Absorption responses of chlorophyll in vivo to treatment with acetone

Aspidistra elatior chloroplasts are treated with buffer to which acetone of various concentrations is added.

Upon replacement of the solvent-containing medium by buffer, it appears that acetone concentrations up to about 40% produce a reversible shift of the main absorption maximum to the short-wave side. With higher concentrations, such a shift is, least partially, irreversible. The magnitude of this shift proceeds linearly with acetone concentration.

Acetone in concentrations lower than about 50% most probably solubilizes chlorophyll-protein complexes. The position of the main absorption maximum of these complexes in the acetone-containing medium is shifted to the short-wave side, whereas, also in this case, the magnitude of the shift is dependent on the applied solvent concentration.

At least some of the individual chlorophyll a types are extracted by acetone of various concentrations at mutually different rates. The latter result stresses the individuality of these chlorophyll a types.