K Group and Related Quinones

We have chosen the first lUPAC suggestion (in [90]) for the consistent nomenclature and abbreviations of some of these quinones, the list of which is continuously growing  

Vitamin Vitamin Kg Vitamin Kg Plastoquinones Ubiquinones, Coenzyme Q a-Tocopherylquinone 

A few of the large number of TLC systems hitherto used are compiled in Table 47. They serve mostly for solving particular problems. 

The length and degree of saturation of the isoprene side-chain has less influence on the separation of the naphthoquinone derivatives in adsorption TLC than in other procedures. The i /-values increase with increasing molecular size in accordance with the general rule. Thus all the ubiquinones migrate together [141]. The principal adsorbents used have been siUca gel and alumina. Thus menadione in the preparations in which 

52 = Silica gel G, activated, impregnated with paraffin oil-petrol ether (40—60°) 

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