scholarly journals HPTLC determination of diosgenin in fenugreek seeds

2018 ◽  
Vol 68 (1) ◽  
pp. 97-107 ◽  
Author(s):  
Barbara Król-Kogus ◽  
Khenifi Mohammed Lamine ◽  
Piotr Migas ◽  
Messaoud Boudjeniba ◽  
Mirosława Krauze-Baranowska
Keyword(s):  
Ethyl Acetate ◽  
Acid Hydrolysis ◽  
Methanolic Extract ◽  
Soxhlet Extraction ◽  
African Origin ◽  
Fenugreek Seeds ◽  
Hydrolysis Products ◽  
Hydrolysis Of

Abstract A new HPTLC-densitometric method for diosgenin determination in fenugreek seeds was established after optimization of the conditions for efficient saponin extraction and acid hydrolysis. Several procedures were tested, the best of which was a three-step Soxhlet extraction, followed by hydrolysis of the obtained methanolic extract with 2 mol L-1 H2SO4. Best diosgenin separation from other hydrolysis products was obtained on HPTLC Si60F254 plates u sing a mixture of n-heptane/ethyl acetate (7:3, V/V) and modified anisaldehyde as a spraying reagent. The method was preliminarily validated and the determined amounts of diosgenin in fenugreek seeds of Polish and African origin were found to be similar and ranged from 0.12-0.18 %.

DETERMINATION OF MICRO-AMOUNTS OF 5β-PREGNAN-3α-OL-20-ONE IN URINE USING INFRARED-SPECTROMETRY

1962 ◽  
Vol 41 (2) ◽  
pp. 234-246 ◽  
Author(s):  
H. J. van der Molen
Keyword(s):  
Infrared Spectrum ◽  
Quantitative Determination ◽  
Acid Hydrolysis ◽  
Chromatographic Separation ◽  
Pure Form ◽  
Infrared Spectrometry ◽  
Hydrolysis Of

ABSTRACT A procedure for the quantitative determination of 5β-pregnan-3α-ol-20-one in urine is described. After acid hydrolysis of the pregnanolone-conjugates in urine, the free steroids are extracted with toluene. Pregnanolone is isolated in a pure form as its acetate; after chromatographic separation of the free steroids on alumina, the fraction containing pregnanolone is acetylated and rechromatographed on alumina. Quantitative determination of the isolated pregnanolone-acetate is carried out with the aid of the infrared spectrum recorded by a micro KBr-wafermethod. The reliability of the method under various conditions is discussed under the headings, specificity, accuracy, precision and sensitivity. It is possible to determine 30–40 μg pregnanolone in a 24-hours urine portion with a precision of 25%.

Determination of Unconjugated and Total N-Acetyl-p-aminophenol (NAPA) in Urine and Serum

1967 ◽  
Vol 13 (3) ◽  
pp. 215-219 ◽  
Author(s):  
Karel P M Heirwegh ◽  
Johan Fevery
Keyword(s):  
Liver Disease ◽  
Acid Hydrolysis ◽  
Azo Dye ◽  
Acidic Medium ◽  
Diazonium Salt ◽  
Accurate Method ◽  
Total N ◽  
Hydrolysis Of ◽  
Urine And Serum

Abstract A sensitive and accurate method is described for the determination of N-acetyl-p-aminophenol (NAPA) and its metabolites in urine and serum. In strongly acidic medium, p-aminophenol (PAP) resulting from differential extraction and acid hydrolysis of total NAPA and unconjugated NAPA, is diazotized and the diazonium salt coupled with N-(1-naphthyl)ethylenediamine (NED) in the presence of ethanol. The blue azo dye formed is determined spectrophotometrically. Application to liver disease is briefly reported.

scholarly journals Kinetic study of hydrolysis of ethyl acetate using caustic soda

2018 ◽  
Vol 7 (4) ◽  
pp. 1995 ◽  
Author(s):  
Mostafa Ghobashy ◽  
Mamdouh Gadallah ◽  
Tamer T.El-Idreesy ◽  
M. A.Sadek ◽  
Hany A.Elazab
Keyword(s):  
Caustic Soda ◽  
Ethyl Acetate ◽  
Flow Reactor ◽  
Design Method ◽  
Plug Flow ◽  
Tubular Reactor ◽  
Acid Base ◽  
Chemical Reaction Kinetics ◽  
Hydrolysis Of

We report here, the hydrolysis of ethyl acetate by using caustic soda which is followed by means of conductance measurements which is widely used in chemical industry. The main aim of this research is to study the parameters of production of ethyl acetate by chemical reaction kinetics using an anion ion-exchange acting as a catalyst and acid-base titrations. The reaction of ethyl acetate and sodium hydroxide (caustic-soda) is done in a plug-flow reactor (steady-state tubular reactor) under the effect of different parameters including temperature, concentration and flow-rate, which allows the determination of activation energy and rate constants, due to large number of experiments. Factorial design method is used for the calculations of the experiment. It was determined that the order of the reaction is a second-order reaction.  

Phytol And Glycerol Derivatives From The Marine Green Alga Codium Iyengarii Of The Karachi Coast (Arabian Sea)

2001 ◽  
Vol 56 (8) ◽  
pp. 837-841 ◽  
Author(s):  
Muhammad Shaiq Ali ◽  
Muhammad Saleem ◽  
Viqar Uddin Ahmad ◽  
Simin Shameel
Keyword(s):  
Ethyl Acetate ◽  
Acid Hydrolysis ◽  
Green Alga ◽  
Arabian Sea ◽  
Methanolic Extract ◽  
Derivatives Of ◽  
Soluble Part ◽  
Marine Green Alga

The ethyl acetate soluble part of a methanolic extract of the marine green alga Codium iyengarii, collected from the Karachi coast of the Arabian Sea, afforded four new derivatives of glycerol named : codioside A,B,C,D (1-4), a new derivative of frans-phytol named codioester (5) and rrans-phytol (6). The structures of 1 -5 were elucidated with the aid of acid hydrolysis, methylation, GC-MS, and spectroscopy. The structure of 1 was confirmed through the HMBC NMR technique and the structures of compounds 2 -4 were based on the assignments made for 1

Determination of 5-methylcytosine by acid hydrolysis of DNA with hydrofluoric acid

1987 ◽  
Vol 167 (2) ◽  
pp. 347-351 ◽  
Author(s):  
J. Catania ◽  
B.C. Keenan ◽  
G.P. Margison ◽  
D.S. Fairweather
Keyword(s):  
Acid Hydrolysis ◽  
Hydrofluoric Acid ◽  
Hydrolysis Of ◽  
Hydrolysis Of Dna

scholarly journals Determination of flavones in species of Thymus L. (Lamiaceae) from Macedonian flora

2001 ◽  
Vol 47 ◽  
pp. 9-14
Author(s):  
Svetlana Kulevanova ◽  
Marina Stefova ◽  
Tatjana Kadifkova Panovska ◽  
Jasmina Tonic ◽  
Trajce Stafilov
Keyword(s):  
Ethyl Acetate ◽  
High Performance ◽  
Gradient Elution ◽  
Hplc Method ◽  
Total Flavonoids ◽  
Column Temperature ◽  
Plant Samples ◽  
Layer Chromatography ◽  
Hydrolysis Of

Assay of flavonoids in extracts of seven Thymus L. (Lamiaceae) species from Macedonia including identification and quantification was performed. Extracts obtained after hydrolysis of air dried samples (A1) were analyzed by thin layer chromatography (TLC) and high performance liquid chromatography (HPLC). Luteolin and apigenin were identified in comparison to authentic standard substances. The content of total flavonoids in plant samples determined by UV-Vis spectrometry (with AlCl3) ranged from 0.05-0.13 %. Two other extracts were prepared by extraction with a mixture of ethanol:water (7:3, V/V), evaporation until only water remained and extraction first with diethylether (A2) and secondly with ethyl acetate (A3). The content of flavonoids in diethyl-ether and ethyl acetate extracts ranged from 52.5-244.4 mg·ml-1 and 48.7 -117.5 mg·ml-1, respectively. For quantification of luteolin and total flavonoids the HPLC method was applied, using reverse phase column C18, mobile phase consisting of 5% acetic acid and methanol in gradient elution mode and column temperature set to 40 o C. The content of luteolin in the plant samples ranged from 0.23-0.48 % (m/m), while the content of total flavonoids was found to be 0.26-0.52 %.

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