NATURAL WAXES 381 



of pomades, polishes, and leather dressings. Because of its high triglycer- 

 ide content, it is used in the manufacture of soap. 



b'. Apple Cuticle Wax: The wax from the cuticle of the apple, Malus 

 pujuila (Pyrus malus L.) is one of the best known fruit waxes. According to 

 Sando,''^^ the proportion of wax obtained varies with the species of apple. 

 One hundred grams of fresh tissue yields 140 to 175 milligrams of wax, in the 

 form of a greenish yellow powder which is extremely water-repellent and 

 which melts at 80 °C. 



The composition of apple wax has been extensively studied by Markley 

 and collaborators^^ as well as by Chibnall and his co-workers. ^^ The 

 principal hydrocarbon was proved, by Markley et al.,-^^ to be n-nonacosane, 

 CH3(CH2)27CH3, instead of triacontane, C30H62, which had previously been 

 reported. ^^^'^^ The hydrocarbon was identified by its x-ray diffraction 

 pattern, which corresponded with that reported by Piper and collabora- 

 tors,^^* and by its melting point. ^2- '^^ Heptacosane, C27H56, has likewise 

 been reported as a hydrocarbon in apple wax. 



In addition to the hydrocarbons, several alcohols have been found in 

 apple cuticle wax. The chief one is apparently a secondary alcohol, ^2'^" 10- 

 nonacosanol, CH3(CH2)i8CHOH(CH2)8CH3, instead of 14-heptacosanol as 

 previously reported by Sando.^^^ The confusion apparently arose because 

 the two alcohols have the same melting points as do their acetate esters. 

 Octacosanol and triacontanol have also been reported as minor constituent 

 alcohols. a-Ursolic acid, HOC29H46COOH, has Hkewise been found as 

 an important constituent of apple cuticle wax. 



c'- Pear Cuticle Wax: Markley and collaborators^^" reported a com- 

 prehensive investigation of the wax from the skin of the common pear 

 {Pyrus communis L.). As in the apple, the predominant ether-soluble com- 

 ponent was found to be w-nonacosane. The usual C2o-Csn primary alco- 

 hols, including those usually designated as lignoceryl and ceryl, were found. 

 Ursolic acid was identified by its elementary composition, melting point, 

 and by its oxidation product, ursonic acid, C28H45-CO-COOH. However, 

 neither 10-nonacosanol nor any other secondary alcohols were found in 

 pear wax, in contradistinction to apple cuticle wax. 



d'. Waxes from the Cherry: Markley and Sando^®^ have investigated 

 the composition of the wax obtained from the skins of Bing sweet cherries 

 (Prunus avium L.). In addition to such acids as palmitic, stearic, oleic, 



356 C. E. Sando, /. Biol. Chem., 56, 457-468 (1923). 



357 F. B. Power and V. K. Chestnut, ./. Am. Chem. Soc, 4M, 1509-1526 (1920). 



558 S. H. Piper, A. C. Chibnall, S. J. Hopkins, A. Pollard, J. A. B. Smith, and E. F. 

 Williams, Biochem. J,, 25, 2072-2094 (1931). 



36» K. S. Markley and C. E. Sando, J. Biol. Chem., 101, 431 (1933). 



'^ K. S. Markley, S. B. Hendricks, and C. E. Sando, /. Biol. Chem., Ill, 133-146 

 (19:i5). 



36' K. S. Markley and C. E. Sando, ./. Biol. Chem., 119, 641-645 (1937). 



