Oily substances, insolubility

The nitration of d-xylose 69 yields d-xylose tetranitrate, C5HeO (0N02)4, an oily substance insoluble in water, and a crystalline by-product, m.p. 141°, insoluble in water, which is evidently the trinitrate, C5H702 (0N02) 3. Xylosan dinitrate, C5H 02(0N02)2, has been prepared by the action of mixed acid on d-xylose. It consists of little spherical crystal aggregates, soluble in alcohol and melting at 75-80°. 

In addition to films that originate at least in part in the corroding metal, there are others that originate in the corrosive solution. These include various salts, such as carbonates and sulfates, which may be precipitated from heated solutions, and insoluble compounds, such as beer stone, which form on metal surfaces in contac t with certain specific products. In addition, there are films of oil and grease that may protect a material from direct contact with corrosive substances. Such oil films may be apphed intentionally or may occur naturally, as in the case of metals submerged in sewage or equipment used for the processing of oily substances. 

Tocopherols are pale yellow viscous oily substances that are insoluble in water but are soluble in fats and oils. a-Tocopherol and its acetate are made synthetically. The synthetic products are racemates and are... 

Phospholipids, when dispersed in water, may exhibit self-assembly properties (either as micellar self-assembly aggregates or larger structures). This may lead to aggregates that are called liposomes or vesicles. Liposomes are structures that are empty cells and that are currently being used by some industries. They are microscopic vesicles or containers formed by the membrane alone, and are widely used in the pharmaceutical and cosmetic fields because it is possible to insert chemicals inside them. Liposomes may also be used solubilize (in its hydrophobic part) hydro-phobic chemicals (water-insoluble organic compounds) such as oily substances so that they can be dispersed in an aqueous medium by virtue of the hydrophilic properties of the liposomes (in the alkyl region). 

The reaction mixture after supercritical treatment of water consists of the water-soluble portion and water-insoluble residues with oily substances. The oily substances seem to be solvated with w ater in its supercritical state due to their hydrophobic nature, but separated in ordinary condition of water, Such oily substances shown by the arrows in Fig. 7 are recovered with water-insoluble residues, but can be washed with methanol. Therefore, they may be collected as MeOH-soluble fraction. 

Fig- 7. Light micrographs of water-insoluble residue of sugi wood (left) and MeOH-insoluble residue after washing with MeOH (right). The arrows show the oily substances present with MeOH-insoluble residue. 

The seeds of Hernandia ovigera (8 kg), which were collected in Okinawa, were crushed into small species. Dried seeds (2 kg) were extracted with MeOH (31 x 3) under reflux. The combined extracts were evaporated under reduced pressure to give a residue (1.09 kg). This residue was treated with petroleum ether to remove soluble materials, which afforded the insoluble materials (518 g). This solid residue was extracted with benzene under reflux. After removal of the solvent under reduced pressure, an oily substance (242 g) was obtained. This oily material was recrystallized from EtOH to afford crude crystals of desoxypodophyllotoxin... 

If almost none of the solute dissolves in a solvent, then it is said to be insoluble in that solvent. Metals, except those that react with water, are insoluble in water. Oily substances are also insoluble in water, as is water in oily substances. The low solubility of oily substances in water is caused by a lack of attraction between the highly polar water molecules and the nonpolar molecules of an oily substance. The water solubility of a nonpolar molecule can be increased if a polar part can be added. Conversely, the water solubility of a molecule decreases as the nonpolar portion of the molecule increases. The simpler alcohols are very water soluble because the —OH group is polar and forms strong hydrogen bonds with water. As the hydrocarbon chain lengthens, the influence of the... 

The nitrosamines are insoluble in water, and the lower members are liquid at ordinary temperatures. The separation of an oily liquid when an aqueous solution of an amine salt is treated with sodium nitrite is therefore strong evidence that the amine is secondary. Diphenylnitrosoamine is selected as a preparation because it is a crystalline substance and is thus easier to manipulate on a small scale than one of the lower liquid members. For this preparation, a fairly pure (and therefore almost colourless) sample of diphenyl-amine should be used. Technical diphenylamine, which is almost black in colour, should not be employed. 

Place together in a 50 ml. conical flask about 1 g. of the substance and 10 ml. of 10% NaOH solution (or use apparatus in Fig. 38, p. 63)-Add a few pieces of unglazed porcelain, fit a reflux water- condenser, and boil gently for about 20 minutes. Nitriles require longer heating than amides, usually about 30 minutes. The completion of the hydrolysis of an insoluble nitrile ( .g., benzonitrile) is indicated by the disappearance of oily drops in the liquid. Cool the flask, add an excess of dil. H2SO4 and cool thoroughly. 

Tetranitromethane, C(N02)4, is a heavy oily liquid (sp. gr. 1.65), which solidifies at +3°C and boils at 126°C without decomposition. It is insoluble in water, but it dissolves easily in alcohol and benzene. It is a volatile substance with a characteristic smell, reminiscent of nitrogen oxides. 

Lipids are water insoluble, oily, or greasy organic substances. They are the most important storage forms of chemical energy in the body. In our context, one group of lipids is of... 

Lipids are water-insoluble, oily or greasy substances that can be extracted from cells and tissues by non-polar solvents. The most abundant kinds are fats, which are triglycerides, and they act as major storage fuels in most organisms. 

Lipids are a group of oily, greasy organic substances found in living organisms that are water insoluble but soluble in organic solvents, such as diethyl ether, benzene, and chloroform. Unlike carbohydrates, lipids share no common chemical structure. The most abundant lipids are the fats and oils, which make up one of the three important classes of foods. 

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