Dehydrophylloquinone, α-dehydrotocopherolquinone and dehydrotocopherols from etiolated maize and barley shoots

Dehydrophylloquinone, α-dehydrotocopherolquinone, α-dehydrotocopherol and γ-dehydrotocopherol have been isolated from etiolated maize and barley shoots and excised etiolated maize shoots that have been exposed to light. They are not present, however, in green maize shoots, spinach leaves and etiolated bean leaves. Demethylphylloquinone was not detected in any of the tissues analysed.     

Cancer mortality in metal workers.

Age-standardized proportional mortality ratios (PMRs) were calculated for 10 036 metal workers in British Columbia with the use of information on cause of death and occupation recorded in death registrations from 1950 to 1978. Metal workers were found to have a significantly increased risk of death from lung cancer (PMR = 134). In addition, certain occupational groups of metal workers were found, for the first time, to be at increased risk of death from other types of cancer; these included leukemia (PMR = 356) and cancer of the rectum (PMR = 248) in metal mill workers, Hodgkin''s disease in welders (PMR = 242) and multiple myeloma in machinists (PMR = 209).     

Nature, intracellular distribution and formation of terpenoid quinones in Euglena gracilis

1. Light-grown cells of Euglena gracilis strain Z, var. bacillaris and 1224/5g contain phylloquinone, plastoquinone, alpha-tocopherol, alpha-tocopherolquinone and ubiquinone-9 (i.e. ubiquinone with 9 isoprene units/mol.). 2. The concentration (per g. dry wt.) of plastoquinone (and chlorophyll) in light-grown cells of strain Z was governed by the composition of the culture medium and age of the cells. Highest yields of plastoquinone were obtained under autotrophic conditions, the concentration reaching a maximum after 6-8 days' growth. The concentrations were less in heterotrophic media. The concentration of ubiquinone was relatively unaffected by the age of the cells or composition of the medium. 3. In light-grown cells of strain Z plastoquinone, alpha-tocopherolquinone and alpha-tocopherol were mainly localized in the chloroplast; ubiquinone was found to be in the mitochondria. 4. Etiolated (dark-grown) cells of strain Z contained no phylloquinone, plastoquinone or alpha-tocopherolquinone; alpha-tocopherol was present in lower concentrations compared with light-grown cells; ubiquinone concentrations were similar to those for light-grown cells. The presence of alpha-tocopherol in etiolated cells suggested that this chromanol was not entirely confined to the chloroplast. 5. On illumination of etiolated cells of strain Z the chloroplastidic components plastoquinone, alpha-tocopherolquinone and alpha-tocopherol were synthesized in step with chloroplast formation. Ubiquinone concentrations, as expected, were unaffected. 6. [2-(14)C]Mevalonic acid, the specific distal terpenoid precursor, was not incorporated into any of the terpenoid components examined. This was attributed to the impermeability of the cell wall to this compound, rather than to a novel pathway of terpenoid biosynthesis.