the BNT162b2 vaccine. We compared their immunoglobulin G (IgG) titers 14 days after the second dose with those 21 days after the booster. We also compared their anthropometric and body composition parameters with IgG concentrations at the same time points. Results: Twenty-one days aft…
Chemical Composition of the Essential Oils of Three Species of Apiaceae Growing Wild in Sicily: Bonannia graeca, Eryngium maritimum and Opopanax chir…
2013
In the present study the chemical composition of the essential oils from aerial parts of Bonannia graeca (L.) Halácsy and Opopanax chironium (L.) Kock, and from aerial parts and roots of Eryngium maritimum L. was evaluated by GC and GC-MS. α-Pinene (15.2%) and β-pinene were recognized as the main constituents of B. graeca, whereas the aerial parts of O. chironium contained mainly the diterpene cembrene and the coumarin angelicin. In both aerial parts and roots of E. maritimum germacrene D (10.4% and 15.9%, respectively) and 2,4,5-trimethylbenzaldehyde (8.3% and 6.7%) were the most abundant components.
Essential Oil Composition and Antibacterial Activity of Anthemis mixta and A. Tomentosa(Asteraceae)
2012
In the present study the chemical composition of the essential oils from aerial parts and roots of Anthemis mixta L. and A. tomentosa L. was evaluated by GC and GC-MS, and their antibacterial activity tested against ten bacterial species. Hexadecanoic acid (15.2%) was recognized as the main constituent of A. mixta, together with τ-cadinol (6.7%), while in both aerial parts and roots of A. tomentosa nonacosane (21.9% and 20.7%), heptacosane (8.1% and 6.0%), hexadecanoic acid (8.1% and 27.1%) and hexahydrofarnesylacetone (6.8% and 5.5%) prevailed. The oils from aerial parts of both species showed a good activity against Gram-positive bacteria. These results suggest that the plants could be p…
Analysis of Essential Oils from Scutellaria orientalis ssp. alpina and S. utriculata by GC and GC-MS
2011
The chemical composition of the essential oils obtained from aerial parts of Scutellaria orientalis L. ssp. alpina (Boiss.) O. Schwarz and S. utriculata Labill. growing wild in Lebanon, were analyzed by GC and GC-MS. In S. orientalis ssp. alpina, strongly characterized by sesquiterpenes (41.2%) and particularly sesquiterpene hydrocarbons (31.7%), hexahydrofarnesylacetone (11.7%) was recognized as the main constituent, together with hexadecanoic acid (7.6%), caryophyllene (7.4%), caryophyllene oxide (6.8%), 4-vinylguaiacol (5.4%) and germacrene D (5.4%). S. utriculata oil was instead constituted above all by monoterpenes (42.2%), particularly oxygen containing monoterpenes (39.9%), and in t…
The Structure and the Stereochemistry of Atractyliretin
1986
The nor-kaurane diterpene Atractyliretin was obtained by acid hydrolysis of Atractyloside, a toxic substance isolated from ATRACTYLIS GUMMIFERA L (Compositae). On the basis of spectral (IR, (1)H-NMR, (13)C-NMR and MS) analysis and chemical degradation its structure and stereochemistry was identified as 4.
Chemical Composition and Antibacterial Activity of Extracts of Helleborus bocconei Ten. subsp. intermedius
2007
Helleborus bocconei Ten. subsp. intermedius (Ranunculaceae) is a Sicilian medicinal plant used for the treatment of pneumonia affecting cows and horses and for the removal of human decayed molars. The goal of our study was to assess the biological activity of Helleborus bocconei subsp. intermedius by testing its extracts for their activity against bacteria known to cause respiratory diseases. The two more active extracts (light petroleum from roots and aerial parts), as well as the dichloromethane extracts, were analyzed by GC/MS and their composition is reported.
Essential Oil Composition of Tanacetum vulgare Subsp. Siculum (Guss.) Raimondo et Spadaro (Asteraceae) from Sicily
2009
Ninety-four components of the essential oils from aerial parts and capitula of Tanacetum vulgare subsp. siculum (Guss.) Raimondo et Spadaro were detected. α-Thujone, β-thujone and 1,8-cineole were the main constituents of the oils. The analysis allows the assignment of this Tanacetum species to the thujone chemotype.