Cytotoxic oplopane sesquiterpenoids from Arnoglossum atriplicifolium

Pale Indian plantain (Arnoglossum atriplicifolium (L.) H. Rob.) is a plant with traditional medicinal usage among the Cherokee Native American tribe for treating cancer. Two oplopane sesquiterpenoids were isolated from an extract of A. atriplicifolium from Western North Carolina. The compounds were isolated by bioassay-guided fractionation using an MCF-7 breast tumour cell line assay. The known compound (1S,6R,7R,8R)-1-acetoxy-6,7-diangeloxy-8,10-epoxy-2-oxo-oplopa-3,14Z,11,12-dien-13-al (1) had an EC₅₀ value of 9.0 μM against MCF-7 cells, while the new compound (1S,3R,6R,7R,8R,11S)-1-acetoxy-6,7-diangeloxy-8,10,11,13-bisepoxyoplopan-2-one (2) had an EC₅₀ value of 96 μM. The compounds were characterised by 1D and 2D NMR spectroscopy and by comparison with literature values in the case for 1. Based on NOESY analysis, a correction of the relative configuration for 1 is presented. The presence of these compounds may help to explain the folk remedy usage of this plant as an anticancer agent.     

Rapid Determination Of Total Sulfur In Plants And Soils By Combustion Sulfur Analysis

Abstract

An automatic sulfur titrator paired with a high-frequency induction furnace were used to determine total sulfur concentrations in Alaska soil and plant material. Results were in close agreement with those obtained by turbidimetric and gravimetric methods and by similar combustion methods.     

Statistical Model for Organic Chromatographic Trace Analysis of Complex Samples. A Case Study: Plant Extracts

Abstract

The use of pooled plant extracts is described in the estimation of matrix interference in HPLC (UV and EC) determinations of organic compounds in plant extracts. An extract from freeze dried leaves of 134 different plant species was used for this purpose. It was split in different subgroups with solid extraction clean-up procedures. UV, EC and chromatographic data of the subgroups were used in the calculation of minimum concentrations of organic compounds which are still accurately determinable in plant samples with HPLC methods. The UV and/or EC characteristics of the compound must be known. The contribution of the solid phase extraction procedures and of the analytical system to the selectivity of the method can be estimated. Information is also supplied which allows rapid comparison of the selectivity of the UV and EC (single, or dual parallel) detectors for the determination of a specified compound.     

微波作用下1-苯基-5-[5-(芳胺羰基甲硫基)-4-苯基-1,2,4-三唑-3-甲硫基]四唑的合成及生物活性

采用微波和相转移催化法通过1-苯基-5-(4-苯基-1,2,4-三唑-5-巯基-3-甲硫基)四唑(2)与2-氯乙酰芳胺(3)反应高效、快速地合成了10种尚未见文献报道的1-苯基-5-[5-(芳胺羰基甲硫基)-4-苯基-1,2,4-三唑-3-甲硫基]四唑. 其结构经 IR, ¹H NMR, ¹³C NMR 和元素分析表征. 生物活性实验结果表明, 该类化合物在较低浓度下部分化合物对小麦芽有很好的促进作用.     

Comparison and Evaluation of Extraction Media and Their Suitability in a Simple Model to Predict the Biological Relevance of Heavy Metal Concentrations in Contaminated Soils

Abstract

The concentrations of heavy metals in agricultural soils are increasing gradually from various diffuse sources. The metals can transfer from contaminated soils into the growing plants or may affect the respiration rate of soil microorganisms.

In the first part of this paper, the following simple model to predict the biorelevant metal concentration in anthropogenically or artificially contaminated soils is reported: log M_p = α + β log [M_NaNO3] log M_R = α' + β' log [M_NaNO3] log M_P = log Metal concentration in test plant (mg/kg dry weight) log M_R = log percent Redution in the respiration or enzyme activity [M_NaNO3] = Metal concentration in NaNO3-soil extract (mg/kg soil) α and β & α' + β' = Intercepts and slopes of the linear regression lines.

The model has been tested in laboratory experiments, in growth experiments either in a greenhouse or in the field. Also, an attempt is made to present a theoretical interpretation.

Critical concentrations are calculated with the help of the relationship between metal concentration in soil solution [M_NaNO3] and metal concentration in plants. The critical concentration, which is able to induce either phyto- or zootoxic concentrations in the plant parts (productive or vegetative) or reduce their growth or to reduce significantly the growth of soil microorganisms, are found to be uniform in a wide range of soils (pH 3 to 8 and CEC 10–50 millimol/100g soil), the critical concentrations of NaNO₃ in soil extracts are comparable with the values obtained with plant growth experiments in nutrient solution and also with the concentrations obtained from soil respiration experiments reported in literature.     

ORGANIC PHOSPHORUS COMPOUNDS 93.1 PREPARATION,PROPERTIES AND HERBICIDAL ACTIVITY OF 2-SUBSTITUTED 5-PHENOXY- AND 5-PYRIDY LOXY-PHENYLAMINOALKYLPHOSPHONIC-AND-PHOSPHINIC ACILAS WELL AS-PHOSPHINE OXIDE DERIVATIVES*

Abstract

Interaction of 4-phenoxy and 4-pyridyloxy substituted 1.2-dinitrobenzenes and aminoalkylphosphonates,-phosphinates, and -phosphine oxides produces mainly 5-phenoxy- and 5-pyridyloxy substituted 2-nitrophenylaminoalkyIphosphonates. -phosphinates and -phosphine oxides (Table I to IV and Figure 1 to 5). some of which show high herbicidal and plant growth regulating activity. The herbicidal activity increases from pyridyloxy-phenylaminoalkylphosphonates to phenoxy-phenylaminoalkyl-phosphonates, -phosphinates, -phosphine oxides. Of all the compounds tested the phosphine oxide 4a was at all concentrations the most active compound.     

A new diaryl 1, 2-diketone from the heartwood of Dalbergia latifolia

A new diaryl 1,2-diketone, named 1-(2,5-dihydroxy-4-methoxyphenyl)-2-phenylethane-1,2-dione (1), along with eight known compounds (2–9), were isolated from the heartwood of Dalbergia latifolia. They were identified on the basis of spectral data. Compounds 1–7 were obtained from the Dalbergia genus for the first time. Compounds 8 and 9 were firstly isolated from the plant. Compound 1 exhibited inactive against Staphylococcus aureus ATCC 6538 and Escherichia coli ATCC 21530 with the minimum inhibitory concentrations of 10.0 and 10.0 mg/mL, respectively.     

N-Alkylamides from Piper longum L. and their stimulative effects on the melanin content and tyrosinase activity in B16 melanoma cells

Abstract

Piper longum L., known as long pepper, is an edible and medicinal plant used as spice and for the treatment of stomach disease and analgesia in traditional Chinese medicine. N-Alkylamides are the major secondary metabolites in this plant. Sixteen known N-alkylamides were isolated from P. longum. Their structures were established on the basis of spectroscopic data and comparison to reported literatures. Among them, five compounds were isolated from this plant for the first time. Ethanol extract, compounds 1, 2, 3, 7 and 11 exhibited potent ability to increase the melanin content and weak stimulative effect on the tyrosinase activity in a concentration-dependent manner. Moreover, compound 2 also presented strong capacity to increase the tyrosinase activity in a concentration-dependent manner. These results indicated that P. longum might be a good natural source of lead compound for skin disorder diseases.     

Capabilities of high resolution inductively coupled plasma mass spectrometry for trace element determination in plant sample digests

The analytical performance of inductively coupled plasma mass spectrometry (ICP-MS) for the analysis of plant sample digests was evaluated using double focusing sector field ICP-MS (ICP-SMS). Instrumental detection limits of ICP-SMS are superior to those obtained by quadrupole systems (ICP-QMS) and reach the fg mL^–1 range for elements with high m/z ratios. Matrix effects caused by a plant digest after sample preparation resulting in 200-fold dilution were found to be negligible. The usefulness of high mass resolution for overcoming some spectral interferences is demonstrated. Mathematical correction possibilities could be necessary to improve accuracy. The concentrations of more than 20 elements can be determined in 5 min and only one internal standard is necessary to correct for instrumental drift. Received: 30 March 1998 / Revised: 4 May 1998 / Accepted: 16 May 1998     

Capabilities of high resolution inductively coupled plasma mass spectrometry for trace element determination in plant sample digests

The analytical performance of inductively coupled plasma mass spectrometry (ICP-MS) for the analysis of plant sample digests was evaluated using double focusing sector field ICP-MS (ICP-SMS). Instrumental detection limits of ICP-SMS are superior to those obtained by quadrupole systems (ICP-QMS) and reach the fg mL^–1 range for elements with high m/z ratios. Matrix effects caused by a plant digest after sample preparation resulting in 200-fold dilution were found to be negligible. The usefulness of high mass resolution for overcoming some spectral interferences is demonstrated. Mathematical correction possibilities could be necessary to improve accuracy. The concentrations of more than 20 elements can be determined in 5 min and only one internal standard is necessary to correct for instrumental drift. Received: 30 March 1998 / Revised: 4 May 1998 / Accepted: 16 May 1998     

Determination of Ultra-Trace Amouris of Uranium by Icp-Aes Technique

Abstract

An Atomic Emission Spectrometric method based on the use of Inductively coupled argon Plasma source has been developed for the determination of ultra trace concentrations of uranium in aqueous solutions. Using the optimised experimental conditions for the ICP source, uranium can be determined at 0.05 μg/ml concentration in 0.3M HNO₃ solutions with either of the two analytical lines viz. 3859.6 Å or 4090.1 Å. The precision of determinations at the lowest detection limit is better than 2% R.S.D. The uranium estimation has been corrected for the interference due to the presence of eighteen metallic elements using an inter-element correction procedure. A number of spiked samples and NBL reference samples with concomitant impurities have been analysed using the standardised procedure and good agreement has been observed with their certified values.     

Assessment of chemically characterised Myristica fragrans essential oil against fungi contaminating stored scented rice and its mode of action as novel aflatoxin inhibitor

Abstract

The study reports chemically characterised Myristica fragrans essential oil (MFEO) as plant based food preservative against fungal and aflatoxin B₁ (AFB₁) contamination of scented rice varieties. The chemical profile of MFEO revealed elemicin (27.08%), myristicine (21.29%) and thujanol (18.55%) as major components. The minimum inhibitory and minimum aflatoxin inhibitory concentrations of MFEO were 2.75 and 1.5?mg/ml, respectively. The MFEO was efficacious against a broad spectrum of food deteriorating fungi. MFEO caused decrease in ergosterol content of fungal plasma membrane and enhanced leakage of cellular ions, depicting plasma membrane as the site of action. The MFEO caused reduction in cellular methylglyoxal content, the aflatoxin inducer. This is the first report on MFEO as aflatoxin suppressor. The essential oil may be recommended as plant based food preservative after large scale trials and reduction in methylglyoxal suggests its application for development of aflatoxin resistant varieties through green transgenics.     

Determination of nitrite with a nano-gold modified glassy carbon electrode by cyclic voltammetry

Abstract

Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) was employed to determine the concentration of rare earth elements (REEs) in plants and soils. Sample preparation and analytical conditions were investigated to set up a simple routine procedure for measuring rare earth elements. For prompt sample decomposition, a microwave digestion technique was successfully used with an acid mixture of HCl+HNO₃+HF. Detection limits, reproducibility, accuracy and possible interference were also studied. ICP-MS provided extremely low detection limits for REEs (0.6–6ng/l). Precision was typically better than 6% RSD (relative standard deviation) for soil and 10% for plant. The potential of the method was evaluated by analysis of standard reference materials of soils and plants. A good agreement between the experimental results and certified values was observed. The spectroscopic interference of Ba with Eu and light REEs(LREEs, La-Eu) with heavy REEs(HREEs, Gd-Lu) were eliminated by the algebra correction.

The results suggested that REEs in soil samples existed mainly as light REEs, and the same concentration distribution patterns of Oddo-Hakins law were observed, showing negative gradient from La to Lu concentrations. The REE contents in plants were very low, less than 20μg/g and varied with plant species. Apart from rape leaf(Brassica juncea), the REE distribution patterns in other plant leaves were consistent with soils, indicating that these plants generally absorbed REEs from soil without selectivity. Rape leaf showed selective absorption for LREEs, especially for La. The REE concentration distribution in parts of hot pepper(Capsicum annuum) was characteriaed by root>leaf>stem>fruit. The REEs absorbed by hot pepper concentrated mainly in roots and leaves, very little migrated into fruit. Transfer factors(TFs) of REEs in plants were very low. Although the contents of LREEs were relatively more than those of HREEs, no distinct difference of TFs between LREEs and HREEs was observed, meaning that LREEs and HREEs have the same abilities of transportation. However, for rape leaf, the TFs of LREEs were one or two orders of magnitude higher than those of HREEs.     

Heavy Metal Concentrations in Water,Sediment and Fish from Izmit Bay,Turkey

Abstract

Mercury, cadmium and lead levels in water, sediment and fish samples from Izmit Bay, Turkey have been determined. Sampling and analysis methods are described. Variations of heavy metal concentrations from different sampling stations are discussed. Results indicate that the levels of mercury and cadmium were highest in the vicinity of a chlor-alkali plant while the highest concentration of lead was near a metallic pipe factory. The amounts of heavy metals found in the shoreline sediment samples were similar to those found in fish species from the bay.     

A Simple,Efficient Device for Determining Terpenes Present as Traces in the Atmosphere

Abstract

Up to the present it has been established that natural hydrocarbons, such as isoprene and the monoterpenes, play an important role in the physical chemistry of the atmosphere because of their high reactivity.

However, their true contribution to the natural chemical system has not yet been clearly defined as the seasonal variations in their concentrations are not sufficiently accurately known due to their low content in the atmosphere (a few hundredths of a ppb to a few ppb). We have developed an analysis procedure which enables quantitative trapping to be carried out together with excellent chromatographic separation. It consists of enrichment on adsorbents followed by very rapid thermal desorption and instantaneous chromatographic injection without further cryogenic trapping.

Our adsorption-desorption cycle does not reduce the efficiency of the chromatographic separation at all and does not bring about any decomposition of these highly reactive plant oils.     

Determining trace amounts of nickel in plant samples by neutron activation analysis

Neutron activation analysis of plant samples for trace amounts of nickel has applications in various fields. Landsberger and Robinson (Trans Am Nucl Soc 102:187–188, 2010) found their measurement of the concentrations of nickel for different NIST reference materials to be significantly greater than the certified values when measuring nickel from the 810.8 keV gamma ray that comes from ⁵⁸Co from the ⁵⁸Ni(n,p) reaction. They determined that this overestimation was due to a significant interference by the presence of ¹⁵²Eu at 810.5 keV, and presented a method for correcting this interference. Their method involved a long thermal irradiation and correction of gamma ray counts based on the 1,408 keV belonging to ¹⁵²Eu. This paper presents an alternative approach, which involves irradiating the samples with epithermal neutrons, which suppressed the ¹⁵²Eu to the point of being negligible for samples with low levels of europium. Both methods were determined to work well for the identification of nickel concentrations by neutron activation analysis.     

Pine Needles (Pinus Sylvestris) as a Bioindicator of Sulphur and Heavy Metal Deposition in the Area Around a Pulp and Paper Mill Complex at Kemi,Northern Finland

Abstract

The determination of sulphur and heavy metals in plants is an integral part of many environmental studies. Pine needles (Pinus Sylvestris) have proved to be suitable air quality indicators for pollutants, especially for sulphur. This study was carried out in the vicinity of Kemi, a town situated on the Gulf of Bothnia in northern Finland. An industrial complex comprising two pulp and paper mills is located in the centre of the area. Scots pine (Pinus Sylvestris) needles were collected from 29 sampling sites. The samples were dried, homogenized and digested with nitric acid. The concentrations of the elements S, Fe, Zn, Ca, V, and Pb were determined by ICP-AES. According to our results pine needles (Pinus sylvestris) appear to be an ideal bioindicator and sampling material for identifying and assessing atmospheric sulphur pollution derived from pulp and paper mills and can complement the information provided by plant mapping studies around pulp and paper mills.     

Determination of Pulegone in H. pulegioides and Peppermint Oil by Thin Layer Chromatography with Densitometry

Abstract

A method was developed for determination of the phytotoxic terpene pulegone using silica gel thin layer chromatography with detection by acetic acid-sulfuric acid-anisaldehyde reagent and densitometric scanning. The method was used to monitor levels of pulegone in the plant Hedeoma pulegioides and to assay the compound in a commercial peppermint oil. The storage of pulegone was found to be localized in the foliage and stem of the plant and to be highest in the spring.     

Corrections in the Measurement of Fluorescence Polarization

Abstract

Blank corrections in polarization measurements with single beam spectrofluorometers are straightforward and permit characterization of polarization spectra of samples having quantum yields of less than 0.01. Few samples require no such correction. Problems in determining what is a suitable blank are discussed. Such blanks have unfortunately been ignored in many studies, and dual phototube instruments have been advocated in which it is difficult to apply such corrections. G, the grating correction factor, is shown to vary sharply with emission wavelength, in contrast to other reports, but is independent of slit width. Therefore, a calibration curve of G vs. emission wavelength may be obtained for a given instrument, thus avoiding the need to determine G for each sample.     

New approximate formulae for the retardation factors of nematic liquid crystals with simple uniaxial anisotropy

Abstract

Simple formulae which yield a close approximation to the exact analytic solution for the longitudinal and transverse relaxation times T _|| and T _⊥ of the components of the dipole moment of a nematic liquid crystal with simple uniaxial anisotropy are presented. The new formula for T _|| yields a substantial correction to the Meier-Saupe formula [1966, Molec. Crystals, 1, 515]. It appears that both the longitudinal and transverse relaxation processes may be accurately described by a single Debye type relaxation mechanism with relaxation times T _|| and T _⊥.