Secalonic acid D; A cytotoxic constituent from marine lichen-derived fungus Gliocladium sp. T31

Marine natural products

This review covers the literature published in 2006 for marine natural products, with 758 citations (534 for the period January to December 2006) referring to compounds isolated from marine microorganisms and phytoplankton, green algae, brown algae, red algae, sponges, cnidaria, bryozoans, molluscs, tunicates and echinoderms. The emphasis is on new compounds (779 for 2006), together with their relevant biological activities, source organisms and country of origin. Biosynthetic studies, first syntheses, and syntheses that lead to the revision of structures or stereochemistries, have been included.

(1)H and (13)C NMR signal assignments of paecilin A and B, two new chromone derivatives from mangrove endophytic fungus Paecilomyces sp. (tree 1-7)

Two new natural products, named paecilin A (1) and B (2), together with two known compounds secalonic acid D (3) and (11)-cytochalasa-6(12),13-diene-1,21-dione-16,18-dimethyl-7-hydroxy-10-phenyl-(7S*,13E,16S*,18S*) (4), were isolated from the mangrove endophytic fungus, Paecilomyces sp. (tree 1-7) from the South China Sea. 1D and 2D NMR experiments including COSY, HMQC, and HMBC were used for the determination of their structures. In our cytotoxicity assays, secalonic D (3) showed cytotoxicity toward KB cells with IC(50) < 1 microg ml(-1) and inhibiting human topoisomerase I with IC(50) at 0.16 micromol ml(-1). 1, 2, and 4 showed no activity to KB cells.