Monodictyochromes A and B, Dimeric Xanthone Derivatives from the Marine Algicolous Fungus Monodictys putredinis
journal contributionposted on 01.12.2008, 00:00 by Alexander Pontius, Anja Krick, Ronak Mesry, Stefan Kehraus, Silke E. Foegen, Michael Müller, Karin Klimo, Clarissa Gerhäuser, Gabriele M. König
Investigations of the marine-derived fungus Monodictys putredinis led to the isolation of two novel dimeric chromanones (1, 2) that consist of two uniquely modified xanthone-derived units. The structures were elucidated by extensive spectroscopic measurements including NOE experiments and CD analysis to deduce the configuration. The compounds (1, 2) were examined for their cancer chemopreventive potential and shown to inhibit cytochrome P450 1A activity with IC50 values of 5.3 and 7.5 μM, respectively. In addition, both compounds displayed moderate activity as inducers of NAD(P)H:quinone reductase (QR) in cultured mouse Hepa 1c1c7 cells, with CD values (concentration required to double the specific activity of QR) of 22.1 and 24.8 μM, respectively. Compound 1 was slightly less potent than compound 2 in inhibiting aromatase activity, with IC50 values of 24.4 and 16.5 μM.