Algae yellow-brown

Haptophyceae yellow-brown algae (e.g. prymnesiophyte coccolithophores) [mostly M]... 

The brown alga Leathesia nana from the gulf of the Yellow Sea in China has yielded the new bromophenols 1855 and 1856 (1736-1738), and the Chinese red... 

Brown algae are found in most parts of the ocean, including the intertidal zones. The colors of these plants, which range from yellow to black, are due to combinations of chlorophyll and accessory pigments. Most types of brown algae produce chemicals that protect them from predators. 

CgHgOg) ) A yellow-white organic solid that is found in brown algae. It is a complex polysaccharide and produces, in even very dilute solutions, a viscous liquid. Alginic acid has various uses, especially in the food industry as a stabilizer and texture agent. 

Typical algae found on surfaces include Chlorella, which looks green when the surface is wet, but black or blue green when the surface dries out. The other most common algae are Trentepohlia, which may show a variety of colours from dark blue-green to yellow, red, brown, black or even orange. 

The bioreduction of Au (III) to Au (0) was carried out using the biomass of brown algae, F. vesiculosus, studied by Mata et al. (2009). The color change occurred due to a decrease in parameters like pH, temperamre, and the redox potential of solution from yellow to reddish purple. The hydroxyl compounds in the F. vesiculosus were responsible for the bioreduction resulting in the formation of AuNPs. The bioreduction method was an alternative and eco-friendly process compared with various physical and chemical methods which resulted in highly stable AgNPs. 

Constit. of the red alga Delisea elegans. Viscous pale brown-yellow oil. 

The xanthophylls and carotenes of plants are examined conveniently after removal of the chlorophylls by saponification with alkali. For this saponification, add 10 ml of 30% potassium hydroxide in methanol to the centrifuged acetone or methanol extract in the separatory funnel. After 30 min with occasional swirling, add 40 ml of cold petroleum ether (20-40°C)-diethyl ether (1 1) plus 100 ml of 10% aqueous sodium chloride solution. Wash the resultant upper golden-yellow layer with water and take to dryness as above. Prepare the sample solution by dissolving the residue in 1 ml of petroleum ether (60-110°C)-diethyl ether (1 1). This saponification procedure should not be employed with plant extracts containing xanthophylls that are decomposed by alkalies, as are fucoxanthin from diatoms and brown algae and peridinin from dinoflagellates. 

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