PubMed Health⌕ Search
Home/Archive/PubMed

PubMed · 14067884

DEVICES FOR CONTINUOUS DEVELOPMENT AND SAMPLE APPLICATION IN PREPARATIVE THIN-LAYER CHROMATOGRAPHY.

R D BENNETT·E HEFTMANN
View original source ↗Export metadata ↓

Abstract

The source did not provide an abstract. Follow the original record for more information.

Explore related subjects

CholesterolChromatographyChromatography, Thin LayerEquipment and SuppliesSterolsCHOLESTEROLCHROMATOGRAPHYEQUIPMENT AND SUPPLIESSTEROLSJournal Article

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

R D BENNETT, E HEFTMANN. 1963. DEVICES FOR CONTINUOUS DEVELOPMENT AND SAMPLE APPLICATION IN PREPARATIVE THIN-LAYER CHROMATOGRAPHY.. https://doi.org/10.1016/s0021-9673(01)83677-3

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

KEEP EXPLORING

Related citations

PubMed2005

A thin layer chromatographic method for determining the enzymatic activity of peroxidases catalyzing the two-electron reduction of lipid hydroperoxides.

Thiol-dependent peroxidases catalyzing the reductive detoxification of lipid hydroperoxides (LOOHs) are crucial antioxidant components of mammalian cells. There is a growing interest in manipulating expression of such enzymes to better understand their biological roles. A new approach for determining their cellular activity is described, whereby LOOH reduction kinetics are tracked by high performance thin layer chromatography with peroxide-sensitive tetramethyl-p-phenylenediamine detection (HPTLC-TPD). The approach was tested on a tumor cell transfectant clone (7G4) over-expressing selenoperoxidase GP x 4. Timed incubation of Triton-solubilized 7G4 cells with GSH and peroxidized phosphatidylcholine (PCOOH), followed by lipid extraction, HPTLC-TPD and densitometry revealed an exponential decay of PCOOH at a rate approximately 80-times greater than that for GP x 4-deficient controls (VC). A TPD-detectable cholesterol hydroperoxide (7alpha-OOH) was also reduced much faster by 7G4 than VC extracts. Spraying with H(2)SO(4) after TPD revealed both 7alpha-OOH loss and resolved diol product (7alpha-OH) accumulation, the kinetics of which were identical. The approach described is relatively convenient, highly specific, and much more sensitive than conventional assays for cellular LOOH reducing enzymes.

Cholesterol↗
PubMed2005

Effect of cholesterol and temperature on the elastic properties of niosomal membranes.

The mechanical characteristics of non-ionic bilayer membranes composed of sorbitan monostearate, cholesterol and poly-24-oxyethylene cholesteryl were studied by measuring the modulus of surface elasticity (mu), a measure of membrane strength, as a function of cholesterol content and temperature. The modulus of surface elasticity increased slowly with increasing cholesterol concentration, with a sharp increase around 40 mol% cholesterol (on average an increment of 0.43x10(6) Nm(-2) per molar percentage), and displayed a maximum of 6.5x10(6) Nm(-2) around 47.5 mol% cholesterol. Further cholesterol resulted in a decrease in mu. Generally the interaction of cholesterol with sorbitan monostearate should increase the rigidity of the membrane. However, the latter effect may be due to the formation of cholesterol clusters at high cholesterol content where excess amounts of cholesterol cannot interact with the sorbitan monostearate, and deposits on the bilayers compromising their uniformity, strength and permeability. This behavior was evident when measurements were carried out above and below 25 degrees C.

Cholesterol↗
PubMed2005

The relative flow of the walls of phospholipid tether bilayers.

Lipid nanotubes or "tethers" can be formed from liposomes or niosomes, pulled from the parent vesicles by micromanipulation. The tethers are cylindrical multibilayer tubes. Here, we describe the movement of these multilamellar walls, initiated by creating a surface tension gradient along the tether. The movement of lipid can give rise to a visible moving boundary. In the case of bilayer membranes, a tangential gradient in surface tension produces membrane bulk flow toward regions of higher surface tension. The flow of the bilayers comprising the tether nanotubes seems to be restricted to the inner bilayers, creating a velocity gradient in the bilayers. In this study, we discuss the implementation of tension-driven flows as a transport method in a tether-vesicle network. Interactions between fluid within the tether channels and the lipid layers are important, leading to anomalies in the transport of fluids and particles compared to bulk systems.

Cholesterol↗