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Content available remote Mycosporine-like amino acids in six scleractinian coral species
EN
Mycosporine-like amino acids (MAAs) were studied in stony coral species (Fungiidae) along the Eastern coast of the Red Sea. Six species - Fungia scutaria, F. danai, F. corona, F. repanda, Ctenactis echinata and Lithophyllor lobata - were examined for MAAs at water depths of 5, 10, 15 and 20 m. Protein and chlorophyll were also determined and showed higher contents in winter than in summer. Generally, the total content of MAAs in summer was found to be approximately three times greater than in winter. Overall, concentrations of MAAs were greatest at a depth of 5 m. Porphyra-334 was the most abundant MAA in F. Scutaria and F. Danai, whereas asterina-330 was either not detectable (e.g. L. lobata) or present in low concentrations (e.g. F. danai, F. repanda and C. echinata). Shinorine was not detected in F. danai or L. lobata. Both C. echinata and L. Lobata had the lowest concentrations of MAAs, presumably because of their large calcareous skeletons. The variation in MAA concentrations among seasons and water depths is probably due to a number of factors, including the intensity of solar radiation, turbidity and phylogenetic variation.
EN
2,3-Dimethyl-3H-quinazoline derivatives 2a,b reacted with malonic acid in the presence of anhydrous ZnCl2 to afford -(4-quinazolinylideneJ acetic acid derivatives 3a,b which then reacted with thionyl chloride to give the corresponding acid chlorides. The acid chlorides reacted with arenes in the presence of AlCl3 to yield substituted 4-quinazolinylideneacetophenones 4a-d. Compounds 4a-d were treated with hydrazine derivatives, hydroxylamine hydrochloride, urea and thiourea to yield the spiro compounds 5a-h, 6a-d and 7a-h, respectively.
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