II. CHEMISTRY 335 



lipositol has been suggested, ^"^ appears to be complex. The best charac- 

 terized inositol-contaiiiing lipid doubtless is the diphosphoinositide iso- 

 lated from brain by Folch,^^ which contains meso-inositol in the form of a 

 diphosphate. The structure of this diphosphoric acid ester is not yet known 

 except for the relative position of the two acid residues, which is meta. 

 There exist probably many other forms in which inositol occurs in tissues; 

 one could think of polyinositol phosphates and even of inositol polyphos- 

 phates. Indications of the existence of highly polymerized substances con- 

 taining inositol have been reported.^^' *" No more than brief reference can 

 be made here to streptamine, a component of streptomycin, which is a 

 me/a-diaminocyclotetritol .^^ 



2. SCYLLITOL 



This cyclohexitol (structure VII) has been found in the organs of several 

 fish varieties (dogfish, sharks, etc.),^^-^* in acorns,"*^ and in the leaves of the 

 coconut palm'*® and of dogwood.^^ Its occurrence in human urine has been 

 reported recently.'*^ A C-methyl derivatives^ of scyllitol, mytilitol, has been 

 isolated from the mussel Mytilus edulis}^'^'^ 



3. d- AND Z-Inositol 



The optically active cyclohexitols occur in nature in the form of mono- 

 methyl ethers. The dextrorotatory pinitol, which gives rise to d-inositol 

 (structure VIII), was first found in Pinus lambertiana,^^ but it occurs also 

 in a variety of other plants or plant products (Madagascar rubber, red- 

 wood, loco weed).^' ^ The following structure has recently been assigned to 



38 J. Folch, /. Biol. Chem. 177, 505 (1949). 



" D. W. Woolley, /. Biol. Chem. 139, 29 (1941). 



<" J. Folch and F. N. Le Baron, Federation Proc. 10, 183 (1951). 



■*! R. U. Lemieux and M. L. Wolfrom, Advances in Carbohydrate Chem. 3, 337 (1948). 



« G. Staedeler and F. T. Frerichs, J. prakt. Chem. 73, 48 (1858). - 



« D. Ackermann and M. Mohr, Z. Biol. 98, 37 (1937). 



**M. Mohr, Z. Biol. 98, 276 (1937). 



^5 C. Vincent and Delachanal, Compt. rend. 104, 1855 (1887). 



^« H. Muller, /. Che7n. Soc. 91, 1767 (1907); 101, 2383 (1912). 



" C. E. Sando, K. S. Markley, and M. B. Matlack, J. Biol. Chem. 114, 39 (1936). 



*^ P. F. Fleury, J. E. Courtois, and A. L. Jouannet, Abstr. 12th Intern. Congr. Pure 



and Applied Chem. New York p. 82 (1951). 

 ^« T. Posternak, Helv. Chim. Acta 27, 457 (1944). 

 5" B. C. P. Jansen, Hoppe-Seyler's Z. physiol. Chem. 85, 231 (1913). 

 " D. Ackermann, Ber. deut. chem. Ges. 54, 1938 (1921). 

 " R. J. Daniel and W. Doran, Biochem. J. 20, 676 (1926). 

 " M. Berthelot, Compt. rend. 41, 392 (1855); Ann. chim. phys. 46, 66 (1856). 



