Absorption responses of chlorophyll in vivo to treatment with acetone

Abstract

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.