In article <3c40ks$klc at brachio.zrz.TU-Berlin.DE>,
gardiner at echo.chem.tu-berlin.de wrote:
> Could someone please tell me the extinction coefficient
> of bacteriochlorophyll b at 794nm when extracted into
> acetone:methanol (7:2)
> Thanks,
> Alastair Gardiner
>>gardiner at echo.chem.tu-berlin.de
As listed on p. 731 of Chlorophylls (H. Scheer, CRC Press, 1991; the
original reference is Oelze, J. Methods Microbiol. 18, 257, 1985)
bacteriochlorophyll b absorbs maximally at 794 nm in ether, but at 791 nm
in acetone. I suspect that the spectrum in acetone:methanol (7:2) is
probably the same as in acetone. Unless you're interested in super
accuracy, the absorption at 794 won't be that much different from the
absorption at 791 nm. This reference lists the absorption coefficient at
791 in acetone as 106 l g-1 cm-1. If you use a molecular weight of 909.5
(assuming that the esterifying alcohol is phytol), this translates to a
molar absorption coefficient of 96,407. I hope this helps.
