PTERIDINES, STEROLS, AND INDOLE-DERIVATIVES FROM THE LITHISTID SPONGECORALLISTES-UNDULATUS OF THE CORAL SEA

The lithistid sponge Corallistes undulatus, which inhabits the base (- 510 m) of the New Caledonian coral reef, is shown here to contain the pteridines 1-methylpteridine-2,4-dione[2], already known from another Corallistes, and the new 1',2'-dihydfoxypropyl)-1-methylpteridine-2,4- dione [(-)-8], together with the steroids 3beta-hydroxy-24-methylenech olest-5-en-7-one [15], 7alpha-hydroxysitosterol [16],7beta-hydroxysito sterol [17], and 3beta-hydroxystigmast-5-en-7-one [18], typical of hig her terrestrial plants, and the indole derivatives methyl(2E)-3-(indol -3-yl)-2-propenoate [19], methyl(2E)-3-(6-bromoindol-3-yl)-2-propenoat e [20], and serotonin [21]. The presence of the same compounds in taxo nomically, phyletically, and ecologically unrelated organisms is viewe d here as resulting from evolutionary convergence toward adaptive prod ucts.