Dimeric phenanthrenes from two Agrostophyllum species
1998
Majumder, P.L. | Banerjee, S. | Lahiri, S. | Mukhoti, N. | Sen, S.
The structures of agrostonin and agrostonidin, two new dimeric phenanthrene derivatives isolated from the orchids, Agrostrophyllum khasiyanum and A. callosum, were established as 2,2',7,7'-tetrahydroxy-4,4',6,6'-tetramethoxy-1, 1'-biphenanthryl and 2,2',6,6'-tetrahydroxy-4,4',7,7'-tetramethoxy- 1, 1'-biphenanthryl, respectively, from spectral and chemical evidence, including regioselective biomimetic synthesis from their respective 9,10-dihydro monomers by oxidative coupling with phosphomolybdic acid (PMA) on a silica gel surface.
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