Isolation of Putative Biosynthetic Intermediates of Prenylated Indole Alkaloids from a Thermophilic Fungus Talaromyces thermophilus

The putative key biosynthetic intermediates of prenylated indole alkaloids have long been proposed but never isolated. Two such alkaloids, named talathermophilins A and B (1 and 2), were isolated from a thermophilic fungus Talaromyces thermophilus strain YM1-3 and were identified by NMR and MS spectroscopic analyses. The ratio of 1 and 2 in the culture broths was unexpectedly rather constant (about 2:3), which even remained unchanged despite the addition of exogenous 1 or 2, suggesting that talathermophilins might be of special function for the extremophilic fungus.