Martefragin A, a Novel Indole Alkaloid Isolated from Red Alga, Inhibits Lipid Peroxidation.

Reactivity of 3-Cyanoacetylindole Derivatives: Synthesisof 3-Hydrazonopyrazolyl and 3-Thiadiazolyl Indole Derivatives

“…They show cytotoxicity toward murine tumor cell lines and have potent inhibition against several protein kinases [9,10]. Along with these, the substitution at the 3-position of the indole ring can take place by connecting an additional heterocyclic ring, such as imidazole (topsentins [11,12], nortopsentins [13]), dihydroimidazole (disc odermindole [14]), oxazole (martefragin [15], amazole [16]), oxadiazine (alboinon [17]), maleimide (didemidines [18]), and piperazine (dragmacidone [19]). Therefore, 3-substituted indoles still represent a significant synthetic challenge.…”

Macroalgal palatability and the flux of ciguatera toxins through marine food webs

“…Hundreds of bioactive secondary metabolites have been isolated from this cyanobacterial genus Various studies have shown strong deterrence and toxicity of these metabolites against vertebrate and invertebrate consumers (Nagle et al, 1996;Thacker et al, 1997;Nagle and Paul, 1999;Cruz-Rivera and Paul, 2002), however, some specialized gastropods prefer to feed on this genus (Paul and Pennings, 1991;Pennings et al, 1996;Nagle et al, 1998;Cruz-Rivera and Paul, 2002) Gillespie et al (1985a), Bourdeau and DurandClement (1991) Martensia Epiphytic, flattened fan-like red algae Some species produce indole alkaloids (Kirkup and Moore, 1983;Murakami et al, 1994;Takahashi et al, 1998), suggesting a potential chemical defense, but no data are available on palatability…”

Natural Product‐Like Combinatorial Libraries

“…For example, Martefragin A (177) is a strong inhibitor of lipid peroxidation, 188 Pimprinine (178) inhibits monoamine oxidase (MAO) and as an anti-epiletic effect, 189 and WS-30581 A and B (179 and 180) are reported to have inhibitory effects on platelet aggregation. 190,191 Based on the fact that the synthetic analogue 181 showed stronger activity than the mother compound itself, Nakagawa and co-workers 192 Figure 46.…”

“…According with the developed strategy and on the basis of the results from qualification studies with a diverse range of building blocks, a lead-seeking library containing 1920 pairs of diastereoisomeric tetrahydroquinolines (187) was prepared under a 96-well plates format, using a high throughput robot starting with 80 aldehydes, 24 anilines and one alkene (2,3-dihydropyran) (Figure 48). A similar methodology for library construction in liquid phase of quinoline derivatives (188), which is based on lanthanide triflate [Ln(OTf) 3 ]-catalyzed three-component reactions of aldehydes, amines and alkenes, has been developed by Kobayashi and coworkers (Figure 48). 195 The key is to use Ln(OTf) 3 as a Lewis acid catalyst, which is not decomposed during the work-up and purification steps, and is easily separated from products.…”