Kaempferol, a mutagenic flavonol from Helichrysum simillimum.

Helichrysum simillimum is native to South Africa. It is used for the treatment of coughs, colds, fever, infections, headache, and menstrual pain. Extracts of this species showed mutagenic effects in the Salmonella/microsome assay.

In vitro pharmacological effects of manufactured herbal concoctions used in KwaZulu-Natal South Africa.

Ethnopharmacology Relevance: Manufactured and packaged herbal mixtures, known locally as muthi concoctions, have become a new feature of traditional medicine in South Africa. These herbal concoctions are often claimed to cure several diseases ranging from minor illness to life threatening conditions.

Aim Of The Study: To document the prevalence, variety and evaluate the efficacy of selected herbal concoctions sold in KwaZulu-Natal.

Stress-related genes define essential steps in the response of maize seedlings to smoke-water.

Smoke from burning vegetation is widely recognised as a germination cue for seed germination and recent reports suggest that smoke treatments can improve seedling vigour also. We investigated the effect of smoke-water on seedling vigour and changes of the global transcriptome in the early post-germination phase in maize. Application of smoke-water improved the germination characteristics and seedling vigour.

In vitro pharmacological evaluation of three Barleria species.

Ethnopharmacological Relevance: Various parts of Barleria prionitis L. (Acanthaceae) are used in traditional medicine to treat infection-related ailments. A comparison of their activities and knowledge of their mechanisms of action are important for drug development and conservation.

Sequential injection spectrophotometric determination of ritodrine hydrochloride using 4-aminoantipyrine.

A sequential injection spectrophotometric determination of ritodrine hydrochloride is described. The method is based on the condensation of aminoantipyrine with phenols in the presence of an alkaline oxidizing agent to yield a pink coloured product the absorbance of which is monitored at 503nm. Different sequential injection analysis (SIA) parameters including reagent concentrations have been optimised and used to obtain the analytical figures of merit.

Enantioanalysis of l-2-hydroxyglutaric acid in urine samples using enantioselective, potentiometric membrane electrodes based on maltodextrins.

Quantitative assay of l-2-hydroxyglutaric acid (l-2-HGA) is important for the diagnosis of l-2-hydroxyglutaric aciduria. Three enantioselective, potentiometric membrane electrodes (EPMEs) based on maltodextrins with different dextrose equivalent (DE) (DE: 4.0-7.

Sequential injection spectrophotometric determination of trace amounts of iodide by its catalytic effect on the 4,4'-methylenebis(N,N-dimethylaniline)-chloramine-T reaction.

A simple and sensitive sequential injection spectrophotometric procedure is proposed for the determination of trace amounts of iodide in pharmaceutical preparations. The method is based on the catalytic effect of iodide on the (tetra base) 4,4'-methylenebis(N,N-dimethylaniline)-chloramine-T reaction in acidic solution. The method involves a sequential aspiration of 255mul sample/standard followed by 170mul tetra base and then 128mul chloramine-T solutions into a carrier stream to be stacked inside a holding coil and flow reversed through a reaction coil towards a detector.

Determination of Lead(II), Copper(II), Zinc(II), Cobalt(II), Cadmium(II), Iron(III), Mercury(II) using sequential injection extractions.

Sequential injection analysis is still dominated by single component analysis. In this proposed robust, economical simple instrumental system seven different metal ions are determined simultaneously using thin-film sequential injection extraction (SIE) with multivariate calibration and multiwavelength detection. Dithizone, in ethanol, is used as extractant and the metal dithizonates' spectra are generated by a diode array spectrophotometer between 300 and 700nm.

Spectrophotometric determination of bromate by sequential injection analysis.

A simple and rapid on-line spectrophotometric method for the determination of bromate is proposed. The method is based on the reaction of bromate and 2-(5-bromo-2-pyridylazo)-5-diethylaminophenol (5-bromo-PADAP) with SCN(-), a red complex is formed and monitored at 550nm. The linear range found is between 0.

Sequential injection spectrophotometric determination of iron as Fe(II) in multi-vitamin preparations using 1,10-phenanthroline as complexing agent.

A sequential injection analysis (SIA) system is proposed for the determination of iron (II). Fe(II) was determined by SIA based on the reaction between 1,10-phenanthroline and iron (II), yielding an orange-red colour complex with absorption maximum at 512nm. The method involved aspiration of 187mul sample/standard zone followed by a zone of a reagent solution containing 140mul of 7.

Chemical speciation by sequential injection analysis: an overview.

The simplicity of the sequential injection (SIA) manifold and its low need for maintenance makes it an ideal tool in speciation. As miniaturization and reduction of reagent consumption are also ultimate goals in chemical sensing, it is useful to review the use of combined injection and programmed flow as a central issue in designing SIA systems with chemical sensors and structurally simplified chemical analysers. This overview gives an insight into the current state, analytical scope and performance characteristics of sequential injection systems as analytical tools for speciation.

Spectrophotometric determination of magnesium in pharmaceutical preparations by cost-effective sequential injection analysis.

A simple and rapid, inexpensive spectrophotometric method was proposed for magnesium assay in pharmaceutical preparations by sequential injection analysis (SIA). The method is based on the reaction between o-cresolphthalein complexone (CPC) and Mg(II) in alkaline media, yielding a pink colored complex with absorption maximum at 570nm. Since the formation constant between Ca-CPC and Mg-CPC is similar, initially a sample/standard solution was aspirated into the holding coil followed by a mixture of masking-buffer solutions.

Simultaneous determination of l-thyroxine (l-T(4)), d-thyroxine (d-T(4)), and l-triiodothyronine (l-T(3)) using a sensors/sequential injection analysis system.

Requirements of high purity and enantiopurity for the raw materials of active substances used for the pharmaceutical formulations involved utilization of high reliable analytical techniques for the analysis of the active compound. Sequential injection analysis system with electrochemical sensors as detectors proved to be a very good alternative for the chromatographic methods, as it is more reliable, not expensive, and faster. Drugs containing only l-thyroxine (l-T(4)) or both l-T(4) and l-triiodothyronine (l-T(3)) are formulated for the dysfunctions of thyroid.

Macrocyclic antibiotics as chiral selectors in the design of enantioselective, potentiometric membrane electrodes for the determination of l- and d-enantiomers of methotrexate.

Three enantioselective, potentiometric membrane electrodes (EPMEs) based on macrocyclic glycopeptide antibiotics-vancomycin and teicoplanin (modified or not with acetonitrile)-were proposed for the determination of l- and d-enantiomers of methotrexate (Mtx). The linear concentration ranges for the proposed enantioselective membrane electrodes were between 10(-6) and 10(-3)moll(-1) for l- and d- methotrexate. The slopes of the electrodes were 58.

Sequential injection spectrophotometric determination of phenylephrine hydrochloride in pharmaceutical preparations.

A fully automated sequential injection spectrophotometric method for the determination of phenylephrine hydrochloride in pharmaceutical preparations is reported. The method is based on the condensation reaction of the analyte with 4-aminoantipyrine in the presence of potassium ferricyanide. The absorbance of the condensation product was monitored at 503nm.

Determination of l-carnitine using enantioselective, potentiometric membrane electrodes based on macrocyclic antibiotics.

In order to determine the enantiopurity of l-carnitine three enantioselective, potentiometric membrane electrodes were proposed for the assay of l-carnitine. The electrodes were designed using macrocyclic glycopeptide antibiotics-vancomycin and teicoplanin. Acetonitrile was added to the teicoplanine to design a modified teicoplanine based electrode.

Utilization of maltodextrin based enantioselective, potentiometric membrane electrodes for the enantioselective assay of S-perindopril.

Enantioselective, potentiometric membrane electrodes (EPMEs) based on carbon paste impregnated with different maltodextrins {dextrose equivalent (DE) 4.0-7.0 (I), 13.

Simultaneous determination of creatine and creatinine using amperometric biosensors.

In order to determine creatine and creatinine amperometric biosensors were proposed. A bienzymatic biosensor based on creatinase (CI) and sarcosine oxidase (SO) was used for the assay of creatine and a trienzymatic biosensor based on CI, SO and creatininase (CA) for the assay of creatinine. The linear concentration ranges are of pmol l(-1) to nmol l(-1) magnitude order, with very low limits of detection.

Determination of L- and D-enantiomers of methotrexate using amperometric biosensors.

In order to determine the enantiopurity of methotrexate (Mtx), seven biosensors were proposed for the assay of L-Mtx and three biosensors for the assay of D-Mtx. The biosensors were designed using physical and chemical immobilization of glutamate oxidase and/or L-amino acid oxidase (L-AAOD) and/or horseradish peroxidase (HRP) for the assay of L-methotherexate, and D-amino acid oxidase (D-AAOD) and HRP for the assay of D-Mtx. Electrode characteristics were obtained and compared for the different carbon paste based biosensors.

Immunosensor for the determination of azidothymidine: its utilization as detector in a sequential injection analysis system.

An amperometric immunosensor based on graphite paste (graphite powder and paraffin oil) has been constructed for the assay of azidothymidine (AZT). The graphite paste is impregnated with anti-AZT. The immunosensor can be reliably used for the assay of AZT in its pharmaceutical formulation.

On-line separation, simultaneous dilution and spectrophotometric determination of zinc in fertilisers with a sequential injection system and xylenol orange as complexing agent.

A dialyser unit, equipped with a passive neutral membrane, was incorporated into the conduits of a sequential injection (SI) system for the on-line removal of suspended solids and simultaneous dilution of the analyte before reaction and detection of the analyte. The system was applied to the determination of zinc(II) in fertilisers. The fully automated system is able to analyse zinc at a sampling frequency of ten samples per hour at a %R.

Determination of the total acidity in soft drinks using potentiometric sequential injection titration.

A potentiometric SI titration system for the determination of total acidity in soft drinks is proposed. The concept is based on the aspiration of the acid soft drink sample between two base zones into a holding coil with the volume of the first base zone twice to that of the second one and channelled by flow reversal through a reaction coil to a potentiometric sensor. A solution of 0.

Determination of boron as boric acid in eye lotions using a sequential injection system.

A simple and reliable sequential injection analysis (SIA) system is described for the determination of boron as boric acid in eye lotions. This method is based on the complexation reaction between d-sorbitol and boric acid followed by the acid-base reaction with methyl orange (MO). The colour change reaction is monitored at 520 nm.

Determination of paracetamol in pharmaceutical formulations using a sequential injection system.

A simple method for the rapid determination of paracetamol in pharmaceutical formulations is described. The method involves oxidation of paracetamol by potassium hexacyanoferrate(III) and a subsequent reaction with phenol in the presence of ammonia. The blue complex formed is measured at 630 nm.