PubMed Health⌕ Search
Home/Archive/PubMed

PubMed · 9159914

Elemental concentrations in medicinally important leafy materials.

P R Reddy·S J Reddy
View original source ↗Export metadata ↓

Abstract

Concentrations of elements, especially of trace elements toxic as well as non-toxic in biological materials show a high degree of biological, seasonal and spatial variability. These factors should be taken care of while sampling. Samples, even though collected at a great distance of time and space, should be representative and quantitatively comparable which is important for biomonitoring. Reference Materials (RM's) from biological materials such as leaves acquire importance in Analytical Quality Assurance work. A knowledge of element concentrations in highly consumed leafy samples is of interest. A large number of medicinally important leafy samples (50) have been analysed for elemental concentrations such as Zn, Cu, Ni, Co, Pb, As, Se, K, Cr, Na, P, S, Fe, Ca Mg, Mn and Fe. The concentrations of macro nutrients such as Ca, P, Mg, K, Fe and S range from 9.62 to 4174, 1.00-8.630, 3.53-35.50, 12.04-56.28, 0.111-3.845 g/kg and 1.124-5.843 mg/kg, of micro nutrients such as Cr, Co, Cu, Mn, Na and Zn range from 0.360-8.630, 0.050-3.470, 17.60-57.30, 10.5-81.6, 1.47-27.10 and 10.06-145.6 mg/kg whereas those of trace metals such as Pb, Cd, Ni, As and Se range from 1.19-16.30, 0.0036-0.453, 1.23-19.60, 0.12-7.360 and 0.654-3.50 mg/kg respectively. Influence of sampling parameters such as season and spatial variations has been assessed and the results are interpreted. Spatial variation and seasonal variation are observed to be statistically significant for Cu, Zn and Mn. Preparation of Secondary Reference Materials (SRM's) from the samples analysed is explored. Nutritive values of the leaves and intercorrelation between the metals are also discussed.

Explore related subjects

ElementsEnvironmental MonitoringLinear ModelsMetalsNutritive ValuePlant LeavesPlants, MedicinalQuality ControlSeasonsJournal ArticleResearch Support, Non-U.S. Gov't

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

P R Reddy, S J Reddy. 1997. Elemental concentrations in medicinally important leafy materials.. https://doi.org/10.1016/s0045-6535(97)00078-7

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

PubMed2007

Use of energy filtering transmission electron microscopy for image generation and element analysis in plant organisms.

Energy filtering TEM (EFTEM) with modern spectrometers and software offers new possibilities for element analysis and image generation in plant cells. In the present review, applications of EFTEM in plant physiology, such as identification of light elements and ion transport, analyses of natural cell incrustations, determination of element exchange between fungi and rootlets during mycorrhiza development, heavy metal storage and detoxification, and employment in plant physiological experiments are summarized. In addition, it is demonstrated that EFTEM can be successfully used in more practical approaches, for example, in phytoremediation, food and wood industry, and agriculture. Preparation methods for plant material as prerequisites for EFTEM analysis are compared with respect to their suitability and technical problems are discussed.

Elements↗
PubMed2006

RM1: a reparameterization of AM1 for H, C, N, O, P, S, F, Cl, Br, and I.

Twenty years ago, the landmark AM1 was introduced, and has since had an increasingly wide following among chemists due to its consistently good results and time-tested reliability--being presently available in countless computational quantum chemistry programs. However, semiempirical molecular orbital models still are of limited accuracy and need to be improved if the full potential of new linear scaling techniques, such as MOZYME and LocalSCF, is to be realized. Accordingly, in this article we present RM1 (Recife Model 1): a reparameterization of AM1. As before, the properties used in the parameterization procedure were: heats of formation, dipole moments, ionization potentials and geometric variables (bond lengths and angles). Considering that the vast majority of molecules of importance to life can be assembled by using only six elements: C, H, N, O, P, and S, and that by adding the halogens we can now build most molecules of importance to pharmaceutical research, our training set consisted of 1736 molecules, representative of organic and biochemistry, containing C, H, N, O, P, S, F, Cl, Br, and I atoms. Unlike AM1, and similar to PM3, all RM1 parameters have been optimized. For enthalpies of formation, dipole moments, ionization potentials, and interatomic distances, the average errors in RM1, for the 1736 molecules, are less than those for AM1, PM3, and PM5. Indeed, the average errors in kcal x mol(-1) of the enthalpies of formation for AM1, PM3, and PM5 are 11.15, 7.98, and 6.03, whereas for RM1 this value is 5.77. The errors, in Debye, of the dipole moments for AM1, PM3, PM5, and RM1 are, respectively, 0.37, 0.38, 0.50, and 0.34. Likewise, the respective errors for the ionization potentials, in eV, are 0.60, 0.55, 0.48, and 0.45, and the respective errors, in angstroms, for the interatomic distances are 0.036, 0.029, 0.037, and 0.027. The RM1 average error in bond angles of 6.82 degrees is only slightly higher than the AM1 figure of 5.88 degrees, and both are much smaller than the PM3 and PM5 figures of 6.98 degrees and 9.83 degrees, respectively. Moreover, a known error in PM3 nitrogen charges is corrected in RM1. Therefore, RM1 represents an improvement over AM1 and its similar successor PM3, and is probably very competitive with PM5, which is a somewhat different model, and not fully disclosed. RM1 possesses the same analytical construct and the same number of parameters for each atom as AM1, and, therefore, can be easily implemented in any software that already has AM1, not requiring any change in any line of code, with the sole exception of the values of the parameters themselves.

Elements↗