Quantitative determination of oleane derivatives in Terminalia arjuna by high performance thin layer chromatography

A simple, precise and rapid high performance thin layer chromatographic method has been developed for the simultaneous quantitative determination of five oleane derivatives, namely, arjunic acid, arjunolic acid, arjungenin, arjunetin and arjunglucoside I from stem bark extract of Terminalia arjuna. The isolation and separation of these compounds was carried out on 60F254 layers eluted with chloroform:methanol (90:10), and the analytes were visualised through colour development with vanillin in concentrated sulphuric acid:ethanol. Scanning and quantification of the spots at 640 nm showed good recoveries in the range 96.40-101.7%.     

Quantitative determination of phyllanthin and hypophyllanthin in Phyllanthus species by high-performance thin layer chromatography

A simple, precise and rapid high-performance thin-layer chromatographic method has been developed for the estimation of phyllanthin (1) and hypophyllanthin (2), the important lignans of Phyllanthus species, especially Phyllanthus amarus. Separation of 1 and 2 was carried out on silica gel 60 F254 layers eluted with hexane:acetone:ethyl acetate (74:12:8), and the analytes were visualised through colour development with vanillin in concentrated sulphuric acid and ethanol. Scanning and quantification of spots was performed at 580 nm. Recoveries of 1 and 2 were 98.7 and 97.3%, respectively. The method was validated and the peak purities and limits of detection and quantification were determined.     

Analysis of brain and myelin lipids by high-performance thin layer chromatography and densitometry

We have developed a simple method involving high-performance thin layer chromatographic separation of total brain and myelin lipids. Only two solvent systems consisting of chloroform: methanol: acetic acid and water at different concentrations were needed. The plate was then stained with three sequential procedures to visualize phospholipids, cholesterol and galactolipids. Densitometric procedure at each step of staining was utilized to obtain quantitative analysis of brain and myelin samples.     

Determination of plasma progesterone using thin layer chromatography during pregnancy and normal menstrual cycle]

Plasma progesterone levels were measured during pregnancy and the normal human menstrual cycle by thin-layer densitometry of a specific fluorescence reaction for delta4-3-ketosteroids. 94 determinations were carried out from the 7th week of pregnancy until term. 84 plasma progesterone concentrations were estimated between day 16 and day 26 and other 10 during the preovulatory phase of the normal menstrual cycle.     

The serine protease HtrA1 is upregulated in the human placenta during pregnancy.

The placenta has a dynamic and continuous capacity for self-renewal. The molecular mechanisms responsible for controlling trophoblast proliferation are still unclear. It is generally accepted that the simultaneous activity of proteins involved in cell proliferation, apoptosis, and extracellular matrix degradation plays an important role in correct placental development. We investigated in depth the expression of the serine protease HtrA1 during pregnancy in human placenta by in situ hybridization and immunohistochemistry, we demonstrated that HtrA1 displayed a low level of expression in the first trimester of gestation and a strong increase of HtrA1 expression in the third trimester. Finally, by electron microscopy, we demonstrated that HtrA1 was localized either in the cytoplasm of placental cells, especially close to microvilli that characterized the plasma membrane of syncytiotrophoblast cells, or in the extracytoplasmic space of the stroma of placental villi, particularly in the spaces between collagen fibers and on collagen fibers themselves. The expression pattern of HtrA1 in human placentas strongly suggests a role for this protein in placental development and function. Moreover, on the basis of its subcellular distribution it can be postulated that HtrA1 acts on different targets, such as intracellular growth factors or extracellular matrix proteins, to favor the correct formation/function of the placenta.     

A new fluorometric method for the determination of spermidine and spermine in tissues by thin layer chromatography.

A new fluorometric method is described for the rapid, sensitive analysis of spermidine and spermine in animal tissues. The polyamines added with N-3-aminopropylheptane-1, 7-diamine as internal standard were chromatographed on a silica-gel sintered-glass plate in a solvent system of n-BuOH-AcOH-Pyridine-H₂O, and the chromatograms were developed with an acetone solution of fluorescamine. Determination, using a scanning fluorometer, was performed by measuring peak area ratio with respect to the internal standard. The precision and accuracy of the method were established, and the limits of determination were of the order of 100 pmoles.