PROPERTIES OF 2 SPECTRALLY DIFFERENT COMPONENTS IN CHLOROPHYLL C PREPARATIONS

1. 1. Chlorophyll c, isolated from a variety of marine algae, is a mixture of two spectrally distinct components, chlorophylls c1 and c2, which were separated on thin layers of a special Dow polyethylene powder. Each component possessed the typical three-banded chlorophyll c spectrum, but the band ratios of chlorophyll c2 in diethyl ether, acetone and methanol were significantly higher than those of chlorophyll c1, and absorption maxima were shifted several nm to higher wavelengths. In diethyl ether, the absorption maxima of chlorophyll c1 from Sargassum flavicans were at 444.5, 578.6 and 628.2 nm with band ratios of 10.1, 0.68 and 1.00, respectively, whereas absorption maxima of chlorophyll c2 were at 448.5, 581.8 and 628.8 nm with band ratios of 14.5, 1.13 and 1.00, respectively. 2. 2. Preparations of chlorophyll c1 from a variety of different algae were spectrally identical, as were those of chlorophyll c2. Both chlorophylls c1 and c2 were present in brown seaweeds, diatoms and chrysomonads, but only chlorophyll c2 was found in dinoflagellates, symbiotic dinoflagellates and cryptomonads. Chlorophyll c2 was the universally distributed component. 3. 3. Chlorophylls c1 and c2 were extremely susceptible to aggregation, and these changes were accompanied by a loss in intensity of the absorption bands. Storage of chlorophyll c2 solutions in the cold under ceratin conditions favoured the formation of a third chromatographically and spectrally distinct chlorophyll c compound, with properties suggestive of a chlorophyll c aggregate. The presence of spectrally different components in chlorophyll c preparations, their varied distribution in the marine algae, and their ease of aggregation provide an adequate explanation for differences in absorption spectra and extinction coefficients recorded by different authors. © 1969.