Pheophytin

[Jon Monroe]

Sam Beal wrote:

> The definitive reference for absorption properties of pheophytins is
> Lichtenthaler, H. K. (1987) Chlorophylls and carotenoides: pigments of
> photosynthetic biomembranes.  Methods Enzymol. 148: 350-382.
> 
> Pheophytin a has absorption maxima at 666.6 nm (60.1 l/mg-cm) and 408.8 nm
> (126.51 l/mg-cm) in diethyl ether.  
> 
> Pheophytin b has absorption maxima at 654.2 nm (43.62 l/mg-cm) and 433.2
> nm (218.87 l/mg-cm) in diethyl ether.


Sam:  Can you tell us why the pheophytin spot on silica gel TLC (Reiss 1994)
appears to be only a single spot and not two?  Is one of the chlorophylls more
sensitive to degradation, or is what we see the normal level of pheophytin
in extracts (either a or be but not both)?  Since chl a and b separate so well
I would assume the respective pheophytins would also.  

Thanks,  Jon

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