Helmut K. Mangold

Thin-layer chromatography of lipids

Technique Thin-Layer Chromatography as an Analytical Tool Qualitative Analysis Quantitative Analysis Thin-Layer Chromatography as a Preparative Tool

Fractionation of fats, oils, and waxes on thin layers of silicic acid.

SummaryAdsorption chromatography on thin layers of silicic acid or alumina provides a new and highly efficient analytical tool for the rapid separation of lipids according to classes of compounds.

Analysis of complex lipid mixtures by thin-layer chromatography and complementary methods.

ConclusionFurther work has been done on the application of thin-layer adsorption chromatography to the fractionation of complex lipid mixtures into classes.New methods, the use of siliconized silicic acid plates and the application of thin-layer adsorption chromatography combined with the complementary techniques of gas-liquid chromatography and paper chromatography, are presented for the resolution of classes of lipids into their constituents.In contrast to such elaborate conventional techniques as column chromatography, analyses using the methods reported in this paper can be performed rapidly in large numbers on a routine basis.

New methods of analyzing industrial aliphatic lipids

Methods are described for the rapid fractionation of classes of lipids containing the hetero elements N, P, and S such as primary amines, secondary amines, tertiary amines, and quaternary ammonium salts containing one, two, or three long-chain moieties; amides, nitriles, and other nitrogenous lipids; alkyl sulfates and sulfonates; alkyl phosphates and phosphonates.Thin-layer chromatography on silicic acid separates lipids according to classes of compounds. After isolation by thin-layer chromatography, each lipid class is amenable to further fractionation, according to chain length and degree of unsaturation, by complementary methods, such as paper chromatography and/or gas-liquid chromatography.These procedures permit rapid analyses of complex mixtures of industrial lipids, such as surface-active agents, and identification of industrial compounds synthesized from fatty raw materials.

Alkoxylipids. IV. Synthesis and characterization of naturally occurring ethers, esters and ether esters of diols.

Abstract Long-chain alkyl ethers of 1,2-ethanediol were prepared from alkyl glyceryl-(1) ethers by glycol cleavage and subsequent reduction of the resulting alkoxy-acetaldehydes. Alkyl ethers of 1,3-propanediol were synthesized by alkylation of 3-trityloxy-propanol with methanesulfonates, followed by hydrolytic removal of the trityl group. Dialkyl ethers, ether esters, as well as mono- and diesters of 1,2-ethanediol and 1,3-propanediol also were prepared. Chromatographic methods based on partition rather than on adsorption phenomena were found to be suitable for the separation of diol lipids, as classes, from the corresponding glycerol derived lipids. The critical solution temperatures of the compounds synthesized proved to be a satisfactory means of distinction.

Paper chromatography of lipides

SummaryProcedures for qualitative and quantitative paper chromatography of lipides have been described in detail, together with some practical applications.With the monochain lipides it was found that one developing system serves universally. The long aliphatic chains essentially determine the chromatographic properties so that suitable conditions for chromatographing any lipide or lipide-like entity are predictable. For the same reason total analysis of natural mixtures cannot be done on one paper chromatogram due to superpositions.For complete analysis of natural mixtures of fatty acids it is advisable at the present time to combine paper chromatography with some other separation method. Distillation supplements best but requires gram quantities of material while paper chromatography is applicable on gamma or milligram scale. Chain-length analysis by paper chromatography and low-temperature chromatography have been introduced and are promising methods to approach a completely micro method for analyzing complex mixtures.

Biosynthesis and biotransformation of ether lipids

Some naturally occurring as well as synthetic ether lipids are biologically active. In certain cases, the effects of these substances are enhanced, in others, they are inhibited by compounds that were isolated from natural sources or prepared by chemical synthesis. The biotrans-formation of natural or “unnatural” ether lipids in microorganisms, plant or animal tissue also can lead to substances that elicit biological effects. The production of such compounds through various biotechnological techniques is a field wide open for future exploration. In addition to animal cell cultures, plant cell cultures may become useful tools in biomedical studies concerned with ether lipids.

Alkoxylipids: III. naturally occurring (+)-1-IO-cis-alk-1′-enyl-diglycerides

Abstract Three classes of neutral lipids were isolated from liver oil of the ratfish (Hydrolagus colliei). Spectroscopic data, specific optical rotations and chemical reactions proved that the least polar fraction consisted of d -(+)-1-O-cis- alk -1′- enyl-diglycerides (“neutral plasmalogens”). The long-chain moieties of these compounds and of the alkyl-diglycerides (“alkoxy-diglycerides”) and triglycerides were analyzed.

A facile method for the preparation of 1-O-alkyl-2-O-acetoyl-sn-glycero-3-phosphocholines (platelet activating factor)

Abstract Biologically active 1-O-alkyl-2-O-acetoyl-sn-glycero-3-phosphocholines are prepared in good yields from ratfish (Hydrolagus colliei) liver oil, an inexpensive natural product, that contains over 70% neutral ether lipids.

Alkoxylipids: I. Preparation and characterization of alkoxy-diglycerides and dialkoxy-glycerides

Abstract Alkoxy-diglycerides (3-alkoxy-1,2-di-O-acyl-propanediols) and dialkoxy-glycerides (2,3-dialkoxy-1-O-acyl-propanols) were prepared from the corresponding glyceryl ethers by reaction with acid chlorides in benzene-pyridine solution. The physical properties of these alkoxylipids are described, and their occurrence in nature is demonstrated.