Ambiguine isonitriles, fungicidal hapalindole-type alkaloids from three genera of blue-green algae belonging to the Stigonemataceae

The zebrafish (Danio rerio) embryo as a model system for identification and characterization of developmental toxins from marine and freshwater microalgae

“…Details of the purification and characterization of these compounds is reported elsewhere (Berry et al, submitted for publication), however, chemical characterization has identified these compounds as belonging to the hapalindoles, a group of indole alkaloids previously identified from Fischerella and related genera (Moore et al, 1984(Moore et al, ,1987Smitka et al, 1992;Stratmann et al, 1994). Although previous work (Moore et al, 1997;Smitka et al, 1992;Doan et al, 2000;Doan et al, 2001) has characterized biological activity of these compounds (e.g. antimicrobial activity, inhibition of RNA polymerase), this is the first identification of apparent developmental toxicity associated with these compounds.…”

Human Anticancers and Antidiabetic Activities of the Cyanobacterium Fischerella sp. BS1-EG Isolated from River Nile, Egypt

“…Several authors reported that Fischerella spp. can produce several compounds (Hagmann andJüttner, 1996 andGhasemi et al, 2003) and some of these identified substances include fischerindole L (Park et al, 1992), fischerellin A (Hagmann & Jüttner, 1996), ambiguine isonitriles A-F (Smitka et al, 1992), ambigol A and B (Falch et al, 1993), and tjipanazole D (Falch et al, 1995).…”

Identification, Isolation, and Characterization of Developmental Toxins from the Cyanobacterium Fischerella 52-1 Using the Zebrafish (Danio rerio) Embryo Model

“…The masses of peaks 3 and 7 are too high for a hapalindole, but fall into the mass range of the ambiguines also discussed in Chapter 1 (Smitka et al, 1992). In fact, the mass of Peak 7 matches the mass of Ambiguine B Isonitrile and Peak 3 matched Ambiguine C Isonitrile (Smitka et al, 1992). Further chemical characterization of Peaks 7 and 8 is presented in Chapter 3.…”

“…A number of alkaloids have been isolated from Fischerella, Hapalosiphon, Westiella, and Westiellopsis that include indole and enediyne containg alkaloids, which are also depicted in Figure 1 Smitka et al, 1992;Hagmann et al, 1996). The main enediyne, unsaturated polyacetylene, containing alkaloids are Fischerellin A and B, isolated from Fischerella muscicola by Hagmann et al, (1996).…”

“…The novel compound 2 was originally identified as Ambiguine B Isonitrile from the mass spectrometer data, however, further investigation via IR and NMR showed the absence of the isonitrile group (Smitka et al, 1992). It was then observed that the structure for 2 and Ambiguine B Isonitrile were similar, and using various NMR correlation experiments, the structure of 2 was deduced.…”