II. CHEMISTRY 329 



et al}^ prepared a monoamino monodesoxyinositol by nitrous acid deamina- 

 tion of a derivative of streptamine in which one amino group was blocked. 

 Such deamination generally occurs with Walden inversion. ^^ Synthetic 

 DL-?/??/o-inosamine-4 (XXI-XXII) is identical with the compound pro- 

 duced from streptamine bj^ Wintersteiner, thus confirming the all trans 

 structure (XXIII) for streptamine.^' 



II. Chemistry 



ERWIN CHARGAFF 



The inositols^ are a family of isomeric hexahydroxy derivatives of cyclo- 

 hexane. They are the ultimate representatives of the series of hydroxy- 

 cyclohexanes that can be subsumed under the general term cyclitol.- The 

 designation cyclohexitol to describe the inositols is also sometimes en- 

 countered in the literature, in contrast to the cyelopentitols or desoxy- 

 inositols (quercitols), the cyclotetritols, etc. The hexahydroxycyclohexanes 

 can exist in two optically active and seven inactive configurations, in addi- 

 tion to the racemic dl compound. Only a few of those, however, have so 

 far been found to occur in nature, and two of the isomers do not appear to 

 have been prepared as yet. 



A. NOMENCLATURE 



In a cyclic compound of the molecular formula (CH0H)6 it is sufficient 

 to indicate the positions of the hydroxyl groups; the corresponding steric 

 positions of the hydrogen atoms are thereby defined and need not be speci- 

 fied. In the following discussion all numbers and graphic representations 

 will, therefore, refer only to the hydroxyl groups. 



The difficulties facing attempts at arriving at a numbering system that, 

 with a single convention, will permit an unequivocal description of all 

 inositol isomers and their derivatives are almost insuperable. Maciuenne^ 

 adopted the practice, at that time followed in carbohydrate chemistry, 

 of denoting the numbers of the carbon atoms carrying hydroxyl groups 

 situated above and below the plane of the ring respectively by way of a 



f .■ T f 1 +V. ^A^ 1235 1240 1356 1345'.,^. 



traction. ?neso-lnositoi thus would be — —- or — - or _— or ^^r-» ii the 



" O. Wintersteiner and A. Klingsberg, ./. Am. Chem. Soc. 73, 2917 (1951). 

 ' P. Fleury and P. Balatre, Les Inositols — Chimie et Biochimie. Masson, Paris, 19 17. 

 ^ For a recent review on the chemistry of cyclitols, see H. G. Fletcher, Jr., Ad- 

 vances in Carbohiidratc Chon. 3, 45 (1948). 

 ' L. Ma([uenne, Los Sucros et leurs Princip;iux Derives, Carrd et Xaud, Paris, 1900. 



