Brominated indoles from

Halogenated Organic Molecules of Rhodomelaceae Origin: Chemistry and Biology

“…302 Apart from the cytotoxic haloterpenes and C 15 -acetogenins, some haloindoles from these algae also proved to be active in cytotoxicity assays. 2,3,5,6-Tetrabromoindole (573) showed cytotoxicity against L1210 tumor cells (ID 50 3.6 μg/mL), 354 while the sulfur-containing polybromobisindoles 595 and 596 were reported to possess cytotoxicity against HT-29 and P-388 tumor cells, respectively. 356 Additionally, some phenylethanolderived bromophenols (620−622 and 655) showed moderate cytotoxicity against five tumor cell lines (A-549, A-2780, Bel-7402, BGC-823, and HCT-8) with IC 50 values ranging from 9.4 to 20.8 μg/mL.…”

“…505 At a level of 100 μg per 12.7 mm disc, 2,3,5,6-tetrabromoindole (573) displayed an inhibition zone of 16 mm against Bacillus subtilis after 24 h of growth. 354 The crude extract of Laurencia pannosa exhibited antibacterial activity against three out of 13 species of marine bacteria isolated from algal habitats in Malaysian waters. Three of these species (Chromobacterium violaceum, Proteus mirabilis, and Vibrio cholerae) were then used to evaluate the antibacterial activity of two halosesquiterpenes, pannosanol (247) and pannosane (248), as well as an ACG derivative, (3Z)-chlorofucin (468), that were isolated from L. pannosa.…”

“…390 At a level of 100 μg per 12.7 mm disc, 2,3,5,6-tetrabromoindole (573) displayed an inhibition zone of 16 mm against Saccharomyces cerevisiae after 24 h of growth. 354 More recently, bromophenol 649 was reported to have potent activity against four fungal strains with MIC values ranging from 0.78 to 1.56 μg/mL. 505 8.1.4.…”

Brominated Metabolites from the Marine Red Alga Laurencia similis

“…In the course of our continuing studies on structurally interesting secondary metabolites from the genus Laurencia [5 -11], the species of L. similis was re-investigated, and as a result one new sesquiterpenoid, aristolan-1α-bromo-9β ,10β -epoxide (1), and one new indole alkaloid, 2,5-dibromo-N-methylindole (2), were identified. In addition, six known compounds including aristol-8(9)-en-1-one (3) [5], aristol-9(10)-en-8-one (4) [12], 9β -aristol-1(10)-en-9-ol (5) [13], 2,3,5-tribromo-1-methyl-1H-indole (6) [14], 2,3,5,6-tetrabromo-1H-indole (7) [14], and 3,5,6-tribromo-1H-indole (8) [5], were also isolated and identified. Herein, we report the isolation and structure elucidation of the new compounds.…”

Terpenes and Polybromoindoles from the Marine Red Alga Laurencia decumbens (Rhodomelaceae)

“…From this species, we isolated and identified three new compounds including two new brominated diterpenes, named laurendecumtriol (1) and 11-O-deacetylpinnaterpene C 1 ) (2), and one new polybromoindole, 2,3,4,6-tetrabromo-1-methyl-1H-indole (7). In addition, six known compounds, pinnaterpene C (3) [7], 1(10)-aristolene (4) [8], obtusane (5) [9], elatol (6) [10], 2,3,5-tribromo-1-methyl-1H-indole (8) [5] [11], and 2,3,5,6-tetrabromo-1-methyl-1H-indole (9) [11], were also isolated and identified. The isolation and structural determination of compounds 1 -9 are the main subject of this paper.…”