A sulfolipid-S35 was isolated from photosynthetic microorganisms and higher plants after culture in media containing radiosulfate. Alcohol extracts of Chlorella, Scenedesmus, Rhodospirillum rubrum,' barley, clover, New Zealand spinach (Tetragonia expansa) chloroplasts, chive, and green sections of coleus were Ch/orefla-S chromatographed on paper and found Alcoho;) Extract to contain varying amounts of a radioactive compound with high Rf values ( Fig. 1). Its concentration in Chlorella Sulfoipid was 4 10-M, which exceeds those of the major plant phosphatides. The radiochromatographic method has revealed its chemical composition and aspects of its molecular structure. Materials and Methods.-Isolation of sulfolipid-S35: A suspension of approximately 100 mg of C. pyrenoidosa or of Scsnedesmus D3 in 30 ml of low-sulfur (ca. 10-5 M total sulfates) culture medium R containing 1 mc carrier-free sulfate-SM5 in a glass cylinder was perfused with 5 per FIG. 1.-Radiogram of alcohol extract of cent carbon dioxide-enriched air and illu-Chlorella-S35. Chromatograms are developed minated with a 20-watt fluorescent lamp. from the origin at the lower left with phenol-During one week the cells increased fivewater (1) to the right and with butanol-propionic acid-water (2) upwards.fold. They were centrifuged from the medium and washed three times with water. The cells were extracted twice with 5-ml portions of hot absolute ethanol and twice with hot 25 per cent chloroform in ethanol. The extract of 20-mg cells was chromatographed two-dimensionally on Whatman No. 1 paper in phenol-water (PW) and

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While the diurnal deposition of starch within the chloroplast has long been recognized, little has been known of the photosynthate reservoirs more intimately associated with the photochemical apparatus. This paper reports recognition of chloroplast and chromatophore lipids containing significant concentrations of available carbohydrate.A high degree of orientation of lipids within the chloroplast has been revealed by observation of positive dichroism (1, 2) when dye molecules were adsorbed in the lipid regions. Positional relationships of the photoacceptors, chlorophylls and carotenoids (3), and the chloroplast lipids almost certainly exist. Most concepts of chloroplast structure embrace these observations. It now appears that these lipids may participate in carbohydrate metabolism as well. They consist largely of galactosyl monoglycerides (4) : water, x-direction, and in butanol : propionic acid : water, y-direction (9).IDENTIFICATION OF LIPIDS: Although there are applicable methods for direct separation of plant lipids their analysis is greatly simplified by preliminarv deacylation followed by paper chromatography of the water-soluble products. 8-D-Galactosyl-1 -glycerol and a-D-galactosyl-(l -* 6)-,8-D-galactosyl-l-glycerol (10) were identified by cochromatography with authentic compounds kindly provided by Professor H. E.Carter. 83-D( Galactosyl 6-sulfate)-1-glycerol5 (11) was identified by cochromatography with the readily recognized compound from clover leaves. This in turn, had been identified by cochromatography with the authentic S35-labeled compound from Chlorella or Scenedesmus.Diglycerophosphate was identified by cochromatography with synthetic material. For identification of diglycerophosphate from chromatophores by neutron activation chromatography a small amount of lipids of Chlorella-P32 was hydrolyzed with the chromatophore lipids. The authentic diglycerophosphate-P32 5 Note added in proof: The nature of the glycose in the sulfolipid is uncertain. Although analytically similar to the structure presented in figure 1, the