Abstract: . . .  equally menacing. They are absent in natural fatty acids, but are produced by catalytic hydrogenation of plant oils. That is, when cis double bonds are exposed to a metallic catalyst in a hydrogen atmosphere, hydrogen is added to some of the double bonds but other undergo cis-trans isomerization instead of addition. The effect of saturated and trans fatty acids upon the formation of arterial plaque is clearly related to their physical properties. The trends in melting points seen in the fatty acids are reflected in the melting points of triglycerides which contain them. Dietary triglycerides (fats and oils) are hydrolyzed in the intestines to glycerol and fatty acids, which are then absorbed into the blood. Saturated triglycerides melt at much higher temperatures than unsaturated ones, and ones containing Page 5 5 trans fatty acids melt at higher temperatures than those containing cis fatty acids. The trend can be seen in the melting points of the following triglycerides. Note the notation: C 18 is stearate (saturated), C 18 is oleate (cis), and C 18 t is elaidate (trans). glyceryl tristearate (C 18 C 18 C 18 ) 55 glyceryl distearate monooleate (C 18 C 18 C 18 ) 28 glyceryl monostearate dioleate . . .
. . .  (CH 2 ) 7 CH = CH (CH 2 ) 7 CH 3 H C O C O (CH 2 ) 16 CH 3 Cyclohexene and cyclohexane are flammable. No flames, please. Page 8 8 The next step is to evaporate the solvents. Clean the 5 mL conical flask thoroughly, transfer the filtrate to it (pasteur pipet), and secure it to the air condenser tube. Holding it by the condenser, immerse it in hot water (about 80) and evaporate the cyclohexene and cyclhexane with a gentle stream of nitrogen from a pasteur pipet held about half an inch above the surface of the liquid. Regulate the flow of nitrogen before placing the pipet in the tube and conical flask, and approach the liquid surface gingerly. Too much gas will blow the liquid out of the flask into the tube, and you will have to rinse it down with cyclohexane and start over. Continue the evaporation until bout 0.5 mL of viscous oil remains (the initial volume of the olive oil before the cyclohexene was added). Finish the evaporation in vacuo. Almost all the solvent must be evaporated before taking this step. If it is not, the liquid may boil excessively when the vacuum is applied. Attach the Hickman still to the flask, seal the top of the still with a septum, and connect the side arm of the still of the vacuum line. Used this way, . . .
--3000,2,750,3150,19438