Antifungal activity carbazole alkaloids

In 2001, Greger et al. isolated the stress-induced carbazole phytoalexins carbalexin A (57), B (58), and C (59) from the leaves of Glycosmis parviflora. These carbazole alkaloids showed strong antifungal activity in bioautographic tests on TLC plates with Cladosporium herbarum (86). 

In 1988, Nakamura et al. reported the isolation of carbazomycins G (269) and H (270) from the culture broth of Streptoverticillium ehimense. These alkaloids have a structurally unique carbazole-l,4-quinol framework and were obtained from Nature in racemic form. Carbazomycin G showed moderate antifungal activity against... 

Carbazomycin G and H have been isolated from Streptoverticillium ehimense [38]. In nature carbazomycin G occurs as a racemic mixture and the same is assumed for carbazomycin H. Garbazomycin G was reported to show antifungal activity. The two compounds share a unique structure, namely the carbazole-l,4-quinol moiety. Starting from the appropriate iron complex salt, iron-mediated arylamine cydization provides a simple route to both alkaloids (Scheme 15.10) [39]. 

A new carbazole alkaloid, streptoverticillin, has been isolated from Streptoverticillium morookaense, and has been shown to exhibit antifungal activity against Peronophythora litchii <2007JAN179>. 

The tjipanazoles (18, 19a-d, 20a-b) a group of A-glycosides of indolo-[2,3-a]carbazole, have been isolated from the moderately antifungal extract of the blue-green alga Tolypothrix tjipanasensis. These alkaloids do not exhibit antitumor or protein kinase C (PKC) inhibitory activity, which is in contrast with the... 

The majority of indolocarbazole alkaloids, isolated so far from nature, are derivatives of the indolo[2,3-fl]pyrrolo[3,4-c]carbazole ring system 292. They have been isolated from soil organisms, slime molds, and marine sources (3,7,8,252-255), and have shown a broad range of potent biological activities, such as antifungal, antimicrobial, antitumor, and antihypertensive activity (3,7,256-260,267-270). Their activity as potent inhibitors of protein kinase C (PKC) has received special attention, and was the focus of several investigations (8,257,258,271-280). The history of these natural products dates back about 30 years (Scheme 2.73). 

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