Chaetoglobins A and B, two unusual alkaloids from endophytic Chaetomium globosum culture

Abstract

Chaetoglobins A (1) and B (2), two azaphilone alkaloid dimers with an unprecedented skeleton, were characterized from an endophytic fungus Chaetomium globosum with the former ascertained to be a significant cytotoxin valuable for anti-tumor drug discovery.

Structural Characterization Of Secondary Metabolites Produced By Fungi Obtained From Damp Canadian Buildings

“…This also appears to be the first report of phenylacetic acid and phydroxybenzaldehyde from W. sebi of which the former metabolite was confirmed by an analytical standard. Phenylacetic acid has been reported from numerous fungi including Penicillium herquei (Ding et al 2008), Penicillium digitatum (Ariza et al 2002), as well as Biscogniauxia mediterranea (Evidente et al 2005). p-hydroxybenzaldehyde has been reported from Ophiostoma crassivaginata and an unidentified endophyte of a Chilean coniferous tree,…”

“…Isochromophilone XIII (2.8) had the same N-2-hydroxy ethyl moiety that is also present in isochromophilone VI (Arai et al 1995) and the cytotoxic chaetoglobin B (Ming et al 2008).…”

“…Chaetoglobins A and B inhibited the breast cancer cell line MCF-7 as well as the colon cancer cell line SW1116 with IC 50 values of 26.8 and 35.4 µg mL -1 , respectively (Ming et al 2008). Chaetoglobosin A and C, were shown to be produced on various naturally and artificially infested damp building materials in the US and Denmark (Fogle et al 2007;Nielsen et al 1999).…”

“…They have been isolated from more than 23 fungal genera and have a variety of intriguing biological activities (Osmanova et al 2010). Azaphilones isolated from C. globosum include chaetoviridins as well as chaetomugilins, chaetoglobins, and isochromophilones (Ming et al 2008;McMullin et al 2013).…”

“…However, the non-selective cytotoxicity most azaphilones elicit prevents them from being pursued as useful pharmaceutical targets (Osmanova et al 2010). (Ding et al 2006) and chaetoglobins A and B (Ming et al 2008) from the normal stem of Imperata cylindrical, the benzaldehyde derivative chaetopyranin from the marine red algae Polysiphonia urceolata (Wang et al 2006), globosumones A-C from the stem tissue of Ephedra fasiculata (Bharat et al 2005) and various azaphilones from the leaves of a Viguiera robusta endophytic strain (Borges et al 2011). The structures of chaetoglobosin U and chaetoglobin A characterized from endophytic C. globosum isolates can be found in figure 2.6.…”