Chromatospectrophotometric method for the determination of total phenolcarboxylic acids in a tanacin preparation and the racemes ofTanacetum vulgare

1979 ◽  
Vol 13 (5) ◽  
pp. 554-556
Author(s):  
K. B. Adikhodzhaeva
1979 ◽  
Vol 13 (5) ◽  
pp. 549-552
Author(s):  
M. Ya. Paberza ◽  
V. Ya. Parinov ◽  
A. P. Gilev ◽  
V. P. Kadysh

2021 ◽  
Vol 10 (1) ◽  
pp. 74-81
Author(s):  
L. N. Nikiforov ◽  
S. V. Krivoshchekov ◽  
N. E. Kolomiets ◽  
T. V. Kadyrova ◽  
N. V. Isaikina ◽  
...  

Introduction. Lemna minor L. (duckweed) refers to the duckweed subfamily (Lemnaceae S. F. Gray) and widely distributed in ponds of Russia. Literature data confirm the possibility of harvesting significant volumes of this raw material in natural habitat and grown in aquaculture. The process of biosynthetic accumulation in duckweed fronds provides a variety of compounds with a wide spectrum of biological activity. Therefore, the use of raw materials Lemna minor L. is promising for the development of drugs and parapharmaceutical products. Thus, it is an urgent task to quantify active components of duckweed and standardize (determination of criteria for identification, quality and safety) plant material.Aim. Establish macro- and microscopic characteristics of raw materials and develop methods for the quantitative determination of the main groups of biologically active substances (BAS) for standardization of raw duckweed.Materials and methods. Samples of duckweed was collected in natural habitats of Western Siberia. Macro- and microscopic assay, HPLC, UV-spectrometry were used in research process.Results and discussion. Were established the criteria for identification of duckweed fronds by studying external (macroscopic) and microscopic features of raw material Lemna minor L. Was developed and validated the procedure of the quantitative determination of phenolcarboxylic acids in raw material Lemna minor L.Conclusion. The study of external (macroscopic) and microscopic features provided the criteria for identification of the raw material Lemna minor L. The technique for the quantitative analysis of polysaccharides using gravimetry does not need validation, because is a direct method of substance measurement. Was validated quantification method of phenolcarboxylic acids (in terms of chlorogenic acid) by criteria of linearity, repeatability, in-laboratory precision and accuracy. Was established quality criteria for identification and quantitative assay, which can be used in the draft for normative documents for medicinal plant raw material of Lemna minor L. «Duckweed fronds».


1966 ◽  
Vol 25 ◽  
pp. 93-97
Author(s):  
Richard Woolley

It is now possible to determine proper motions of high-velocity objects in such a way as to obtain with some accuracy the velocity vector relevant to the Sun. If a potential field of the Galaxy is assumed, one can compute an actual orbit. A determination of the velocity of the globular clusterωCentauri has recently been completed at Greenwich, and it is found that the orbit is strongly retrograde in the Galaxy. Similar calculations may be made, though with less certainty, in the case of RR Lyrae variable stars.


1999 ◽  
Vol 190 ◽  
pp. 549-554
Author(s):  
Nino Panagia

Using the new reductions of the IUE light curves by Sonneborn et al. (1997) and an extensive set of HST images of SN 1987A we have repeated and improved Panagia et al. (1991) analysis to obtain a better determination of the distance to the supernova. In this way we have derived an absolute size of the ringRabs= (6.23 ± 0.08) x 1017cm and an angular sizeR″ = 808 ± 17 mas, which give a distance to the supernovad(SN1987A) = 51.4 ± 1.2 kpc and a distance modulusm–M(SN1987A) = 18.55 ± 0.05. Allowing for a displacement of SN 1987A position relative to the LMC center, the distance to the barycenter of the Large Magellanic Cloud is also estimated to bed(LMC) = 52.0±1.3 kpc, which corresponds to a distance modulus ofm–M(LMC) = 18.58±0.05.


1961 ◽  
Vol 13 ◽  
pp. 29-41
Author(s):  
Wm. Markowitz
Keyword(s):  

A symposium on the future of the International Latitude Service (I. L. S.) is to be held in Helsinki in July 1960. My report for the symposium consists of two parts. Part I, denoded (Mk I) was published [1] earlier in 1960 under the title “Latitude and Longitude, and the Secular Motion of the Pole”. Part II is the present paper, denoded (Mk II).


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