436 THE CHEMICAL EXAMIXATIOX OF MACROZAMIA SPIRALIS, 



These positive reactions place the substance in the group of phj-tosterols. 



Purification and physical properties of the phytosterol. — After five recrys- 

 tallisations from 95 % alcohol the greater portion of the substance was obtained 

 in one fraction which, under the microscope, showed crystals of a uniform kind, 

 laths with pointed ends. A second small fraction contained a mixture of the 

 phytosterol with some few crystals like cholesterol. The first fraction was used 

 for the following determinations : — 



Estimation of water of cri/stallisation. 



0.3301 gm. heated in the oven at 110° C. lost 0.015 gm. 

 Loss in weight 4.54 ^r water 



C27H40O.H2O contains 4.46 



Formation of acetate. 

 .2657 gm. of the anhydrous crystals was boiled with acetic 

 anhydride; the product evaporated and weighed, gave 

 .2937 gm. of phytosterol acetate. 



Increase in weight 10 . % 



C27H460(CO.CH3) requires 10.9 

 Melting points. — The first fraction of the phytosterol containing its water of 

 crystallisation showed a constant melting point of 132° C. (corrected). The 

 second fraction gave a melting point of 135° ('. The phytosterol acetate crystals 

 melted at 120° C. (corrected^. 



Optical properties. — A polarimetric deteruiination nf the substance was made 

 with a Schmidt and Haensch polarimeter. A solution of .2657 gm. of the 

 phytosterol crystals in 15 ccs. of ether, and equivalent to a 1.7714 '^,'c solution, 

 was used in a 1 dcm. tul)e. A laevo-rotation was recorded of — 0.61° at a tem- 

 perature of 16° C. 



The specific rotatory jiower. „ = — 34.5. 



This biochemical group, of which cholesterin is flic licst known, has l)een 

 called by Abderhalden the sterins (Lehrbuch der physiol. Chemie) . These ap- 

 pear to be intimately a^^sociated with the fats and oils in all living cells, and have 

 certain well defined properties. Their physical constants, however, are found to 

 vary within certain limits, showing that not one substance but several closely 

 related compounds exist. 



Cholesterin of animal tissue has been known for fifty years, but of the 

 analogous compounds iu plants, the pliytosterins, our knowledge is very recent. 

 They occur both in the free state and as esters. Chemically, they are unsaturated 

 alcohols of high molecular weight, having the constitution of cyclic polyterpenes. 



In the literature available to the author the investigation of 06 different plants 

 includes the isolation and identification of their phytosterins . In the English 

 literature the term phytosterols is adhered to throughout. In ultimate composi- 

 tion they arc found to range from C20 to C.-io. l)ut two-thirds of the number have 

 the formula ('27H4(iO and the great majority possess tlie general formula 

 C^Hon—gO. These 44 phytosterols have — 



a melting point between 130° and 138° C. 



optical rotation „ — 30 „ — 41 



2 groups of acotafcs fl ) m.]-). ., 118 „ 122 



(2) „ „ 125 ., 128 



